fix(api): rework from-lineup to generated playlist design + review fixes (#63)

Adversarial review found the previous multi-flood design non-viable:
PlayoutModeSchedulerFlood never yields to a following Dynamic-start
schedule item, so only the first item ever played, and grouping
media items into a Collection silently dropped the requested order.

Redesign:
- Single-item lineup: one ProgramScheduleItemFlood referencing the
  target directly (media item / collection / smart / multi / rerun /
  playlist); no generated collection or playlist. Response PlaylistId
  is null.
- Multi-item lineup (>= 2): one generated IsSystem Playlist in a
  get-or-created IsSystem PlaylistGroup ("Channel Lineups"), one
  PlaylistItem per entry in lineup order with PlayAll=true, referenced
  by a single Flood schedule item. Rerun collections and playlists are
  rejected (422) in multi lineups (PlaylistItem/CollectionKey lack the
  fields to enumerate them).

Review fixes:
- Normalize + strict-validate MediaType<->CollectionType pairs once up
  front (422 on mismatch / wrong id / not exactly one id).
- Reject MultiCollection with non-Shuffle order (mirrors
  PlayoutModeMustBeValid), Mirror playout source, all via 422.
- OnDemand parity: queue TimeShiftOnDemandPlayout post-commit.
- De-collide generated ProgramSchedule and Playlist names against their
  unique indexes instead of leaking a UNIQUE-constraint DbUpdateException.
- Generic 422 on save failure + ILogger; AnyAsync existence checks;
  Either/Validation unwrap via Match; XML doc on request DTO + endpoint.
- Response model: ChannelId, PlaylistId (nullable), ProgramScheduleId,
  PlayoutId (CollectionId removed). Regenerated OpenAPI v1.json + v1.d.ts.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CLAUDE.md

@@ -36,7 +36,7 @@ Custom IPTV channel server for Jellyfin. Forked from [ErsatzTV/ErsatzTV](https:/
 - **Docker host**: jazz (192.168.1.99), container `ersatztv`, port 8409
 - **Config volume**: `~/downloadswarm/ersatztv/` on jazz → `/config` in container
 - **SQLite DB**: `/config/ersatztv.sqlite3` (WAL mode, root-owned)
-- **Images** (our fork, built by `.gitea/workflows/docker-build.yml` → `192.168.1.95:3000/timothy/ersatztv`): push to `main` → `:latest` + `:<sha>` (test image); push `v*` tag → `:prod` + `:<version>` + `:<sha>`. Prod container still runs upstream `ghcr.io/ersatztv/ersatztv:latest` pending cutover (server-management#481). Pipeline details: `docs/ci-cd.md`.
+- **Images** (our fork, built by `.gitea/workflows/docker-build.yml` → `192.168.1.95:3000/timothy/ersatztv`): push to `main` → `:latest` + `:<sha>` (test image); push `v*` tag → `:prod` + `:<version>` + `:<sha>`. Cutover done (2026-06-27, server-management#481/#482): prod container runs fork `:prod` (currently v26.3.1), test container tracks `:latest`; prod advances only when a new `v*` tag is pushed (next: `v26.4.0`, first app-change release). Pipeline details: `docs/ci-cd.md`.
 
 ## Development
 

ErsatzTV.Application/ChannelTemplates/ChannelTemplateDefault.cs

@@ -0,0 +1,24 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+internal static class ChannelTemplateDefault
+{
+    public static async Task<int?> GetDefaultTemplateId(
+        IConfigElementRepository configElementRepository,
+        CancellationToken cancellationToken)
+    {
+        Option<int> maybeDefault =
+            await configElementRepository.GetValue<int>(
+                ConfigElementKey.ChannelTemplatesDefaultTemplateId,
+                cancellationToken);
+        int? result = null;
+        foreach (int id in maybeDefault)
+        {
+            result = id;
+        }
+
+        return result;
+    }
+}

ErsatzTV.Application/ChannelTemplates/ChannelTemplateMapper.cs

@@ -0,0 +1,38 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public static class ChannelTemplateMapper
+{
+    public static ChannelTemplateResponseModel ProjectToResponseModel(ChannelTemplate template, int? defaultTemplateId) =>
+        new(
+            template.Id,
+            template.Name,
+            template.Description,
+            template.IsSystem,
+            defaultTemplateId == template.Id,
+            template.FFmpegProfileId,
+            template.WatermarkId,
+            template.FallbackFillerId,
+            template.PreRollFillerId,
+            template.MidRollFillerId,
+            template.PostRollFillerId,
+            template.StreamSelectorMode,
+            template.StreamSelector,
+            template.PreferredAudioLanguageCode,
+            template.PreferredAudioTitle,
+            template.PlayoutSource,
+            template.PlayoutMode,
+            template.StreamingMode,
+            template.PreferredSubtitleLanguageCode,
+            template.SubtitleMode,
+            template.MusicVideoCreditsMode,
+            template.MusicVideoCreditsTemplate,
+            template.SongVideoMode,
+            template.TranscodeMode,
+            template.IdleBehavior,
+            template.ShuffleScheduleItems,
+            template.RandomStartPoint,
+            template.FixedStartTimeBehavior);
+}

ErsatzTV.Application/ChannelTemplates/Commands/ChannelTemplateCommandBase.cs

@@ -0,0 +1,155 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Scheduling;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public abstract record ChannelTemplateCommandBase(
+    string Name,
+    string Description,
+    int FFmpegProfileId,
+    int? WatermarkId,
+    int? FallbackFillerId,
+    int? PreRollFillerId,
+    int? MidRollFillerId,
+    int? PostRollFillerId,
+    ChannelStreamSelectorMode StreamSelectorMode,
+    string StreamSelector,
+    string PreferredAudioLanguageCode,
+    string PreferredAudioTitle,
+    ChannelPlayoutSource PlayoutSource,
+    ChannelPlayoutMode PlayoutMode,
+    StreamingMode StreamingMode,
+    string PreferredSubtitleLanguageCode,
+    ChannelSubtitleMode SubtitleMode,
+    ChannelMusicVideoCreditsMode MusicVideoCreditsMode,
+    string MusicVideoCreditsTemplate,
+    ChannelSongVideoMode SongVideoMode,
+    ChannelTranscodeMode TranscodeMode,
+    ChannelIdleBehavior IdleBehavior,
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint,
+    FixedStartTimeBehavior FixedStartTimeBehavior)
+{
+    internal static async Task<Option<BaseError>> ValidateCommon(
+        TvContext dbContext,
+        ChannelTemplateCommandBase request,
+        int? existingTemplateId,
+        CancellationToken cancellationToken)
+    {
+        string name = NormalizeName(request.Name);
+        if (string.IsNullOrWhiteSpace(name))
+        {
+            return BaseError.New("Name is required.");
+        }
+
+        if (name.Length > 50)
+        {
+            return BaseError.New("Name must be 50 characters or less.");
+        }
+
+        if (request.Description?.Length > 500)
+        {
+            return BaseError.New("Description must be 500 characters or less.");
+        }
+
+        bool duplicateName = await dbContext.ChannelTemplates
+            .AnyAsync(t => t.Id != existingTemplateId && t.Name == name, cancellationToken);
+        if (duplicateName)
+        {
+            return BaseError.New("Channel template name must be unique.");
+        }
+
+        bool ffmpegProfileExists = await dbContext.FFmpegProfiles
+            .AnyAsync(p => p.Id == request.FFmpegProfileId, cancellationToken);
+        if (!ffmpegProfileExists)
+        {
+            return new NotFoundError($"FFmpegProfile {request.FFmpegProfileId} does not exist.");
+        }
+
+        foreach (int watermarkId in Optional(request.WatermarkId))
+        {
+            bool watermarkExists = await dbContext.ChannelWatermarks
+                .AnyAsync(w => w.Id == watermarkId, cancellationToken);
+            if (!watermarkExists)
+            {
+                return new NotFoundError($"Watermark {watermarkId} does not exist.");
+            }
+        }
+
+        Option<BaseError> maybeFillerError =
+            await FillerMustExist(dbContext, request.FallbackFillerId, FillerKind.Fallback, cancellationToken);
+        if (maybeFillerError.IsSome)
+        {
+            return maybeFillerError;
+        }
+
+        maybeFillerError = await FillerMustExist(dbContext, request.PreRollFillerId, FillerKind.PreRoll, cancellationToken);
+        if (maybeFillerError.IsSome)
+        {
+            return maybeFillerError;
+        }
+
+        maybeFillerError = await FillerMustExist(dbContext, request.MidRollFillerId, FillerKind.MidRoll, cancellationToken);
+        if (maybeFillerError.IsSome)
+        {
+            return maybeFillerError;
+        }
+
+        return await FillerMustExist(dbContext, request.PostRollFillerId, FillerKind.PostRoll, cancellationToken);
+    }
+
+    internal void ApplyTo(ChannelTemplate template)
+    {
+        template.Name = NormalizeName(Name);
+        template.Description = Description ?? string.Empty;
+        template.FFmpegProfileId = FFmpegProfileId;
+        template.WatermarkId = WatermarkId;
+        template.FallbackFillerId = FallbackFillerId;
+        template.PreRollFillerId = PreRollFillerId;
+        template.MidRollFillerId = MidRollFillerId;
+        template.PostRollFillerId = PostRollFillerId;
+        template.StreamSelectorMode = StreamSelectorMode;
+        template.StreamSelector = StreamSelector ?? string.Empty;
+        template.PreferredAudioLanguageCode = PreferredAudioLanguageCode ?? string.Empty;
+        template.PreferredAudioTitle = PreferredAudioTitle ?? string.Empty;
+        template.PlayoutSource = PlayoutSource;
+        template.PlayoutMode = PlayoutMode;
+        template.StreamingMode = StreamingMode;
+        template.PreferredSubtitleLanguageCode = PreferredSubtitleLanguageCode ?? string.Empty;
+        template.SubtitleMode = SubtitleMode;
+        template.MusicVideoCreditsMode = MusicVideoCreditsMode;
+        template.MusicVideoCreditsTemplate = MusicVideoCreditsTemplate ?? string.Empty;
+        template.SongVideoMode = SongVideoMode;
+        template.TranscodeMode = TranscodeMode;
+        template.IdleBehavior = IdleBehavior;
+        template.ShuffleScheduleItems = ShuffleScheduleItems;
+        template.RandomStartPoint = RandomStartPoint;
+        template.FixedStartTimeBehavior = FixedStartTimeBehavior;
+    }
+
+    internal static string NormalizeName(string name) => (name ?? string.Empty).Trim();
+
+    private static async Task<Option<BaseError>> FillerMustExist(
+        TvContext dbContext,
+        int? fillerPresetId,
+        FillerKind fillerKind,
+        CancellationToken cancellationToken)
+    {
+        foreach (int id in Optional(fillerPresetId))
+        {
+            bool exists = await dbContext.FillerPresets
+                .AnyAsync(f => f.Id == id && f.FillerKind == fillerKind, cancellationToken);
+            if (!exists)
+            {
+                return new NotFoundError($"{fillerKind} filler {id} does not exist.");
+            }
+        }
+
+        return Option<BaseError>.None;
+    }
+}

ErsatzTV.Application/ChannelTemplates/Commands/CreateChannelTemplate.cs

@@ -0,0 +1,60 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record CreateChannelTemplate(
+    string Name,
+    string Description,
+    int FFmpegProfileId,
+    int? WatermarkId,
+    int? FallbackFillerId,
+    int? PreRollFillerId,
+    int? MidRollFillerId,
+    int? PostRollFillerId,
+    ChannelStreamSelectorMode StreamSelectorMode,
+    string StreamSelector,
+    string PreferredAudioLanguageCode,
+    string PreferredAudioTitle,
+    ChannelPlayoutSource PlayoutSource,
+    ChannelPlayoutMode PlayoutMode,
+    StreamingMode StreamingMode,
+    string PreferredSubtitleLanguageCode,
+    ChannelSubtitleMode SubtitleMode,
+    ChannelMusicVideoCreditsMode MusicVideoCreditsMode,
+    string MusicVideoCreditsTemplate,
+    ChannelSongVideoMode SongVideoMode,
+    ChannelTranscodeMode TranscodeMode,
+    ChannelIdleBehavior IdleBehavior,
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint,
+    FixedStartTimeBehavior FixedStartTimeBehavior)
+    : ChannelTemplateCommandBase(
+        Name,
+        Description,
+        FFmpegProfileId,
+        WatermarkId,
+        FallbackFillerId,
+        PreRollFillerId,
+        MidRollFillerId,
+        PostRollFillerId,
+        StreamSelectorMode,
+        StreamSelector,
+        PreferredAudioLanguageCode,
+        PreferredAudioTitle,
+        PlayoutSource,
+        PlayoutMode,
+        StreamingMode,
+        PreferredSubtitleLanguageCode,
+        SubtitleMode,
+        MusicVideoCreditsMode,
+        MusicVideoCreditsTemplate,
+        SongVideoMode,
+        TranscodeMode,
+        IdleBehavior,
+        ShuffleScheduleItems,
+        RandomStartPoint,
+        FixedStartTimeBehavior),
+        IRequest<Either<BaseError, ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Commands/CreateChannelTemplateHandler.cs

@@ -0,0 +1,36 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class CreateChannelTemplateHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<CreateChannelTemplate, Either<BaseError, ChannelTemplateResponseModel>>
+{
+    public async Task<Either<BaseError, ChannelTemplateResponseModel>> Handle(
+        CreateChannelTemplate request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Option<BaseError> maybeError =
+            await ChannelTemplateCommandBase.ValidateCommon(dbContext, request, null, cancellationToken);
+        foreach (BaseError error in maybeError)
+        {
+            return error;
+        }
+
+        var template = new ChannelTemplate();
+        request.ApplyTo(template);
+        await dbContext.ChannelTemplates.AddAsync(template, cancellationToken);
+        await dbContext.SaveChangesAsync(cancellationToken);
+
+        int? defaultTemplateId =
+            await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+        return ChannelTemplateMapper.ProjectToResponseModel(template, defaultTemplateId);
+    }
+}

ErsatzTV.Application/ChannelTemplates/Commands/DeleteChannelTemplate.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record DeleteChannelTemplate(int ChannelTemplateId) : IRequest<Either<BaseError, Unit>>;

ErsatzTV.Application/ChannelTemplates/Commands/DeleteChannelTemplateHandler.cs

@@ -0,0 +1,42 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class DeleteChannelTemplateHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<DeleteChannelTemplate, Either<BaseError, Unit>>
+{
+    public async Task<Either<BaseError, Unit>> Handle(DeleteChannelTemplate request, CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Option<ChannelTemplate> maybeTemplate = await dbContext.ChannelTemplates
+            .SelectOneAsync(t => t.Id, t => t.Id == request.ChannelTemplateId, cancellationToken);
+        foreach (ChannelTemplate template in maybeTemplate)
+        {
+            if (template.IsSystem)
+            {
+                return BaseError.New("System templates cannot be deleted.");
+            }
+
+            int? defaultTemplateId =
+                await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+            if (defaultTemplateId == template.Id)
+            {
+                return BaseError.New("Default channel template cannot be deleted.");
+            }
+
+            dbContext.ChannelTemplates.Remove(template);
+            await dbContext.SaveChangesAsync(cancellationToken);
+            return Unit.Default;
+        }
+
+        return new NotFoundError($"ChannelTemplate {request.ChannelTemplateId} does not exist.");
+    }
+}

ErsatzTV.Application/ChannelTemplates/Commands/SetDefaultChannelTemplate.cs

@@ -0,0 +1,6 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record SetDefaultChannelTemplate(int ChannelTemplateId) : IRequest<Either<BaseError, ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Commands/SetDefaultChannelTemplateHandler.cs

@@ -0,0 +1,36 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class SetDefaultChannelTemplateHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<SetDefaultChannelTemplate, Either<BaseError, ChannelTemplateResponseModel>>
+{
+    public async Task<Either<BaseError, ChannelTemplateResponseModel>> Handle(
+        SetDefaultChannelTemplate request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Option<ChannelTemplate> maybeTemplate = await dbContext.ChannelTemplates
+            .AsNoTracking()
+            .SelectOneAsync(t => t.Id, t => t.Id == request.ChannelTemplateId, cancellationToken);
+        foreach (ChannelTemplate template in maybeTemplate)
+        {
+            await configElementRepository.Upsert(
+                ConfigElementKey.ChannelTemplatesDefaultTemplateId,
+                template.Id,
+                cancellationToken);
+            return ChannelTemplateMapper.ProjectToResponseModel(template, template.Id);
+        }
+
+        return new NotFoundError($"ChannelTemplate {request.ChannelTemplateId} does not exist.");
+    }
+}

ErsatzTV.Application/ChannelTemplates/Commands/UpdateChannelTemplate.cs

@@ -0,0 +1,61 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record UpdateChannelTemplate(
+    int ChannelTemplateId,
+    string Name,
+    string Description,
+    int FFmpegProfileId,
+    int? WatermarkId,
+    int? FallbackFillerId,
+    int? PreRollFillerId,
+    int? MidRollFillerId,
+    int? PostRollFillerId,
+    ChannelStreamSelectorMode StreamSelectorMode,
+    string StreamSelector,
+    string PreferredAudioLanguageCode,
+    string PreferredAudioTitle,
+    ChannelPlayoutSource PlayoutSource,
+    ChannelPlayoutMode PlayoutMode,
+    StreamingMode StreamingMode,
+    string PreferredSubtitleLanguageCode,
+    ChannelSubtitleMode SubtitleMode,
+    ChannelMusicVideoCreditsMode MusicVideoCreditsMode,
+    string MusicVideoCreditsTemplate,
+    ChannelSongVideoMode SongVideoMode,
+    ChannelTranscodeMode TranscodeMode,
+    ChannelIdleBehavior IdleBehavior,
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint,
+    FixedStartTimeBehavior FixedStartTimeBehavior)
+    : ChannelTemplateCommandBase(
+        Name,
+        Description,
+        FFmpegProfileId,
+        WatermarkId,
+        FallbackFillerId,
+        PreRollFillerId,
+        MidRollFillerId,
+        PostRollFillerId,
+        StreamSelectorMode,
+        StreamSelector,
+        PreferredAudioLanguageCode,
+        PreferredAudioTitle,
+        PlayoutSource,
+        PlayoutMode,
+        StreamingMode,
+        PreferredSubtitleLanguageCode,
+        SubtitleMode,
+        MusicVideoCreditsMode,
+        MusicVideoCreditsTemplate,
+        SongVideoMode,
+        TranscodeMode,
+        IdleBehavior,
+        ShuffleScheduleItems,
+        RandomStartPoint,
+        FixedStartTimeBehavior),
+        IRequest<Either<BaseError, ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Commands/UpdateChannelTemplateHandler.cs

@@ -0,0 +1,51 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class UpdateChannelTemplateHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<UpdateChannelTemplate, Either<BaseError, ChannelTemplateResponseModel>>
+{
+    public async Task<Either<BaseError, ChannelTemplateResponseModel>> Handle(
+        UpdateChannelTemplate request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Option<ChannelTemplate> maybeTemplate = await dbContext.ChannelTemplates
+            .SelectOneAsync(t => t.Id, t => t.Id == request.ChannelTemplateId, cancellationToken);
+        foreach (ChannelTemplate template in maybeTemplate)
+        {
+            if (template.IsSystem)
+            {
+                return BaseError.New("System templates cannot be updated.");
+            }
+
+            Option<BaseError> maybeError =
+                await ChannelTemplateCommandBase.ValidateCommon(
+                    dbContext,
+                    request,
+                    request.ChannelTemplateId,
+                    cancellationToken);
+            foreach (BaseError error in maybeError)
+            {
+                return error;
+            }
+
+            request.ApplyTo(template);
+            await dbContext.SaveChangesAsync(cancellationToken);
+            int? defaultTemplateId =
+                await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+            return ChannelTemplateMapper.ProjectToResponseModel(template, defaultTemplateId);
+        }
+
+        return new NotFoundError($"ChannelTemplate {request.ChannelTemplateId} does not exist.");
+    }
+}

ErsatzTV.Application/ChannelTemplates/Queries/GetAllChannelTemplates.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record GetAllChannelTemplates : IRequest<List<ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Queries/GetAllChannelTemplatesHandler.cs

@@ -0,0 +1,28 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class GetAllChannelTemplatesHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<GetAllChannelTemplates, List<ChannelTemplateResponseModel>>
+{
+    public async Task<List<ChannelTemplateResponseModel>> Handle(
+        GetAllChannelTemplates request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        int? defaultTemplateId =
+            await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+        return await dbContext.ChannelTemplates
+            .AsNoTracking()
+            .OrderBy(t => t.IsSystem ? 0 : 1)
+            .ThenBy(t => t.Name)
+            .Select(t => ChannelTemplateMapper.ProjectToResponseModel(t, defaultTemplateId))
+            .ToListAsync(cancellationToken);
+    }
+}

ErsatzTV.Application/ChannelTemplates/Queries/GetChannelTemplateById.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record GetChannelTemplateById(int ChannelTemplateId) : IRequest<Option<ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Queries/GetChannelTemplateByIdHandler.cs

@@ -0,0 +1,27 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class GetChannelTemplateByIdHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<GetChannelTemplateById, Option<ChannelTemplateResponseModel>>
+{
+    public async Task<Option<ChannelTemplateResponseModel>> Handle(
+        GetChannelTemplateById request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        int? defaultTemplateId =
+            await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+        Option<ChannelTemplate> maybeTemplate = await dbContext.ChannelTemplates
+            .AsNoTracking()
+            .SelectOneAsync(t => t.Id, t => t.Id == request.ChannelTemplateId, cancellationToken);
+        return maybeTemplate.Map(t => ChannelTemplateMapper.ProjectToResponseModel(t, defaultTemplateId));
+    }
+}

ErsatzTV.Application/ChannelTemplates/Queries/GetDefaultChannelTemplate.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public record GetDefaultChannelTemplate : IRequest<Option<ChannelTemplateResponseModel>>;

ErsatzTV.Application/ChannelTemplates/Queries/GetDefaultChannelTemplateHandler.cs

@@ -0,0 +1,40 @@
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.ChannelTemplates;
+
+public class GetDefaultChannelTemplateHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IConfigElementRepository configElementRepository)
+    : IRequestHandler<GetDefaultChannelTemplate, Option<ChannelTemplateResponseModel>>
+{
+    public async Task<Option<ChannelTemplateResponseModel>> Handle(
+        GetDefaultChannelTemplate request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+        int? defaultTemplateId =
+            await ChannelTemplateDefault.GetDefaultTemplateId(configElementRepository, cancellationToken);
+        foreach (int id in Optional(defaultTemplateId))
+        {
+            Option<ChannelTemplate> maybeConfigured = await dbContext.ChannelTemplates
+                .AsNoTracking()
+                .SelectOneAsync(t => t.Id, t => t.Id == id, cancellationToken);
+            foreach (ChannelTemplate template in maybeConfigured)
+            {
+                return ChannelTemplateMapper.ProjectToResponseModel(template, id);
+            }
+        }
+
+        ChannelTemplate fallback = await dbContext.ChannelTemplates
+            .AsNoTracking()
+            .Where(t => t.IsSystem)
+            .OrderBy(t => t.Name)
+            .FirstOrDefaultAsync(cancellationToken);
+        return Optional(fallback).Map(t => ChannelTemplateMapper.ProjectToResponseModel(t, t.Id));
+    }
+}

ErsatzTV.Application/Channels/Commands/CreateChannelFromLineup.cs

@@ -0,0 +1,56 @@
+using ErsatzTV.Application.Artworks;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.Channels;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Application.Channels;
+
+public record CreateChannelFromLineup(
+    string Name,
+    string Number,
+    string Group,
+    string Categories,
+    ArtworkContentTypeModel Logo,
+    bool IsEnabled,
+    bool ShowInEpg,
+    int TemplateId,
+    CreateChannelFromLineupAdvancedOptions Advanced,
+    List<CreateChannelFromLineupItem> Lineup) : IRequest<Either<BaseError, CreateChannelFromLineupResponseModel>>;
+
+public record CreateChannelFromLineupAdvancedOptions(
+    PlaybackOrder? PlaybackOrder = null,
+    int? FFmpegProfileId = null,
+    int? WatermarkId = null,
+    int? FallbackFillerId = null,
+    int? PreRollFillerId = null,
+    int? MidRollFillerId = null,
+    int? PostRollFillerId = null,
+    ChannelStreamSelectorMode? StreamSelectorMode = null,
+    string StreamSelector = null,
+    string PreferredAudioLanguageCode = null,
+    string PreferredAudioTitle = null,
+    ChannelPlayoutSource? PlayoutSource = null,
+    ChannelPlayoutMode? PlayoutMode = null,
+    StreamingMode? StreamingMode = null,
+    string PreferredSubtitleLanguageCode = null,
+    ChannelSubtitleMode? SubtitleMode = null,
+    ChannelMusicVideoCreditsMode? MusicVideoCreditsMode = null,
+    string MusicVideoCreditsTemplate = null,
+    ChannelSongVideoMode? SongVideoMode = null,
+    ChannelTranscodeMode? TranscodeMode = null,
+    ChannelIdleBehavior? IdleBehavior = null,
+    bool? ShuffleScheduleItems = null,
+    bool? RandomStartPoint = null,
+    FixedStartTimeBehavior? FixedStartTimeBehavior = null);
+
+public record CreateChannelFromLineupItem(
+    LibraryBrowseMediaType MediaType,
+    CollectionType CollectionType,
+    int? CollectionId,
+    int? MultiCollectionId,
+    int? SmartCollectionId,
+    int? RerunCollectionId,
+    int? MediaItemId,
+    int? PlaylistId);

ErsatzTV.Application/Channels/Commands/CreateChannelFromLineupHandler.cs

@@ -0,0 +1,754 @@
+using System.Globalization;
+using System.Text.RegularExpressions;
+using System.Threading.Channels;
+using ErsatzTV.Application.Playouts;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.Channels;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Search;
+using ErsatzTV.Core.Scheduling;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Channel = ErsatzTV.Core.Domain.Channel;
+
+namespace ErsatzTV.Application.Channels;
+
+public class CreateChannelFromLineupHandler(
+    ChannelWriter<IBackgroundServiceRequest> workerChannel,
+    IDbContextFactory<TvContext> dbContextFactory,
+    ISearchTargets searchTargets,
+    ILogger<CreateChannelFromLineupHandler> logger)
+    : IRequestHandler<CreateChannelFromLineup, Either<BaseError, CreateChannelFromLineupResponseModel>>
+{
+    // The single system playlist group that holds every generated channel-lineup playlist.
+    // Matches the Trakt "Trakt Lists" precedent (DbInitializer + delete guards on IsSystem).
+    private const string SystemPlaylistGroupName = "Channel Lineups";
+
+    public async Task<Either<BaseError, CreateChannelFromLineupResponseModel>> Handle(
+        CreateChannelFromLineup request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        Either<BaseError, PreparedCreate> validation = await Validate(dbContext, request, cancellationToken);
+        return await validation.Match(
+            Left: error => Task.FromResult<Either<BaseError, CreateChannelFromLineupResponseModel>>(error),
+            Right: prepared => PersistAndDispatch(dbContext, prepared, cancellationToken));
+    }
+
+    private async Task<Either<BaseError, CreateChannelFromLineupResponseModel>> PersistAndDispatch(
+        TvContext dbContext,
+        PreparedCreate prepared,
+        CancellationToken cancellationToken)
+    {
+        await using var transaction = await dbContext.Database.BeginTransactionAsync(cancellationToken);
+        try
+        {
+            dbContext.Channels.Add(prepared.Channel);
+            if (prepared.Playlist is not null)
+            {
+                dbContext.Playlists.Add(prepared.Playlist);
+            }
+
+            dbContext.ProgramSchedules.Add(prepared.ProgramSchedule);
+            dbContext.Playouts.Add(prepared.Playout);
+
+            await dbContext.SaveChangesAsync(cancellationToken);
+            await transaction.CommitAsync(cancellationToken);
+        }
+        catch (DbUpdateException ex)
+        {
+            await transaction.RollbackAsync(cancellationToken);
+            logger.LogError(ex, "Failed to persist channel created from lineup");
+            return BaseError.New("Unable to create channel from lineup");
+        }
+
+        searchTargets.SearchTargetsChanged();
+        await workerChannel.WriteAsync(
+            new BuildPlayout(prepared.Playout.Id, PlayoutBuildMode.Reset),
+            cancellationToken);
+
+        // Mirror CreateClassicPlayoutHandler: on-demand playouts must be time-shifted to "now" after build.
+        if (prepared.Channel.PlayoutMode is ChannelPlayoutMode.OnDemand)
+        {
+            await workerChannel.WriteAsync(
+                new TimeShiftOnDemandPlayout(prepared.Playout.Id, DateTimeOffset.Now, false),
+                cancellationToken);
+        }
+
+        await workerChannel.WriteAsync(new RefreshChannelList(), cancellationToken);
+
+        return new CreateChannelFromLineupResponseModel(
+            prepared.Channel.Id,
+            prepared.Playlist?.Id,
+            prepared.ProgramSchedule.Id,
+            prepared.Playout.Id);
+    }
+
+    private static async Task<Either<BaseError, PreparedCreate>> Validate(
+        TvContext dbContext,
+        CreateChannelFromLineup request,
+        CancellationToken cancellationToken)
+    {
+        string name = (request.Name ?? string.Empty).Trim();
+        string number = (request.Number ?? string.Empty).Trim();
+        string group = (request.Group ?? string.Empty).Trim();
+        string categories = (request.Categories ?? string.Empty).Trim();
+        CreateChannelFromLineupAdvancedOptions advanced = request.Advanced ?? new CreateChannelFromLineupAdvancedOptions();
+
+        if (string.IsNullOrWhiteSpace(name))
+        {
+            return BaseError.New("Channel name is required");
+        }
+
+        if (name.Length > 50)
+        {
+            return BaseError.New("Channel name must be 50 characters or fewer");
+        }
+
+        if (string.IsNullOrWhiteSpace(group))
+        {
+            return BaseError.New("Channel group is required");
+        }
+
+        if (!Regex.IsMatch(number, Channel.NumberValidator))
+        {
+            return BaseError.New("Invalid channel number; two decimals are allowed for subchannels");
+        }
+
+        if (await dbContext.Channels.AnyAsync(c => c.Number == number, cancellationToken))
+        {
+            return BaseError.New("Channel number must be unique");
+        }
+
+        if (!request.IsEnabled && request.ShowInEpg)
+        {
+            return BaseError.New("Disabled channels cannot be shown in EPG");
+        }
+
+        if (!string.IsNullOrWhiteSpace(request.Logo?.Path) &&
+            Uri.TryCreate(request.Logo.Path, UriKind.Absolute, out _) &&
+            !Artwork.IsExternalUrl(request.Logo.Path))
+        {
+            return BaseError.New("External logo url is invalid");
+        }
+
+        if (request.Lineup is null || request.Lineup.Count == 0)
+        {
+            return BaseError.New("Lineup must contain at least one item");
+        }
+
+        ChannelTemplate template = await dbContext.ChannelTemplates
+            .AsNoTracking()
+            .SingleOrDefaultAsync(t => t.Id == request.TemplateId, cancellationToken);
+        if (template is null)
+        {
+            return new NotFoundError($"Channel template {request.TemplateId} does not exist.");
+        }
+
+        int ffmpegProfileId = advanced.FFmpegProfileId ?? template.FFmpegProfileId;
+        int? fallbackFillerId = advanced.FallbackFillerId ?? template.FallbackFillerId;
+        int? preRollFillerId = advanced.PreRollFillerId ?? template.PreRollFillerId;
+        int? midRollFillerId = advanced.MidRollFillerId ?? template.MidRollFillerId;
+        int? postRollFillerId = advanced.PostRollFillerId ?? template.PostRollFillerId;
+        PlaybackOrder playbackOrder = advanced.PlaybackOrder ?? PlaybackOrder.Chronological;
+        ChannelPlayoutSource playoutSource = advanced.PlayoutSource ?? template.PlayoutSource;
+
+        // Mirror channels need special MirrorSourceChannelId plumbing (see CreateChannelHandler);
+        // this endpoint only builds generated playouts.
+        if (playoutSource is ChannelPlayoutSource.Mirror)
+        {
+            return BaseError.New("Mirror playout source is not supported by this endpoint");
+        }
+
+        Either<BaseError, Unit> referenceValidation = await ValidateReferences(
+            dbContext,
+            advanced,
+            template,
+            cancellationToken);
+        foreach (BaseError error in referenceValidation.LeftToSeq())
+        {
+            return error;
+        }
+
+        // Normalize + validate every lineup entry once, so validation and build see the same data.
+        var normalized = new List<NormalizedLineupItem>();
+        for (int i = 0; i < request.Lineup.Count; i++)
+        {
+            Either<BaseError, NormalizedLineupItem> itemValidation =
+                await NormalizeLineupItem(dbContext, request.Lineup[i], i, cancellationToken);
+            foreach (BaseError error in itemValidation.LeftToSeq())
+            {
+                return error;
+            }
+
+            foreach (NormalizedLineupItem item in itemValidation.RightToSeq())
+            {
+                normalized.Add(item);
+            }
+        }
+
+        bool multiItem = normalized.Count >= 2;
+
+        // MultiCollection entries only support Shuffle / ShuffleInOrder (mirrors PlayoutModeMustBeValid).
+        if (normalized.Any(i => i.CollectionType is CollectionType.MultiCollection) &&
+            playbackOrder is not (PlaybackOrder.Shuffle or PlaybackOrder.ShuffleInOrder))
+        {
+            return BaseError.New($"Invalid playback order for multi collection: '{playbackOrder}'");
+        }
+
+        if (multiItem)
+        {
+            // The generated playlist cannot express rerun collections or nested playlists
+            // (PlaylistItem + CollectionKey.ForPlaylistItem lack those fields).
+            for (int i = 0; i < normalized.Count; i++)
+            {
+                if (normalized[i].CollectionType is CollectionType.RerunFirstRun or CollectionType.Playlist)
+                {
+                    return BaseError.New(
+                        $"lineup[{normalized[i].Index}]: rerun collections and playlists are only " +
+                        "supported as a single-item lineup");
+                }
+            }
+        }
+
+        Channel channel = BuildChannel(
+            request,
+            template,
+            advanced,
+            name,
+            number,
+            group,
+            categories,
+            ffmpegProfileId,
+            fallbackFillerId);
+
+        string scheduleName = await DeCollideName(
+            GeneratedName(number, name, "Schedule"),
+            (candidate, ct) => dbContext.ProgramSchedules.AnyAsync(ps => ps.Name == candidate, ct),
+            cancellationToken);
+
+        ProgramSchedule schedule = BuildProgramSchedule(scheduleName, template, advanced);
+
+        Playlist playlist = null;
+        ProgramScheduleItemFlood floodItem = BuildFloodBase(
+            playbackOrder,
+            advanced,
+            template,
+            fallbackFillerId,
+            preRollFillerId,
+            midRollFillerId,
+            postRollFillerId);
+
+        if (multiItem)
+        {
+            playlist = await BuildPlaylist(dbContext, number, name, normalized, playbackOrder, cancellationToken);
+            floodItem.CollectionType = CollectionType.Playlist;
+            floodItem.Playlist = playlist;
+        }
+        else
+        {
+            NormalizedLineupItem only = normalized[0];
+            floodItem.CollectionType = only.CollectionType;
+            floodItem.CollectionId = only.CollectionId;
+            floodItem.MultiCollectionId = only.MultiCollectionId;
+            floodItem.SmartCollectionId = only.SmartCollectionId;
+            floodItem.RerunCollectionId = only.RerunCollectionId;
+            floodItem.MediaItemId = only.MediaItemId;
+            floodItem.PlaylistId = only.PlaylistId;
+        }
+
+        schedule.Items = [floodItem];
+
+        var playout = new Playout
+        {
+            Channel = channel,
+            ProgramSchedule = schedule,
+            ScheduleKind = PlayoutScheduleKind.Classic
+        };
+
+        return new PreparedCreate(channel, playlist, schedule, playout);
+    }
+
+    private static async Task<Playlist> BuildPlaylist(
+        TvContext dbContext,
+        string channelNumber,
+        string channelName,
+        List<NormalizedLineupItem> lineup,
+        PlaybackOrder playbackOrder,
+        CancellationToken cancellationToken)
+    {
+        // Reuse the single system playlist group, creating it on first use.
+        PlaylistGroup playlistGroup = await dbContext.PlaylistGroups
+            .FirstOrDefaultAsync(pg => pg.IsSystem && pg.Name == SystemPlaylistGroupName, cancellationToken);
+        playlistGroup ??= new PlaylistGroup { Name = SystemPlaylistGroupName, IsSystem = true };
+
+        string playlistName = await DeCollideName(
+            GeneratedName(channelNumber, channelName, "Lineup"),
+            (candidate, ct) => dbContext.Playlists.AnyAsync(
+                p => p.PlaylistGroupId == playlistGroup.Id && p.Name == candidate,
+                ct),
+            cancellationToken);
+
+        var playlist = new Playlist
+        {
+            Name = playlistName,
+            IsSystem = true,
+            PlaylistGroup = playlistGroup,
+            PlaylistGroupId = playlistGroup.Id,
+            Items = []
+        };
+
+        int index = 1;
+        foreach (NormalizedLineupItem item in lineup)
+        {
+            playlist.Items.Add(new PlaylistItem
+            {
+                Playlist = playlist,
+                Index = index++,
+                CollectionType = item.CollectionType,
+                CollectionId = item.CollectionId,
+                MultiCollectionId = item.MultiCollectionId,
+                SmartCollectionId = item.SmartCollectionId,
+                MediaItemId = item.MediaItemId,
+                PlaybackOrder = playbackOrder,
+
+                // Play every item in each entry before advancing so lineup order is honored
+                // (PlaylistEnumerator round-robins one-per-entry unless PlayAll/Count).
+                PlayAll = true,
+                IncludeInProgramGuide = true
+            });
+        }
+
+        return playlist;
+    }
+
+    private static Channel BuildChannel(
+        CreateChannelFromLineup request,
+        ChannelTemplate template,
+        CreateChannelFromLineupAdvancedOptions advanced,
+        string name,
+        string number,
+        string group,
+        string categories,
+        int ffmpegProfileId,
+        int? fallbackFillerId)
+    {
+        var artwork = new List<Artwork>();
+        if (!string.IsNullOrWhiteSpace(request.Logo?.Path))
+        {
+            string logo = request.Logo.Path;
+            if (logo.StartsWith("iptv/logos/", StringComparison.Ordinal))
+            {
+                logo = logo.Replace("iptv/logos/", string.Empty);
+            }
+
+            artwork.Add(new Artwork
+            {
+                Path = logo,
+                ArtworkKind = ArtworkKind.Logo,
+                OriginalContentType = !string.IsNullOrEmpty(request.Logo.ContentType) ? request.Logo.ContentType : null,
+                DateAdded = DateTime.UtcNow,
+                DateUpdated = DateTime.UtcNow
+            });
+        }
+
+        return new Channel(Guid.NewGuid())
+        {
+            Name = name,
+            Number = number,
+            SortNumber = double.Parse(number, CultureInfo.InvariantCulture),
+            Group = group,
+            Categories = categories,
+            FFmpegProfileId = ffmpegProfileId,
+            SlugSeconds = null,
+            PlayoutSource = advanced.PlayoutSource ?? template.PlayoutSource,
+            PlayoutMode = advanced.PlayoutMode ?? template.PlayoutMode,
+            StreamingMode = advanced.StreamingMode ?? template.StreamingMode,
+            WatermarkId = advanced.WatermarkId ?? template.WatermarkId,
+            FallbackFillerId = fallbackFillerId,
+            Artwork = artwork,
+            StreamSelectorMode = advanced.StreamSelectorMode ?? template.StreamSelectorMode,
+            StreamSelector = advanced.StreamSelector ?? template.StreamSelector ?? string.Empty,
+            PreferredAudioLanguageCode =
+                advanced.PreferredAudioLanguageCode ?? template.PreferredAudioLanguageCode ?? string.Empty,
+            PreferredAudioTitle = advanced.PreferredAudioTitle ?? template.PreferredAudioTitle ?? string.Empty,
+            PreferredSubtitleLanguageCode =
+                advanced.PreferredSubtitleLanguageCode ?? template.PreferredSubtitleLanguageCode ?? string.Empty,
+            SubtitleMode = advanced.SubtitleMode ?? template.SubtitleMode,
+            MusicVideoCreditsMode = advanced.MusicVideoCreditsMode ?? template.MusicVideoCreditsMode,
+            MusicVideoCreditsTemplate =
+                advanced.MusicVideoCreditsTemplate ?? template.MusicVideoCreditsTemplate ?? string.Empty,
+            SongVideoMode = advanced.SongVideoMode ?? template.SongVideoMode,
+            TranscodeMode = advanced.TranscodeMode ?? template.TranscodeMode,
+            IdleBehavior = advanced.IdleBehavior ?? template.IdleBehavior,
+            IsEnabled = request.IsEnabled,
+            ShowInEpg = request.IsEnabled && request.ShowInEpg
+        };
+    }
+
+    private static ProgramSchedule BuildProgramSchedule(
+        string scheduleName,
+        ChannelTemplate template,
+        CreateChannelFromLineupAdvancedOptions advanced) =>
+        new()
+        {
+            Name = scheduleName,
+            KeepMultiPartEpisodesTogether = true,
+            TreatCollectionsAsShows = true,
+            ShuffleScheduleItems = advanced.ShuffleScheduleItems ?? template.ShuffleScheduleItems,
+            RandomStartPoint = advanced.RandomStartPoint ?? template.RandomStartPoint,
+            FixedStartTimeBehavior = advanced.FixedStartTimeBehavior ?? template.FixedStartTimeBehavior,
+            Items = []
+        };
+
+    private static ProgramScheduleItemFlood BuildFloodBase(
+        PlaybackOrder playbackOrder,
+        CreateChannelFromLineupAdvancedOptions advanced,
+        ChannelTemplate template,
+        int? fallbackFillerId,
+        int? preRollFillerId,
+        int? midRollFillerId,
+        int? postRollFillerId) =>
+        new()
+        {
+            Index = 1,
+            PlaybackOrder = playbackOrder,
+            GuideMode = GuideMode.Normal,
+            CustomTitle = string.Empty,
+            SearchTitle = string.Empty,
+            SearchQuery = string.Empty,
+            PreRollFillerId = preRollFillerId,
+            MidRollFillerId = midRollFillerId,
+            PostRollFillerId = postRollFillerId,
+            FallbackFillerId = fallbackFillerId,
+            PreferredAudioLanguageCode =
+                advanced.PreferredAudioLanguageCode ?? template.PreferredAudioLanguageCode ?? string.Empty,
+            PreferredAudioTitle = advanced.PreferredAudioTitle ?? template.PreferredAudioTitle ?? string.Empty,
+            PreferredSubtitleLanguageCode =
+                advanced.PreferredSubtitleLanguageCode ?? template.PreferredSubtitleLanguageCode ?? string.Empty,
+            SubtitleMode = advanced.SubtitleMode ?? template.SubtitleMode
+        };
+
+    private static string GeneratedName(string channelNumber, string channelName, string suffix)
+    {
+        string prefix = $"{channelNumber} {channelName}".Trim();
+        int maxPrefixLength = Math.Max(0, 50 - suffix.Length - 1);
+        if (prefix.Length > maxPrefixLength)
+        {
+            prefix = prefix[..maxPrefixLength].TrimEnd();
+        }
+
+        return $"{prefix} {suffix}".Trim();
+    }
+
+    // De-collide a generated (already <= 50 char) name against a unique index by appending " 2", " 3", ...
+    // rather than leaking a raw UNIQUE-constraint failure.
+    private static async Task<string> DeCollideName(
+        string baseName,
+        Func<string, CancellationToken, Task<bool>> exists,
+        CancellationToken cancellationToken)
+    {
+        if (!await exists(baseName, cancellationToken))
+        {
+            return baseName;
+        }
+
+        for (int n = 2; ; n++)
+        {
+            string suffix = $" {n}";
+            string candidate = baseName.Length + suffix.Length > 50
+                ? baseName[..(50 - suffix.Length)].TrimEnd() + suffix
+                : baseName + suffix;
+
+            if (!await exists(candidate, cancellationToken))
+            {
+                return candidate;
+            }
+        }
+    }
+
+    private static async Task<Either<BaseError, Unit>> ValidateReferences(
+        TvContext dbContext,
+        CreateChannelFromLineupAdvancedOptions advanced,
+        ChannelTemplate template,
+        CancellationToken cancellationToken)
+    {
+        int ffmpegProfileId = advanced.FFmpegProfileId ?? template.FFmpegProfileId;
+        if (!await dbContext.FFmpegProfiles.AnyAsync(p => p.Id == ffmpegProfileId, cancellationToken))
+        {
+            return new NotFoundError($"FFmpegProfile {ffmpegProfileId} does not exist.");
+        }
+
+        Either<BaseError, Unit> channelReferences = await ValidateChannelReferences(
+            dbContext,
+            advanced.WatermarkId ?? template.WatermarkId,
+            advanced.FallbackFillerId ?? template.FallbackFillerId,
+            cancellationToken);
+        foreach (BaseError error in channelReferences.LeftToSeq())
+        {
+            return error;
+        }
+
+        Either<BaseError, Unit> itemFillers = await ValidateItemFillers(
+            dbContext,
+            advanced.PreRollFillerId ?? template.PreRollFillerId,
+            advanced.MidRollFillerId ?? template.MidRollFillerId,
+            advanced.PostRollFillerId ?? template.PostRollFillerId,
+            cancellationToken);
+        foreach (BaseError error in itemFillers.LeftToSeq())
+        {
+            return error;
+        }
+
+        return Unit.Default;
+    }
+
+    private static async Task<Either<BaseError, Unit>> ValidateChannelReferences(
+        TvContext dbContext,
+        int? watermarkId,
+        int? fallbackFillerId,
+        CancellationToken cancellationToken)
+    {
+        if (watermarkId.HasValue &&
+            !await dbContext.ChannelWatermarks.AnyAsync(w => w.Id == watermarkId.Value, cancellationToken))
+        {
+            return new NotFoundError($"Watermark {watermarkId.Value} does not exist.");
+        }
+
+        if (fallbackFillerId.HasValue && !await dbContext.FillerPresets.AnyAsync(
+                fp => fp.Id == fallbackFillerId.Value && fp.FillerKind == FillerKind.Fallback,
+                cancellationToken))
+        {
+            return new NotFoundError($"Fallback filler {fallbackFillerId.Value} does not exist.");
+        }
+
+        return Unit.Default;
+    }
+
+    private static async Task<Either<BaseError, Unit>> ValidateItemFillers(
+        TvContext dbContext,
+        int? preRollFillerId,
+        int? midRollFillerId,
+        int? postRollFillerId,
+        CancellationToken cancellationToken)
+    {
+        if (preRollFillerId.HasValue && !await FillerExists(dbContext, preRollFillerId.Value, FillerKind.PreRoll, cancellationToken))
+        {
+            return new NotFoundError($"Pre-roll filler {preRollFillerId.Value} does not exist.");
+        }
+
+        if (midRollFillerId.HasValue && !await FillerExists(dbContext, midRollFillerId.Value, FillerKind.MidRoll, cancellationToken))
+        {
+            return new NotFoundError($"Mid-roll filler {midRollFillerId.Value} does not exist.");
+        }
+
+        if (postRollFillerId.HasValue && !await FillerExists(dbContext, postRollFillerId.Value, FillerKind.PostRoll, cancellationToken))
+        {
+            return new NotFoundError($"Post-roll filler {postRollFillerId.Value} does not exist.");
+        }
+
+        return Unit.Default;
+    }
+
+    private static Task<bool> FillerExists(
+        TvContext dbContext,
+        int id,
+        FillerKind fillerKind,
+        CancellationToken cancellationToken) =>
+        dbContext.FillerPresets.AnyAsync(fp => fp.Id == id && fp.FillerKind == fillerKind, cancellationToken);
+
+    private static async Task<Either<BaseError, NormalizedLineupItem>> NormalizeLineupItem(
+        TvContext dbContext,
+        CreateChannelFromLineupItem item,
+        int index,
+        CancellationToken cancellationToken)
+    {
+        int providedIds = new int?[]
+        {
+            item.CollectionId,
+            item.MultiCollectionId,
+            item.SmartCollectionId,
+            item.RerunCollectionId,
+            item.MediaItemId,
+            item.PlaylistId
+        }.Count(id => id.HasValue);
+
+        if (providedIds != 1)
+        {
+            return BaseError.New($"lineup[{index}] must provide exactly one typed id.");
+        }
+
+        switch (item.MediaType)
+        {
+            case LibraryBrowseMediaType.Movie:
+                return await NormalizeMediaItem(
+                    dbContext.Movies, item, CollectionType.Movie, index, "Movie", cancellationToken);
+            case LibraryBrowseMediaType.TelevisionShow:
+                return await NormalizeMediaItem(
+                    dbContext.Shows, item, CollectionType.TelevisionShow, index, "TelevisionShow", cancellationToken);
+            case LibraryBrowseMediaType.TelevisionSeason:
+                return await NormalizeMediaItem(
+                    dbContext.Seasons, item, CollectionType.TelevisionSeason, index, "TelevisionSeason", cancellationToken);
+            case LibraryBrowseMediaType.Artist:
+                return await NormalizeMediaItem(
+                    dbContext.Artists, item, CollectionType.Artist, index, "Artist", cancellationToken);
+            case LibraryBrowseMediaType.Collection:
+                if (item.CollectionType != CollectionType.Collection)
+                {
+                    return Mismatch(index, item);
+                }
+
+                if (!item.CollectionId.HasValue)
+                {
+                    return WrongId(index, item.MediaType, "collectionId");
+                }
+
+                return await ExistsThen(
+                    dbContext.Collections,
+                    item.CollectionId.Value,
+                    $"lineup[{index}] Collection",
+                    new NormalizedLineupItem(index, CollectionType.Collection, CollectionId: item.CollectionId),
+                    cancellationToken);
+            case LibraryBrowseMediaType.SmartCollection:
+                if (item.CollectionType != CollectionType.SmartCollection)
+                {
+                    return Mismatch(index, item);
+                }
+
+                if (!item.SmartCollectionId.HasValue)
+                {
+                    return WrongId(index, item.MediaType, "smartCollectionId");
+                }
+
+                return await ExistsThen(
+                    dbContext.SmartCollections,
+                    item.SmartCollectionId.Value,
+                    $"lineup[{index}] SmartCollection",
+                    new NormalizedLineupItem(index, CollectionType.SmartCollection, SmartCollectionId: item.SmartCollectionId),
+                    cancellationToken);
+            case LibraryBrowseMediaType.MultiCollection:
+                if (item.CollectionType != CollectionType.MultiCollection)
+                {
+                    return Mismatch(index, item);
+                }
+
+                if (!item.MultiCollectionId.HasValue)
+                {
+                    return WrongId(index, item.MediaType, "multiCollectionId");
+                }
+
+                return await ExistsThen(
+                    dbContext.MultiCollections,
+                    item.MultiCollectionId.Value,
+                    $"lineup[{index}] MultiCollection",
+                    new NormalizedLineupItem(index, CollectionType.MultiCollection, MultiCollectionId: item.MultiCollectionId),
+                    cancellationToken);
+            case LibraryBrowseMediaType.RerunCollection:
+                if (item.CollectionType != CollectionType.RerunFirstRun)
+                {
+                    return Mismatch(index, item);
+                }
+
+                if (!item.RerunCollectionId.HasValue)
+                {
+                    return WrongId(index, item.MediaType, "rerunCollectionId");
+                }
+
+                return await ExistsThen(
+                    dbContext.RerunCollections,
+                    item.RerunCollectionId.Value,
+                    $"lineup[{index}] RerunCollection",
+                    new NormalizedLineupItem(index, CollectionType.RerunFirstRun, RerunCollectionId: item.RerunCollectionId),
+                    cancellationToken);
+            case LibraryBrowseMediaType.Playlist:
+                if (item.CollectionType != CollectionType.Playlist)
+                {
+                    return Mismatch(index, item);
+                }
+
+                if (!item.PlaylistId.HasValue)
+                {
+                    return WrongId(index, item.MediaType, "playlistId");
+                }
+
+                return await ExistsThen(
+                    dbContext.Playlists,
+                    item.PlaylistId.Value,
+                    $"lineup[{index}] Playlist",
+                    new NormalizedLineupItem(index, CollectionType.Playlist, PlaylistId: item.PlaylistId),
+                    cancellationToken);
+            default:
+                return BaseError.New($"lineup[{index}] has an unsupported media type '{item.MediaType}'.");
+        }
+    }
+
+    private static async Task<Either<BaseError, NormalizedLineupItem>> NormalizeMediaItem<TEntity>(
+        DbSet<TEntity> set,
+        CreateChannelFromLineupItem item,
+        CollectionType expectedType,
+        int index,
+        string label,
+        CancellationToken cancellationToken)
+        where TEntity : class
+    {
+        if (item.CollectionType != expectedType)
+        {
+            return Mismatch(index, item);
+        }
+
+        if (!item.MediaItemId.HasValue)
+        {
+            return WrongId(index, item.MediaType, "mediaItemId");
+        }
+
+        return await ExistsThen(
+            set,
+            item.MediaItemId.Value,
+            $"lineup[{index}] {label}",
+            new NormalizedLineupItem(index, expectedType, MediaItemId: item.MediaItemId),
+            cancellationToken);
+    }
+
+    private static BaseError Mismatch(int index, CreateChannelFromLineupItem item) =>
+        BaseError.New(
+            $"lineup[{index}]: media type '{item.MediaType}' does not match collection type '{item.CollectionType}'.");
+
+    private static BaseError WrongId(int index, LibraryBrowseMediaType mediaType, string expectedField) =>
+        BaseError.New($"lineup[{index}]: media type '{mediaType}' requires a {expectedField}.");
+
+    private static async Task<Either<BaseError, NormalizedLineupItem>> ExistsThen<TEntity>(
+        DbSet<TEntity> set,
+        int id,
+        string label,
+        NormalizedLineupItem normalized,
+        CancellationToken cancellationToken)
+        where TEntity : class
+    {
+        bool exists = await set.AsNoTracking()
+            .AnyAsync(e => EF.Property<int>(e, "Id") == id, cancellationToken);
+        return exists
+            ? normalized
+            : new NotFoundError($"{label} {id} does not exist.");
+    }
+
+    private sealed record NormalizedLineupItem(
+        int Index,
+        CollectionType CollectionType,
+        int? CollectionId = null,
+        int? MultiCollectionId = null,
+        int? SmartCollectionId = null,
+        int? RerunCollectionId = null,
+        int? MediaItemId = null,
+        int? PlaylistId = null);
+
+    private sealed record PreparedCreate(
+        Channel Channel,
+        Playlist Playlist,
+        ProgramSchedule ProgramSchedule,
+        Playout Playout);
+}

ErsatzTV.Application/LibraryBrowse/Queries/GetLibraryBrowseItems.cs

@@ -0,0 +1,10 @@
+using ErsatzTV.Core.Api.LibraryBrowse;
+
+namespace ErsatzTV.Application.LibraryBrowse;
+
+public record GetLibraryBrowseItems(
+    string Query,
+    int? LibraryId,
+    LibraryBrowseMediaType? MediaType,
+    int PageNum,
+    int PageSize) : IRequest<PagedLibraryBrowseItemsResponseModel>;

ErsatzTV.Application/LibraryBrowse/Queries/GetLibraryBrowseItemsHandler.cs

@@ -0,0 +1,953 @@
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Emby;
+using ErsatzTV.Core.Interfaces.Search;
+using ErsatzTV.Core.Jellyfin;
+using ErsatzTV.Core.Search;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Search;
+using Flurl;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.LibraryBrowse;
+
+public class GetLibraryBrowseItemsHandler(
+    ISearchIndex searchIndex,
+    IDbContextFactory<TvContext> dbContextFactory)
+    : IRequestHandler<GetLibraryBrowseItems, PagedLibraryBrowseItemsResponseModel>
+{
+    private const string LibraryIdField = "library_id";
+
+    public async Task<PagedLibraryBrowseItemsResponseModel> Handle(
+        GetLibraryBrowseItems request,
+        CancellationToken cancellationToken)
+    {
+        int offset = request.PageNum * request.PageSize;
+        SearchResult mediaResult = await SearchMedia(request, offset, request.PageSize, cancellationToken);
+
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        List<LibraryBrowseItemResponseModel> mediaItems = await HydrateMediaItems(
+            dbContext,
+            mediaResult.Items,
+            cancellationToken);
+
+        int collectionTotal = await CountCollections(dbContext, request, cancellationToken);
+        // Lucene total count can briefly include stale media ids until the async rescan catches up; collection
+        // paging may drift in that window, matching the staleness behavior accepted by the existing search UI.
+        int collectionSkip = Math.Max(0, offset - mediaResult.TotalCount);
+        int collectionTake = request.PageSize - mediaItems.Count;
+        List<LibraryBrowseItemResponseModel> collectionItems = collectionTake > 0
+            ? await GetCollectionItems(dbContext, request, collectionSkip, collectionTake, cancellationToken)
+            : [];
+
+        return new PagedLibraryBrowseItemsResponseModel(
+            mediaResult.TotalCount + collectionTotal,
+            mediaItems.Concat(collectionItems).ToList());
+    }
+
+    private async Task<SearchResult> SearchMedia(
+        GetLibraryBrowseItems request,
+        int offset,
+        int pageSize,
+        CancellationToken cancellationToken)
+    {
+        List<string> typeFilters = MediaTypesFor(request.MediaType).ToList();
+        if (typeFilters.Count == 0)
+        {
+            return new SearchResult([], 0);
+        }
+
+        var clauses = new List<string>
+        {
+            typeFilters.Count == 1
+                ? $"type:{typeFilters[0]}"
+                : $"({string.Join(" OR ", typeFilters.Map(t => $"type:{t}"))})"
+        };
+
+        if (request.LibraryId.HasValue)
+        {
+            clauses.Add($"{LibraryIdField}:{request.LibraryId.Value}");
+        }
+
+        if (!string.IsNullOrWhiteSpace(request.Query))
+        {
+            clauses.Add($"({request.Query})");
+        }
+
+        return await searchIndex.Search(
+            string.Join(" AND ", clauses),
+            string.Empty,
+            offset,
+            pageSize,
+            [LuceneSearchIndex.TitleAndYearSearchField],
+            cancellationToken);
+    }
+
+    private static IEnumerable<string> MediaTypesFor(LibraryBrowseMediaType? mediaType) =>
+        mediaType switch
+        {
+            LibraryBrowseMediaType.Movie => [LuceneSearchIndex.MovieType],
+            LibraryBrowseMediaType.TelevisionShow => [LuceneSearchIndex.ShowType],
+            LibraryBrowseMediaType.TelevisionSeason => [LuceneSearchIndex.SeasonType],
+            LibraryBrowseMediaType.Artist => [LuceneSearchIndex.ArtistType],
+            null =>
+            [
+                LuceneSearchIndex.MovieType,
+                LuceneSearchIndex.ShowType,
+                LuceneSearchIndex.SeasonType,
+                LuceneSearchIndex.ArtistType
+            ],
+            _ => []
+        };
+
+    private static async Task<List<LibraryBrowseItemResponseModel>> HydrateMediaItems(
+        TvContext dbContext,
+        List<SearchItem> searchItems,
+        CancellationToken cancellationToken)
+    {
+        if (searchItems.Count == 0)
+        {
+            return [];
+        }
+
+        List<int> movieIds = searchItems.Where(i => i.Type == LuceneSearchIndex.MovieType).Select(i => i.Id).ToList();
+        List<int> showIds = searchItems.Where(i => i.Type == LuceneSearchIndex.ShowType).Select(i => i.Id).ToList();
+        List<int> seasonIds = searchItems.Where(i => i.Type == LuceneSearchIndex.SeasonType).Select(i => i.Id).ToList();
+        List<int> artistIds = searchItems.Where(i => i.Type == LuceneSearchIndex.ArtistType).Select(i => i.Id).ToList();
+
+        Dictionary<(string Type, int Id), LibraryBrowseItemResponseModel> hydrated = [];
+
+        foreach (LibraryBrowseItemResponseModel item in await GetMovies(dbContext, movieIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.MovieType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in await GetShows(dbContext, showIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.ShowType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in await GetSeasons(dbContext, seasonIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.SeasonType, item.Id)] = item;
+        }
+
+        foreach (LibraryBrowseItemResponseModel item in await GetArtists(dbContext, artistIds, cancellationToken))
+        {
+            hydrated[(LuceneSearchIndex.ArtistType, item.Id)] = item;
+        }
+
+        return searchItems
+            .Where(i => hydrated.ContainsKey((i.Type, i.Id)))
+            .Select(i => hydrated[(i.Type, i.Id)])
+            .ToList();
+    }
+
+    private static async Task<List<LibraryBrowseItemResponseModel>> GetMovies(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        return await dbContext.MovieMetadata
+            .AsNoTracking()
+            .Where(mm => ids.Contains(mm.MovieId))
+            .Include(mm => mm.Artwork)
+            .Include(mm => mm.Movie)
+            .ThenInclude(m => m.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .Include(mm => mm.Movie)
+            .ThenInclude(m => m.MediaVersions)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(mm => mm.MovieId)
+                .Select(g => g.OrderBy(mm => mm.Id).First())
+                .Map(mm => new LibraryBrowseItemResponseModel(
+                mm.MovieId,
+                LibraryBrowseMediaType.Movie,
+                mm.Title ?? string.Empty,
+                mm.Movie.LibraryPath.LibraryId,
+                mm.Movie.LibraryPath.Library.Name,
+                Artwork(mm, ArtworkKind.Poster),
+                BestDuration(mm.Movie.MediaVersions),
+                1,
+                null,
+                CollectionType.Movie,
+                null,
+                null,
+                null,
+                null,
+                mm.MovieId,
+                null)).ToList());
+    }
+
+    private static async Task<List<LibraryBrowseItemResponseModel>> GetShows(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        Dictionary<int, int> counts = await dbContext.Episodes
+            .AsNoTracking()
+            .Where(e => ids.Contains(e.Season.ShowId))
+            .GroupBy(e => e.Season.ShowId)
+            .Select(g => new { ShowId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.ShowId, g => g.Count, cancellationToken);
+
+        return await dbContext.ShowMetadata
+            .AsNoTracking()
+            .Where(sm => ids.Contains(sm.ShowId))
+            .Include(sm => sm.Artwork)
+            .Include(sm => sm.Show)
+            .ThenInclude(s => s.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(sm => sm.ShowId)
+                .Select(g => g.OrderBy(sm => sm.Id).First())
+                .Map(sm => new LibraryBrowseItemResponseModel(
+                sm.ShowId,
+                LibraryBrowseMediaType.TelevisionShow,
+                sm.Title ?? string.Empty,
+                sm.Show.LibraryPath.LibraryId,
+                sm.Show.LibraryPath.Library.Name,
+                Artwork(sm, ArtworkKind.Poster),
+                null,
+                counts.TryGetValue(sm.ShowId, out int count) ? count : 0,
+                null,
+                CollectionType.TelevisionShow,
+                null,
+                null,
+                null,
+                null,
+                sm.ShowId,
+                null)).ToList());
+    }
+
+    private static async Task<List<LibraryBrowseItemResponseModel>> GetSeasons(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        Dictionary<int, int> counts = await dbContext.Episodes
+            .AsNoTracking()
+            .Where(e => ids.Contains(e.SeasonId))
+            .GroupBy(e => e.SeasonId)
+            .Select(g => new { SeasonId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.SeasonId, g => g.Count, cancellationToken);
+
+        return await dbContext.SeasonMetadata
+            .AsNoTracking()
+            .Where(sm => ids.Contains(sm.SeasonId))
+            .Include(sm => sm.Artwork)
+            .Include(sm => sm.Season)
+            .ThenInclude(s => s.Show)
+            .ThenInclude(s => s.ShowMetadata)
+            .Include(sm => sm.Season)
+            .ThenInclude(s => s.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(sm => sm.SeasonId)
+                .Select(g => g.OrderBy(sm => sm.Id).First())
+                .Map(sm => new LibraryBrowseItemResponseModel(
+                sm.SeasonId,
+                LibraryBrowseMediaType.TelevisionSeason,
+                SeasonTitle(sm),
+                sm.Season.LibraryPath.LibraryId,
+                sm.Season.LibraryPath.Library.Name,
+                Artwork(sm, ArtworkKind.Poster),
+                null,
+                counts.TryGetValue(sm.SeasonId, out int count) ? count : 0,
+                null,
+                CollectionType.TelevisionSeason,
+                null,
+                null,
+                null,
+                null,
+                sm.SeasonId,
+                null)).ToList());
+    }
+
+    private static async Task<List<LibraryBrowseItemResponseModel>> GetArtists(
+        TvContext dbContext,
+        List<int> ids,
+        CancellationToken cancellationToken)
+    {
+        if (ids.Count == 0)
+        {
+            return [];
+        }
+
+        Dictionary<int, int> counts = await dbContext.MusicVideos
+            .AsNoTracking()
+            .Where(mv => ids.Contains(mv.ArtistId))
+            .GroupBy(mv => mv.ArtistId)
+            .Select(g => new { ArtistId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.ArtistId, g => g.Count, cancellationToken);
+
+        return await dbContext.ArtistMetadata
+            .AsNoTracking()
+            .Where(am => ids.Contains(am.ArtistId))
+            .Include(am => am.Artwork)
+            .Include(am => am.Artist)
+            .ThenInclude(a => a.LibraryPath)
+            .ThenInclude(lp => lp.Library)
+            .ToListAsync(cancellationToken)
+            .Map(list => list
+                .GroupBy(am => am.ArtistId)
+                .Select(g => g.OrderBy(am => am.Id).First())
+                .Map(am => new LibraryBrowseItemResponseModel(
+                am.ArtistId,
+                LibraryBrowseMediaType.Artist,
+                am.Title ?? string.Empty,
+                am.Artist.LibraryPath.LibraryId,
+                am.Artist.LibraryPath.Library.Name,
+                Artwork(am, ArtworkKind.Thumbnail),
+                null,
+                counts.TryGetValue(am.ArtistId, out int count) ? count : 0,
+                null,
+                CollectionType.Artist,
+                null,
+                null,
+                null,
+                null,
+                am.ArtistId,
+                null)).ToList());
+    }
+
+    private static async Task<int> CountCollections(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        CancellationToken cancellationToken)
+    {
+        int count = 0;
+        if (ShouldInclude(request.MediaType, LibraryBrowseMediaType.Collection))
+        {
+            count += await FilterCollections(dbContext.Collections.AsNoTracking(), request)
+                .CountAsync(cancellationToken);
+        }
+
+        if (!request.LibraryId.HasValue && ShouldInclude(request.MediaType, LibraryBrowseMediaType.SmartCollection))
+        {
+            count += await FilterByName(dbContext.SmartCollections.AsNoTracking(), request.Query)
+                .CountAsync(cancellationToken);
+        }
+
+        if (!request.LibraryId.HasValue && ShouldInclude(request.MediaType, LibraryBrowseMediaType.MultiCollection))
+        {
+            count += await FilterByName(dbContext.MultiCollections.AsNoTracking(), request.Query)
+                .CountAsync(cancellationToken);
+        }
+
+        if (!request.LibraryId.HasValue && ShouldInclude(request.MediaType, LibraryBrowseMediaType.RerunCollection))
+        {
+            count += await FilterByName(dbContext.RerunCollections.AsNoTracking(), request.Query)
+                .CountAsync(cancellationToken);
+        }
+
+        if (!request.LibraryId.HasValue && ShouldInclude(request.MediaType, LibraryBrowseMediaType.Playlist))
+        {
+            count += await FilterByName(dbContext.Playlists.AsNoTracking(), request.Query)
+                .CountAsync(cancellationToken);
+        }
+
+        return count;
+    }
+
+    private static async Task<List<LibraryBrowseItemResponseModel>> GetCollectionItems(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        int skip,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        var results = new List<LibraryBrowseItemResponseModel>();
+
+        int remainingSkip = skip;
+
+        if (ShouldInclude(request.MediaType, LibraryBrowseMediaType.Collection))
+        {
+            IQueryable<Collection> collectionQuery = FilterCollections(dbContext.Collections.AsNoTracking(), request);
+            int count = await collectionQuery.CountAsync(cancellationToken);
+            int pageSkip = Math.Min(remainingSkip, count);
+            remainingSkip -= pageSkip;
+
+            List<Collection> collections = await collectionQuery
+                .OrderBy(c => c.Name)
+                .Skip(pageSkip)
+                .Take(take)
+                .ToListAsync(cancellationToken);
+            List<int> collectionIds = collections.Map(c => c.Id).ToList();
+            Dictionary<int, int> itemCounts = await dbContext.CollectionItems
+                .AsNoTracking()
+                .Where(ci => collectionIds.Contains(ci.CollectionId))
+                .GroupBy(ci => ci.CollectionId)
+                .Select(g => new { CollectionId = g.Key, Count = g.Count() })
+                .ToDictionaryAsync(g => g.CollectionId, g => g.Count, cancellationToken);
+            Dictionary<int, TimeSpan?> durations = await GetManualCollectionDurations(
+                dbContext,
+                collectionIds,
+                cancellationToken);
+            Dictionary<int, string> artwork = await GetManualCollectionArtwork(dbContext, collectionIds, cancellationToken);
+
+            results.AddRange(collections.Map(c => new LibraryBrowseItemResponseModel(
+                c.Id,
+                LibraryBrowseMediaType.Collection,
+                c.Name,
+                null,
+                null,
+                artwork.TryGetValue(c.Id, out string poster) ? poster : string.Empty,
+                durations.TryGetValue(c.Id, out TimeSpan? duration) ? duration : null,
+                itemCounts.TryGetValue(c.Id, out int itemCount) ? itemCount : 0,
+                "Manual",
+                CollectionType.Collection,
+                c.Id,
+                null,
+                null,
+                null,
+                null,
+                null)));
+        }
+
+        if (results.Count >= take || request.LibraryId.HasValue)
+        {
+            return results.Take(take).ToList();
+        }
+
+        remainingSkip = await AppendSmartCollections(dbContext, request, results, remainingSkip, take, cancellationToken);
+        remainingSkip = await AppendMultiCollections(dbContext, request, results, remainingSkip, take, cancellationToken);
+        remainingSkip = await AppendRerunCollections(dbContext, request, results, remainingSkip, take, cancellationToken);
+        await AppendPlaylists(dbContext, request, results, remainingSkip, take, cancellationToken);
+        return results.Take(take).ToList();
+    }
+
+    private static async Task<int> AppendSmartCollections(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        List<LibraryBrowseItemResponseModel> results,
+        int skip,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        if (!ShouldInclude(request.MediaType, LibraryBrowseMediaType.SmartCollection) || results.Count >= take)
+        {
+            return skip;
+        }
+
+        IQueryable<SmartCollection> query = FilterByName(dbContext.SmartCollections.AsNoTracking(), request.Query);
+        int count = await query.CountAsync(cancellationToken);
+        int pageSkip = Math.Min(skip, count);
+
+        List<SmartCollection> page = await query
+            .OrderBy(c => c.Name)
+            .Skip(pageSkip)
+            .Take(take - results.Count)
+            .ToListAsync(cancellationToken);
+
+        results.AddRange(page.Map(c => new LibraryBrowseItemResponseModel(
+            c.Id,
+            LibraryBrowseMediaType.SmartCollection,
+            c.Name,
+            null,
+            null,
+            string.Empty,
+            null,
+            null,
+            "Smart",
+            CollectionType.SmartCollection,
+            null,
+            null,
+            c.Id,
+            null,
+            null,
+            null)));
+
+        return skip - pageSkip;
+    }
+
+    private static async Task<int> AppendMultiCollections(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        List<LibraryBrowseItemResponseModel> results,
+        int skip,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        if (!ShouldInclude(request.MediaType, LibraryBrowseMediaType.MultiCollection) || results.Count >= take)
+        {
+            return skip;
+        }
+
+        IQueryable<MultiCollection> query = FilterByName(dbContext.MultiCollections.AsNoTracking(), request.Query);
+        int count = await query.CountAsync(cancellationToken);
+        int pageSkip = Math.Min(skip, count);
+
+        List<MultiCollection> page = await query
+            .OrderBy(c => c.Name)
+            .Skip(pageSkip)
+            .Take(take - results.Count)
+            .ToListAsync(cancellationToken);
+        List<int> ids = page.Map(c => c.Id).ToList();
+        Dictionary<int, int> collectionCounts = await dbContext.Set<MultiCollectionItem>()
+            .AsNoTracking()
+            .Where(i => ids.Contains(i.MultiCollectionId))
+            .GroupBy(i => i.MultiCollectionId)
+            .Select(g => new { MultiCollectionId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.MultiCollectionId, g => g.Count, cancellationToken);
+        Dictionary<int, int> smartCollectionCounts = await dbContext.Set<MultiCollectionSmartItem>()
+            .AsNoTracking()
+            .Where(i => ids.Contains(i.MultiCollectionId))
+            .GroupBy(i => i.MultiCollectionId)
+            .Select(g => new { MultiCollectionId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.MultiCollectionId, g => g.Count, cancellationToken);
+
+        results.AddRange(page.Map(c => new LibraryBrowseItemResponseModel(
+            c.Id,
+            LibraryBrowseMediaType.MultiCollection,
+            c.Name,
+            null,
+            null,
+            string.Empty,
+            null,
+            (collectionCounts.TryGetValue(c.Id, out int collectionCount) ? collectionCount : 0) +
+            (smartCollectionCounts.TryGetValue(c.Id, out int smartCollectionCount) ? smartCollectionCount : 0),
+            "Multi",
+            CollectionType.MultiCollection,
+            null,
+            c.Id,
+            null,
+            null,
+            null,
+            null)));
+
+        return skip - pageSkip;
+    }
+
+    private static async Task<int> AppendRerunCollections(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        List<LibraryBrowseItemResponseModel> results,
+        int skip,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        if (!ShouldInclude(request.MediaType, LibraryBrowseMediaType.RerunCollection) || results.Count >= take)
+        {
+            return skip;
+        }
+
+        IQueryable<RerunCollection> query = FilterByName(dbContext.RerunCollections.AsNoTracking(), request.Query);
+        int count = await query.CountAsync(cancellationToken);
+        int pageSkip = Math.Min(skip, count);
+
+        List<RerunCollection> page = await query
+            .OrderBy(c => c.Name)
+            .Skip(pageSkip)
+            .Take(take - results.Count)
+            .ToListAsync(cancellationToken);
+
+        results.AddRange(page.Map(c => new LibraryBrowseItemResponseModel(
+            c.Id,
+            LibraryBrowseMediaType.RerunCollection,
+            c.Name,
+            null,
+            null,
+            string.Empty,
+            null,
+            null,
+            "Rerun",
+            // RerunFirstRun addresses the first-run side; the SPA can substitute RerunRerun for rerun schedule items.
+            CollectionType.RerunFirstRun,
+            null,
+            null,
+            null,
+            c.Id,
+            null,
+            null)));
+
+        return skip - pageSkip;
+    }
+
+    private static async Task AppendPlaylists(
+        TvContext dbContext,
+        GetLibraryBrowseItems request,
+        List<LibraryBrowseItemResponseModel> results,
+        int skip,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        if (!ShouldInclude(request.MediaType, LibraryBrowseMediaType.Playlist) || results.Count >= take)
+        {
+            return;
+        }
+
+        IQueryable<Playlist> query = FilterByName(dbContext.Playlists.AsNoTracking(), request.Query);
+        int count = await query.CountAsync(cancellationToken);
+        int pageSkip = Math.Min(skip, count);
+
+        List<Playlist> page = await query
+            .OrderBy(c => c.Name)
+            .Skip(pageSkip)
+            .Take(take - results.Count)
+            .ToListAsync(cancellationToken);
+        List<int> ids = page.Map(c => c.Id).ToList();
+        Dictionary<int, int> itemCounts = await dbContext.PlaylistItems
+            .AsNoTracking()
+            .Where(i => ids.Contains(i.PlaylistId))
+            .GroupBy(i => i.PlaylistId)
+            .Select(g => new { PlaylistId = g.Key, Count = g.Count() })
+            .ToDictionaryAsync(g => g.PlaylistId, g => g.Count, cancellationToken);
+
+        results.AddRange(page.Map(c => new LibraryBrowseItemResponseModel(
+            c.Id,
+            LibraryBrowseMediaType.Playlist,
+            c.Name,
+            null,
+            null,
+            string.Empty,
+            null,
+            itemCounts.TryGetValue(c.Id, out int itemCount) ? itemCount : 0,
+            null,
+            CollectionType.Playlist,
+            null,
+            null,
+            null,
+            null,
+            null,
+            c.Id)));
+    }
+
+    private static IQueryable<Collection> FilterCollections(
+        IQueryable<Collection> query,
+        GetLibraryBrowseItems request)
+    {
+        query = FilterByName(query, request.Query);
+        if (request.LibraryId.HasValue)
+        {
+            query = query.Where(c => c.MediaItems.Any(mi => mi.LibraryPath.LibraryId == request.LibraryId.Value));
+        }
+
+        return query;
+    }
+
+    private static IQueryable<T> FilterByName<T>(IQueryable<T> query, string searchQuery)
+        where T : class
+    {
+        if (string.IsNullOrWhiteSpace(searchQuery))
+        {
+            return query;
+        }
+
+        return query.Where(c => EF.Functions.Like(EF.Property<string>(c, "Name"), $"%{EscapeLike(searchQuery)}%", "\\"));
+    }
+
+    private static bool ShouldInclude(LibraryBrowseMediaType? requestType, LibraryBrowseMediaType itemType) =>
+        requestType is null || requestType == itemType;
+
+    private static TimeSpan? BestDuration(IEnumerable<MediaVersion> versions)
+    {
+        TimeSpan duration = versions
+            .Select(v => v.Duration)
+            .Where(d => d > TimeSpan.Zero)
+            .DefaultIfEmpty()
+            .Max();
+        return duration > TimeSpan.Zero ? duration : null;
+    }
+
+    private static async Task<Dictionary<int, TimeSpan?>> GetManualCollectionDurations(
+        TvContext dbContext,
+        List<int> collectionIds,
+        CancellationToken cancellationToken)
+    {
+        List<CollectionMediaItem> items = await GetCollectionMediaItems(dbContext, collectionIds, cancellationToken);
+        List<int> mediaItemIds = items.Map(i => i.MediaItemId).Distinct().ToList();
+        Dictionary<int, TimeSpan> mediaItemDurations = [];
+
+        foreach (Movie movie in await dbContext.Movies
+                     .AsNoTracking()
+                     .Where(m => mediaItemIds.Contains(m.Id))
+                     .Include(m => m.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = BestDuration(movie.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[movie.Id] = duration.Value;
+            }
+        }
+
+        foreach (Episode episode in await dbContext.Episodes
+                     .AsNoTracking()
+                     .Where(e => mediaItemIds.Contains(e.Id))
+                     .Include(e => e.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = BestDuration(episode.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[episode.Id] = duration.Value;
+            }
+        }
+
+        foreach (MusicVideo musicVideo in await dbContext.MusicVideos
+                     .AsNoTracking()
+                     .Where(mv => mediaItemIds.Contains(mv.Id))
+                     .Include(mv => mv.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = BestDuration(musicVideo.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[musicVideo.Id] = duration.Value;
+            }
+        }
+
+        foreach (OtherVideo otherVideo in await dbContext.OtherVideos
+                     .AsNoTracking()
+                     .Where(ov => mediaItemIds.Contains(ov.Id))
+                     .Include(ov => ov.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = BestDuration(otherVideo.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[otherVideo.Id] = duration.Value;
+            }
+        }
+
+        foreach (Song song in await dbContext.Songs
+                     .AsNoTracking()
+                     .Where(s => mediaItemIds.Contains(s.Id))
+                     .Include(s => s.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = BestDuration(song.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[song.Id] = duration.Value;
+            }
+        }
+
+        foreach (Image image in await dbContext.Images
+                     .AsNoTracking()
+                     .Where(i => mediaItemIds.Contains(i.Id))
+                     .Include(i => i.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = BestDuration(image.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[image.Id] = duration.Value;
+            }
+        }
+
+        foreach (RemoteStream remoteStream in await dbContext.RemoteStreams
+                     .AsNoTracking()
+                     .Where(rs => mediaItemIds.Contains(rs.Id))
+                     .Include(rs => rs.MediaVersions)
+                     .ToListAsync(cancellationToken))
+        {
+            TimeSpan? duration = BestDuration(remoteStream.MediaVersions);
+            if (duration.HasValue)
+            {
+                mediaItemDurations[remoteStream.Id] = duration.Value;
+            }
+        }
+
+        return items
+            .Where(i => mediaItemDurations.ContainsKey(i.MediaItemId))
+            .GroupBy(i => i.CollectionId)
+            .ToDictionary(
+                g => g.Key,
+                g => (TimeSpan?)g.Aggregate(TimeSpan.Zero, (sum, item) => sum + mediaItemDurations[item.MediaItemId]));
+    }
+
+    private static async Task<Dictionary<int, string>> GetManualCollectionArtwork(
+        TvContext dbContext,
+        List<int> collectionIds,
+        CancellationToken cancellationToken)
+    {
+        List<CollectionMediaItem> items = await GetCollectionMediaItems(dbContext, collectionIds, cancellationToken);
+        List<int> mediaItemIds = items.Map(i => i.MediaItemId).Distinct().ToList();
+        Dictionary<int, string> mediaItemArtwork = [];
+
+        foreach (MovieMetadata metadata in await dbContext.MovieMetadata
+                     .AsNoTracking()
+                     .Where(mm => mediaItemIds.Contains(mm.MovieId))
+                     .Include(mm => mm.Artwork)
+                     .OrderBy(mm => mm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.MovieId))
+            {
+                mediaItemArtwork[metadata.MovieId] = poster;
+            }
+        }
+
+        foreach (ShowMetadata metadata in await dbContext.ShowMetadata
+                     .AsNoTracking()
+                     .Where(sm => mediaItemIds.Contains(sm.ShowId))
+                     .Include(sm => sm.Artwork)
+                     .OrderBy(sm => sm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.ShowId))
+            {
+                mediaItemArtwork[metadata.ShowId] = poster;
+            }
+        }
+
+        foreach (SeasonMetadata metadata in await dbContext.SeasonMetadata
+                     .AsNoTracking()
+                     .Where(sm => mediaItemIds.Contains(sm.SeasonId))
+                     .Include(sm => sm.Artwork)
+                     .OrderBy(sm => sm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.SeasonId))
+            {
+                mediaItemArtwork[metadata.SeasonId] = poster;
+            }
+        }
+
+        foreach (OtherVideoMetadata metadata in await dbContext.OtherVideoMetadata
+                     .AsNoTracking()
+                     .Where(ovm => mediaItemIds.Contains(ovm.OtherVideoId))
+                     .Include(ovm => ovm.Artwork)
+                     .OrderBy(ovm => ovm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.OtherVideoId))
+            {
+                mediaItemArtwork[metadata.OtherVideoId] = poster;
+            }
+        }
+
+        foreach (SongMetadata metadata in await dbContext.SongMetadata
+                     .AsNoTracking()
+                     .Where(sm => mediaItemIds.Contains(sm.SongId))
+                     .Include(sm => sm.Artwork)
+                     .OrderBy(sm => sm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.SongId))
+            {
+                mediaItemArtwork[metadata.SongId] = poster;
+            }
+        }
+
+        foreach (ImageMetadata metadata in await dbContext.ImageMetadata
+                     .AsNoTracking()
+                     .Where(im => mediaItemIds.Contains(im.ImageId))
+                     .Include(im => im.Artwork)
+                     .OrderBy(im => im.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.ImageId))
+            {
+                mediaItemArtwork[metadata.ImageId] = poster;
+            }
+        }
+
+        foreach (RemoteStreamMetadata metadata in await dbContext.RemoteStreamMetadata
+                     .AsNoTracking()
+                     .Where(rsm => mediaItemIds.Contains(rsm.RemoteStreamId))
+                     .Include(rsm => rsm.Artwork)
+                     .OrderBy(rsm => rsm.Id)
+                     .ToListAsync(cancellationToken))
+        {
+            string poster = Artwork(metadata, ArtworkKind.Poster);
+            if (!string.IsNullOrWhiteSpace(poster) && !mediaItemArtwork.ContainsKey(metadata.RemoteStreamId))
+            {
+                mediaItemArtwork[metadata.RemoteStreamId] = poster;
+            }
+        }
+
+        return items
+            .Where(i => mediaItemArtwork.ContainsKey(i.MediaItemId))
+            .GroupBy(i => i.CollectionId)
+            .ToDictionary(
+                g => g.Key,
+                g => mediaItemArtwork[g.OrderBy(i => i.CustomIndex ?? int.MaxValue).ThenBy(i => i.MediaItemId).First().MediaItemId]);
+    }
+
+    private static async Task<List<CollectionMediaItem>> GetCollectionMediaItems(
+        TvContext dbContext,
+        List<int> collectionIds,
+        CancellationToken cancellationToken) =>
+        await dbContext.CollectionItems
+            .AsNoTracking()
+            .Where(ci => collectionIds.Contains(ci.CollectionId))
+            .Select(ci => new CollectionMediaItem(ci.CollectionId, ci.MediaItemId, ci.CustomIndex))
+            .ToListAsync(cancellationToken);
+
+    private static string SeasonTitle(SeasonMetadata metadata)
+    {
+        string showTitle = metadata.Season.Show.ShowMetadata.HeadOrNone()
+            .Map(sm => sm.Title ?? string.Empty)
+            .IfNone(string.Empty);
+        string seasonTitle = metadata.Season.SeasonNumber == 0
+            ? "Specials"
+            : $"Season {metadata.Season.SeasonNumber}";
+        return string.IsNullOrWhiteSpace(showTitle) ? seasonTitle : $"{showTitle} - {seasonTitle}";
+    }
+
+    private static string Artwork(Metadata metadata, ArtworkKind artworkKind)
+    {
+        string artwork = Optional(metadata.Artwork.FirstOrDefault(a => a.ArtworkKind == artworkKind))
+            .Match(a => a.Path, string.Empty);
+
+        if (artwork.StartsWith("jellyfin://", StringComparison.OrdinalIgnoreCase))
+        {
+            Url url = JellyfinUrl.RelativeProxyForArtwork(artwork);
+            if (artworkKind is ArtworkKind.Poster or ArtworkKind.Thumbnail)
+            {
+                url.SetQueryParam("fillHeight", 440);
+            }
+
+            return url;
+        }
+
+        if (artwork.StartsWith("emby://", StringComparison.OrdinalIgnoreCase))
+        {
+            Url url = EmbyUrl.RelativeProxyForArtwork(artwork);
+            if (artworkKind is ArtworkKind.Poster or ArtworkKind.Thumbnail)
+            {
+                url.SetQueryParam("maxHeight", 440);
+            }
+
+            return url;
+        }
+
+        return artwork;
+    }
+
+    private static string EscapeLike(string searchQuery) =>
+        searchQuery
+            .Replace("\\", "\\\\", StringComparison.Ordinal)
+            .Replace("%", "\\%", StringComparison.Ordinal)
+            .Replace("_", "\\_", StringComparison.Ordinal);
+
+    private sealed record CollectionMediaItem(int CollectionId, int MediaItemId, int? CustomIndex);
+}

ErsatzTV.Core/Api/ChannelTemplates/ChannelTemplateResponseModel.cs

@@ -0,0 +1,36 @@
+#nullable enable
+
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Core.Api.ChannelTemplates;
+
+public record ChannelTemplateResponseModel(
+    int Id,
+    string Name,
+    string Description,
+    bool IsSystem,
+    bool IsDefault,
+    int FFmpegProfileId,
+    int? WatermarkId,
+    int? FallbackFillerId,
+    int? PreRollFillerId,
+    int? MidRollFillerId,
+    int? PostRollFillerId,
+    ChannelStreamSelectorMode StreamSelectorMode,
+    string? StreamSelector,
+    string? PreferredAudioLanguageCode,
+    string? PreferredAudioTitle,
+    ChannelPlayoutSource PlayoutSource,
+    ChannelPlayoutMode PlayoutMode,
+    StreamingMode StreamingMode,
+    string? PreferredSubtitleLanguageCode,
+    ChannelSubtitleMode SubtitleMode,
+    ChannelMusicVideoCreditsMode MusicVideoCreditsMode,
+    string? MusicVideoCreditsTemplate,
+    ChannelSongVideoMode SongVideoMode,
+    ChannelTranscodeMode TranscodeMode,
+    ChannelIdleBehavior IdleBehavior,
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint,
+    FixedStartTimeBehavior FixedStartTimeBehavior);

ErsatzTV.Core/Api/Channels/CreateChannelFromLineupResponseModel.cs

@@ -0,0 +1,9 @@
+#nullable enable
+
+namespace ErsatzTV.Core.Api.Channels;
+
+public record CreateChannelFromLineupResponseModel(
+    int ChannelId,
+    int? PlaylistId,
+    int ProgramScheduleId,
+    int PlayoutId);

ErsatzTV.Core/Api/LibraryBrowse/LibraryBrowseItemResponseModel.cs

@@ -0,0 +1,22 @@
+#nullable enable
+using ErsatzTV.Core.Domain;
+
+namespace ErsatzTV.Core.Api.LibraryBrowse;
+
+public record LibraryBrowseItemResponseModel(
+    int Id,
+    LibraryBrowseMediaType MediaType,
+    string Title,
+    int? LibraryId,
+    string? LibraryName,
+    string Artwork,
+    TimeSpan? Duration,
+    int? ItemCount,
+    string? CollectionKind,
+    CollectionType CollectionType,
+    int? CollectionId,
+    int? MultiCollectionId,
+    int? SmartCollectionId,
+    int? RerunCollectionId,
+    int? MediaItemId,
+    int? PlaylistId);

ErsatzTV.Core/Api/LibraryBrowse/LibraryBrowseMediaType.cs

@@ -0,0 +1,15 @@
+#nullable enable
+namespace ErsatzTV.Core.Api.LibraryBrowse;
+
+public enum LibraryBrowseMediaType
+{
+    Movie = 1,
+    TelevisionShow = 2,
+    TelevisionSeason = 3,
+    Artist = 4,
+    Collection = 5,
+    SmartCollection = 6,
+    MultiCollection = 7,
+    RerunCollection = 8,
+    Playlist = 9
+}

ErsatzTV.Core/Api/LibraryBrowse/PagedLibraryBrowseItemsResponseModel.cs

@@ -0,0 +1,6 @@
+#nullable enable
+namespace ErsatzTV.Core.Api.LibraryBrowse;
+
+public record PagedLibraryBrowseItemsResponseModel(
+    int TotalCount,
+    List<LibraryBrowseItemResponseModel> Page);

ErsatzTV.Core/Domain/ChannelTemplate.cs

@@ -0,0 +1,41 @@
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Core.Domain;
+
+public class ChannelTemplate
+{
+    public int Id { get; set; }
+    public string Name { get; set; }
+    public string Description { get; set; }
+    public bool IsSystem { get; set; }
+    public int FFmpegProfileId { get; set; }
+    public FFmpegProfile FFmpegProfile { get; set; }
+    public int? WatermarkId { get; set; }
+    public ChannelWatermark Watermark { get; set; }
+    public int? FallbackFillerId { get; set; }
+    public FillerPreset FallbackFiller { get; set; }
+    public int? PreRollFillerId { get; set; }
+    public FillerPreset PreRollFiller { get; set; }
+    public int? MidRollFillerId { get; set; }
+    public FillerPreset MidRollFiller { get; set; }
+    public int? PostRollFillerId { get; set; }
+    public FillerPreset PostRollFiller { get; set; }
+    public ChannelStreamSelectorMode StreamSelectorMode { get; set; }
+    public string StreamSelector { get; set; }
+    public string PreferredAudioLanguageCode { get; set; }
+    public string PreferredAudioTitle { get; set; }
+    public ChannelPlayoutSource PlayoutSource { get; set; }
+    public ChannelPlayoutMode PlayoutMode { get; set; }
+    public StreamingMode StreamingMode { get; set; }
+    public string PreferredSubtitleLanguageCode { get; set; }
+    public ChannelSubtitleMode SubtitleMode { get; set; }
+    public ChannelMusicVideoCreditsMode MusicVideoCreditsMode { get; set; }
+    public string MusicVideoCreditsTemplate { get; set; }
+    public ChannelSongVideoMode SongVideoMode { get; set; }
+    public ChannelTranscodeMode TranscodeMode { get; set; }
+    public ChannelIdleBehavior IdleBehavior { get; set; }
+    public bool ShuffleScheduleItems { get; set; }
+    public bool RandomStartPoint { get; set; }
+    public FixedStartTimeBehavior FixedStartTimeBehavior { get; set; }
+}

ErsatzTV.Core/Domain/ConfigElementKey.cs

@@ -23,6 +23,7 @@ public class ConfigElementKey
     public static ConfigElementKey FFmpegPreferredLanguageCode => new("ffmpeg.preferred_language_code");
     public static ConfigElementKey FFmpegGlobalWatermarkId => new("ffmpeg.global_watermark_id");
     public static ConfigElementKey FFmpegGlobalFallbackFillerId => new("ffmpeg.global_fallback_filler_id");
+    public static ConfigElementKey ChannelTemplatesDefaultTemplateId => new("channel_templates.default_template_id");
     public static ConfigElementKey FFmpegSegmenterTimeout => new("ffmpeg.segmenter.timeout_seconds");
     public static ConfigElementKey FFmpegWorkAheadSegmenters => new("ffmpeg.segmenter.work_ahead_limit");
     public static ConfigElementKey FFmpegInitialSegmentCount => new("ffmpeg.segmenter.initial_segment_count");

ErsatzTV.Infrastructure.MySql/Migrations/20260706155538_AddChannelTemplates.cs

@@ -0,0 +1,140 @@
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ErsatzTV.Infrastructure.MySql.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddChannelTemplates : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "ChannelTemplate",
+                columns: table => new
+                {
+                    Id = table.Column<int>(type: "int", nullable: false)
+                        .Annotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn),
+                    Name = table.Column<string>(type: "varchar(50)", maxLength: 50, nullable: false, collation: "utf8mb4_general_ci")
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    Description = table.Column<string>(type: "varchar(500)", maxLength: 500, nullable: false, defaultValue: "")
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    IsSystem = table.Column<bool>(type: "tinyint(1)", nullable: false),
+                    FFmpegProfileId = table.Column<int>(type: "int", nullable: false),
+                    WatermarkId = table.Column<int>(type: "int", nullable: true),
+                    FallbackFillerId = table.Column<int>(type: "int", nullable: true),
+                    PreRollFillerId = table.Column<int>(type: "int", nullable: true),
+                    MidRollFillerId = table.Column<int>(type: "int", nullable: true),
+                    PostRollFillerId = table.Column<int>(type: "int", nullable: true),
+                    StreamSelectorMode = table.Column<int>(type: "int", nullable: false),
+                    StreamSelector = table.Column<string>(type: "longtext", nullable: true)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    PreferredAudioLanguageCode = table.Column<string>(type: "longtext", nullable: true)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    PreferredAudioTitle = table.Column<string>(type: "longtext", nullable: true)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    PlayoutSource = table.Column<int>(type: "int", nullable: false),
+                    PlayoutMode = table.Column<int>(type: "int", nullable: false),
+                    StreamingMode = table.Column<int>(type: "int", nullable: false),
+                    PreferredSubtitleLanguageCode = table.Column<string>(type: "longtext", nullable: true)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    SubtitleMode = table.Column<int>(type: "int", nullable: false),
+                    MusicVideoCreditsMode = table.Column<int>(type: "int", nullable: false),
+                    MusicVideoCreditsTemplate = table.Column<string>(type: "longtext", nullable: true)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    SongVideoMode = table.Column<int>(type: "int", nullable: false),
+                    TranscodeMode = table.Column<int>(type: "int", nullable: false),
+                    IdleBehavior = table.Column<int>(type: "int", nullable: false),
+                    ShuffleScheduleItems = table.Column<bool>(type: "tinyint(1)", nullable: false),
+                    RandomStartPoint = table.Column<bool>(type: "tinyint(1)", nullable: false),
+                    FixedStartTimeBehavior = table.Column<int>(type: "int", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_ChannelTemplate", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_ChannelWatermark_WatermarkId",
+                        column: x => x.WatermarkId,
+                        principalTable: "ChannelWatermark",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_FFmpegProfile_FFmpegProfileId",
+                        column: x => x.FFmpegProfileId,
+                        principalTable: "FFmpegProfile",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_FillerPreset_FallbackFillerId",
+                        column: x => x.FallbackFillerId,
+                        principalTable: "FillerPreset",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_FillerPreset_MidRollFillerId",
+                        column: x => x.MidRollFillerId,
+                        principalTable: "FillerPreset",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_FillerPreset_PostRollFillerId",
+                        column: x => x.PostRollFillerId,
+                        principalTable: "FillerPreset",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_FillerPreset_PreRollFillerId",
+                        column: x => x.PreRollFillerId,
+                        principalTable: "FillerPreset",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                })
+                .Annotation("MySql:CharSet", "utf8mb4");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_FallbackFillerId",
+                table: "ChannelTemplate",
+                column: "FallbackFillerId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_FFmpegProfileId",
+                table: "ChannelTemplate",
+                column: "FFmpegProfileId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_MidRollFillerId",
+                table: "ChannelTemplate",
+                column: "MidRollFillerId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_Name",
+                table: "ChannelTemplate",
+                column: "Name",
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_PostRollFillerId",
+                table: "ChannelTemplate",
+                column: "PostRollFillerId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_PreRollFillerId",
+                table: "ChannelTemplate",
+                column: "PreRollFillerId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_WatermarkId",
+                table: "ChannelTemplate",
+                column: "WatermarkId");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "ChannelTemplate");
+        }
+    }
+}

ErsatzTV.Infrastructure.MySql/Migrations/TvContextModelSnapshot.cs

@@ -403,6 +403,119 @@ namespace ErsatzTV.Infrastructure.MySql.Migrations
                     b.ToTable("Channel", (string)null);
                 });
 
+            modelBuilder.Entity("ErsatzTV.Core.Domain.ChannelTemplate", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    MySqlPropertyBuilderExtensions.UseMySqlIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasMaxLength(500)
+                        .HasColumnType("varchar(500)")
+                        .HasDefaultValue("");
+
+                    b.Property<int>("FFmpegProfileId")
+                        .HasColumnType("int");
+
+                    b.Property<int?>("FallbackFillerId")
+                        .HasColumnType("int");
+
+                    b.Property<int>("FixedStartTimeBehavior")
+                        .HasColumnType("int");
+
+                    b.Property<int>("IdleBehavior")
+                        .HasColumnType("int");
+
+                    b.Property<bool>("IsSystem")
+                        .HasColumnType("tinyint(1)");
+
+                    b.Property<int?>("MidRollFillerId")
+                        .HasColumnType("int");
+
+                    b.Property<int>("MusicVideoCreditsMode")
+                        .HasColumnType("int");
+
+                    b.Property<string>("MusicVideoCreditsTemplate")
+                        .HasColumnType("longtext");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("varchar(50)")
+                        .UseCollation("utf8mb4_general_ci");
+
+                    b.Property<int>("PlayoutMode")
+                        .HasColumnType("int");
+
+                    b.Property<int>("PlayoutSource")
+                        .HasColumnType("int");
+
+                    b.Property<int?>("PostRollFillerId")
+                        .HasColumnType("int");
+
+                    b.Property<int?>("PreRollFillerId")
+                        .HasColumnType("int");
+
+                    b.Property<string>("PreferredAudioLanguageCode")
+                        .HasColumnType("longtext");
+
+                    b.Property<string>("PreferredAudioTitle")
+                        .HasColumnType("longtext");
+
+                    b.Property<string>("PreferredSubtitleLanguageCode")
+                        .HasColumnType("longtext");
+
+                    b.Property<bool>("RandomStartPoint")
+                        .HasColumnType("tinyint(1)");
+
+                    b.Property<bool>("ShuffleScheduleItems")
+                        .HasColumnType("tinyint(1)");
+
+                    b.Property<int>("SongVideoMode")
+                        .HasColumnType("int");
+
+                    b.Property<string>("StreamSelector")
+                        .HasColumnType("longtext");
+
+                    b.Property<int>("StreamSelectorMode")
+                        .HasColumnType("int");
+
+                    b.Property<int>("StreamingMode")
+                        .HasColumnType("int");
+
+                    b.Property<int>("SubtitleMode")
+                        .HasColumnType("int");
+
+                    b.Property<int>("TranscodeMode")
+                        .HasColumnType("int");
+
+                    b.Property<int?>("WatermarkId")
+                        .HasColumnType("int");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("FFmpegProfileId");
+
+                    b.HasIndex("FallbackFillerId");
+
+                    b.HasIndex("MidRollFillerId");
+
+                    b.HasIndex("Name")
+                        .IsUnique();
+
+                    b.HasIndex("PostRollFillerId");
+
+                    b.HasIndex("PreRollFillerId");
+
+                    b.HasIndex("WatermarkId");
+
+                    b.ToTable("ChannelTemplate", (string)null);
+                });
+
             modelBuilder.Entity("ErsatzTV.Core.Domain.ChannelWatermark", b =>
                 {
                     b.Property<int>("Id")
@@ -4559,6 +4672,52 @@ namespace ErsatzTV.Infrastructure.MySql.Migrations
                     b.Navigation("Watermark");
                 });
 
+            modelBuilder.Entity("ErsatzTV.Core.Domain.ChannelTemplate", b =>
+                {
+                    b.HasOne("ErsatzTV.Core.Domain.FFmpegProfile", "FFmpegProfile")
+                        .WithMany()
+                        .HasForeignKey("FFmpegProfileId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.HasOne("ErsatzTV.Core.Domain.Filler.FillerPreset", "FallbackFiller")
+                        .WithMany()
+                        .HasForeignKey("FallbackFillerId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("ErsatzTV.Core.Domain.Filler.FillerPreset", "MidRollFiller")
+                        .WithMany()
+                        .HasForeignKey("MidRollFillerId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("ErsatzTV.Core.Domain.Filler.FillerPreset", "PostRollFiller")
+                        .WithMany()
+                        .HasForeignKey("PostRollFillerId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("ErsatzTV.Core.Domain.Filler.FillerPreset", "PreRollFiller")
+                        .WithMany()
+                        .HasForeignKey("PreRollFillerId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("ErsatzTV.Core.Domain.ChannelWatermark", "Watermark")
+                        .WithMany()
+                        .HasForeignKey("WatermarkId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.Navigation("FFmpegProfile");
+
+                    b.Navigation("FallbackFiller");
+
+                    b.Navigation("MidRollFiller");
+
+                    b.Navigation("PostRollFiller");
+
+                    b.Navigation("PreRollFiller");
+
+                    b.Navigation("Watermark");
+                });
+
             modelBuilder.Entity("ErsatzTV.Core.Domain.CollectionItem", b =>
                 {
                     b.HasOne("ErsatzTV.Core.Domain.Collection", "Collection")

ErsatzTV.Infrastructure.Sqlite/Migrations/20260706155532_AddChannelTemplates.cs

@@ -0,0 +1,131 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ErsatzTV.Infrastructure.Sqlite.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddChannelTemplates : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "ChannelTemplate",
+                columns: table => new
+                {
+                    Id = table.Column<int>(type: "INTEGER", nullable: false)
+                        .Annotation("Sqlite:Autoincrement", true),
+                    Name = table.Column<string>(type: "varchar(50)", maxLength: 50, nullable: false, collation: "NOCASE"),
+                    Description = table.Column<string>(type: "varchar(500)", maxLength: 500, nullable: false, defaultValue: ""),
+                    IsSystem = table.Column<bool>(type: "INTEGER", nullable: false),
+                    FFmpegProfileId = table.Column<int>(type: "INTEGER", nullable: false),
+                    WatermarkId = table.Column<int>(type: "INTEGER", nullable: true),
+                    FallbackFillerId = table.Column<int>(type: "INTEGER", nullable: true),
+                    PreRollFillerId = table.Column<int>(type: "INTEGER", nullable: true),
+                    MidRollFillerId = table.Column<int>(type: "INTEGER", nullable: true),
+                    PostRollFillerId = table.Column<int>(type: "INTEGER", nullable: true),
+                    StreamSelectorMode = table.Column<int>(type: "INTEGER", nullable: false),
+                    StreamSelector = table.Column<string>(type: "TEXT", nullable: true),
+                    PreferredAudioLanguageCode = table.Column<string>(type: "TEXT", nullable: true),
+                    PreferredAudioTitle = table.Column<string>(type: "TEXT", nullable: true),
+                    PlayoutSource = table.Column<int>(type: "INTEGER", nullable: false),
+                    PlayoutMode = table.Column<int>(type: "INTEGER", nullable: false),
+                    StreamingMode = table.Column<int>(type: "INTEGER", nullable: false),
+                    PreferredSubtitleLanguageCode = table.Column<string>(type: "TEXT", nullable: true),
+                    SubtitleMode = table.Column<int>(type: "INTEGER", nullable: false),
+                    MusicVideoCreditsMode = table.Column<int>(type: "INTEGER", nullable: false),
+                    MusicVideoCreditsTemplate = table.Column<string>(type: "TEXT", nullable: true),
+                    SongVideoMode = table.Column<int>(type: "INTEGER", nullable: false),
+                    TranscodeMode = table.Column<int>(type: "INTEGER", nullable: false),
+                    IdleBehavior = table.Column<int>(type: "INTEGER", nullable: false),
+                    ShuffleScheduleItems = table.Column<bool>(type: "INTEGER", nullable: false),
+                    RandomStartPoint = table.Column<bool>(type: "INTEGER", nullable: false),
+                    FixedStartTimeBehavior = table.Column<int>(type: "INTEGER", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_ChannelTemplate", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_ChannelWatermark_WatermarkId",
+                        column: x => x.WatermarkId,
+                        principalTable: "ChannelWatermark",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_FFmpegProfile_FFmpegProfileId",
+                        column: x => x.FFmpegProfileId,
+                        principalTable: "FFmpegProfile",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_FillerPreset_FallbackFillerId",
+                        column: x => x.FallbackFillerId,
+                        principalTable: "FillerPreset",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_FillerPreset_MidRollFillerId",
+                        column: x => x.MidRollFillerId,
+                        principalTable: "FillerPreset",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_FillerPreset_PostRollFillerId",
+                        column: x => x.PostRollFillerId,
+                        principalTable: "FillerPreset",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "FK_ChannelTemplate_FillerPreset_PreRollFillerId",
+                        column: x => x.PreRollFillerId,
+                        principalTable: "FillerPreset",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_FallbackFillerId",
+                table: "ChannelTemplate",
+                column: "FallbackFillerId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_FFmpegProfileId",
+                table: "ChannelTemplate",
+                column: "FFmpegProfileId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_MidRollFillerId",
+                table: "ChannelTemplate",
+                column: "MidRollFillerId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_Name",
+                table: "ChannelTemplate",
+                column: "Name",
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_PostRollFillerId",
+                table: "ChannelTemplate",
+                column: "PostRollFillerId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_PreRollFillerId",
+                table: "ChannelTemplate",
+                column: "PreRollFillerId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ChannelTemplate_WatermarkId",
+                table: "ChannelTemplate",
+                column: "WatermarkId");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "ChannelTemplate");
+        }
+    }
+}

ErsatzTV.Infrastructure.Sqlite/Migrations/TvContextModelSnapshot.cs

@@ -390,6 +390,117 @@ namespace ErsatzTV.Infrastructure.Sqlite.Migrations
                     b.ToTable("Channel", (string)null);
                 });
 
+            modelBuilder.Entity("ErsatzTV.Core.Domain.ChannelTemplate", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasMaxLength(500)
+                        .HasColumnType("varchar(500)")
+                        .HasDefaultValue("");
+
+                    b.Property<int>("FFmpegProfileId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("FallbackFillerId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("FixedStartTimeBehavior")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("IdleBehavior")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<bool>("IsSystem")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("MidRollFillerId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("MusicVideoCreditsMode")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("MusicVideoCreditsTemplate")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("varchar(50)")
+                        .UseCollation("NOCASE");
+
+                    b.Property<int>("PlayoutMode")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("PlayoutSource")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("PostRollFillerId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("PreRollFillerId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("PreferredAudioLanguageCode")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PreferredAudioTitle")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PreferredSubtitleLanguageCode")
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("RandomStartPoint")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<bool>("ShuffleScheduleItems")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("SongVideoMode")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("StreamSelector")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("StreamSelectorMode")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("StreamingMode")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("SubtitleMode")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("TranscodeMode")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("WatermarkId")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("FFmpegProfileId");
+
+                    b.HasIndex("FallbackFillerId");
+
+                    b.HasIndex("MidRollFillerId");
+
+                    b.HasIndex("Name")
+                        .IsUnique();
+
+                    b.HasIndex("PostRollFillerId");
+
+                    b.HasIndex("PreRollFillerId");
+
+                    b.HasIndex("WatermarkId");
+
+                    b.ToTable("ChannelTemplate", (string)null);
+                });
+
             modelBuilder.Entity("ErsatzTV.Core.Domain.ChannelWatermark", b =>
                 {
                     b.Property<int>("Id")
@@ -4386,6 +4497,52 @@ namespace ErsatzTV.Infrastructure.Sqlite.Migrations
                     b.Navigation("Watermark");
                 });
 
+            modelBuilder.Entity("ErsatzTV.Core.Domain.ChannelTemplate", b =>
+                {
+                    b.HasOne("ErsatzTV.Core.Domain.FFmpegProfile", "FFmpegProfile")
+                        .WithMany()
+                        .HasForeignKey("FFmpegProfileId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.HasOne("ErsatzTV.Core.Domain.Filler.FillerPreset", "FallbackFiller")
+                        .WithMany()
+                        .HasForeignKey("FallbackFillerId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("ErsatzTV.Core.Domain.Filler.FillerPreset", "MidRollFiller")
+                        .WithMany()
+                        .HasForeignKey("MidRollFillerId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("ErsatzTV.Core.Domain.Filler.FillerPreset", "PostRollFiller")
+                        .WithMany()
+                        .HasForeignKey("PostRollFillerId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("ErsatzTV.Core.Domain.Filler.FillerPreset", "PreRollFiller")
+                        .WithMany()
+                        .HasForeignKey("PreRollFillerId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("ErsatzTV.Core.Domain.ChannelWatermark", "Watermark")
+                        .WithMany()
+                        .HasForeignKey("WatermarkId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.Navigation("FFmpegProfile");
+
+                    b.Navigation("FallbackFiller");
+
+                    b.Navigation("MidRollFiller");
+
+                    b.Navigation("PostRollFiller");
+
+                    b.Navigation("PreRollFiller");
+
+                    b.Navigation("Watermark");
+                });
+
             modelBuilder.Entity("ErsatzTV.Core.Domain.CollectionItem", b =>
                 {
                     b.HasOne("ErsatzTV.Core.Domain.Collection", "Collection")

ErsatzTV.Infrastructure/Data/Configurations/ChannelTemplateConfiguration.cs

@@ -0,0 +1,62 @@
+using ErsatzTV.Core.Domain;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+
+namespace ErsatzTV.Infrastructure.Data.Configurations;
+
+public class ChannelTemplateConfiguration : IEntityTypeConfiguration<ChannelTemplate>
+{
+    public void Configure(EntityTypeBuilder<ChannelTemplate> builder)
+    {
+        builder.ToTable("ChannelTemplate");
+
+        builder.HasIndex(t => t.Name)
+            .IsUnique();
+
+        builder.Property(t => t.Name)
+            .HasMaxLength(50)
+            .HasColumnType("varchar(50)")
+            .IsRequired();
+
+        builder.Property(t => t.Description)
+            .HasMaxLength(500)
+            .HasColumnType("varchar(500)")
+            .HasDefaultValue(string.Empty)
+            .IsRequired();
+
+        builder.HasOne(t => t.FFmpegProfile)
+            .WithMany()
+            .HasForeignKey(t => t.FFmpegProfileId)
+            .OnDelete(DeleteBehavior.Restrict);
+
+        builder.HasOne(t => t.Watermark)
+            .WithMany()
+            .HasForeignKey(t => t.WatermarkId)
+            .OnDelete(DeleteBehavior.SetNull)
+            .IsRequired(false);
+
+        builder.HasOne(t => t.FallbackFiller)
+            .WithMany()
+            .HasForeignKey(t => t.FallbackFillerId)
+            .OnDelete(DeleteBehavior.SetNull)
+            .IsRequired(false);
+
+        builder.HasOne(t => t.PreRollFiller)
+            .WithMany()
+            .HasForeignKey(t => t.PreRollFillerId)
+            .OnDelete(DeleteBehavior.SetNull)
+            .IsRequired(false);
+
+        builder.HasOne(t => t.MidRollFiller)
+            .WithMany()
+            .HasForeignKey(t => t.MidRollFillerId)
+            .OnDelete(DeleteBehavior.SetNull)
+            .IsRequired(false);
+
+        builder.HasOne(t => t.PostRollFiller)
+            .WithMany()
+            .HasForeignKey(t => t.PostRollFillerId)
+            .OnDelete(DeleteBehavior.SetNull)
+            .IsRequired(false);
+    }
+}

ErsatzTV.Infrastructure/Data/DbInitializer.cs

@@ -2,6 +2,8 @@
 using System.Reflection;
 using Dapper;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+using Microsoft.EntityFrameworkCore;
 
 namespace ErsatzTV.Infrastructure.Data;
 
@@ -84,54 +86,180 @@ public static class DbInitializer
             await context.SaveChangesAsync(cancellationToken);
         }
 
-        if (context.Resolutions.Any(x => x.Width == 1920))
+        if (!context.Resolutions.Any(x => x.Width == 1920))
         {
-            return Unit.Default;
+            var resolutions = new List<Resolution>
+            {
+                new() { Id = 1, Name = "720x480", Width = 720, Height = 480 },
+                new() { Id = 2, Name = "1280x720", Width = 1280, Height = 720 },
+                new() { Id = 3, Name = "1920x1080", Width = 1920, Height = 1080 },
+                new() { Id = 4, Name = "3840x2160", Width = 3840, Height = 2160 }
+            };
+            await context.Resolutions.AddRangeAsync(resolutions, cancellationToken);
+            await context.SaveChangesAsync(cancellationToken);
+
+            var resolutionConfig = new ConfigElement
+            {
+                Key = ConfigElementKey.FFmpegDefaultResolutionId.Key,
+                Value = "3" // 1920x1080
+            };
+            await context.ConfigElements.AddAsync(resolutionConfig, cancellationToken);
+            await context.SaveChangesAsync(cancellationToken);
+
+            var defaultProfile = FFmpegProfile.New("1920x1080 x264 aac", resolutions[2]);
+            await context.FFmpegProfiles.AddAsync(defaultProfile, cancellationToken);
+            await context.SaveChangesAsync(cancellationToken);
+
+            var profileConfig = new ConfigElement
+            {
+                Key = ConfigElementKey.FFmpegDefaultProfileId.Key,
+                Value = defaultProfile.Id.ToString(CultureInfo.InvariantCulture)
+            };
+            await context.ConfigElements.AddAsync(profileConfig, cancellationToken);
+            await context.SaveChangesAsync(cancellationToken);
+
+            var defaultChannel = new Channel(Guid.NewGuid())
+            {
+                Number = "1",
+                Name = "ErsatzTV",
+                FFmpegProfile = defaultProfile,
+                StreamingMode = StreamingMode.TransportStreamHybrid,
+                IsEnabled = true,
+                ShowInEpg = true
+            };
+            await context.Channels.AddAsync(defaultChannel, cancellationToken);
+            await context.SaveChangesAsync(cancellationToken);
         }
 
-        var resolutions = new List<Resolution>
-        {
-            new() { Id = 1, Name = "720x480", Width = 720, Height = 480 },
-            new() { Id = 2, Name = "1280x720", Width = 1280, Height = 720 },
-            new() { Id = 3, Name = "1920x1080", Width = 1920, Height = 1080 },
-            new() { Id = 4, Name = "3840x2160", Width = 3840, Height = 2160 }
-        };
-        await context.Resolutions.AddRangeAsync(resolutions, cancellationToken);
-        await context.SaveChangesAsync(cancellationToken);
-
-        var resolutionConfig = new ConfigElement
-        {
-            Key = ConfigElementKey.FFmpegDefaultResolutionId.Key,
-            Value = "3" // 1920x1080
-        };
-        await context.ConfigElements.AddAsync(resolutionConfig, cancellationToken);
-        await context.SaveChangesAsync(cancellationToken);
-
-        var defaultProfile = FFmpegProfile.New("1920x1080 x264 aac", resolutions[2]);
-        await context.FFmpegProfiles.AddAsync(defaultProfile, cancellationToken);
-        await context.SaveChangesAsync(cancellationToken);
-
-        var profileConfig = new ConfigElement
-        {
-            Key = ConfigElementKey.FFmpegDefaultProfileId.Key,
-            Value = defaultProfile.Id.ToString(CultureInfo.InvariantCulture)
-        };
-        await context.ConfigElements.AddAsync(profileConfig, cancellationToken);
-        await context.SaveChangesAsync(cancellationToken);
-
-        var defaultChannel = new Channel(Guid.NewGuid())
-        {
-            Number = "1",
-            Name = "ErsatzTV",
-            FFmpegProfile = defaultProfile,
-            StreamingMode = StreamingMode.TransportStreamHybrid,
-            IsEnabled = true,
-            ShowInEpg = true
-        };
-        await context.Channels.AddAsync(defaultChannel, cancellationToken);
-        await context.SaveChangesAsync(cancellationToken);
+        await SeedChannelTemplates(context, cancellationToken);
 
         // TODO: create looping static image that mentions configuring via web
         return Unit.Default;
     }
+
+    private static async Task SeedChannelTemplates(TvContext context, CancellationToken cancellationToken)
+    {
+        if (await context.ChannelTemplates.AnyAsync(t => t.Name == "Standard", cancellationToken) &&
+            await context.ChannelTemplates.AnyAsync(t => t.Name == "Music videos", cancellationToken))
+        {
+            await EnsureDefaultChannelTemplateConfig(context, cancellationToken);
+            return;
+        }
+
+        FFmpegProfile defaultProfile = await GetDefaultFFmpegProfile(context, cancellationToken);
+        if (defaultProfile is null)
+        {
+            return;
+        }
+
+        if (!await context.ChannelTemplates.AnyAsync(t => t.Name == "Standard", cancellationToken))
+        {
+            await context.ChannelTemplates.AddAsync(
+                NewSystemTemplate(
+                    "Standard",
+                    "Balanced defaults for generated channels.",
+                    defaultProfile.Id,
+                    ChannelMusicVideoCreditsMode.None,
+                    ChannelSongVideoMode.Default,
+                    shuffleScheduleItems: false,
+                    randomStartPoint: false),
+                cancellationToken);
+            await context.SaveChangesAsync(cancellationToken);
+        }
+
+        if (!await context.ChannelTemplates.AnyAsync(t => t.Name == "Music videos", cancellationToken))
+        {
+            await context.ChannelTemplates.AddAsync(
+                NewSystemTemplate(
+                    "Music videos",
+                    "Defaults for shuffled music-video channels with generated credit subtitles.",
+                    defaultProfile.Id,
+                    ChannelMusicVideoCreditsMode.GenerateSubtitles,
+                    ChannelSongVideoMode.WithProgress,
+                    shuffleScheduleItems: true,
+                    randomStartPoint: true),
+                cancellationToken);
+            await context.SaveChangesAsync(cancellationToken);
+        }
+
+        await EnsureDefaultChannelTemplateConfig(context, cancellationToken);
+    }
+
+    private static async Task<FFmpegProfile> GetDefaultFFmpegProfile(
+        TvContext context,
+        CancellationToken cancellationToken)
+    {
+        string defaultProfileConfigKey = ConfigElementKey.FFmpegDefaultProfileId.Key;
+        ConfigElement profileConfig = await context.ConfigElements
+            .AsNoTracking()
+            .FirstOrDefaultAsync(c => c.Key == defaultProfileConfigKey, cancellationToken);
+        if (profileConfig is not null &&
+            int.TryParse(profileConfig.Value, NumberStyles.Integer, CultureInfo.InvariantCulture, out int profileId))
+        {
+            FFmpegProfile configuredProfile = await context.FFmpegProfiles
+                .FirstOrDefaultAsync(p => p.Id == profileId, cancellationToken);
+            if (configuredProfile is not null)
+            {
+                return configuredProfile;
+            }
+        }
+
+        return await context.FFmpegProfiles.OrderBy(p => p.Id).FirstOrDefaultAsync(cancellationToken);
+    }
+
+    private static async Task EnsureDefaultChannelTemplateConfig(TvContext context, CancellationToken cancellationToken)
+    {
+        string defaultTemplateConfigKey = ConfigElementKey.ChannelTemplatesDefaultTemplateId.Key;
+        bool configExists = await context.ConfigElements
+            .AnyAsync(c => c.Key == defaultTemplateConfigKey, cancellationToken);
+        if (configExists)
+        {
+            return;
+        }
+
+        ChannelTemplate standard = await context.ChannelTemplates
+            .AsNoTracking()
+            .FirstAsync(t => t.Name == "Standard", cancellationToken);
+        await context.ConfigElements.AddAsync(
+            new ConfigElement
+            {
+                Key = defaultTemplateConfigKey,
+                Value = standard.Id.ToString(CultureInfo.InvariantCulture)
+            },
+            cancellationToken);
+        await context.SaveChangesAsync(cancellationToken);
+    }
+
+    private static ChannelTemplate NewSystemTemplate(
+        string name,
+        string description,
+        int ffmpegProfileId,
+        ChannelMusicVideoCreditsMode musicVideoCreditsMode,
+        ChannelSongVideoMode songVideoMode,
+        bool shuffleScheduleItems,
+        bool randomStartPoint) =>
+        new()
+        {
+            Name = name,
+            Description = description,
+            IsSystem = true,
+            FFmpegProfileId = ffmpegProfileId,
+            StreamSelectorMode = ChannelStreamSelectorMode.Default,
+            StreamSelector = string.Empty,
+            PreferredAudioLanguageCode = string.Empty,
+            PreferredAudioTitle = string.Empty,
+            PlayoutSource = ChannelPlayoutSource.Generated,
+            PlayoutMode = ChannelPlayoutMode.Continuous,
+            StreamingMode = StreamingMode.TransportStreamHybrid,
+            PreferredSubtitleLanguageCode = string.Empty,
+            SubtitleMode = ChannelSubtitleMode.None,
+            MusicVideoCreditsMode = musicVideoCreditsMode,
+            MusicVideoCreditsTemplate = string.Empty,
+            SongVideoMode = songVideoMode,
+            TranscodeMode = ChannelTranscodeMode.OnDemand,
+            IdleBehavior = ChannelIdleBehavior.StopOnDisconnect,
+            ShuffleScheduleItems = shuffleScheduleItems,
+            RandomStartPoint = randomStartPoint,
+            FixedStartTimeBehavior = FixedStartTimeBehavior.Flexible
+        };
 }

ErsatzTV.Infrastructure/Data/TvContext.cs

@@ -30,6 +30,7 @@ public class TvContext : DbContext
 
     public DbSet<ConfigElement> ConfigElements { get; set; }
     public DbSet<Channel> Channels { get; set; }
+    public DbSet<ChannelTemplate> ChannelTemplates { get; set; }
     public DbSet<ChannelWatermark> ChannelWatermarks { get; set; }
     public DbSet<MediaSource> MediaSources { get; set; }
     public DbSet<LocalMediaSource> LocalMediaSources { get; set; }
@@ -160,6 +161,7 @@ public class TvContext : DbContext
             modelBuilder.Entity<Block>().Property(b => b.Name).UseCollation(collation);
             modelBuilder.Entity<BlockGroup>().Property(b => b.Name).UseCollation(collation);
             modelBuilder.Entity<Channel>().Property(c => c.Name).UseCollation(collation);
+            modelBuilder.Entity<ChannelTemplate>().Property(c => c.Name).UseCollation(collation);
             modelBuilder.Entity<ChannelWatermark>().Property(c => c.Name).UseCollation(collation);
             modelBuilder.Entity<Collection>().Property(c => c.Name).UseCollation(collation);
             modelBuilder.Entity<Deco>().Property(d => d.Name).UseCollation(collation);

ErsatzTV.Tests/Application/ChannelTemplates/ChannelTemplateHandlerTests.cs

@@ -0,0 +1,288 @@
+using ErsatzTV.Application.ChannelTemplates;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Core.Scheduling;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Data.Repositories;
+using ErsatzTV.Tests.Support;
+using LanguageExt;
+using NUnit.Framework;
+using Shouldly;
+using Unit = LanguageExt.Unit;
+
+namespace ErsatzTV.Tests.Application.ChannelTemplates;
+
+[TestFixture]
+public class ChannelTemplateHandlerTests
+{
+    private InMemoryTvContext _db = null!;
+    private IConfigElementRepository _config = null!;
+
+    [SetUp]
+    public async Task SetUp()
+    {
+        _db = await InMemoryTvContext.CreateAsync();
+        _config = new ConfigElementRepository(_db.Factory);
+    }
+
+    [TearDown]
+    public async Task TearDown() => await _db.DisposeAsync();
+
+    [Test]
+    public async Task Create_Should_Persist_Template_With_Reference_Ids()
+    {
+        await SeedProfile(1);
+        await SeedFiller(2, FillerKind.PreRoll);
+        await SeedFiller(3, FillerKind.MidRoll);
+        await SeedFiller(4, FillerKind.PostRoll);
+        var handler = new CreateChannelTemplateHandler(_db.Factory, _config);
+
+        Either<BaseError, ChannelTemplateResponseModel> result =
+            await handler.Handle(MakeCreate("Custom"), CancellationToken.None);
+
+        ChannelTemplateResponseModel vm = RightOf(result);
+        vm.Id.ShouldBeGreaterThan(0);
+        vm.Name.ShouldBe("Custom");
+        vm.IsSystem.ShouldBeFalse();
+        vm.PreRollFillerId.ShouldBe(2);
+        vm.MidRollFillerId.ShouldBe(3);
+        vm.PostRollFillerId.ShouldBe(4);
+
+        await using TvContext context = _db.CreateContext();
+        context.ChannelTemplates.Single().Name.ShouldBe("Custom");
+    }
+
+    [Test]
+    public async Task Create_Should_Return_NotFoundError_When_Profile_Missing()
+    {
+        var handler = new CreateChannelTemplateHandler(_db.Factory, _config);
+
+        Either<BaseError, ChannelTemplateResponseModel> result =
+            await handler.Handle(MakeCreate("Missing", ffmpegProfileId: 99), CancellationToken.None);
+
+        LeftOf(result).ShouldBeOfType<NotFoundError>();
+    }
+
+    [Test]
+    public async Task Create_Should_Return_Error_When_Trimmed_Name_Already_Exists()
+    {
+        await SeedProfile(1);
+        await SeedTemplate(7, "Standard");
+        var handler = new CreateChannelTemplateHandler(_db.Factory, _config);
+
+        Either<BaseError, ChannelTemplateResponseModel> result =
+            await handler.Handle(MakeCreate("Standard "), CancellationToken.None);
+
+        LeftOf(result).Value.ShouldBe("Channel template name must be unique.");
+    }
+
+    [Test]
+    public async Task Create_Should_Validate_Filler_Kind()
+    {
+        await SeedProfile(1);
+        await SeedFiller(2, FillerKind.PostRoll);
+        var handler = new CreateChannelTemplateHandler(_db.Factory, _config);
+
+        Either<BaseError, ChannelTemplateResponseModel> result =
+            await handler.Handle(MakeCreate("Bad", preRollFillerId: 2), CancellationToken.None);
+
+        LeftOf(result).ShouldBeOfType<NotFoundError>();
+    }
+
+    [Test]
+    public async Task Update_Should_Reject_System_Template()
+    {
+        await SeedProfile(1);
+        await SeedTemplate(7, "Standard", isSystem: true);
+        var handler = new UpdateChannelTemplateHandler(_db.Factory, _config);
+
+        Either<BaseError, ChannelTemplateResponseModel> result =
+            await handler.Handle(MakeUpdate(7, "Changed"), CancellationToken.None);
+
+        LeftOf(result).Value.ShouldBe("System templates cannot be updated.");
+    }
+
+    [Test]
+    public async Task Delete_Should_Reject_Default_Template()
+    {
+        await SeedProfile(1);
+        await SeedTemplate(7, "Default");
+        await _config.Upsert(ConfigElementKey.ChannelTemplatesDefaultTemplateId, 7, CancellationToken.None);
+        var handler = new DeleteChannelTemplateHandler(_db.Factory, _config);
+
+        Either<BaseError, Unit> result = await handler.Handle(new DeleteChannelTemplate(7), CancellationToken.None);
+
+        LeftOf(result).Value.ShouldBe("Default channel template cannot be deleted.");
+    }
+
+    [Test]
+    public async Task SetDefault_Should_Update_Config_And_Return_Template()
+    {
+        await SeedProfile(1);
+        await SeedTemplate(7, "Default");
+        var handler = new SetDefaultChannelTemplateHandler(_db.Factory, _config);
+
+        Either<BaseError, ChannelTemplateResponseModel> result =
+            await handler.Handle(new SetDefaultChannelTemplate(7), CancellationToken.None);
+
+        ChannelTemplateResponseModel vm = RightOf(result);
+        vm.IsDefault.ShouldBeTrue();
+        Option<int> defaultId =
+            await _config.GetValue<int>(ConfigElementKey.ChannelTemplatesDefaultTemplateId, CancellationToken.None);
+        defaultId.IfNone(0).ShouldBe(7);
+    }
+
+    [Test]
+    public async Task GetAll_Should_Flag_Configured_Default()
+    {
+        await SeedProfile(1);
+        await SeedTemplate(7, "Standard");
+        await SeedTemplate(8, "Music videos");
+        await _config.Upsert(ConfigElementKey.ChannelTemplatesDefaultTemplateId, 8, CancellationToken.None);
+        var handler = new GetAllChannelTemplatesHandler(_db.Factory, _config);
+
+        List<ChannelTemplateResponseModel> result =
+            await handler.Handle(new GetAllChannelTemplates(), CancellationToken.None);
+
+        result.Single(t => t.Id == 7).IsDefault.ShouldBeFalse();
+        result.Single(t => t.Id == 8).IsDefault.ShouldBeTrue();
+    }
+
+    [Test]
+    public async Task GetDefault_Should_Fall_Back_To_First_System_Template_By_Name()
+    {
+        await SeedProfile(1);
+        await SeedTemplate(1, "Zulu", isSystem: true);
+        await SeedTemplate(99, "Alpha", isSystem: true);
+        var handler = new GetDefaultChannelTemplateHandler(_db.Factory, _config);
+
+        Option<ChannelTemplateResponseModel> result =
+            await handler.Handle(new GetDefaultChannelTemplate(), CancellationToken.None);
+
+        ChannelTemplateResponseModel vm = result.IfNone(() => throw new AssertionException("Expected a template"));
+        vm.Id.ShouldBe(99);
+        vm.Name.ShouldBe("Alpha");
+        vm.IsDefault.ShouldBeTrue();
+    }
+
+    private async Task SeedProfile(int id)
+    {
+        await using TvContext context = _db.CreateContext();
+        context.FFmpegProfiles.Add(new FFmpegProfile { Id = id, Name = $"profile-{id}" });
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedFiller(int id, FillerKind fillerKind)
+    {
+        await using TvContext context = _db.CreateContext();
+        context.FillerPresets.Add(new FillerPreset
+        {
+            Id = id,
+            Name = $"filler-{id}",
+            FillerKind = fillerKind,
+            FillerMode = FillerMode.Count,
+            Count = 1,
+            CollectionType = CollectionType.Collection
+        });
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedTemplate(int id, string name, bool isSystem = false)
+    {
+        await using TvContext context = _db.CreateContext();
+        context.ChannelTemplates.Add(new ChannelTemplate
+        {
+            Id = id,
+            Name = name,
+            Description = string.Empty,
+            IsSystem = isSystem,
+            FFmpegProfileId = 1,
+            StreamSelectorMode = ChannelStreamSelectorMode.Default,
+            StreamSelector = string.Empty,
+            PreferredAudioLanguageCode = string.Empty,
+            PreferredAudioTitle = string.Empty,
+            PlayoutSource = ChannelPlayoutSource.Generated,
+            PlayoutMode = ChannelPlayoutMode.Continuous,
+            StreamingMode = StreamingMode.TransportStreamHybrid,
+            PreferredSubtitleLanguageCode = string.Empty,
+            SubtitleMode = ChannelSubtitleMode.None,
+            MusicVideoCreditsMode = ChannelMusicVideoCreditsMode.None,
+            MusicVideoCreditsTemplate = string.Empty,
+            SongVideoMode = ChannelSongVideoMode.Default,
+            TranscodeMode = ChannelTranscodeMode.OnDemand,
+            IdleBehavior = ChannelIdleBehavior.StopOnDisconnect,
+            FixedStartTimeBehavior = FixedStartTimeBehavior.Flexible
+        });
+        await context.SaveChangesAsync();
+    }
+
+    private static CreateChannelTemplate MakeCreate(
+        string name,
+        int ffmpegProfileId = 1,
+        int? preRollFillerId = 2) =>
+        new(
+            name,
+            "Description",
+            ffmpegProfileId,
+            null,
+            null,
+            preRollFillerId,
+            3,
+            4,
+            ChannelStreamSelectorMode.Default,
+            string.Empty,
+            string.Empty,
+            string.Empty,
+            ChannelPlayoutSource.Generated,
+            ChannelPlayoutMode.Continuous,
+            StreamingMode.TransportStreamHybrid,
+            string.Empty,
+            ChannelSubtitleMode.None,
+            ChannelMusicVideoCreditsMode.None,
+            string.Empty,
+            ChannelSongVideoMode.Default,
+            ChannelTranscodeMode.OnDemand,
+            ChannelIdleBehavior.StopOnDisconnect,
+            true,
+            false,
+            FixedStartTimeBehavior.Flexible);
+
+    private static UpdateChannelTemplate MakeUpdate(int id, string name) =>
+        new(
+            id,
+            name,
+            "Description",
+            1,
+            null,
+            null,
+            null,
+            null,
+            null,
+            ChannelStreamSelectorMode.Default,
+            string.Empty,
+            string.Empty,
+            string.Empty,
+            ChannelPlayoutSource.Generated,
+            ChannelPlayoutMode.Continuous,
+            StreamingMode.TransportStreamHybrid,
+            string.Empty,
+            ChannelSubtitleMode.None,
+            ChannelMusicVideoCreditsMode.None,
+            string.Empty,
+            ChannelSongVideoMode.Default,
+            ChannelTranscodeMode.OnDemand,
+            ChannelIdleBehavior.StopOnDisconnect,
+            false,
+            false,
+            FixedStartTimeBehavior.Flexible);
+
+    private static BaseError LeftOf<TR>(Either<BaseError, TR> either) =>
+        either.Match(Left: e => e, Right: _ => throw new AssertionException("Expected a Left result"));
+
+    private static TR RightOf<TR>(Either<BaseError, TR> either) =>
+        either.Match(Left: e => throw new AssertionException($"Expected a Right result but got {e.Value}"), Right: r => r);
+}

ErsatzTV.Tests/Application/Channels/CreateChannelFromLineupHandlerTests.cs

@@ -0,0 +1,751 @@
+using System.Threading.Channels;
+using ErsatzTV.Application;
+using ErsatzTV.Application.Artworks;
+using ErsatzTV.Application.Channels;
+using ErsatzTV.Application.Playouts;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.Channels;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Interfaces.Search;
+using ErsatzTV.Core.Scheduling;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Tests.Support;
+using LanguageExt;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging.Abstractions;
+using NSubstitute;
+using NUnit.Framework;
+using Shouldly;
+using DomainChannel = ErsatzTV.Core.Domain.Channel;
+using DomainPlaylistItem = ErsatzTV.Core.Domain.PlaylistItem;
+
+namespace ErsatzTV.Tests.Application.Channels;
+
+[TestFixture]
+public class CreateChannelFromLineupHandlerTests
+{
+    private Channel<IBackgroundServiceRequest> _background = null!;
+    private InMemoryTvContext _db = null!;
+    private ISearchTargets _searchTargets = null!;
+
+    [SetUp]
+    public async Task SetUp()
+    {
+        _background = System.Threading.Channels.Channel.CreateUnbounded<IBackgroundServiceRequest>();
+        _db = await InMemoryTvContext.CreateAsync();
+        _searchTargets = Substitute.For<ISearchTargets>();
+    }
+
+    [TearDown]
+    public async Task TearDown() => await _db.DisposeAsync();
+
+    [Test]
+    public async Task Should_Create_Single_Media_Item_Directly_Without_Playlist()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(), CancellationToken.None);
+
+        CreateChannelFromLineupResponseModel response = RightOf(result);
+        response.ChannelId.ShouldBeGreaterThan(0);
+        response.PlaylistId.ShouldBeNull();
+        response.ProgramScheduleId.ShouldBeGreaterThan(0);
+        response.PlayoutId.ShouldBeGreaterThan(0);
+
+        await using TvContext context = _db.CreateContext();
+
+        // No generated playlist or collection for a single-item lineup.
+        (await context.Playlists.CountAsync()).ShouldBe(0);
+        (await context.Collections.CountAsync()).ShouldBe(0);
+
+        DomainChannel channel = await context.Channels.SingleAsync();
+        channel.Name.ShouldBe("Movies");
+        channel.Number.ShouldBe("12");
+        channel.Group.ShouldBe("Kids");
+        channel.FFmpegProfileId.ShouldBe(1);
+        channel.FallbackFillerId.ShouldBe(5);
+        channel.StreamingMode.ShouldBe(StreamingMode.HttpLiveStreamingSegmenter);
+        channel.ShowInEpg.ShouldBeTrue();
+
+        ProgramSchedule schedule = await context.ProgramSchedules.Include(ps => ps.Items).SingleAsync();
+        schedule.Name.ShouldBe("12 Movies Schedule");
+        schedule.ShuffleScheduleItems.ShouldBeTrue();
+        schedule.RandomStartPoint.ShouldBeTrue();
+        schedule.FixedStartTimeBehavior.ShouldBe(FixedStartTimeBehavior.Strict);
+
+        ProgramScheduleItem item = schedule.Items.Single();
+        item.ShouldBeOfType<ProgramScheduleItemFlood>();
+        item.CollectionType.ShouldBe(CollectionType.Movie);
+        item.MediaItemId.ShouldBe(42);
+        item.CollectionId.ShouldBeNull();
+        item.PlaylistId.ShouldBeNull();
+        item.PlaybackOrder.ShouldBe(PlaybackOrder.Shuffle);
+        item.PreRollFillerId.ShouldBe(2);
+        item.MidRollFillerId.ShouldBe(3);
+        item.PostRollFillerId.ShouldBe(4);
+        item.FallbackFillerId.ShouldBe(5);
+
+        Playout playout = await context.Playouts.SingleAsync();
+        playout.ChannelId.ShouldBe(channel.Id);
+        playout.ProgramScheduleId.ShouldBe(schedule.Id);
+        playout.ScheduleKind.ShouldBe(PlayoutScheduleKind.Classic);
+
+        _background.Reader.TryRead(out IBackgroundServiceRequest? buildRequest).ShouldBeTrue();
+        BuildPlayout buildPlayout = buildRequest.ShouldBeOfType<BuildPlayout>();
+        buildPlayout.PlayoutId.ShouldBe(playout.Id);
+        buildPlayout.Mode.ShouldBe(PlayoutBuildMode.Reset);
+
+        _background.Reader.TryRead(out IBackgroundServiceRequest? refreshRequest).ShouldBeTrue();
+        refreshRequest.ShouldBeOfType<RefreshChannelList>();
+        _searchTargets.Received(1).SearchTargetsChanged();
+    }
+
+    [Test]
+    public async Task Should_Create_Single_Collection_Item_Directly()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedCollection(7);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(lineup: [CollectionItem(7)]), CancellationToken.None);
+
+        RightOf(result).PlaylistId.ShouldBeNull();
+
+        await using TvContext context = _db.CreateContext();
+        (await context.Playlists.CountAsync()).ShouldBe(0);
+        ProgramScheduleItem item = await context.ProgramScheduleItems.SingleAsync();
+        item.CollectionType.ShouldBe(CollectionType.Collection);
+        item.CollectionId.ShouldBe(7);
+    }
+
+    [Test]
+    public async Task Should_Create_Single_Playlist_Item_Directly()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedExistingPlaylist(9);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(lineup: [PlaylistEntry(9)]), CancellationToken.None);
+
+        // The generated-playlist id is null for a single-item lineup, even when it references a playlist.
+        RightOf(result).PlaylistId.ShouldBeNull();
+
+        await using TvContext context = _db.CreateContext();
+        ProgramScheduleItem item = await context.ProgramScheduleItems.SingleAsync();
+        item.CollectionType.ShouldBe(CollectionType.Playlist);
+        item.PlaylistId.ShouldBe(9);
+    }
+
+    [Test]
+    public async Task Should_Create_Single_Rerun_Collection_As_First_Run()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedRerunCollection(11);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(lineup: [RerunItem(11)]), CancellationToken.None);
+
+        RightOf(result).PlaylistId.ShouldBeNull();
+
+        await using TvContext context = _db.CreateContext();
+        ProgramScheduleItem item = await context.ProgramScheduleItems.SingleAsync();
+        item.CollectionType.ShouldBe(CollectionType.RerunFirstRun);
+        item.RerunCollectionId.ShouldBe(11);
+    }
+
+    [Test]
+    public async Task Should_Create_Multi_Item_Lineup_As_Generated_System_Playlist()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+        await SeedShow(43);
+        await SeedCollection(7);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(
+                MakeRequest(lineup: [MovieItem(42), ShowItem(43), CollectionItem(7)]),
+                CancellationToken.None);
+
+        CreateChannelFromLineupResponseModel response = RightOf(result);
+        response.PlaylistId.ShouldNotBeNull();
+
+        await using TvContext context = _db.CreateContext();
+
+        PlaylistGroup group = await context.PlaylistGroups.SingleAsync();
+        group.Name.ShouldBe("Channel Lineups");
+        group.IsSystem.ShouldBeTrue();
+
+        Playlist playlist = await context.Playlists.Include(p => p.Items).SingleAsync();
+        playlist.Id.ShouldBe(response.PlaylistId!.Value);
+        playlist.Name.ShouldBe("12 Movies Lineup");
+        playlist.IsSystem.ShouldBeTrue();
+        playlist.PlaylistGroupId.ShouldBe(group.Id);
+
+        List<DomainPlaylistItem> items = playlist.Items.OrderBy(i => i.Index).ToList();
+        items.Count.ShouldBe(3);
+        items.ShouldAllBe(i => i.PlayAll);
+        items.ShouldAllBe(i => i.IncludeInProgramGuide);
+        items.ShouldAllBe(i => i.PlaybackOrder == PlaybackOrder.Shuffle);
+
+        items[0].Index.ShouldBe(1);
+        items[0].CollectionType.ShouldBe(CollectionType.Movie);
+        items[0].MediaItemId.ShouldBe(42);
+
+        items[1].Index.ShouldBe(2);
+        items[1].CollectionType.ShouldBe(CollectionType.TelevisionShow);
+        items[1].MediaItemId.ShouldBe(43);
+
+        items[2].Index.ShouldBe(3);
+        items[2].CollectionType.ShouldBe(CollectionType.Collection);
+        items[2].CollectionId.ShouldBe(7);
+
+        // Exactly one flood schedule item, referencing the generated playlist.
+        ProgramScheduleItem scheduleItem = await context.ProgramScheduleItems.SingleAsync();
+        scheduleItem.ShouldBeOfType<ProgramScheduleItemFlood>();
+        scheduleItem.CollectionType.ShouldBe(CollectionType.Playlist);
+        scheduleItem.PlaylistId.ShouldBe(playlist.Id);
+    }
+
+    [Test]
+    public async Task Should_Reject_Rerun_Collection_In_Multi_Item_Lineup()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+        await SeedRerunCollection(11);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(
+                MakeRequest(lineup: [MovieItem(42), RerunItem(11)]),
+                CancellationToken.None);
+
+        BaseError error = LeftOf(result);
+        error.ShouldNotBeOfType<NotFoundError>();
+        error.Value.ShouldContain("single-item");
+    }
+
+    [Test]
+    public async Task Should_Reject_Playlist_In_Multi_Item_Lineup()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+        await SeedExistingPlaylist(9);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(
+                MakeRequest(lineup: [MovieItem(42), PlaylistEntry(9)]),
+                CancellationToken.None);
+
+        BaseError error = LeftOf(result);
+        error.ShouldNotBeOfType<NotFoundError>();
+        error.Value.ShouldContain("single-item");
+    }
+
+    [Test]
+    public async Task Advanced_Overrides_Should_Beat_Template_Defaults()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+
+        await using (TvContext context = _db.CreateContext())
+        {
+            context.FFmpegProfiles.Add(new FFmpegProfile { Id = 2, Name = "advanced-profile" });
+            context.ChannelWatermarks.Add(new ChannelWatermark { Id = 21, Name = "wm", Image = "wm.png" });
+            context.FillerPresets.AddRange(
+                MakeFiller(6, FillerKind.Fallback),
+                MakeFiller(7, FillerKind.PreRoll));
+            await context.SaveChangesAsync();
+        }
+
+        var advanced = new CreateChannelFromLineupAdvancedOptions(
+            PlaybackOrder: PlaybackOrder.Shuffle,
+            FFmpegProfileId: 2,
+            WatermarkId: 21,
+            FallbackFillerId: 6,
+            PreRollFillerId: 7,
+            StreamingMode: StreamingMode.TransportStream);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(advanced: advanced), CancellationToken.None);
+
+        RightOf(result);
+
+        await using TvContext assert = _db.CreateContext();
+        DomainChannel channel = await assert.Channels.SingleAsync();
+
+        // Advanced wins over the template's values (template = profile 1, no watermark, HLS, fallback 5).
+        channel.FFmpegProfileId.ShouldBe(2);
+        channel.WatermarkId.ShouldBe(21);
+        channel.StreamingMode.ShouldBe(StreamingMode.TransportStream);
+        channel.FallbackFillerId.ShouldBe(6);
+
+        ProgramScheduleItem item = await assert.ProgramScheduleItems.SingleAsync();
+        item.PlaybackOrder.ShouldBe(PlaybackOrder.Shuffle);
+        item.PreRollFillerId.ShouldBe(7);
+        item.FallbackFillerId.ShouldBe(6);
+
+        // Not overridden in Advanced -> falls through to the template value.
+        item.MidRollFillerId.ShouldBe(3);
+    }
+
+    [Test]
+    public async Task Should_Return_Validation_Error_When_Not_Exactly_One_Id_Provided()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+
+        var item = new CreateChannelFromLineupItem(
+            LibraryBrowseMediaType.Movie, CollectionType.Movie, null, null, null, null, null, null);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(lineup: [item]), CancellationToken.None);
+
+        LeftOf(result).Value.ShouldContain("exactly one typed id");
+    }
+
+    [Test]
+    public async Task Should_Return_Validation_Error_When_Media_Type_Does_Not_Match_Collection_Type()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+
+        var item = new CreateChannelFromLineupItem(
+            LibraryBrowseMediaType.Movie, CollectionType.Playlist, null, null, null, null, 42, null);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(lineup: [item]), CancellationToken.None);
+
+        BaseError error = LeftOf(result);
+        error.ShouldNotBeOfType<NotFoundError>();
+        error.Value.ShouldContain("does not match");
+    }
+
+    [Test]
+    public async Task Should_Reject_MultiCollection_With_Non_Shuffle_Playback_Order()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMultiCollection(15);
+
+        var advanced = new CreateChannelFromLineupAdvancedOptions(PlaybackOrder: PlaybackOrder.Chronological);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(
+                MakeRequest(advanced: advanced, lineup: [MultiCollectionItem(15)]),
+                CancellationToken.None);
+
+        LeftOf(result).Value.ShouldContain("Invalid playback order for multi collection");
+    }
+
+    [Test]
+    public async Task Should_Reject_Mirror_Playout_Source()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+
+        var advanced = new CreateChannelFromLineupAdvancedOptions(
+            PlaybackOrder: PlaybackOrder.Shuffle,
+            PlayoutSource: ChannelPlayoutSource.Mirror);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(advanced: advanced), CancellationToken.None);
+
+        LeftOf(result).Value.ShouldContain("Mirror playout source");
+    }
+
+    [Test]
+    public async Task OnDemand_Playout_Mode_Should_Queue_TimeShift_After_Build()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+
+        var advanced = new CreateChannelFromLineupAdvancedOptions(
+            PlaybackOrder: PlaybackOrder.Shuffle,
+            PlayoutMode: ChannelPlayoutMode.OnDemand);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(advanced: advanced), CancellationToken.None);
+
+        CreateChannelFromLineupResponseModel response = RightOf(result);
+
+        _background.Reader.TryRead(out IBackgroundServiceRequest? first).ShouldBeTrue();
+        first.ShouldBeOfType<BuildPlayout>();
+
+        _background.Reader.TryRead(out IBackgroundServiceRequest? second).ShouldBeTrue();
+        TimeShiftOnDemandPlayout timeShift = second.ShouldBeOfType<TimeShiftOnDemandPlayout>();
+        timeShift.PlayoutId.ShouldBe(response.PlayoutId);
+        timeShift.Force.ShouldBeFalse();
+
+        _background.Reader.TryRead(out IBackgroundServiceRequest? third).ShouldBeTrue();
+        third.ShouldBeOfType<RefreshChannelList>();
+    }
+
+    [Test]
+    public async Task Should_Recreate_With_De_Collided_Names_After_Channel_Delete()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+        await SeedShow(43);
+
+        // First create builds "12 Movies Schedule" + "12 Movies Lineup".
+        RightOf(await MakeHandler().Handle(
+            MakeRequest(lineup: [MovieItem(42), ShowItem(43)]),
+            CancellationToken.None));
+
+        // Delete the channel + playout but leave the generated schedule/playlist rows behind.
+        await using (TvContext context = _db.CreateContext())
+        {
+            context.Playouts.RemoveRange(await context.Playouts.ToListAsync());
+            context.Channels.RemoveRange(await context.Channels.ToListAsync());
+            await context.SaveChangesAsync();
+        }
+
+        // Second create with the same name must succeed via de-collided names.
+        CreateChannelFromLineupResponseModel response = RightOf(await MakeHandler().Handle(
+            MakeRequest(lineup: [MovieItem(42), ShowItem(43)]),
+            CancellationToken.None));
+
+        await using TvContext assert = _db.CreateContext();
+
+        bool scheduleExists = await assert.ProgramSchedules.AnyAsync(ps => ps.Name == "12 Movies Schedule 2");
+        scheduleExists.ShouldBeTrue();
+
+        Playlist newPlaylist = await assert.Playlists.SingleAsync(p => p.Id == response.PlaylistId!.Value);
+        newPlaylist.Name.ShouldBe("12 Movies Lineup 2");
+
+        // Only one system playlist group is ever created.
+        (await assert.PlaylistGroups.CountAsync(pg => pg.Name == "Channel Lineups")).ShouldBe(1);
+    }
+
+    [Test]
+    public async Task Should_Return_NotFound_For_Missing_Advanced_References()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+
+        await AssertNotFound(
+            new CreateChannelFromLineupAdvancedOptions(FFmpegProfileId: 999),
+            "FFmpegProfile 999");
+        await AssertNotFound(
+            new CreateChannelFromLineupAdvancedOptions(WatermarkId: 999),
+            "Watermark 999");
+        await AssertNotFound(
+            new CreateChannelFromLineupAdvancedOptions(FallbackFillerId: 999),
+            "Fallback filler 999");
+        await AssertNotFound(
+            new CreateChannelFromLineupAdvancedOptions(PreRollFillerId: 999),
+            "Pre-roll filler 999");
+        await AssertNotFound(
+            new CreateChannelFromLineupAdvancedOptions(MidRollFillerId: 999),
+            "Mid-roll filler 999");
+        await AssertNotFound(
+            new CreateChannelFromLineupAdvancedOptions(PostRollFillerId: 999),
+            "Post-roll filler 999");
+    }
+
+    [Test]
+    public async Task Should_Roll_Back_When_Save_Fails()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+        await SeedShow(43);
+
+        // A non-system group with the reserved name forces the handler's new system group insert
+        // to violate the unique Name index at save time (multi-item lineup path).
+        await using (TvContext context = _db.CreateContext())
+        {
+            context.PlaylistGroups.Add(new PlaylistGroup { Id = 99, Name = "Channel Lineups", IsSystem = false });
+            await context.SaveChangesAsync();
+        }
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(
+                MakeRequest(lineup: [MovieItem(42), ShowItem(43)]),
+                CancellationToken.None);
+
+        BaseError error = LeftOf(result);
+        error.ShouldNotBeOfType<NotFoundError>();
+        error.Value.ShouldBe("Unable to create channel from lineup");
+
+        await using TvContext assertContext = _db.CreateContext();
+        (await assertContext.Channels.CountAsync()).ShouldBe(0);
+        (await assertContext.Playlists.CountAsync()).ShouldBe(0);
+        (await assertContext.ProgramSchedules.CountAsync()).ShouldBe(0);
+        (await assertContext.Playouts.CountAsync()).ShouldBe(0);
+        _background.Reader.TryRead(out _).ShouldBeFalse();
+    }
+
+    [Test]
+    public async Task Should_Return_NotFound_When_Template_Is_Missing()
+    {
+        await SeedTemplateDependencies();
+        await SeedMovie(42);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(templateId: 999), CancellationToken.None);
+
+        LeftOf(result).ShouldBeOfType<NotFoundError>();
+    }
+
+    [Test]
+    public async Task Should_Return_Validation_Error_When_Channel_Number_Already_Exists_After_Trim()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+        await using (TvContext context = _db.CreateContext())
+        {
+            context.Channels.Add(new DomainChannel(Guid.NewGuid())
+            {
+                Number = "12",
+                Name = "Existing",
+                Group = "Kids",
+                Categories = string.Empty,
+                FFmpegProfileId = 1,
+                StreamSelector = string.Empty,
+                PreferredAudioLanguageCode = string.Empty,
+                PreferredAudioTitle = string.Empty,
+                PreferredSubtitleLanguageCode = string.Empty,
+                MusicVideoCreditsTemplate = string.Empty
+            });
+            await context.SaveChangesAsync();
+        }
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(number: " 12 "), CancellationToken.None);
+
+        BaseError error = LeftOf(result);
+        error.ShouldNotBeOfType<NotFoundError>();
+        error.Value.ShouldContain("Channel number must be unique");
+    }
+
+    [Test]
+    public async Task Should_Return_Validation_Error_When_Disabled_But_Shown_In_Epg()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(
+                MakeRequest(isEnabled: false, showInEpg: true),
+                CancellationToken.None);
+
+        BaseError error = LeftOf(result);
+        error.ShouldNotBeOfType<NotFoundError>();
+        error.Value.ShouldContain("Disabled channels cannot be shown in EPG");
+    }
+
+    [Test]
+    public async Task Should_Return_Validation_Error_For_Invalid_External_Logo()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+        await SeedMovie(42);
+
+        var logo = new ArtworkContentTypeModel("ftp://example.com/logo.png", string.Empty);
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(logo: logo), CancellationToken.None);
+
+        LeftOf(result).Value.ShouldContain("External logo url is invalid");
+    }
+
+    [Test]
+    public async Task Should_Return_NotFound_When_Lineup_Target_Is_Missing()
+    {
+        await SeedTemplateDependencies();
+        await SeedTemplate();
+
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(), CancellationToken.None);
+
+        NotFoundError error = LeftOf(result).ShouldBeOfType<NotFoundError>();
+        error.Value.ShouldContain("lineup[0]");
+        error.Value.ShouldContain("Movie 42");
+    }
+
+    private async Task AssertNotFound(CreateChannelFromLineupAdvancedOptions advanced, string expectedFragment)
+    {
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await MakeHandler().Handle(MakeRequest(advanced: advanced), CancellationToken.None);
+
+        NotFoundError error = LeftOf(result).ShouldBeOfType<NotFoundError>();
+        error.Value.ShouldContain(expectedFragment);
+    }
+
+    private CreateChannelFromLineupHandler MakeHandler() =>
+        new(
+            _background.Writer,
+            _db.Factory,
+            _searchTargets,
+            NullLogger<CreateChannelFromLineupHandler>.Instance);
+
+    private async Task SeedTemplateDependencies()
+    {
+        await using TvContext context = _db.CreateContext();
+        context.FFmpegProfiles.Add(new FFmpegProfile { Id = 1, Name = "profile" });
+        context.FillerPresets.AddRange(
+            MakeFiller(2, FillerKind.PreRoll),
+            MakeFiller(3, FillerKind.MidRoll),
+            MakeFiller(4, FillerKind.PostRoll),
+            MakeFiller(5, FillerKind.Fallback));
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedTemplate()
+    {
+        await using TvContext context = _db.CreateContext();
+        context.ChannelTemplates.Add(new ChannelTemplate
+        {
+            Id = 10,
+            Name = "Template",
+            Description = string.Empty,
+            FFmpegProfileId = 1,
+            FallbackFillerId = 5,
+            PreRollFillerId = 2,
+            MidRollFillerId = 3,
+            PostRollFillerId = 4,
+            StreamSelectorMode = ChannelStreamSelectorMode.Default,
+            StreamSelector = string.Empty,
+            PreferredAudioLanguageCode = string.Empty,
+            PreferredAudioTitle = string.Empty,
+            PlayoutSource = ChannelPlayoutSource.Generated,
+            PlayoutMode = ChannelPlayoutMode.Continuous,
+            StreamingMode = StreamingMode.HttpLiveStreamingSegmenter,
+            PreferredSubtitleLanguageCode = string.Empty,
+            SubtitleMode = ChannelSubtitleMode.None,
+            MusicVideoCreditsMode = ChannelMusicVideoCreditsMode.None,
+            MusicVideoCreditsTemplate = string.Empty,
+            SongVideoMode = ChannelSongVideoMode.Default,
+            TranscodeMode = ChannelTranscodeMode.OnDemand,
+            IdleBehavior = ChannelIdleBehavior.StopOnDisconnect,
+            ShuffleScheduleItems = true,
+            RandomStartPoint = true,
+            FixedStartTimeBehavior = FixedStartTimeBehavior.Strict
+        });
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedMovie(int id)
+    {
+        await using TvContext context = _db.CreateContext();
+        context.Movies.Add(new Movie { Id = id });
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedShow(int id)
+    {
+        await using TvContext context = _db.CreateContext();
+        context.Shows.Add(new Show { Id = id });
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedCollection(int id)
+    {
+        await using TvContext context = _db.CreateContext();
+        context.Collections.Add(new Collection { Id = id, Name = $"Collection {id}" });
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedMultiCollection(int id)
+    {
+        await using TvContext context = _db.CreateContext();
+        context.MultiCollections.Add(new MultiCollection { Id = id, Name = $"Multi {id}" });
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedRerunCollection(int id)
+    {
+        await using TvContext context = _db.CreateContext();
+        context.RerunCollections.Add(new RerunCollection
+        {
+            Id = id,
+            Name = $"Rerun {id}",
+            CollectionType = CollectionType.Collection
+        });
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedExistingPlaylist(int id)
+    {
+        await using TvContext context = _db.CreateContext();
+        context.PlaylistGroups.Add(new PlaylistGroup { Id = 500, Name = "User Group", IsSystem = false });
+        context.Playlists.Add(new Playlist { Id = id, Name = $"Playlist {id}", PlaylistGroupId = 500, IsSystem = false });
+        await context.SaveChangesAsync();
+    }
+
+    private static FillerPreset MakeFiller(int id, FillerKind kind) =>
+        new()
+        {
+            Id = id,
+            Name = $"filler-{id}",
+            FillerKind = kind,
+            FillerMode = FillerMode.Count,
+            Count = 1,
+            CollectionType = CollectionType.Collection
+        };
+
+    private static CreateChannelFromLineupItem MovieItem(int id) =>
+        new(LibraryBrowseMediaType.Movie, CollectionType.Movie, null, null, null, null, id, null);
+
+    private static CreateChannelFromLineupItem ShowItem(int id) =>
+        new(LibraryBrowseMediaType.TelevisionShow, CollectionType.TelevisionShow, null, null, null, null, id, null);
+
+    private static CreateChannelFromLineupItem CollectionItem(int id) =>
+        new(LibraryBrowseMediaType.Collection, CollectionType.Collection, id, null, null, null, null, null);
+
+    private static CreateChannelFromLineupItem MultiCollectionItem(int id) =>
+        new(LibraryBrowseMediaType.MultiCollection, CollectionType.MultiCollection, null, id, null, null, null, null);
+
+    private static CreateChannelFromLineupItem RerunItem(int id) =>
+        new(LibraryBrowseMediaType.RerunCollection, CollectionType.RerunFirstRun, null, null, null, id, null, null);
+
+    private static CreateChannelFromLineupItem PlaylistEntry(int id) =>
+        new(LibraryBrowseMediaType.Playlist, CollectionType.Playlist, null, null, null, null, null, id);
+
+    private static CreateChannelFromLineup MakeRequest(
+        string number = "12",
+        string name = "Movies",
+        int templateId = 10,
+        bool isEnabled = true,
+        bool showInEpg = true,
+        ArtworkContentTypeModel logo = null,
+        CreateChannelFromLineupAdvancedOptions advanced = null,
+        List<CreateChannelFromLineupItem> lineup = null) =>
+        new(
+            name,
+            number,
+            "Kids",
+            string.Empty,
+            logo ?? ArtworkContentTypeModel.None,
+            isEnabled,
+            showInEpg,
+            templateId,
+            advanced ?? new CreateChannelFromLineupAdvancedOptions(PlaybackOrder.Shuffle),
+            lineup ?? [MovieItem(42)]);
+
+    private static BaseError LeftOf<TR>(Either<BaseError, TR> either) =>
+        either.Match(Left: e => e, Right: _ => throw new AssertionException("Expected a Left result"));
+
+    private static TR RightOf<TR>(Either<BaseError, TR> either) =>
+        either.Match(Left: e => throw new AssertionException($"Expected a Right result, got {e.Value}"), Right: r => r);
+}

ErsatzTV.Tests/Application/LibraryBrowse/GetLibraryBrowseItemsHandlerTests.cs

@@ -0,0 +1,665 @@
+using ErsatzTV.Application.LibraryBrowse;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Metadata;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Core.Interfaces.Search;
+using ErsatzTV.Core.Search;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Search;
+using ErsatzTV.Tests.Support;
+using NSubstitute;
+using NUnit.Framework;
+using Shouldly;
+
+namespace ErsatzTV.Tests.Application.LibraryBrowse;
+
+[TestFixture]
+public class GetLibraryBrowseItemsHandlerTests
+{
+    private InMemoryTvContext _db = null!;
+    private ISearchIndex _searchIndex = null!;
+
+    [SetUp]
+    public async Task SetUp()
+    {
+        _db = await InMemoryTvContext.CreateAsync();
+        _searchIndex = Substitute.For<ISearchIndex>();
+    }
+
+    [TearDown]
+    public async Task TearDown() => await _db.DisposeAsync();
+
+    [Test]
+    public async Task Handle_Should_Search_Index_With_Type_Library_And_Title_Filters()
+    {
+        _searchIndex.Search(
+                Arg.Any<string>(),
+                Arg.Any<string>(),
+                Arg.Any<int>(),
+                Arg.Any<int>(),
+                Arg.Any<List<string>>(),
+                Arg.Any<CancellationToken>())
+            .Returns(new SearchResult([], 0));
+        var handler = new GetLibraryBrowseItemsHandler(_searchIndex, _db.Factory);
+
+        await handler.Handle(
+            new GetLibraryBrowseItems("star", 5, LibraryBrowseMediaType.Movie, 2, 25),
+            CancellationToken.None);
+
+        await _searchIndex.Received(1).Search(
+            Arg.Is<string>(q => q.Contains("type:movie") && q.Contains("library_id:5") && q.Contains("star")),
+            string.Empty,
+            50,
+            25,
+            Arg.Is<List<string>>(fields => fields.SequenceEqual(new[] { LuceneSearchIndex.TitleAndYearSearchField })),
+            Arg.Any<CancellationToken>());
+    }
+
+    [Test]
+    public async Task Handle_Should_Hydrate_Media_Items_In_Search_Order_With_Artwork_Duration_And_Counts()
+    {
+        await SeedLibraryGraph();
+        _searchIndex.Search(
+                Arg.Any<string>(),
+                Arg.Any<string>(),
+                Arg.Any<int>(),
+                Arg.Any<int>(),
+                Arg.Any<List<string>>(),
+                Arg.Any<CancellationToken>())
+            .Returns(new SearchResult(
+                [
+                    new SearchItem(LuceneSearchIndex.ShowType, 20),
+                    new SearchItem(LuceneSearchIndex.MovieType, 10)
+                ],
+                2));
+        var handler = new GetLibraryBrowseItemsHandler(_searchIndex, _db.Factory);
+
+        PagedLibraryBrowseItemsResponseModel result = await handler.Handle(
+            new GetLibraryBrowseItems("", null, null, 0, 10),
+            CancellationToken.None);
+
+        result.TotalCount.ShouldBe(2);
+        result.Page[0].MediaType.ShouldBe(LibraryBrowseMediaType.TelevisionShow);
+        result.Page[0].Title.ShouldBe("Collision Show");
+        result.Page[0].ItemCount.ShouldBe(1);
+        result.Page[0].MediaItemId.ShouldBe(20);
+        result.Page[1].MediaType.ShouldBe(LibraryBrowseMediaType.Movie);
+        result.Page[1].Title.ShouldBe("Collision Movie");
+        result.Page[1].Artwork.ShouldBe("movie-poster.jpg");
+        result.Page[1].Duration.ShouldBe(TimeSpan.FromMinutes(95));
+        result.Page[1].MediaItemId.ShouldBe(10);
+    }
+
+    [Test]
+    public async Task Handle_Should_Return_Typed_Collection_And_Playlist_Picker_Targets()
+    {
+        await SeedCollectionGraph();
+        _searchIndex.Search(
+                Arg.Any<string>(),
+                Arg.Any<string>(),
+                Arg.Any<int>(),
+                Arg.Any<int>(),
+                Arg.Any<List<string>>(),
+                Arg.Any<CancellationToken>())
+            .Returns(new SearchResult([], 0));
+        var handler = new GetLibraryBrowseItemsHandler(_searchIndex, _db.Factory);
+
+        PagedLibraryBrowseItemsResponseModel result = await handler.Handle(
+            new GetLibraryBrowseItems("", null, null, 0, 10),
+            CancellationToken.None);
+
+        result.TotalCount.ShouldBe(5);
+        result.Page.ShouldContain(i =>
+            i.MediaType == LibraryBrowseMediaType.Collection &&
+            i.CollectionKind == "Manual" &&
+            i.CollectionType == CollectionType.Collection &&
+            i.CollectionId == 20 &&
+            i.ItemCount == 1);
+        result.Page.ShouldContain(i =>
+            i.MediaType == LibraryBrowseMediaType.SmartCollection &&
+            i.CollectionKind == "Smart" &&
+            i.CollectionType == CollectionType.SmartCollection &&
+            i.SmartCollectionId == 30);
+        result.Page.ShouldContain(i =>
+            i.MediaType == LibraryBrowseMediaType.MultiCollection &&
+            i.CollectionKind == "Multi" &&
+            i.CollectionType == CollectionType.MultiCollection &&
+            i.MultiCollectionId == 40);
+        result.Page.ShouldContain(i =>
+            i.MediaType == LibraryBrowseMediaType.RerunCollection &&
+            i.CollectionKind == "Rerun" &&
+            i.CollectionType == CollectionType.RerunFirstRun &&
+            i.RerunCollectionId == 50);
+        result.Page.ShouldContain(i =>
+            i.MediaType == LibraryBrowseMediaType.Playlist &&
+            i.CollectionType == CollectionType.Playlist &&
+            i.PlaylistId == 60);
+    }
+
+    [Test]
+    public async Task Handle_Should_Page_Across_Media_Manual_Collections_And_Smart_Collections()
+    {
+        await SeedMediaAndCollectionPagingGraph();
+        _searchIndex.Search(
+                Arg.Any<string>(),
+                Arg.Any<string>(),
+                Arg.Is<int>(offset => offset == 0),
+                Arg.Any<int>(),
+                Arg.Any<List<string>>(),
+                Arg.Any<CancellationToken>())
+            .Returns(new SearchResult(
+                [
+                    new SearchItem(LuceneSearchIndex.MovieType, 101),
+                    new SearchItem(LuceneSearchIndex.MovieType, 102)
+                ],
+                2));
+        _searchIndex.Search(
+                Arg.Any<string>(),
+                Arg.Any<string>(),
+                Arg.Is<int>(offset => offset > 0),
+                Arg.Any<int>(),
+                Arg.Any<List<string>>(),
+                Arg.Any<CancellationToken>())
+            .Returns(new SearchResult([], 2));
+        var handler = new GetLibraryBrowseItemsHandler(_searchIndex, _db.Factory);
+
+        PagedLibraryBrowseItemsResponseModel page0 = await handler.Handle(
+            new GetLibraryBrowseItems("", null, null, 0, 3),
+            CancellationToken.None);
+        PagedLibraryBrowseItemsResponseModel page1 = await handler.Handle(
+            new GetLibraryBrowseItems("", null, null, 1, 3),
+            CancellationToken.None);
+        PagedLibraryBrowseItemsResponseModel page2 = await handler.Handle(
+            new GetLibraryBrowseItems("", null, null, 2, 3),
+            CancellationToken.None);
+
+        page0.TotalCount.ShouldBe(7);
+        page0.Page.Select(i => i.Title).ShouldBe(["Movie One", "Movie Two", "Manual A"]);
+        page1.TotalCount.ShouldBe(7);
+        page1.Page.Select(i => i.Title).ShouldBe(["Manual B", "Manual C", "Smart A"]);
+        page2.TotalCount.ShouldBe(7);
+        page2.Page.Select(i => i.Title).ShouldBe(["Smart B"]);
+    }
+
+    [Test]
+    public async Task Handle_Should_Hydrate_Manual_Collection_Artwork_And_Total_Duration()
+    {
+        await SeedManualCollectionMetadataGraph();
+        _searchIndex.Search(
+                Arg.Any<string>(),
+                Arg.Any<string>(),
+                Arg.Any<int>(),
+                Arg.Any<int>(),
+                Arg.Any<List<string>>(),
+                Arg.Any<CancellationToken>())
+            .Returns(new SearchResult([], 0));
+        var handler = new GetLibraryBrowseItemsHandler(_searchIndex, _db.Factory);
+
+        PagedLibraryBrowseItemsResponseModel result = await handler.Handle(
+            new GetLibraryBrowseItems("", null, LibraryBrowseMediaType.Collection, 0, 10),
+            CancellationToken.None);
+
+        result.TotalCount.ShouldBe(1);
+        result.Page.Count.ShouldBe(1);
+        result.Page[0].Title.ShouldBe("Manual Metadata");
+        result.Page[0].Artwork.ShouldBe("first-poster.jpg");
+        result.Page[0].Duration.ShouldBe(TimeSpan.FromMinutes(75));
+        result.Page[0].ItemCount.ShouldBe(2);
+    }
+
+    [Test]
+    public async Task Handle_Should_Hydrate_Seasons_With_Composed_Titles_And_Episode_Counts()
+    {
+        await SeedSeasonGraph();
+        _searchIndex.Search(
+                Arg.Any<string>(),
+                Arg.Any<string>(),
+                Arg.Any<int>(),
+                Arg.Any<int>(),
+                Arg.Any<List<string>>(),
+                Arg.Any<CancellationToken>())
+            .Returns(new SearchResult(
+                [
+                    new SearchItem(LuceneSearchIndex.SeasonType, 301),
+                    new SearchItem(LuceneSearchIndex.SeasonType, 302)
+                ],
+                2));
+        var handler = new GetLibraryBrowseItemsHandler(_searchIndex, _db.Factory);
+
+        PagedLibraryBrowseItemsResponseModel result = await handler.Handle(
+            new GetLibraryBrowseItems("", null, LibraryBrowseMediaType.TelevisionSeason, 0, 10),
+            CancellationToken.None);
+
+        result.TotalCount.ShouldBe(2);
+        result.Page[0].Title.ShouldBe("Season Show - Season 2");
+        result.Page[0].ItemCount.ShouldBe(2);
+        result.Page[0].CollectionType.ShouldBe(CollectionType.TelevisionSeason);
+        result.Page[0].MediaItemId.ShouldBe(301);
+        result.Page[1].Title.ShouldBe("Season Show - Specials");
+        result.Page[1].ItemCount.ShouldBe(1);
+        result.Page[1].MediaItemId.ShouldBe(302);
+    }
+
+    [Test]
+    public async Task Handle_Should_Hydrate_Artists_With_Music_Video_Counts()
+    {
+        await SeedArtistGraph();
+        _searchIndex.Search(
+                Arg.Any<string>(),
+                Arg.Any<string>(),
+                Arg.Any<int>(),
+                Arg.Any<int>(),
+                Arg.Any<List<string>>(),
+                Arg.Any<CancellationToken>())
+            .Returns(new SearchResult([new SearchItem(LuceneSearchIndex.ArtistType, 401)], 1));
+        var handler = new GetLibraryBrowseItemsHandler(_searchIndex, _db.Factory);
+
+        PagedLibraryBrowseItemsResponseModel result = await handler.Handle(
+            new GetLibraryBrowseItems("", null, LibraryBrowseMediaType.Artist, 0, 10),
+            CancellationToken.None);
+
+        result.TotalCount.ShouldBe(1);
+        result.Page[0].Title.ShouldBe("Counted Artist");
+        result.Page[0].ItemCount.ShouldBe(2);
+        result.Page[0].Artwork.ShouldBe("artist-thumb.jpg");
+        result.Page[0].CollectionType.ShouldBe(CollectionType.Artist);
+        result.Page[0].MediaItemId.ShouldBe(401);
+    }
+
+    [Test]
+    public async Task Handle_Should_Apply_Library_Filter_To_Manual_Collections_Only()
+    {
+        await SeedLibraryFilteredCollectionsGraph();
+        _searchIndex.Search(
+                Arg.Any<string>(),
+                Arg.Any<string>(),
+                Arg.Any<int>(),
+                Arg.Any<int>(),
+                Arg.Any<List<string>>(),
+                Arg.Any<CancellationToken>())
+            .Returns(new SearchResult([], 0));
+        var handler = new GetLibraryBrowseItemsHandler(_searchIndex, _db.Factory);
+
+        PagedLibraryBrowseItemsResponseModel result = await handler.Handle(
+            new GetLibraryBrowseItems("", 501, null, 0, 10),
+            CancellationToken.None);
+
+        result.TotalCount.ShouldBe(1);
+        result.Page.Count.ShouldBe(1);
+        result.Page[0].Title.ShouldBe("Included Manual");
+        result.Page[0].MediaType.ShouldBe(LibraryBrowseMediaType.Collection);
+        result.Page[0].CollectionId.ShouldBe(510);
+    }
+
+    private async Task SeedLibraryGraph()
+    {
+        await using TvContext context = _db.CreateContext();
+        var library = new LocalLibrary
+        {
+            Id = 1,
+            Name = "Local Movies",
+            MediaKind = LibraryMediaKind.Movies,
+            Paths = []
+        };
+        var path = new LibraryPath
+        {
+            Id = 1,
+            Path = "/media",
+            Library = library,
+            LibraryFolders = [],
+            MediaItems = []
+        };
+        library.Paths.Add(path);
+
+        var movie = new Movie
+        {
+            Id = 10,
+            LibraryPath = path,
+            Collections = [],
+            CollectionItems = [],
+            TraktListItems = [],
+            MediaVersions = [new MediaVersion { Duration = TimeSpan.FromMinutes(95) }],
+            MovieMetadata =
+            [
+                MakeMovieMetadata("Collision Movie", "movie-poster.jpg")
+            ]
+        };
+        var show = new Show
+        {
+            Id = 20,
+            LibraryPath = path,
+            Collections = [],
+            CollectionItems = [],
+            TraktListItems = [],
+            Seasons = [],
+            ShowMetadata = [MakeShowMetadata("Collision Show", "show-poster.jpg")]
+        };
+        var season = new Season
+        {
+            Id = 11,
+            LibraryPath = path,
+            Show = show,
+            Collections = [],
+            CollectionItems = [],
+            TraktListItems = [],
+            Episodes = [],
+            SeasonMetadata = []
+        };
+        var episode = new Episode
+        {
+            Id = 12,
+            LibraryPath = path,
+            Season = season,
+            Collections = [],
+            CollectionItems = [],
+            TraktListItems = [],
+            EpisodeMetadata = [],
+            MediaVersions = [new MediaVersion { Duration = TimeSpan.FromMinutes(25) }]
+        };
+        season.Episodes.Add(episode);
+        show.Seasons.Add(season);
+        path.MediaItems.AddRange([movie, show, season, episode]);
+        context.LocalLibraries.Add(library);
+        context.Movies.Add(movie);
+        context.Shows.Add(show);
+        context.Seasons.Add(season);
+        context.Episodes.Add(episode);
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedCollectionGraph()
+    {
+        await using TvContext context = _db.CreateContext();
+        var collection = new Collection { Id = 20, Name = "Manual", MediaItems = [], CollectionItems = [] };
+        var movie = new Movie
+        {
+            Id = 21,
+            Collections = [collection],
+            CollectionItems = [],
+            TraktListItems = [],
+            MovieMetadata = [],
+            MediaVersions = []
+        };
+        collection.MediaItems.Add(movie);
+        var smart = new SmartCollection { Id = 30, Name = "Smart", Query = "tag:kids" };
+        var multi = new MultiCollection
+        {
+            Id = 40,
+            Name = "Multi",
+            Collections = [collection],
+            SmartCollections = [smart]
+        };
+        var rerun = new RerunCollection { Id = 50, Name = "Rerun", CollectionType = CollectionType.Collection };
+        var playlist = new Playlist
+        {
+            Id = 60,
+            Name = "Playlist",
+            Items = [new PlaylistItem { CollectionType = CollectionType.Collection, CollectionId = 20 }]
+        };
+
+        context.Collections.Add(collection);
+        context.Movies.Add(movie);
+        context.SmartCollections.Add(smart);
+        context.MultiCollections.Add(multi);
+        context.RerunCollections.Add(rerun);
+        context.Playlists.Add(playlist);
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedMediaAndCollectionPagingGraph()
+    {
+        await using TvContext context = _db.CreateContext();
+        (LocalLibrary library, LibraryPath path) = MakeLibrary(100, "Paging Library");
+
+        var movie1 = MakeMovie(101, path, "Movie One", "movie-one.jpg", TimeSpan.FromMinutes(10));
+        var movie2 = MakeMovie(102, path, "Movie Two", "movie-two.jpg", TimeSpan.FromMinutes(20));
+        var manualA = MakeCollection(201, "Manual A");
+        var manualB = MakeCollection(202, "Manual B");
+        var manualC = MakeCollection(203, "Manual C");
+
+        context.LocalLibraries.Add(library);
+        context.Movies.AddRange(movie1, movie2);
+        context.Collections.AddRange(manualA, manualB, manualC);
+        context.SmartCollections.AddRange(
+            new SmartCollection { Id = 301, Name = "Smart A", Query = "tag:a", MultiCollections = [], MultiCollectionSmartItems = [] },
+            new SmartCollection { Id = 302, Name = "Smart B", Query = "tag:b", MultiCollections = [], MultiCollectionSmartItems = [] });
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedManualCollectionMetadataGraph()
+    {
+        await using TvContext context = _db.CreateContext();
+        (LocalLibrary library, LibraryPath path) = MakeLibrary(200, "Manual Metadata Library");
+        var collection = MakeCollection(210, "Manual Metadata");
+        var first = MakeMovie(211, path, "First", "first-poster.jpg", TimeSpan.FromMinutes(30));
+        var second = MakeMovie(212, path, "Second", "second-poster.jpg", TimeSpan.FromMinutes(45));
+        collection.MediaItems.AddRange([first, second]);
+
+        context.LocalLibraries.Add(library);
+        context.Collections.Add(collection);
+        context.Movies.AddRange(first, second);
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedSeasonGraph()
+    {
+        await using TvContext context = _db.CreateContext();
+        (LocalLibrary library, LibraryPath path) = MakeLibrary(300, "Season Library");
+        var show = new Show
+        {
+            Id = 300,
+            LibraryPath = path,
+            Collections = [],
+            CollectionItems = [],
+            TraktListItems = [],
+            Seasons = [],
+            ShowMetadata = [MakeShowMetadata("Season Show", "show.jpg")]
+        };
+        var season = MakeSeason(301, path, show, 2);
+        var specials = MakeSeason(302, path, show, 0);
+        season.Episodes.AddRange([
+            MakeEpisode(311, path, season),
+            MakeEpisode(312, path, season)
+        ]);
+        specials.Episodes.Add(MakeEpisode(313, path, specials));
+        show.Seasons.AddRange([season, specials]);
+        path.MediaItems.AddRange([show, season, specials, .. season.Episodes, .. specials.Episodes]);
+
+        context.LocalLibraries.Add(library);
+        context.Shows.Add(show);
+        context.Seasons.AddRange(season, specials);
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedArtistGraph()
+    {
+        await using TvContext context = _db.CreateContext();
+        (LocalLibrary library, LibraryPath path) = MakeLibrary(400, "Artist Library");
+        var artist = new Artist
+        {
+            Id = 401,
+            LibraryPath = path,
+            Collections = [],
+            CollectionItems = [],
+            TraktListItems = [],
+            MusicVideos = [],
+            ArtistMetadata = [MakeArtistMetadata("Counted Artist", "artist-thumb.jpg")]
+        };
+        var musicVideo1 = MakeMusicVideo(411, path, artist);
+        var musicVideo2 = MakeMusicVideo(412, path, artist);
+        artist.MusicVideos.AddRange([musicVideo1, musicVideo2]);
+        path.MediaItems.AddRange([artist, musicVideo1, musicVideo2]);
+
+        context.LocalLibraries.Add(library);
+        context.Artists.Add(artist);
+        context.MusicVideos.AddRange(musicVideo1, musicVideo2);
+        await context.SaveChangesAsync();
+    }
+
+    private async Task SeedLibraryFilteredCollectionsGraph()
+    {
+        await using TvContext context = _db.CreateContext();
+        (LocalLibrary includedLibrary, LibraryPath includedPath) = MakeLibrary(501, "Included Library");
+        (LocalLibrary excludedLibrary, LibraryPath excludedPath) = MakeLibrary(502, "Excluded Library");
+        var includedCollection = MakeCollection(510, "Included Manual");
+        var excludedCollection = MakeCollection(511, "Excluded Manual");
+        var includedMovie = MakeMovie(520, includedPath, "Included Movie", "included.jpg", TimeSpan.FromMinutes(5));
+        var excludedMovie = MakeMovie(521, excludedPath, "Excluded Movie", "excluded.jpg", TimeSpan.FromMinutes(5));
+        includedCollection.MediaItems.Add(includedMovie);
+        excludedCollection.MediaItems.Add(excludedMovie);
+
+        context.LocalLibraries.AddRange(includedLibrary, excludedLibrary);
+        context.Movies.AddRange(includedMovie, excludedMovie);
+        context.Collections.AddRange(includedCollection, excludedCollection);
+        context.SmartCollections.Add(new SmartCollection { Id = 530, Name = "Smart", Query = "tag", MultiCollections = [], MultiCollectionSmartItems = [] });
+        context.MultiCollections.Add(new MultiCollection { Id = 540, Name = "Multi", Collections = [], SmartCollections = [], MultiCollectionItems = [], MultiCollectionSmartItems = [] });
+        context.RerunCollections.Add(new RerunCollection { Id = 550, Name = "Rerun", CollectionType = CollectionType.Collection });
+        context.Playlists.Add(new Playlist { Id = 560, Name = "Playlist", Items = [] });
+        await context.SaveChangesAsync();
+    }
+
+    private static (LocalLibrary Library, LibraryPath Path) MakeLibrary(int id, string name)
+    {
+        var library = new LocalLibrary
+        {
+            Id = id,
+            Name = name,
+            MediaKind = LibraryMediaKind.Movies,
+            Paths = []
+        };
+        var path = new LibraryPath
+        {
+            Id = id,
+            Path = $"/media/{id}",
+            Library = library,
+            LibraryFolders = [],
+            MediaItems = []
+        };
+        library.Paths.Add(path);
+        return (library, path);
+    }
+
+    private static Collection MakeCollection(int id, string name) =>
+        new()
+        {
+            Id = id,
+            Name = name,
+            MediaItems = [],
+            CollectionItems = [],
+            MultiCollections = [],
+            MultiCollectionItems = []
+        };
+
+    private static Movie MakeMovie(int id, LibraryPath path, string title, string poster, TimeSpan duration) =>
+        new()
+        {
+            Id = id,
+            LibraryPath = path,
+            Collections = [],
+            CollectionItems = [],
+            TraktListItems = [],
+            MovieMetadata = [MakeMovieMetadata(title, poster)],
+            MediaVersions = [new MediaVersion { Duration = duration }]
+        };
+
+    private static Season MakeSeason(int id, LibraryPath path, Show show, int seasonNumber) =>
+        new()
+        {
+            Id = id,
+            LibraryPath = path,
+            Show = show,
+            SeasonNumber = seasonNumber,
+            Collections = [],
+            CollectionItems = [],
+            TraktListItems = [],
+            Episodes = [],
+            SeasonMetadata = [MakeSeasonMetadata()]
+        };
+
+    private static Episode MakeEpisode(int id, LibraryPath path, Season season) =>
+        new()
+        {
+            Id = id,
+            LibraryPath = path,
+            Season = season,
+            Collections = [],
+            CollectionItems = [],
+            TraktListItems = [],
+            EpisodeMetadata = [],
+            MediaVersions = []
+        };
+
+    private static MusicVideo MakeMusicVideo(int id, LibraryPath path, Artist artist) =>
+        new()
+        {
+            Id = id,
+            LibraryPath = path,
+            Artist = artist,
+            Collections = [],
+            CollectionItems = [],
+            TraktListItems = [],
+            MusicVideoMetadata = [],
+            MediaVersions = []
+        };
+
+    private static MovieMetadata MakeMovieMetadata(string title, string poster) =>
+        new()
+        {
+            Title = title,
+            SortTitle = title,
+            Artwork = [new Artwork { Path = poster, ArtworkKind = ArtworkKind.Poster }],
+            Genres = [],
+            Tags = [],
+            Studios = [],
+            Actors = [],
+            Guids = [],
+            Subtitles = [],
+            Directors = [],
+            Writers = []
+        };
+
+    private static ShowMetadata MakeShowMetadata(string title, string poster) =>
+        new()
+        {
+            Title = title,
+            SortTitle = title,
+            Artwork = [new Artwork { Path = poster, ArtworkKind = ArtworkKind.Poster }],
+            Genres = [],
+            Tags = [],
+            Studios = [],
+            Actors = [],
+            Guids = [],
+            Subtitles = []
+        };
+
+    private static SeasonMetadata MakeSeasonMetadata() =>
+        new()
+        {
+            Title = string.Empty,
+            SortTitle = string.Empty,
+            Artwork = [],
+            Genres = [],
+            Tags = [],
+            Studios = [],
+            Actors = [],
+            Guids = [],
+            Subtitles = []
+        };
+
+    private static ArtistMetadata MakeArtistMetadata(string title, string thumbnail) =>
+        new()
+        {
+            Title = title,
+            SortTitle = title,
+            Artwork = [new Artwork { Path = thumbnail, ArtworkKind = ArtworkKind.Thumbnail }],
+            Genres = [],
+            Tags = [],
+            Studios = [],
+            Actors = [],
+            Guids = [],
+            Subtitles = [],
+            Styles = [],
+            Moods = []
+        };
+}

ErsatzTV.Tests/Controllers/ApiErrorResponseMetadataTests.cs

@@ -13,6 +13,8 @@ public class ApiErrorResponseMetadataTests
     [TestCase(typeof(ChannelController), nameof(ChannelController.GetById), StatusCodes.Status404NotFound)]
     [TestCase(typeof(ChannelController), nameof(ChannelController.Create), StatusCodes.Status404NotFound)]
     [TestCase(typeof(ChannelController), nameof(ChannelController.Create), StatusCodes.Status422UnprocessableEntity)]
+    [TestCase(typeof(ChannelController), nameof(ChannelController.CreateFromLineup), StatusCodes.Status404NotFound)]
+    [TestCase(typeof(ChannelController), nameof(ChannelController.CreateFromLineup), StatusCodes.Status422UnprocessableEntity)]
     [TestCase(typeof(ChannelController), nameof(ChannelController.Update), StatusCodes.Status404NotFound)]
     [TestCase(typeof(ChannelController), nameof(ChannelController.Update), StatusCodes.Status422UnprocessableEntity)]
     [TestCase(typeof(ChannelController), nameof(ChannelController.Delete), StatusCodes.Status404NotFound)]
@@ -24,6 +26,16 @@ public class ApiErrorResponseMetadataTests
     [TestCase(typeof(ChannelController), nameof(ChannelController.BulkDelete), StatusCodes.Status404NotFound)]
     [TestCase(typeof(ChannelController), nameof(ChannelController.BulkDelete), StatusCodes.Status422UnprocessableEntity)]
     [TestCase(typeof(ChannelController), nameof(ChannelController.ResetPlayout), StatusCodes.Status404NotFound)]
+    [TestCase(typeof(ChannelTemplateController), nameof(ChannelTemplateController.GetDefault), StatusCodes.Status404NotFound)]
+    [TestCase(typeof(ChannelTemplateController), nameof(ChannelTemplateController.SetDefault), StatusCodes.Status404NotFound)]
+    [TestCase(typeof(ChannelTemplateController), nameof(ChannelTemplateController.SetDefault), StatusCodes.Status422UnprocessableEntity)]
+    [TestCase(typeof(ChannelTemplateController), nameof(ChannelTemplateController.GetById), StatusCodes.Status404NotFound)]
+    [TestCase(typeof(ChannelTemplateController), nameof(ChannelTemplateController.Create), StatusCodes.Status404NotFound)]
+    [TestCase(typeof(ChannelTemplateController), nameof(ChannelTemplateController.Create), StatusCodes.Status422UnprocessableEntity)]
+    [TestCase(typeof(ChannelTemplateController), nameof(ChannelTemplateController.Update), StatusCodes.Status404NotFound)]
+    [TestCase(typeof(ChannelTemplateController), nameof(ChannelTemplateController.Update), StatusCodes.Status422UnprocessableEntity)]
+    [TestCase(typeof(ChannelTemplateController), nameof(ChannelTemplateController.Delete), StatusCodes.Status404NotFound)]
+    [TestCase(typeof(ChannelTemplateController), nameof(ChannelTemplateController.Delete), StatusCodes.Status422UnprocessableEntity)]
     [TestCase(typeof(CollectionController), nameof(CollectionController.GetById), StatusCodes.Status404NotFound)]
     [TestCase(typeof(CollectionController), nameof(CollectionController.Create), StatusCodes.Status404NotFound)]
     [TestCase(typeof(CollectionController), nameof(CollectionController.Create), StatusCodes.Status422UnprocessableEntity)]

ErsatzTV.Tests/Controllers/ChannelControllerTests.cs

@@ -7,6 +7,7 @@ using ErsatzTV.Controllers.Api;
 using ErsatzTV.Controllers.Api.Requests;
 using ErsatzTV.Core;
 using ErsatzTV.Core.Api.Channels;
+using ErsatzTV.Core.Api.LibraryBrowse;
 using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.Errors;
 using ErsatzTV.Core.Scheduling;
@@ -98,6 +99,54 @@ public class ChannelControllerTests
         result.ShouldBeOfType<UnprocessableEntityObjectResult>();
     }
 
+    [Test]
+    public async Task CreateFromLineup_Should_Return_201_With_Location_And_Body()
+    {
+        var response = new CreateChannelFromLineupResponseModel(5, 6, 7, 8);
+        _mediator.Send(Arg.Any<CreateChannelFromLineup>(), Arg.Any<CancellationToken>())
+            .Returns(Right<BaseError, CreateChannelFromLineupResponseModel>(response));
+
+        IActionResult result = await _controller.CreateFromLineup(MakeLineupRequest(), CancellationToken.None);
+
+        var created = result.ShouldBeOfType<CreatedResult>();
+        created.StatusCode.ShouldBe(201);
+        created.Location.ShouldBe("/api/channels/5");
+        created.Value.ShouldBe(response);
+    }
+
+    [Test]
+    public async Task CreateFromLineup_Should_Map_Request_To_Command()
+    {
+        _mediator.Send(Arg.Any<CreateChannelFromLineup>(), Arg.Any<CancellationToken>())
+            .Returns(Right<BaseError, CreateChannelFromLineupResponseModel>(
+                new CreateChannelFromLineupResponseModel(5, 6, 7, 8)));
+
+        await _controller.CreateFromLineup(
+            MakeLineupRequest(number: "12", name: "Movies", templateId: 9),
+            CancellationToken.None);
+
+        await _mediator.Received(1).Send(
+            Arg.Is<CreateChannelFromLineup>(c =>
+                c.Number == "12" &&
+                c.Name == "Movies" &&
+                c.TemplateId == 9 &&
+                c.Lineup.Count == 1 &&
+                c.Lineup[0].CollectionType == CollectionType.Movie &&
+                c.Lineup[0].MediaItemId == 42),
+            Arg.Any<CancellationToken>());
+    }
+
+    [Test]
+    public async Task CreateFromLineup_Should_Return_404_For_NotFoundError()
+    {
+        _mediator.Send(Arg.Any<CreateChannelFromLineup>(), Arg.Any<CancellationToken>())
+            .Returns(Left<BaseError, CreateChannelFromLineupResponseModel>(new NotFoundError("missing")));
+
+        IActionResult result = await _controller.CreateFromLineup(MakeLineupRequest(), CancellationToken.None);
+
+        result.ShouldBeOfType<NotFoundObjectResult>();
+    }
+
     [Test]
     public async Task Update_Should_Return_200_And_Map_Route_Id()
     {
@@ -413,6 +462,30 @@ public class ChannelControllerTests
             true,
             false);
 
+    private static CreateChannelFromLineupRequest MakeLineupRequest(
+        string number = "5",
+        string name = "Test",
+        int templateId = 1) =>
+        new(
+            name,
+            number,
+            "ErsatzTV",
+            string.Empty,
+            ArtworkContentTypeModel.None,
+            true,
+            true,
+            templateId,
+            null,
+            [new CreateChannelFromLineupItemRequest(
+                LibraryBrowseMediaType.Movie,
+                CollectionType.Movie,
+                null,
+                null,
+                null,
+                null,
+                42,
+                null)]);
+
     private static UpdateChannelRequest MakeUpdateRequest(string number = "5", string name = "Test") =>
         new(
             name,

ErsatzTV.Tests/Controllers/ChannelTemplateControllerTests.cs

@@ -0,0 +1,276 @@
+using System.Reflection;
+using ErsatzTV.Application.ChannelTemplates;
+using ErsatzTV.Controllers.Api;
+using ErsatzTV.Controllers.Api.Requests;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Errors;
+using ErsatzTV.Core.Scheduling;
+using LanguageExt;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Routing;
+using NSubstitute;
+using NUnit.Framework;
+using Shouldly;
+using static LanguageExt.Prelude;
+using Unit = LanguageExt.Unit;
+
+namespace ErsatzTV.Tests.Controllers;
+
+[TestFixture]
+public class ChannelTemplateControllerTests
+{
+    private ChannelTemplateController _controller = null!;
+    private IMediator _mediator = null!;
+
+    [SetUp]
+    public void SetUp()
+    {
+        _mediator = Substitute.For<IMediator>();
+        _controller = new ChannelTemplateController(_mediator);
+    }
+
+    [Test]
+    public void Controller_Should_Expose_Named_Rest_Routes()
+    {
+        ShouldHaveActionRoute(
+            nameof(ChannelTemplateController.GetAll),
+            "GET",
+            "/api/channel-templates",
+            "GetChannelTemplates");
+        ShouldHaveActionRoute(
+            nameof(ChannelTemplateController.GetDefault),
+            "GET",
+            "/api/channel-templates/default",
+            "GetDefaultChannelTemplate");
+        ShouldHaveActionRoute(
+            nameof(ChannelTemplateController.SetDefault),
+            "PUT",
+            "/api/channel-templates/default/{id:int}",
+            "SetDefaultChannelTemplate");
+        ShouldHaveActionRoute(
+            nameof(ChannelTemplateController.GetById),
+            "GET",
+            "/api/channel-templates/{id:int}",
+            "GetChannelTemplateById");
+        ShouldHaveActionRoute(
+            nameof(ChannelTemplateController.Create),
+            "POST",
+            "/api/channel-templates",
+            "CreateChannelTemplate");
+        ShouldHaveActionRoute(
+            nameof(ChannelTemplateController.Update),
+            "PUT",
+            "/api/channel-templates/{id:int}",
+            "UpdateChannelTemplate");
+        ShouldHaveActionRoute(
+            nameof(ChannelTemplateController.Delete),
+            "DELETE",
+            "/api/channel-templates/{id:int}",
+            "DeleteChannelTemplate");
+    }
+
+    [Test]
+    public async Task GetAll_Should_Return_ChannelTemplates()
+    {
+        List<ChannelTemplateResponseModel> models = [MakeResponse(1, "Standard", isDefault: true)];
+        _mediator.Send(Arg.Any<GetAllChannelTemplates>(), Arg.Any<CancellationToken>())
+            .Returns(models);
+
+        List<ChannelTemplateResponseModel> result = await _controller.GetAll(CancellationToken.None);
+
+        result.ShouldBe(models);
+    }
+
+    [Test]
+    public async Task GetDefault_Should_Return_404_When_Default_Missing()
+    {
+        _mediator.Send(Arg.Any<GetDefaultChannelTemplate>(), Arg.Any<CancellationToken>())
+            .Returns(Option<ChannelTemplateResponseModel>.None);
+
+        IActionResult result = await _controller.GetDefault(CancellationToken.None);
+
+        result.ShouldBeOfType<NotFoundObjectResult>();
+    }
+
+    [Test]
+    public async Task Create_Should_Return_201_With_Location_And_Body()
+    {
+        ChannelTemplateResponseModel vm = MakeResponse(7, "Custom");
+        _mediator.Send(Arg.Any<CreateChannelTemplate>(), Arg.Any<CancellationToken>())
+            .Returns(Right<BaseError, ChannelTemplateResponseModel>(vm));
+
+        IActionResult result = await _controller.Create(MakeCreateRequest("Custom"), CancellationToken.None);
+
+        var created = result.ShouldBeOfType<CreatedResult>();
+        created.Location.ShouldBe("/api/channel-templates/7");
+        created.Value.ShouldBe(vm);
+    }
+
+    [Test]
+    public async Task Create_Should_Map_Request_To_Command()
+    {
+        _mediator.Send(Arg.Any<CreateChannelTemplate>(), Arg.Any<CancellationToken>())
+            .Returns(Right<BaseError, ChannelTemplateResponseModel>(MakeResponse(7, "Custom")));
+
+        await _controller.Create(MakeCreateRequest("Custom"), CancellationToken.None);
+
+        await _mediator.Received(1).Send(
+            Arg.Is<CreateChannelTemplate>(c =>
+                c.Name == "Custom" &&
+                c.FFmpegProfileId == 1 &&
+                c.PreRollFillerId == 2 &&
+                c.MidRollFillerId == 3 &&
+                c.PostRollFillerId == 4 &&
+                c.ShuffleScheduleItems),
+            Arg.Any<CancellationToken>());
+    }
+
+    [Test]
+    public async Task Update_Should_Return_404_For_NotFoundError()
+    {
+        _mediator.Send(Arg.Any<UpdateChannelTemplate>(), Arg.Any<CancellationToken>())
+            .Returns(Left<BaseError, ChannelTemplateResponseModel>(new NotFoundError("missing")));
+
+        IActionResult result = await _controller.Update(99, MakeUpdateRequest("Missing"), CancellationToken.None);
+
+        result.ShouldBeOfType<NotFoundObjectResult>();
+    }
+
+    [Test]
+    public async Task SetDefault_Should_Return_200_With_Default_Template()
+    {
+        ChannelTemplateResponseModel vm = MakeResponse(8, "Default", isDefault: true);
+        _mediator.Send(Arg.Any<SetDefaultChannelTemplate>(), Arg.Any<CancellationToken>())
+            .Returns(Right<BaseError, ChannelTemplateResponseModel>(vm));
+
+        IActionResult result = await _controller.SetDefault(8, CancellationToken.None);
+
+        result.ShouldBeOfType<OkObjectResult>().Value.ShouldBe(vm);
+        await _mediator.Received(1).Send(
+            Arg.Is<SetDefaultChannelTemplate>(c => c.ChannelTemplateId == 8),
+            Arg.Any<CancellationToken>());
+    }
+
+    [Test]
+    public async Task Delete_Should_Return_204_On_Success()
+    {
+        _mediator.Send(Arg.Any<DeleteChannelTemplate>(), Arg.Any<CancellationToken>())
+            .Returns(Right<BaseError, Unit>(Unit.Default));
+
+        IActionResult result = await _controller.Delete(9, CancellationToken.None);
+
+        result.ShouldBeOfType<NoContentResult>();
+    }
+
+    [Test]
+    public async Task Delete_Should_Return_422_When_System_Template()
+    {
+        _mediator.Send(Arg.Any<DeleteChannelTemplate>(), Arg.Any<CancellationToken>())
+            .Returns(Left<BaseError, Unit>(BaseError.New("System templates cannot be deleted.")));
+
+        IActionResult result = await _controller.Delete(9, CancellationToken.None);
+
+        result.ShouldBeOfType<UnprocessableEntityObjectResult>();
+    }
+
+    private static void ShouldHaveActionRoute(string actionName, string httpMethod, string route, string name)
+    {
+        MethodInfo action = typeof(ChannelTemplateController).GetMethod(actionName)
+            ?? throw new AssertionException($"Missing action {actionName}");
+
+        HttpMethodAttribute attribute = action.GetCustomAttributes<HttpMethodAttribute>(inherit: true).Single();
+        attribute.HttpMethods.ShouldContain(httpMethod);
+        attribute.Template.ShouldBe(route);
+        attribute.Name.ShouldBe(name);
+    }
+
+    private static CreateChannelTemplateRequest MakeCreateRequest(string name) =>
+        new(
+            name,
+            "Description",
+            1,
+            null,
+            null,
+            2,
+            3,
+            4,
+            ChannelStreamSelectorMode.Default,
+            string.Empty,
+            string.Empty,
+            string.Empty,
+            ChannelPlayoutSource.Generated,
+            ChannelPlayoutMode.Continuous,
+            StreamingMode.TransportStreamHybrid,
+            string.Empty,
+            ChannelSubtitleMode.None,
+            ChannelMusicVideoCreditsMode.None,
+            string.Empty,
+            ChannelSongVideoMode.Default,
+            ChannelTranscodeMode.OnDemand,
+            ChannelIdleBehavior.StopOnDisconnect,
+            true,
+            false,
+            FixedStartTimeBehavior.Flexible);
+
+    private static UpdateChannelTemplateRequest MakeUpdateRequest(string name) =>
+        new(
+            name,
+            "Description",
+            1,
+            null,
+            null,
+            null,
+            null,
+            null,
+            ChannelStreamSelectorMode.Default,
+            string.Empty,
+            string.Empty,
+            string.Empty,
+            ChannelPlayoutSource.Generated,
+            ChannelPlayoutMode.Continuous,
+            StreamingMode.TransportStreamHybrid,
+            string.Empty,
+            ChannelSubtitleMode.None,
+            ChannelMusicVideoCreditsMode.None,
+            string.Empty,
+            ChannelSongVideoMode.Default,
+            ChannelTranscodeMode.OnDemand,
+            ChannelIdleBehavior.StopOnDisconnect,
+            false,
+            false,
+            FixedStartTimeBehavior.Flexible);
+
+    private static ChannelTemplateResponseModel MakeResponse(int id, string name, bool isDefault = false) =>
+        new(
+            id,
+            name,
+            "Description",
+            false,
+            isDefault,
+            1,
+            null,
+            null,
+            null,
+            null,
+            null,
+            ChannelStreamSelectorMode.Default,
+            string.Empty,
+            string.Empty,
+            string.Empty,
+            ChannelPlayoutSource.Generated,
+            ChannelPlayoutMode.Continuous,
+            StreamingMode.TransportStreamHybrid,
+            string.Empty,
+            ChannelSubtitleMode.None,
+            ChannelMusicVideoCreditsMode.None,
+            string.Empty,
+            ChannelSongVideoMode.Default,
+            ChannelTranscodeMode.OnDemand,
+            ChannelIdleBehavior.StopOnDisconnect,
+            false,
+            false,
+            FixedStartTimeBehavior.Flexible);
+}

ErsatzTV.Tests/Controllers/LibraryBrowseControllerTests.cs

@@ -0,0 +1,92 @@
+using System.Reflection;
+using ErsatzTV.Application.LibraryBrowse;
+using ErsatzTV.Controllers.Api;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Routing;
+using NSubstitute;
+using NUnit.Framework;
+using Shouldly;
+
+namespace ErsatzTV.Tests.Controllers;
+
+[TestFixture]
+public class LibraryBrowseControllerTests
+{
+    private LibraryBrowseController _controller = null!;
+    private IMediator _mediator = null!;
+
+    [SetUp]
+    public void SetUp()
+    {
+        _mediator = Substitute.For<IMediator>();
+        _controller = new LibraryBrowseController(_mediator);
+    }
+
+    [Test]
+    public void Controller_Should_Expose_Browse_Route_With_Stable_Operation_Name()
+    {
+        MethodInfo action = typeof(LibraryBrowseController).GetMethod(nameof(LibraryBrowseController.Browse))
+            ?? throw new AssertionException($"Missing action {nameof(LibraryBrowseController.Browse)}");
+
+        var attribute = action.GetCustomAttributes<HttpGetAttribute>().Single();
+        attribute.Template.ShouldBe("/api/library/browse");
+        attribute.Name.ShouldBe("BrowseLibrary");
+    }
+
+    [Test]
+    public async Task Browse_Should_Clamp_Paging_And_Send_Query()
+    {
+        _mediator.Send(Arg.Any<GetLibraryBrowseItems>(), Arg.Any<CancellationToken>())
+            .Returns(new PagedLibraryBrowseItemsResponseModel(0, []));
+
+        await _controller.Browse(
+            "star",
+            123,
+            LibraryBrowseMediaType.Movie,
+            -1,
+            500,
+            CancellationToken.None);
+
+        await _mediator.Received(1).Send(
+            Arg.Is<GetLibraryBrowseItems>(q =>
+                q.Query == "star" &&
+                q.LibraryId == 123 &&
+                q.MediaType == LibraryBrowseMediaType.Movie &&
+                q.PageNum == 0 &&
+                q.PageSize == 100),
+            Arg.Any<CancellationToken>());
+    }
+
+    [Test]
+    public async Task Browse_Should_Return_Paged_Response()
+    {
+        var item = new LibraryBrowseItemResponseModel(
+            10,
+            LibraryBrowseMediaType.Movie,
+            "Movie",
+            3,
+            "Movies",
+            "/artwork/posters/movie.jpg",
+            TimeSpan.FromMinutes(90),
+            1,
+            null,
+            CollectionType.Movie,
+            null,
+            null,
+            null,
+            null,
+            10,
+            null);
+        _mediator.Send(Arg.Any<GetLibraryBrowseItems>(), Arg.Any<CancellationToken>())
+            .Returns(new PagedLibraryBrowseItemsResponseModel(1, [item]));
+
+        PagedLibraryBrowseItemsResponseModel result = await _controller.Browse(
+            cancellationToken: CancellationToken.None);
+
+        result.TotalCount.ShouldBe(1);
+        result.Page.ShouldBe([item]);
+    }
+}

ErsatzTV.Tests/Controllers/OpenApiErrorResponseContractTests.cs

@@ -102,6 +102,8 @@ public class OpenApiErrorResponseContractTests
     [TestCase("/api/channels/{id}", "get", "404")]
     [TestCase("/api/channels", "post", "404")]
     [TestCase("/api/channels", "post", "422")]
+    [TestCase("/api/channels/from-lineup", "post", "404")]
+    [TestCase("/api/channels/from-lineup", "post", "422")]
     [TestCase("/api/channels/{id}", "put", "404")]
     [TestCase("/api/channels/{id}", "put", "422")]
     [TestCase("/api/channels/{id}", "delete", "404")]
@@ -113,6 +115,16 @@ public class OpenApiErrorResponseContractTests
     [TestCase("/api/channels/bulk/delete", "post", "404")]
     [TestCase("/api/channels/bulk/delete", "post", "422")]
     [TestCase("/api/channels/{channelNumber}/playout/reset", "post", "404")]
+    [TestCase("/api/channel-templates/default", "get", "404")]
+    [TestCase("/api/channel-templates/default/{id}", "put", "404")]
+    [TestCase("/api/channel-templates/default/{id}", "put", "422")]
+    [TestCase("/api/channel-templates/{id}", "get", "404")]
+    [TestCase("/api/channel-templates", "post", "404")]
+    [TestCase("/api/channel-templates", "post", "422")]
+    [TestCase("/api/channel-templates/{id}", "put", "404")]
+    [TestCase("/api/channel-templates/{id}", "put", "422")]
+    [TestCase("/api/channel-templates/{id}", "delete", "404")]
+    [TestCase("/api/channel-templates/{id}", "delete", "422")]
     [TestCase("/api/collections/{id}", "get", "404")]
     [TestCase("/api/collections", "post", "404")]
     [TestCase("/api/collections", "post", "422")]

ErsatzTV.Tests/Infrastructure/DbInitializerChannelTemplateTests.cs

@@ -0,0 +1,51 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Tests.Support;
+using NUnit.Framework;
+using Shouldly;
+
+namespace ErsatzTV.Tests.Infrastructure;
+
+[TestFixture]
+public class DbInitializerChannelTemplateTests
+{
+    private InMemoryTvContext _db = null!;
+
+    [SetUp]
+    public async Task SetUp() => _db = await InMemoryTvContext.CreateAsync();
+
+    [TearDown]
+    public async Task TearDown() => await _db.DisposeAsync();
+
+    [Test]
+    public async Task Initialize_Should_Seed_System_Channel_Templates_And_Default_Config()
+    {
+        await using TvContext context = _db.CreateContext();
+
+        await DbInitializer.Initialize(context, CancellationToken.None);
+
+        List<ChannelTemplate> templates = context.ChannelTemplates.OrderBy(t => t.Name).ToList();
+        templates.Count.ShouldBe(2);
+        templates.ShouldContain(t => t.Name == "Music videos" && t.IsSystem);
+        ChannelTemplate standard = templates.Single(t => t.Name == "Standard");
+        standard.IsSystem.ShouldBeTrue();
+
+        ConfigElement config = context.ConfigElements.Single(
+            c => c.Key == ConfigElementKey.ChannelTemplatesDefaultTemplateId.Key);
+        config.Value.ShouldBe(standard.Id.ToString());
+    }
+
+    [Test]
+    public async Task Initialize_Should_Not_Clobber_Existing_System_Template()
+    {
+        await using TvContext context = _db.CreateContext();
+        await DbInitializer.Initialize(context, CancellationToken.None);
+        ChannelTemplate standard = context.ChannelTemplates.Single(t => t.Name == "Standard");
+        standard.Description = "User adjusted description";
+        await context.SaveChangesAsync();
+
+        await DbInitializer.Initialize(context, CancellationToken.None);
+
+        context.ChannelTemplates.Single(t => t.Name == "Standard").Description.ShouldBe("User adjusted description");
+    }
+}

ErsatzTV/Controllers/Api/ChannelController.cs

@@ -79,6 +79,32 @@ public class ChannelController(ChannelWriter<IBackgroundServiceRequest> workerCh
             });
     }
 
+    [HttpPost("/api/channels/from-lineup", Name = "CreateChannelFromLineup")]
+    [Tags("Channels")]
+    [EndpointSummary("Create a channel from a library lineup")]
+    [EndpointDescription(
+        "Atomically creates the channel, program schedule, a classic playout, and (for multi-item lineups) a " +
+        "generated system playlist. A single-item lineup produces one flood schedule item that references the " +
+        "target directly (movie, show, season, artist, collection, smart/multi collection, rerun collection, or " +
+        "playlist) and no generated playlist. A lineup with two or more items produces one generated system " +
+        "playlist whose entries play in the given order (each entry played in full before the next) referenced by " +
+        "one flood schedule item; only movies, shows, seasons, artists, collections, smart collections and multi " +
+        "collections are allowed there (rerun collections and playlists are single-item only). playbackOrder sets " +
+        "how items within each lineup entry are ordered. Template defaults are stamped at create time; advanced " +
+        "overrides win.")]
+    [EndpointGroupName("general")]
+    [ProducesResponseType(typeof(CreateChannelFromLineupResponseModel), StatusCodes.Status201Created)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status422UnprocessableEntity)]
+    public async Task<IActionResult> CreateFromLineup(
+        [Required] [FromBody] CreateChannelFromLineupRequest request,
+        CancellationToken cancellationToken)
+    {
+        Either<BaseError, CreateChannelFromLineupResponseModel> result =
+            await mediator.Send(request.ToCommand(), cancellationToken);
+        return result.ToCreatedResult(response => $"/api/channels/{response.ChannelId}", response => response);
+    }
+
     [HttpPut("/api/channels/{id:int}")]
     [Tags("Channels")]
     [EndpointSummary("Update a channel")]

ErsatzTV/Controllers/Api/ChannelTemplateController.cs

@@ -0,0 +1,109 @@
+using System.ComponentModel.DataAnnotations;
+using ErsatzTV.Application.ChannelTemplates;
+using ErsatzTV.Controllers.Api.Requests;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Api.ChannelTemplates;
+using ErsatzTV.Extensions;
+using MediatR;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+
+namespace ErsatzTV.Controllers.Api;
+
+[ApiController]
+public class ChannelTemplateController(IMediator mediator) : ControllerBase
+{
+    [HttpGet("/api/channel-templates", Name = "GetChannelTemplates")]
+    [Tags("Channel Templates")]
+    [EndpointSummary("Get all channel templates")]
+    [EndpointGroupName("general")]
+    [ProducesResponseType(typeof(List<ChannelTemplateResponseModel>), StatusCodes.Status200OK)]
+    public async Task<List<ChannelTemplateResponseModel>> GetAll(CancellationToken cancellationToken) =>
+        await mediator.Send(new GetAllChannelTemplates(), cancellationToken);
+
+    [HttpGet("/api/channel-templates/default", Name = "GetDefaultChannelTemplate")]
+    [Tags("Channel Templates")]
+    [EndpointSummary("Get the default channel template")]
+    [EndpointGroupName("general")]
+    [ProducesResponseType(typeof(ChannelTemplateResponseModel), StatusCodes.Status200OK)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
+    public async Task<IActionResult> GetDefault(CancellationToken cancellationToken)
+    {
+        Option<ChannelTemplateResponseModel> result =
+            await mediator.Send(new GetDefaultChannelTemplate(), cancellationToken);
+        return result.ToGetResult();
+    }
+
+    [HttpPut("/api/channel-templates/default/{id:int}", Name = "SetDefaultChannelTemplate")]
+    [Tags("Channel Templates")]
+    [EndpointSummary("Set the default channel template")]
+    [EndpointGroupName("general")]
+    [ProducesResponseType(typeof(ChannelTemplateResponseModel), StatusCodes.Status200OK)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status422UnprocessableEntity)]
+    public async Task<IActionResult> SetDefault(int id, CancellationToken cancellationToken)
+    {
+        Either<BaseError, ChannelTemplateResponseModel> result =
+            await mediator.Send(new SetDefaultChannelTemplate(id), cancellationToken);
+        return result.ToUpdatedResult();
+    }
+
+    [HttpGet("/api/channel-templates/{id:int}", Name = "GetChannelTemplateById")]
+    [Tags("Channel Templates")]
+    [EndpointSummary("Get a channel template by id")]
+    [EndpointGroupName("general")]
+    [ProducesResponseType(typeof(ChannelTemplateResponseModel), StatusCodes.Status200OK)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
+    public async Task<IActionResult> GetById(int id, CancellationToken cancellationToken)
+    {
+        Option<ChannelTemplateResponseModel> result =
+            await mediator.Send(new GetChannelTemplateById(id), cancellationToken);
+        return result.ToGetResult();
+    }
+
+    [HttpPost("/api/channel-templates", Name = "CreateChannelTemplate")]
+    [Tags("Channel Templates")]
+    [EndpointSummary("Create a channel template")]
+    [EndpointGroupName("general")]
+    [ProducesResponseType(typeof(ChannelTemplateResponseModel), StatusCodes.Status201Created)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status422UnprocessableEntity)]
+    public async Task<IActionResult> Create(
+        [Required] [FromBody] CreateChannelTemplateRequest request,
+        CancellationToken cancellationToken)
+    {
+        Either<BaseError, ChannelTemplateResponseModel> result =
+            await mediator.Send(request.ToCommand(), cancellationToken);
+        return result.ToCreatedResult(vm => $"/api/channel-templates/{vm.Id}", vm => vm);
+    }
+
+    [HttpPut("/api/channel-templates/{id:int}", Name = "UpdateChannelTemplate")]
+    [Tags("Channel Templates")]
+    [EndpointSummary("Update a channel template")]
+    [EndpointGroupName("general")]
+    [ProducesResponseType(typeof(ChannelTemplateResponseModel), StatusCodes.Status200OK)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status422UnprocessableEntity)]
+    public async Task<IActionResult> Update(
+        int id,
+        [Required] [FromBody] UpdateChannelTemplateRequest request,
+        CancellationToken cancellationToken)
+    {
+        Either<BaseError, ChannelTemplateResponseModel> result =
+            await mediator.Send(request.ToCommand(id), cancellationToken);
+        return result.ToUpdatedResult();
+    }
+
+    [HttpDelete("/api/channel-templates/{id:int}", Name = "DeleteChannelTemplate")]
+    [Tags("Channel Templates")]
+    [EndpointSummary("Delete a channel template")]
+    [EndpointGroupName("general")]
+    [ProducesResponseType(StatusCodes.Status204NoContent)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status422UnprocessableEntity)]
+    public async Task<IActionResult> Delete(int id, CancellationToken cancellationToken)
+    {
+        Either<BaseError, Unit> result = await mediator.Send(new DeleteChannelTemplate(id), cancellationToken);
+        return result.ToDeletedResult();
+    }
+}

ErsatzTV/Controllers/Api/LibraryBrowseController.cs

@@ -0,0 +1,33 @@
+using ErsatzTV.Application.LibraryBrowse;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using MediatR;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+
+namespace ErsatzTV.Controllers.Api;
+
+[ApiController]
+public class LibraryBrowseController(IMediator mediator) : ControllerBase
+{
+    private const int MaxPageSize = 100;
+
+    [HttpGet("/api/library/browse", Name = "BrowseLibrary")]
+    [Tags("Libraries")]
+    [EndpointSummary("Browse and search library items")]
+    [EndpointGroupName("general")]
+    [ProducesResponseType(typeof(PagedLibraryBrowseItemsResponseModel), StatusCodes.Status200OK)]
+    public async Task<PagedLibraryBrowseItemsResponseModel> Browse(
+        [FromQuery] string query = "",
+        [FromQuery] int? libraryId = null,
+        [FromQuery] LibraryBrowseMediaType? mediaType = null,
+        [FromQuery] int pageNum = 0,
+        [FromQuery] int pageSize = 100,
+        CancellationToken cancellationToken = default)
+    {
+        int clampedPageNum = Math.Max(0, pageNum);
+        int clampedPageSize = Math.Clamp(pageSize, 1, MaxPageSize);
+        return await mediator.Send(
+            new GetLibraryBrowseItems(query, libraryId, mediaType, clampedPageNum, clampedPageSize),
+            cancellationToken);
+    }
+}

ErsatzTV/Controllers/Api/Requests/CreateChannelFromLineupRequest.cs

@@ -0,0 +1,117 @@
+#nullable enable
+
+using ErsatzTV.Application.Artworks;
+using ErsatzTV.Application.Channels;
+using ErsatzTV.Core.Api.LibraryBrowse;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Controllers.Api.Requests;
+
+/// <summary>
+///     Composite request to create a channel, its generated schedule/playlist and a classic playout in one call.
+///     Template defaults are stamped at create time; any value set in <see cref="Advanced" /> overrides the template.
+///     A single-item lineup references its target directly; a multi-item lineup is played in order via a generated
+///     system playlist.
+/// </summary>
+public record CreateChannelFromLineupRequest(
+    string Name,
+    string Number,
+    string Group,
+    string Categories,
+    ArtworkContentTypeModel Logo,
+    bool IsEnabled,
+    bool ShowInEpg,
+    int TemplateId,
+    CreateChannelFromLineupAdvancedOptionsRequest? Advanced,
+    List<CreateChannelFromLineupItemRequest> Lineup)
+{
+    public CreateChannelFromLineup ToCommand() =>
+        new(
+            Name,
+            Number,
+            Group,
+            Categories,
+            Logo,
+            IsEnabled,
+            ShowInEpg,
+            TemplateId,
+            Advanced?.ToCommand() ?? new CreateChannelFromLineupAdvancedOptions(),
+            Lineup.Map(i => i.ToCommand()).ToList());
+}
+
+public record CreateChannelFromLineupAdvancedOptionsRequest(
+    PlaybackOrder? PlaybackOrder = null,
+    int? FFmpegProfileId = null,
+    int? WatermarkId = null,
+    int? FallbackFillerId = null,
+    int? PreRollFillerId = null,
+    int? MidRollFillerId = null,
+    int? PostRollFillerId = null,
+    ChannelStreamSelectorMode? StreamSelectorMode = null,
+    string? StreamSelector = null,
+    string? PreferredAudioLanguageCode = null,
+    string? PreferredAudioTitle = null,
+    ChannelPlayoutSource? PlayoutSource = null,
+    ChannelPlayoutMode? PlayoutMode = null,
+    StreamingMode? StreamingMode = null,
+    string? PreferredSubtitleLanguageCode = null,
+    ChannelSubtitleMode? SubtitleMode = null,
+    ChannelMusicVideoCreditsMode? MusicVideoCreditsMode = null,
+    string? MusicVideoCreditsTemplate = null,
+    ChannelSongVideoMode? SongVideoMode = null,
+    ChannelTranscodeMode? TranscodeMode = null,
+    ChannelIdleBehavior? IdleBehavior = null,
+    bool? ShuffleScheduleItems = null,
+    bool? RandomStartPoint = null,
+    FixedStartTimeBehavior? FixedStartTimeBehavior = null)
+{
+    public CreateChannelFromLineupAdvancedOptions ToCommand() =>
+        new(
+            PlaybackOrder,
+            FFmpegProfileId,
+            WatermarkId,
+            FallbackFillerId,
+            PreRollFillerId,
+            MidRollFillerId,
+            PostRollFillerId,
+            StreamSelectorMode,
+            StreamSelector,
+            PreferredAudioLanguageCode,
+            PreferredAudioTitle,
+            PlayoutSource,
+            PlayoutMode,
+            StreamingMode,
+            PreferredSubtitleLanguageCode,
+            SubtitleMode,
+            MusicVideoCreditsMode,
+            MusicVideoCreditsTemplate,
+            SongVideoMode,
+            TranscodeMode,
+            IdleBehavior,
+            ShuffleScheduleItems,
+            RandomStartPoint,
+            FixedStartTimeBehavior);
+}
+
+public record CreateChannelFromLineupItemRequest(
+    LibraryBrowseMediaType MediaType,
+    CollectionType CollectionType,
+    int? CollectionId,
+    int? MultiCollectionId,
+    int? SmartCollectionId,
+    int? RerunCollectionId,
+    int? MediaItemId,
+    int? PlaylistId)
+{
+    public CreateChannelFromLineupItem ToCommand() =>
+        new(
+            MediaType,
+            CollectionType,
+            CollectionId,
+            MultiCollectionId,
+            SmartCollectionId,
+            RerunCollectionId,
+            MediaItemId,
+            PlaylistId);
+}

ErsatzTV/Controllers/Api/Requests/CreateChannelTemplateRequest.cs

@@ -0,0 +1,63 @@
+#nullable enable
+
+using ErsatzTV.Application.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Controllers.Api.Requests;
+
+public record CreateChannelTemplateRequest(
+    string Name,
+    string Description,
+    int FFmpegProfileId,
+    int? WatermarkId,
+    int? FallbackFillerId,
+    int? PreRollFillerId,
+    int? MidRollFillerId,
+    int? PostRollFillerId,
+    ChannelStreamSelectorMode StreamSelectorMode,
+    string? StreamSelector,
+    string? PreferredAudioLanguageCode,
+    string? PreferredAudioTitle,
+    ChannelPlayoutSource PlayoutSource,
+    ChannelPlayoutMode PlayoutMode,
+    StreamingMode StreamingMode,
+    string? PreferredSubtitleLanguageCode,
+    ChannelSubtitleMode SubtitleMode,
+    ChannelMusicVideoCreditsMode MusicVideoCreditsMode,
+    string? MusicVideoCreditsTemplate,
+    ChannelSongVideoMode SongVideoMode,
+    ChannelTranscodeMode TranscodeMode,
+    ChannelIdleBehavior IdleBehavior,
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint,
+    FixedStartTimeBehavior FixedStartTimeBehavior)
+{
+    public CreateChannelTemplate ToCommand() =>
+        new(
+            Name,
+            Description,
+            FFmpegProfileId,
+            WatermarkId,
+            FallbackFillerId,
+            PreRollFillerId,
+            MidRollFillerId,
+            PostRollFillerId,
+            StreamSelectorMode,
+            StreamSelector,
+            PreferredAudioLanguageCode,
+            PreferredAudioTitle,
+            PlayoutSource,
+            PlayoutMode,
+            StreamingMode,
+            PreferredSubtitleLanguageCode,
+            SubtitleMode,
+            MusicVideoCreditsMode,
+            MusicVideoCreditsTemplate,
+            SongVideoMode,
+            TranscodeMode,
+            IdleBehavior,
+            ShuffleScheduleItems,
+            RandomStartPoint,
+            FixedStartTimeBehavior);
+}

ErsatzTV/Controllers/Api/Requests/UpdateChannelTemplateRequest.cs

@@ -0,0 +1,64 @@
+#nullable enable
+
+using ErsatzTV.Application.ChannelTemplates;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Controllers.Api.Requests;
+
+public record UpdateChannelTemplateRequest(
+    string Name,
+    string Description,
+    int FFmpegProfileId,
+    int? WatermarkId,
+    int? FallbackFillerId,
+    int? PreRollFillerId,
+    int? MidRollFillerId,
+    int? PostRollFillerId,
+    ChannelStreamSelectorMode StreamSelectorMode,
+    string? StreamSelector,
+    string? PreferredAudioLanguageCode,
+    string? PreferredAudioTitle,
+    ChannelPlayoutSource PlayoutSource,
+    ChannelPlayoutMode PlayoutMode,
+    StreamingMode StreamingMode,
+    string? PreferredSubtitleLanguageCode,
+    ChannelSubtitleMode SubtitleMode,
+    ChannelMusicVideoCreditsMode MusicVideoCreditsMode,
+    string? MusicVideoCreditsTemplate,
+    ChannelSongVideoMode SongVideoMode,
+    ChannelTranscodeMode TranscodeMode,
+    ChannelIdleBehavior IdleBehavior,
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint,
+    FixedStartTimeBehavior FixedStartTimeBehavior)
+{
+    public UpdateChannelTemplate ToCommand(int id) =>
+        new(
+            id,
+            Name,
+            Description,
+            FFmpegProfileId,
+            WatermarkId,
+            FallbackFillerId,
+            PreRollFillerId,
+            MidRollFillerId,
+            PostRollFillerId,
+            StreamSelectorMode,
+            StreamSelector,
+            PreferredAudioLanguageCode,
+            PreferredAudioTitle,
+            PlayoutSource,
+            PlayoutMode,
+            StreamingMode,
+            PreferredSubtitleLanguageCode,
+            SubtitleMode,
+            MusicVideoCreditsMode,
+            MusicVideoCreditsTemplate,
+            SongVideoMode,
+            TranscodeMode,
+            IdleBehavior,
+            ShuffleScheduleItems,
+            RandomStartPoint,
+            FixedStartTimeBehavior);
+}

ErsatzTV/TvContextDesignTimeFactory.cs

@@ -0,0 +1,61 @@
+using ErsatzTV.Infrastructure;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Design;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace ErsatzTV;
+
+public class TvContextDesignTimeFactory : IDesignTimeDbContextFactory<TvContext>
+{
+    public TvContext CreateDbContext(string[] args)
+    {
+        string provider = GetProvider(args);
+
+        var optionsBuilder = new DbContextOptionsBuilder<TvContext>();
+        if (provider.Equals("MySql", StringComparison.OrdinalIgnoreCase))
+        {
+            TvContext.IsSqlite = false;
+            TvContext.LastInsertedRowId = "last_insert_id()";
+            TvContext.CaseInsensitiveCollation = "utf8mb4_general_ci";
+            string connectionString =
+                Environment.GetEnvironmentVariable("MySql__ConnectionString") ??
+                "Server=localhost;Database=ersatztv_design_time;User=root;Password=ersatztv;";
+            optionsBuilder.UseMySql(
+                connectionString,
+                new MySqlServerVersion(new Version(8, 0, 36)),
+                builder => builder.MigrationsAssembly("ErsatzTV.Infrastructure.MySql"));
+        }
+        else
+        {
+            TvContext.IsSqlite = true;
+            TvContext.LastInsertedRowId = "last_insert_rowid()";
+            TvContext.CaseInsensitiveCollation = "NOCASE";
+            string configFolder = Environment.GetEnvironmentVariable("ETV_CONFIG_FOLDER");
+            string databasePath = string.IsNullOrWhiteSpace(configFolder)
+                ? Path.Combine(Path.GetTempPath(), "ersatztv-design-time.sqlite3")
+                : Path.Combine(configFolder, "ersatztv.sqlite3");
+            optionsBuilder.UseSqlite(
+                $"Data Source={databasePath}",
+                builder => builder.MigrationsAssembly("ErsatzTV.Infrastructure.Sqlite"));
+        }
+
+        return new TvContext(
+            optionsBuilder.Options,
+            NullLoggerFactory.Instance,
+            new SlowQueryInterceptor(NullLogger<SlowQueryInterceptor>.Instance));
+    }
+
+    private static string GetProvider(string[] args)
+    {
+        for (int index = 0; index < args.Length - 1; index++)
+        {
+            if (args[index].Equals("--provider", StringComparison.OrdinalIgnoreCase))
+            {
+                return args[index + 1];
+            }
+        }
+
+        return "Sqlite";
+    }
+}

docs/handoffs/chicorytv-issue-queue.md

@@ -5,131 +5,227 @@ UPDATING THIS FILE in place (rewrite the state section and the queue for the nex
 always holds the current handoff. History: created 2026-07-02 after the plan audit (#59 epic)
 filed backend gap issues #100–#111; a 7–9-way parallel workflow build once exhausted RAM, so
 builds are limited to 2–3 concurrent, never wide fan-outs. Backend gaps all landed by
-2026-07-04 (#105/#108/#100+#101+#107+#110/#103+#106/#104/#111/#102 → PRs #113–#119). The
-MERGE PASS (2026-07-04) then landed the whole SPA stack on main via PR #120.
+2026-07-04 (PRs #113–#119); merge pass PR #120; live-data screens: #109 Dashboard (PR #123),
+#84 Channels (PR #124), #86 Schedule editor (PR #125), #87 Playouts (PR #127), #88 Libraries
+(PR #128), #85 Guide/EPG (PR #129); #62 prerequisites: #65 library browse (PR #130), #64
+channel templates (PR #133).
 
-**Session state (2026-07-04, post-#121 merge)**: main = cc6ffcb8 (PR #121 "#99 direct
-stream session tracking"): design-system/ + web/ SPA foundation (#78–#83), backend
-#96/#98/#97, Dockerfile hotfix #122, and direct-stream session tracker #99 support are all
-on main. #97 is closed; #99 remains open for the final `/api/channels/state` wiring only
-(combine `IFFmpegSegmenterService.IsActive` with `IDirectStreamSessionTracker`). Test
-baselines on main after #121: ErsatzTV.Tests **368**, Core.Tests **493** (+1 skip); web/:
-`npm run typecheck` + `build` clean (outputs to ErsatzTV/wwwroot/app/, gitignored; SPA
-types = web/src/api/generated/v1.d.ts, regen via `npm run generate:api`). Post-merge main
-run 224 is fully green, including `Build & push image (amd64)`.
-- **#99 / PR #121 state**: merged after Fable APPROVE. Round-2 fixes removed
-  `DirectStreamSessionTracker` empty-dictionary pruning to avoid orphaned live sessions and
-  bypassed direct-session tracking for HEAD probes in `TrackedFileStreamResult`.
-- Worktrees: .worktrees/issue-99-session-tracking can be removed after this doc update;
-  issue-97/feat-102 removed. The main checkout still sits on docs/59-ui-redesign-brief —
-  fully merged now, safe to switch to main.
+**PROCESS (2026-07-05, binding)**: Fable writes each Codex prompt AND performs the PR review
+(via review subagents — parallel lenses: correctness fork + cheaper contract/tests +
+design-system agents; plus a fork verification pass over any fix diff). Codex implements.
+Every Codex prompt MUST mandate: (a) subagents where appropriate at fitting effort/model
+levels, (b) `npm ci` in each fresh worktree. Review-driven fixes are applied by fitting
+subagents too (NITS: Fable fixes on the branch; SUBSTANTIAL: back to Codex verbatim or fixed
+in-session — user decides). Merges need explicit user consent (standing consent for this
+stretch: merge when reviewers are happy and tests pass).
+
+**RELEASE CHECKPOINT (standing, added 2026-07-06)**: prod cutover to the fork is DONE —
+prod container `ersatztv` on bumblebee runs `192.168.1.95:3000/timothy/ersatztv:prod`
+(= v26.3.1, app-identical to upstream 26.3.0); `ersatztv-test` tracks `:latest` (main).
+Prod only advances on `v*` tags. At every milestone merge, FLAG THE USER: is this slice
+worth tagging **v26.4.0** (reserved for the first app-change release)? Latest sensible tag
+point is #91 (cutover); earlier if a stable API slice should reach prod sooner. Tagging
+needs explicit user consent; NEVER `[skip ci]` a commit you'll tag.
+
+**Session state (2026-07-06, post-#64)**: main = 4854c45a (PR #133 merged): `ChannelTemplate`
+domain entity — composition-by-reference (FFmpegProfileId + optional watermark/fallback/
+pre/mid/post-roll filler refs) plus stream/audio/playout/subtitle/music-video/transcode/idle/
+schedule defaults; `IsSystem` built-ins ("Standard", "Music videos") seeded idempotently in
+DbInitializer (user edits survive restarts, verified by test); default-template selection via
+ConfigElement `channel_templates.default_template_id`; 7 endpoints under /api/channel-templates
+(list/get/get-default/set-default/create/update/delete; delete rejects system + active
+default). FIRST FORK SCHEMA CHANGE: dual migrations `AddChannelTemplates` (SQLite
+20260706155532 / MySQL 20260706155538) + first `IDesignTimeDbContextFactory`
+(ErsatzTV/TvContextDesignTimeFactory.cs — lets `dotnet ef` run without a live MySQL).
+Fable review found 3 CONFIRMED (untrimmed-name uniqueness check → DbUpdateException/500;
+dead `.OrderBy(Name)` before SelectOneAsync in the default fallback; flat folder layout vs
+contributing §2) + nits; Codex fixed all in 1a61b89f (+ shared ChannelTemplateDefault helper,
+ConfigElementKey regrouped); deferred: Validation.Apply conversion (would erase NotFoundError
+→ breaks 404 mapping, stays early-return Option<BaseError>). #64 CLOSED. Templates are
+applied at channel-create time by #63 — NOT live-linked to channels (so #68 unblocked).
+Baselines: ErsatzTV.Tests **419**, Core.Tests **493** (+1 skip); web tests **80**. Main
+checkout sits on docs/59-ui-redesign-brief; .worktrees/issue-64-channel-templates is merged
+(remove it).
 
 **Lessons for all remaining prompts** (accumulated):
-- The image-build job runs ONLY on main pushes — PR CI cannot catch Dockerfile breakage.
-  Any Dockerfile change: verify base tags exist (hub.docker.com API) and, where docker is
-  available, `docker build --target <stage>` locally before merging. (`node:22-noble` cost
-  a red main run; node official images have no `-noble` variant.)
-- DTO records in ErsatzTV.Core/Api MUST get file-scoped `#nullable enable` — else the spec
-  emits `["null","string"]` unions and SPA types get needless `| null`. #96/#98 DTOs were
-  retrofitted in 8d89ab16; ChannelStateResponseModel complied from the start. NOTE:
-  ErsatzTV.Application has NO nullable context — `string?` there trips CS8632.
-- NSubstitute + ConfigElementKey: `ConfigElementKey.X` is a fresh instance per access —
-  stub with `Arg.Any<ConfigElementKey>()` disambiguated by the generic `<T>`.
-- `Option<T>.ToNullable()` doesn't exist here; use `MatchUnsafe(v => (T?)v, () => null)`.
-- ./scripts/update-openapi.sh only runs `-t:GenerateOpenApiDocuments` — do a normal
-  `dotnet build ErsatzTV/ErsatzTV.csproj` FIRST or it fails with MSB3680.
-- Id-taking child-collection GETs 404 on unknown parent via pre-check + ApiResults
-  (precedent: ScheduleController.GetItems) + an OpenApiErrorResponseContractTests entry.
-- Backlog nits (unfiled): unclamped pageSize on paged endpoints; PlayoutController
-  Create/Delete lack route Name=; PlayoutController.GetItems existence pre-check is heavy;
-  >30 MB uploads return bare Kestrel 413; artwork content-type trusted from client (#66);
-  schedule duration estimator: expression/zero Count → null estimate, materializes each
-  referenced collection per GET. From #102 (also on #85): GET /api/guide runs the full
-  21-include eager-load per channel per request — trim projection or add caching before the
-  EPG grid polls it; `fillerKind` is almost always `None` (projector merges filler into
-  adjacent programmes) — discrete filler entries need a JSON-only projection mode.
+- `SelectOneAsync` re-applies `.OrderBy(keySelector)` INTERNALLY, which REPLACES any ordering
+  the caller composed before it (#133) — never pre-`OrderBy` into SelectOneAsync; write the
+  explicit `.Where(...).OrderBy(...).FirstOrDefaultAsync(...)` when ordering matters.
+- Normalize user input ONCE (#133): validate uniqueness/lengths against the SAME normalized
+  (e.g. trimmed) value you persist, or a whitespace variant slips past validation and dies on
+  the unique index as an unhandled 500.
+- Application command/query records + handlers live in `<Domain>/Commands/` and
+  `<Domain>/Queries/` subfolders (contributing §2); namespace stays
+  `ErsatzTV.Application.<Domain>` regardless of subfolder (#133).
+- Deferral wording must ENUMERATE what is deferred (#130): "aggregate collection metadata is
+  deferred" quietly swallowed manual collections, which are a cheap direct join — the review
+  had to split the deferral. Cheap-vs-expensive is per collection kind, not per feature.
+- Merged-source paging pattern (#130): Lucene supplies media ids+total, EF supplies
+  collection-likes; page = media first, then a skip cascade through each collection type
+  (`remainingSkip`/`take` threading). Stale Lucene entries can drift collection paging for a
+  scan window — accepted, documented in-code. Any similar dual-source endpoint should copy
+  the GetLibraryBrowseItemsHandler pattern AND its multi-type-overflow paging test.
+- User text into BOTH Lucene and SQL needs per-side treatment (#130): raw query text is the
+  established Lucene idiom (parser falls back to escaped-literal on ParseException — malformed
+  input degrades to empty/literal results, never throws), but the same text in EF LIKE needs
+  `%`/`_`/escape-char escaping or semantics diverge between the two halves.
+- Direct `*Metadata` DbSet queries need a deterministic winner (#130): items can carry >1
+  metadata row; either go through the navigation + HeadOrNone() idiom or
+  GroupBy(itemId).OrderBy(Id).First().
+- NULL FIELDS ARE OMITTED ON THE WIRE (#129): Startup.cs sets Newtonsoft
+  `NullValueHandling.Ignore` globally, so any null DTO property is ABSENT from the JSON →
+  `undefined` in the browser, even though generated types say `| null`. Frontend guards must
+  use truthiness (`!x`), NEVER `=== null`; fixtures for null cases must OMIT the key (test
+  precedent: "renders the Guide screen when an on-air channel omits nowPlaying").
+- Cross-endpoint correlation needs shared ids (#129): /api/guide titles are show-only
+  (ChannelGuideMetadata.GetTitle) while /api/channels/state nowPlaying uses GetDisplayTitle
+  ("Show - s01e01 - Ep") — string matching across endpoints can never work for episodes.
+  Live match is now timestamps-only; the real fix is a shared programme/playout-item id on
+  both endpoints (backlog).
+- Fixture fidelity (#109/#127/#128): fixtures must be what the actually-called endpoint
+  returns UNDER THE QUERY THE CLIENT SENDS. `percent` is a 0–1 fraction despite its name.
+  Enum-with-None fields are never truthiness-checked. Verify UNITS/scale of numeric wire
+  fields against the producing code, not the field name.
+- Trigger≠started (#128): a 202/200 on a trigger endpoint means QUEUED; poll while
+  pending∪active nonempty with a grace window; drain grace on persistent errors.
+- setState updaters must be PURE — no fetches (#127), no ref mutations (#128); StrictMode
+  double-invokes updaters and the test renderer doesn't, so reviewers must catch it.
+- OpenAPI can UNDER-report the wire (#125/#126); check the serializer before widening types.
+- Every new multi-column grid → the @media (max-width: 980px) collapse block; var() fallback
+  = the token's resolved value; verify the token EXISTS (--ctv-surface-1, --text-faint don't).
+- Prototype affordances: implemented or VISIBLY deferred — never silently dropped.
+- Actionable = visible (#84); disable all mutation triggers while mutating; ref-based
+  double-submit guards; mutations never refetch the world (#125/#127).
+- Honest tests: no scenarios the backend can't produce (no exception middleware → failures
+  are BARE 4xx/5xx unless the controller returns ProblemDetails); mount call-counts assert
+  the DELTA across navigation; status-dot state never color-only (StatusDot has a label).
+- The image-build job runs ONLY on main pushes. DTO records in Core/Api need `#nullable
+  enable`; Application has NO nullable context. NSubstitute+ConfigElementKey:
+  `Arg.Any<ConfigElementKey>()` + `<T>`. `Option<T>.ToNullable()` → `MatchUnsafe`.
+  update-openapi.sh needs a prior normal build. Child GETs 404 unknown parents via pre-check.
+  Validation.Apply ERASES NotFoundError subtypes (#44 gotcha) — multi-check validation that
+  must 404 stays early-return.
+- Backlog nits (unfiled): unclamped pageSize (browse is clamped; older endpoints aren't);
+  PlayoutController Create/Delete lack Name=; heavy GetItems pre-check; >30 MB uploads →
+  bare 413; artwork content-type trusted (#66); schedule estimator materializes collections
+  per GET; /api/health TTL cache; `LibraryScanStatusResponseModel.percent` 0–1 under a
+  percent name; no Dialog/Modal component yet (needed by #89); 1 pre-existing --text-faint
+  usage in shell.css. From #129: shared programme/playout-item id on /api/guide +
+  /api/channels/state; extract the duplicated channel-state poll loop into a shared helper;
+  EPG grid re-renders unmemoized on every tick; /api/guide 21-include eager-load untrimmed.
+  From #130: the two manual-collection metadata helpers each fetch CollectionItems (share
+  one fetch); very large manual collections make the browse duration sum heavy. Filed: #126
+  (OpenAPI polymorphism gap).
 
 ---
 
-# PROMPT FOR CODEX — #109: Dashboard follow-up — replace stubbed data with real sources
+# PROMPT FOR CODEX — #63: composite "create channel from lineup" endpoint
 
-You are Codex working solo in /Users/timothy/ersatztv (ErsatzTV fork; the React SPA
-"ChicoryTV" lives in web/ — Vite + TS, typed client in web/src/api/, generated types
-web/src/api/generated/v1.d.ts). Read CLAUDE.md and docs/contributing.md first; follow the
-SPA foundation's existing patterns (#78–#83) — match, don't invent.
+You are Codex, the IMPLEMENTER, in /Users/timothy/ersatztv (ErsatzTV fork; .NET 10,
+CQRS/MediatR, LanguageExt, EF Core dual-provider). Fable (Claude) reviews your PR read-only
+afterwards — do NOT merge. Read CLAUDE.md and docs/contributing.md first; follow the REST
+API conventions from the #2a foundation (ApiResults, NotFoundError, request DTOs) — copy the
+patterns of existing controllers/handlers and their tests.
 
 HARD CONSTRAINTS:
-- Work in a NEW git worktree: `git worktree add .worktrees/issue-109-dashboard -b
-  feat/109-dashboard-data origin/main` (branch from origin/main; never touch the main
-  checkout or other .worktrees/*).
-- Max 2–3 concurrent builds machine-wide; keep to ONE dotnet build at a time here.
+- USE SUBAGENTS where appropriate, at fitting effort and model levels: cheap/fast agents for
+  mechanical work (DTO/test boilerplate, OpenAPI regen churn); higher-effort agents for
+  judgment work (transaction orchestration, template-defaults stamping).
+- Worktree: `git worktree add .worktrees/issue-63-composite-create -b feat/63-composite-create origin/main`.
+  Never touch the main checkout or other .worktrees/*. Run `npm ci` in web/ in the worktree
+  if you regen typegen.
+- Max 2–3 concurrent builds machine-wide; ONE dotnet build at a time here.
 - NEVER set ETV_UPDATE_GOLDENS. A golden-file diff means your code is wrong.
-- Do NOT merge anything. Open the PR, get CI green, and stop.
-- Backend scope guard: this is a FRONTEND issue. If a widget needs data no endpoint
-  provides, stub that widget's source cleanly and note it in the PR — do not add endpoints.
+- BACKEND-only; regenerating web/src/api/generated/v1.d.ts to prove typegen still works is
+  fine and encouraged.
+- NO schema change expected — this composes EXISTING entities. If you believe you need a
+  migration, STOP and justify on the issue first.
+- DTO records in ErsatzTV.Core/Api get file-scoped `#nullable enable`; Application has NO
+  nullable context. Command/query files go in `<Domain>/Commands|Queries/` subfolders.
 
-## Context
-- main = post-#120/#122/#121: full backend read API + SPA foundation + direct-stream
-  session tracking seam. Baselines: ErsatzTV.Tests 368, Core.Tests 493(+1 skip); web
-  `npm run typecheck` + `npm run build` clean.
-  Gitea: http://192.168.1.95:3000/timothy/ersatztv (basic auth timothy:ded89Lm4).
-- Issue #109: the Dashboard screen (#83) shipped with stubbed data. Replace the stubs with
-  the real sources now on main: /api/health (system health), /api/channels +
-  /api/channels/state (channel counts / on-air), /api/playouts (playout status),
-  /api/version. Read the issue body for the agreed widget list, and locate the stub layer
-  from #83 in web/src/ before writing anything.
-- CRITICAL (#108 lesson): GET /api/health re-runs all ~14 checks per request (only the
-  warn/error summary is cached) — fetch health ON DEMAND (mount + manual refresh), NOT on a
-  fast poll. If live health is wanted, that's a backend TTL-cache follow-up issue, not this
-  PR. Other widgets may poll gently (≥30s) if the design calls for it.
-- Note: /api/channels/state `onAir` is still segmenter-session-based until the final #99
-  wiring combines it with `IDirectStreamSessionTracker` — render it as-is; no workarounds.
+## Task
+Issue #63 (part of epic #62; the backend contract for the #89 Channel Builder): ONE API
+operation that atomically creates everything a working channel needs. Read the FULL issue
+body first. Deliver:
+- Accept: channel basics (name, number, group, image?, always-on?), `templateId` (from #64's
+  /api/channel-templates; default template pre-selected client-side) + optional "Advanced"
+  overrides for the template's knobs, shuffle/order mode, and an ORDERED lineup of library
+  item references (ids as produced by #65's /api/library/browse picker ids — movies, shows,
+  seasons, artists, collections, playlists; decide + document which kinds v1 accepts).
+- Create, in ONE transaction: Channel + Collection (from the lineup) + ProgramSchedule +
+  schedule items + Playout. Roll back cleanly on ANY failure — no orphan entities. State
+  your transaction strategy in the design comment (existing handlers SaveChanges eagerly —
+  you will likely need a single-handler orchestration inside one TvContext transaction
+  rather than chaining existing MediatR commands; check how PlayoutBuilder/rebuild is
+  normally triggered post-create and whether it belongs inside or after the transaction).
+- Apply the selected ChannelTemplate's defaults at create time (stamp values — NOT a live
+  link), with Advanced overrides winning over template values. Missing/deleted templateId →
+  404 via pre-check; invalid lineup ids → 404/422 with the item spelled out.
+- Validation per the #133 lessons: normalize name ONCE and check uniqueness against what you
+  persist; channel-number collision → clean 422.
+- Response: the created channel (existing ChannelResponseModel or a small composite response
+  with created ids — decide, justify, keep it #89-friendly).
+- Route Name= on the endpoint; OpenApiErrorResponseContractTests + ApiErrorResponseMetadataTests
+  entries for every documented 404/422; regenerate v1.json + v1.d.ts.
+- DESIGN FOR (don't implement): #89 wizard flow (template select → lineup pick → advanced
+  overrides → create); #71 (persistent shuffle) and #77 (clock-boundary padding) may add
+  knobs later — keep the request shape extensible.
+
+## Context (main = 4854c45a; baselines: ErsatzTV.Tests 419, Core.Tests 493+1skip, web 80)
+- Gitea: http://192.168.1.95:3000/timothy/ersatztv (basic auth timothy:ded89Lm4).
+- After code changes: normal `dotnet build ErsatzTV/ErsatzTV.csproj` FIRST, then
+  ./scripts/update-openapi.sh (regen is authoritative); commit the regenerated v1.json.
+- Study the Blazor create flows for what "a working channel" minimally needs (Channel editor,
+  Schedule editor, Playout add) — the composite must produce a channel that actually plays.
+- Templates: GET /api/channel-templates/{id} + ChannelTemplate entity (see PR #133) — fields
+  cover FFmpeg profile, watermark, fillers, stream/audio/subtitle/music-video/transcode/idle
+  + schedule defaults (shuffle etc.).
+- Test with the ErsatzTV.Tests harness precedents (NUnit + Shouldly + NSubstitute; SQLite
+  in-memory harness). Add a rollback test (fail mid-transaction → NOTHING persisted).
 
 ## Process
-1. Comment on issue #109 with findings + approach before coding.
-2. Implement: swap stubs for typed client calls (follow #81's client/query patterns);
-   loading/error/empty states per the design-system components. No `any` casts around
-   generated types.
-3. Verify: `cd web && npm ci && npm run typecheck && npm run build`; plus
-   `dotnet build ErsatzTV.sln` and TZ=UTC dotnet test of ErsatzTV.Tests + Core.Tests
-   (sequentially) to prove no backend regression (expect 364 / 488+1skip). If feasible, run
-   the SPA against a live backend (dotnet run + vite dev proxy) and sanity-check the
-   Dashboard renders real data.
-4. Push, open PR → main: `feat(web): Dashboard real data sources (#109)`, body lists each
-   widget → endpoint mapping and the health fetch policy; `closes #109`. Poll CI by head SHA
-   (/api/v1/repos/timothy/ersatztv/commits/<sha>/status) until green. Do not merge.
-5. Comment progress on #109 as you go.
+1. Comment on issue #63 with findings + approach (request/response DTO shape, accepted
+   lineup-id kinds, transaction strategy, playout-build timing, template stamping matrix)
+   BEFORE coding.
+2. Implement; comment progress on #63 as you go.
+3. Verify: TZ=UTC dotnet build ErsatzTV.sln; TZ=UTC dotnet test ErsatzTV.Tests then
+   ErsatzTV.Core.Tests sequentially (expect 419+new / 493+1skip); if v1.json changed,
+   cd web && npm ci && npm run generate:api && npm run typecheck (commit v1.d.ts).
+4. Push, open PR → main: "feat(api): composite create-channel endpoint (#63)", body lists
+   DTO shape + transaction strategy + template-stamping decisions; `closes #63`. Poll CI by
+   head SHA until green. Do NOT merge.
 
 ## On completion — REQUIRED final output
-Print a fenced handoff prompt addressed to Claude (Fable) asking it to:
-- Review the PR diff READ-ONLY in one Fable pass (endpoint usage correctness, health
-  polling discipline, type safety, design-system adherence, scope).
-- Classify findings: NITS Fable may fix directly on the branch; SUBSTANTIAL issues (wrong
-  data contracts, polling violations, state-management flaws) go back to Codex — Fable
-  composes a follow-up Codex prompt with the findings verbatim.
-- After review: comment the verdict on the PR and #109; on approval + user "merge" consent,
-  merge, verify main's post-merge run (image job included!), then update THIS handoff file
-  (pop #109, next prompt = #84 Channels screen for Codex, record PR number + main SHA +
-  baselines) and push it to main.
-Include: PR number, branch, head SHA, files changed, widget→endpoint mapping, test/web
-results, anything deferred or uncertain.
+Print a fenced handoff prompt addressed to Claude (Fable) asking it to review the PR
+READ-ONLY (Fable runs its own review subagents). Include: PR number, branch, head SHA, base,
+files changed, DTO/endpoint table, verification commands + results, deferred/uncertain list,
+and the finding classification (NITS = Fable fixes on the branch; SUBSTANTIAL = back to
+Codex verbatim or fixed in-session with subagents — user decides). After approval + user
+merge consent, Fable merges, verifies main's post-merge run (image job included), updates
+THIS handoff (pop #63, next prompt = #89 Channel Builder, record PR + main SHA + baselines),
+pushes it to main, AND raises the release checkpoint (see standing note above): with #62
+complete the API surface for #89 is done — ask the user whether to tag v26.4.0 now or wait
+for the SPA cutover (#91).
 
 ---
 
 ## Issue queue (work top-down)
-0. HOUSEKEEPING (carry into next session): remove .worktrees/issue-99-session-tracking when
-   no longer needed; #99 remains open for the final `/api/channels/state` onAir wiring.
-1. #109 Dashboard follow-up ← CODEX PROMPT above (review/merge/doc-update falls to the
-   Fable session that Codex's end-of-run handoff spawns).
-2. #84 Channels screen (deps #96/#98/#97 on main; live treatment via /api/channels/state —
-   note its onAir is segmenter-only until #99/#121 lands and gets wired).
-3. UX conversion order: #86 Schedule editor (#111 durations) → #87 Playouts → #88 Libraries
-   → #85 EPG (#102 JSON guide; mind fillerKind + per-request-cost notes above) → #89 Channel
-   Builder (#104 artwork upload; also needs #62: #63/#64/#65) → #93 Settings → #90 rebrand
-   → #91 cutover.
-Cross-refs: #99 direct-session tracking seam landed via PR #121; final channel-state wiring
-still open on #99. Done this pass: MERGE PASS → PR #120 (closed #97; #78–#83/#96/#98
-validated on main), hotfix PR #122 (Dockerfile node tag), PR #121 (direct-stream session
-tracking). Languages-list endpoint from #105 still unimplemented — open a follow-up when
-#86/#89 need it;
-filler/watermark lists return DB order — SPA should client-sort.
+0. HOUSEKEEPING: #99 stays open for the final /api/channels/state onAir wiring; #126
+   (OpenAPI polymorphism gap) is a good backend slot-filler between screens. Six Renovate/
+   dependency PRs are open (#21, #48, #49, #61, #131 security, #132) — cheap batch-merge
+   pass when convenient. MCP PR #76 (#58 read-only server foundation) predates most of the
+   API surface — needs a rebase/refresh pass; good parallel track once the API stops moving
+   (post-#63).
+1. #63 composite create-channel endpoint ← CODEX PROMPT above (last piece of epic #62;
+   unblocks #89; Fable reviews via subagents, merges on consent, updates this file, raises
+   the v26.4.0 release checkpoint).
+2. #89 Channel Builder (needs #63 + #64 ✓ + #65 ✓ + #104 artwork upload ✓; first
+   Dialog/Modal component; languages endpoint follow-up from #105 when needed). #66/#67 as
+   #89 demands.
+3. #93 Settings screen is dependency-free — usable as a frontend interleave if a backend
+   session needs review turnaround.
+4. Then: #90 rebrand → #91 cutover (+ tag v26.4.0 at the latest here — see RELEASE
+   CHECKPOINT note).
+Cross-refs: #99 seam landed (PR #121), final wiring open; #68 unblocked (templates stamp at
+create time, no live link). Done recently: PR #130 (#65 library browse), PR #133 (#64
+channel templates — closed 2026-07-06, main 4854c45a, fix delta 1a61b89f).

web/src/api/channels.ts

@@ -1,8 +1,176 @@
-import { request } from './client';
+import { useCallback, useEffect, useRef, useState } from 'react';
+import { ApiError, request } from './client';
 import type { components } from './generated/v1';
 
 export type ChannelSummary = components['schemas']['ChannelResponseModel'];
+export type ChannelState = components['schemas']['ChannelStateResponseModel'];
+export type BulkRenumberChannelsRequest = components['schemas']['BulkRenumberChannelsRequest'];
+export type BulkMoveChannelsToGroupRequest = components['schemas']['BulkMoveChannelsToGroupRequest'];
+export type BulkDeleteChannelsRequest = components['schemas']['BulkDeleteChannelsRequest'];
+
+export interface ChannelsScreenData {
+  channels: ChannelSummary[];
+  channelStates: ChannelState[];
+}
+
+export type ChannelsScreenQueryState =
+  | { data: ChannelsScreenData; error: null; refresh: () => void; status: 'success' }
+  | { data: null; error: string; refresh: () => void; status: 'error' }
+  | { data: null; error: null; refresh: () => void; status: 'loading' };
+
+type ChannelsScreenState =
+  | { data: ChannelsScreenData; error: null; status: 'success' }
+  | { data: null; error: string; status: 'error' }
+  | { data: null; error: null; status: 'loading' };
 
 export function getChannels(): Promise<ChannelSummary[]> {
   return request<ChannelSummary[]>('/api/channels');
 }
+
+export function getChannelStates(): Promise<ChannelState[]> {
+  return request<ChannelState[]>('/api/channels/state');
+}
+
+export async function getChannelsScreenData(): Promise<ChannelsScreenData> {
+  const [channels, channelStates] = await Promise.all([
+    getChannels(),
+    getChannelStates()
+  ]);
+
+  return { channels, channelStates };
+}
+
+export function bulkRenumberChannels(body: BulkRenumberChannelsRequest): Promise<void> {
+  return request<void>('/api/channels/bulk/renumber', {
+    body,
+    method: 'POST'
+  });
+}
+
+export function bulkMoveChannelsToGroup(body: BulkMoveChannelsToGroupRequest): Promise<void> {
+  return request<void>('/api/channels/bulk/group', {
+    body,
+    method: 'POST'
+  });
+}
+
+export function bulkDeleteChannels(body: BulkDeleteChannelsRequest): Promise<void> {
+  return request<void>('/api/channels/bulk/delete', {
+    body,
+    method: 'POST'
+  });
+}
+
+export function deleteChannel(channelId: number): Promise<void> {
+  return request<void>(`/api/channels/${channelId}`, {
+    method: 'DELETE'
+  });
+}
+
+export function useChannelsScreenQuery(pollMs = 30000): ChannelsScreenQueryState {
+  const [state, setState] = useState<ChannelsScreenState>({
+    data: null,
+    error: null,
+    status: 'loading'
+  });
+  const activeRef = useRef(true);
+
+  useEffect(() => {
+    activeRef.current = true;
+
+    return () => {
+      activeRef.current = false;
+    };
+  }, []);
+
+  const load = useCallback((showLoading = true) => {
+    if (showLoading) {
+      setState({ data: null, error: null, status: 'loading' });
+    }
+
+    getChannelsScreenData()
+      .then((data) => {
+        if (activeRef.current) {
+          setState({ data, error: null, status: 'success' });
+        }
+      })
+      .catch((error: unknown) => {
+        if (activeRef.current) {
+          setState({ data: null, error: messageFromError(error), status: 'error' });
+        }
+      });
+  }, []);
+
+  const loadChannelStates = useCallback(() => {
+    getChannelStates()
+      .then((channelStates) => {
+        if (activeRef.current) {
+          setState((current) => {
+            if (current.status !== 'success') {
+              return current;
+            }
+
+            return {
+              data: { ...current.data, channelStates },
+              error: null,
+              status: 'success'
+            };
+          });
+        }
+      })
+      .catch(() => {
+        // Keep the current table visible on background polling failures.
+      });
+  }, []);
+
+  useEffect(() => {
+    const loadForEffect = () => {
+      getChannelsScreenData()
+        .then((data) => {
+          if (activeRef.current) {
+            setState({ data, error: null, status: 'success' });
+          }
+        })
+        .catch((error: unknown) => {
+          if (activeRef.current) {
+            setState({ data: null, error: messageFromError(error), status: 'error' });
+          }
+        });
+    };
+
+    loadForEffect();
+    const intervalId = window.setInterval(() => {
+      loadChannelStates();
+    }, pollMs);
+
+    return () => {
+      window.clearInterval(intervalId);
+    };
+  }, [loadChannelStates, pollMs]);
+
+  const refresh = useCallback(() => {
+    load();
+  }, [load]);
+
+  if (state.status === 'success') {
+    return { data: state.data, error: null, refresh, status: 'success' };
+  }
+
+  if (state.status === 'error') {
+    return { data: null, error: state.error, refresh, status: 'error' };
+  }
+
+  return { data: null, error: null, refresh, status: 'loading' };
+}
+
+export function messageFromError(error: unknown): string {
+  if (error instanceof ApiError) {
+    return error.detail ?? error.message;
+  }
+
+  if (error instanceof Error) {
+    return error.message;
+  }
+
+  return 'Unable to load channels';
+}

web/src/api/generated/v1.d.ts

@@ -89,6 +89,36 @@ export interface components {
   };
     "ChannelStreamSelectorMode": "Default" | "Custom" | "Troubleshooting";
     "ChannelSubtitleMode": "None" | "Forced" | "Default" | "Any";
+    "ChannelTemplateResponseModel": {
+    "id": number;
+    "name": string;
+    "description": string;
+    "isSystem": boolean;
+    "isDefault": boolean;
+    "fFmpegProfileId": number;
+    "watermarkId": null | number;
+    "fallbackFillerId": null | number;
+    "preRollFillerId": null | number;
+    "midRollFillerId": null | number;
+    "postRollFillerId": null | number;
+    "streamSelectorMode": components["schemas"]["ChannelStreamSelectorMode"];
+    "streamSelector": null | string;
+    "preferredAudioLanguageCode": null | string;
+    "preferredAudioTitle": null | string;
+    "playoutSource": components["schemas"]["ChannelPlayoutSource"];
+    "playoutMode": components["schemas"]["ChannelPlayoutMode"];
+    "streamingMode": components["schemas"]["StreamingMode"];
+    "preferredSubtitleLanguageCode": null | string;
+    "subtitleMode": components["schemas"]["ChannelSubtitleMode"];
+    "musicVideoCreditsMode": components["schemas"]["ChannelMusicVideoCreditsMode"];
+    "musicVideoCreditsTemplate": null | string;
+    "songVideoMode": components["schemas"]["ChannelSongVideoMode"];
+    "transcodeMode": components["schemas"]["ChannelTranscodeMode"];
+    "idleBehavior": components["schemas"]["ChannelIdleBehavior"];
+    "shuffleScheduleItems": boolean;
+    "randomStartPoint": boolean;
+    "fixedStartTimeBehavior": components["schemas"]["FixedStartTimeBehavior"];
+  };
     "ChannelTranscodeMode": "OnDemand";
     "ChannelViewModel": {
     "id": number;
@@ -128,6 +158,60 @@ export interface components {
     "CombinedVersion": {
     "apiVersion": number;
     "appVersion": null | string;
+  };
+    "CreateChannelFromLineupAdvancedOptionsRequest": {
+    "playbackOrder"?: null | components["schemas"]["PlaybackOrder"];
+    "fFmpegProfileId"?: null | number;
+    "watermarkId"?: null | number;
+    "fallbackFillerId"?: null | number;
+    "preRollFillerId"?: null | number;
+    "midRollFillerId"?: null | number;
+    "postRollFillerId"?: null | number;
+    "streamSelectorMode"?: null | components["schemas"]["ChannelStreamSelectorMode"];
+    "streamSelector"?: null | string;
+    "preferredAudioLanguageCode"?: null | string;
+    "preferredAudioTitle"?: null | string;
+    "playoutSource"?: null | components["schemas"]["ChannelPlayoutSource"];
+    "playoutMode"?: null | components["schemas"]["ChannelPlayoutMode"];
+    "streamingMode"?: null | components["schemas"]["StreamingMode"];
+    "preferredSubtitleLanguageCode"?: null | string;
+    "subtitleMode"?: null | components["schemas"]["ChannelSubtitleMode"];
+    "musicVideoCreditsMode"?: null | components["schemas"]["ChannelMusicVideoCreditsMode"];
+    "musicVideoCreditsTemplate"?: null | string;
+    "songVideoMode"?: null | components["schemas"]["ChannelSongVideoMode"];
+    "transcodeMode"?: null | components["schemas"]["ChannelTranscodeMode"];
+    "idleBehavior"?: null | components["schemas"]["ChannelIdleBehavior"];
+    "shuffleScheduleItems"?: null | boolean;
+    "randomStartPoint"?: null | boolean;
+    "fixedStartTimeBehavior"?: null | components["schemas"]["FixedStartTimeBehavior"];
+  };
+    "CreateChannelFromLineupItemRequest": {
+    "mediaType": components["schemas"]["LibraryBrowseMediaType"];
+    "collectionType": components["schemas"]["CollectionType"];
+    "collectionId": null | number;
+    "multiCollectionId": null | number;
+    "smartCollectionId": null | number;
+    "rerunCollectionId": null | number;
+    "mediaItemId": null | number;
+    "playlistId": null | number;
+  };
+    "CreateChannelFromLineupRequest": {
+    "name": string;
+    "number": string;
+    "group": string;
+    "categories": string;
+    "logo": components["schemas"]["ArtworkContentTypeModel"];
+    "isEnabled": boolean;
+    "showInEpg": boolean;
+    "templateId": number;
+    "advanced": null | components["schemas"]["CreateChannelFromLineupAdvancedOptionsRequest"];
+    "lineup": Array<components["schemas"]["CreateChannelFromLineupItemRequest"]>;
+  };
+    "CreateChannelFromLineupResponseModel": {
+    "channelId": number;
+    "playlistId": null | number;
+    "programScheduleId": number;
+    "playoutId": number;
   };
     "CreateChannelRequest": {
     "name": null | string;
@@ -157,6 +241,33 @@ export interface components {
     "idleBehavior": components["schemas"]["ChannelIdleBehavior"];
     "isEnabled": boolean;
     "showInEpg": boolean;
+  };
+    "CreateChannelTemplateRequest": {
+    "name": string;
+    "description": string;
+    "fFmpegProfileId": number;
+    "watermarkId": null | number;
+    "fallbackFillerId": null | number;
+    "preRollFillerId": null | number;
+    "midRollFillerId": null | number;
+    "postRollFillerId": null | number;
+    "streamSelectorMode": components["schemas"]["ChannelStreamSelectorMode"];
+    "streamSelector": null | string;
+    "preferredAudioLanguageCode": null | string;
+    "preferredAudioTitle": null | string;
+    "playoutSource": components["schemas"]["ChannelPlayoutSource"];
+    "playoutMode": components["schemas"]["ChannelPlayoutMode"];
+    "streamingMode": components["schemas"]["StreamingMode"];
+    "preferredSubtitleLanguageCode": null | string;
+    "subtitleMode": components["schemas"]["ChannelSubtitleMode"];
+    "musicVideoCreditsMode": components["schemas"]["ChannelMusicVideoCreditsMode"];
+    "musicVideoCreditsTemplate": null | string;
+    "songVideoMode": components["schemas"]["ChannelSongVideoMode"];
+    "transcodeMode": components["schemas"]["ChannelTranscodeMode"];
+    "idleBehavior": components["schemas"]["ChannelIdleBehavior"];
+    "shuffleScheduleItems": boolean;
+    "randomStartPoint": boolean;
+    "fixedStartTimeBehavior": components["schemas"]["FixedStartTimeBehavior"];
   };
     "CreateCollectionRequest": {
     "name": null | string;
@@ -292,6 +403,25 @@ export interface components {
     "lastAccess": string;
   };
     "IFormFile": string;
+    "LibraryBrowseItemResponseModel": {
+    "id": number;
+    "mediaType": components["schemas"]["LibraryBrowseMediaType"];
+    "title": string;
+    "libraryId": null | number;
+    "libraryName": null | string;
+    "artwork": string;
+    "duration": null | string;
+    "itemCount": null | number;
+    "collectionKind": null | string;
+    "collectionType": components["schemas"]["CollectionType"];
+    "collectionId": null | number;
+    "multiCollectionId": null | number;
+    "smartCollectionId": null | number;
+    "rerunCollectionId": null | number;
+    "mediaItemId": null | number;
+    "playlistId": null | number;
+  };
+    "LibraryBrowseMediaType": "Movie" | "TelevisionShow" | "TelevisionSeason" | "Artist" | "Collection" | "SmartCollection" | "MultiCollection" | "RerunCollection" | "Playlist";
     "LibraryMediaKind": "Movies" | "Shows" | "MusicVideos" | "OtherVideos" | "Songs" | "Images" | "RemoteStreams";
     "LibraryScanStatusResponseModel": {
     "libraryId": number;
@@ -350,6 +480,10 @@ export interface components {
     "name": null | string;
   };
     "NormalizeLoudnessMode": "Off" | "LoudNorm";
+    "PagedLibraryBrowseItemsResponseModel": {
+    "totalCount": number;
+    "page": Array<components["schemas"]["LibraryBrowseItemResponseModel"]>;
+  };
     "PagedPlayoutItemsResponseModel": {
     "totalCount": number;
     "page": null | Array<components["schemas"]["PlayoutItemResponseModel"]>;
@@ -564,6 +698,33 @@ export interface components {
     "idleBehavior": components["schemas"]["ChannelIdleBehavior"];
     "isEnabled": boolean;
     "showInEpg": boolean;
+  };
+    "UpdateChannelTemplateRequest": {
+    "name": string;
+    "description": string;
+    "fFmpegProfileId": number;
+    "watermarkId": null | number;
+    "fallbackFillerId": null | number;
+    "preRollFillerId": null | number;
+    "midRollFillerId": null | number;
+    "postRollFillerId": null | number;
+    "streamSelectorMode": components["schemas"]["ChannelStreamSelectorMode"];
+    "streamSelector": null | string;
+    "preferredAudioLanguageCode": null | string;
+    "preferredAudioTitle": null | string;
+    "playoutSource": components["schemas"]["ChannelPlayoutSource"];
+    "playoutMode": components["schemas"]["ChannelPlayoutMode"];
+    "streamingMode": components["schemas"]["StreamingMode"];
+    "preferredSubtitleLanguageCode": null | string;
+    "subtitleMode": components["schemas"]["ChannelSubtitleMode"];
+    "musicVideoCreditsMode": components["schemas"]["ChannelMusicVideoCreditsMode"];
+    "musicVideoCreditsTemplate": null | string;
+    "songVideoMode": components["schemas"]["ChannelSongVideoMode"];
+    "transcodeMode": components["schemas"]["ChannelTranscodeMode"];
+    "idleBehavior": components["schemas"]["ChannelIdleBehavior"];
+    "shuffleScheduleItems": boolean;
+    "randomStartPoint": boolean;
+    "fixedStartTimeBehavior": components["schemas"]["FixedStartTimeBehavior"];
   };
     "UpdateCollectionRequest": {
     "name": null | string;

web/src/api/guide.ts

@@ -0,0 +1,159 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+import { getChannelStates, messageFromError, type ChannelState } from './channels';
+import { request } from './client';
+import type { components } from './generated/v1';
+
+export type ChannelGuide = components['schemas']['ChannelGuideResponseModel'];
+export type ChannelGuideChannel = components['schemas']['ChannelGuideChannelResponseModel'];
+export type ChannelGuideProgramme = components['schemas']['ChannelGuideProgrammeResponseModel'];
+
+export interface GuideScreenData {
+  channelStates: ChannelState[];
+  guide: ChannelGuide;
+}
+
+export type GuideScreenQueryState =
+  | {
+      data: GuideScreenData;
+      error: null;
+      refresh: () => void;
+      setWindowStart: (start: Date) => void;
+      status: 'success';
+      windowStart: Date;
+      windowEnd: Date;
+    }
+  | { data: null; error: string; refresh: () => void; status: 'error'; windowStart: Date; windowEnd: Date }
+  | { data: null; error: null; refresh: () => void; status: 'loading'; windowStart: Date; windowEnd: Date };
+
+type GuideScreenState =
+  | { data: GuideScreenData; error: null; status: 'success' }
+  | { data: null; error: string; status: 'error' }
+  | { data: null; error: null; status: 'loading' };
+
+export const GUIDE_PAST_MS = 60 * 60 * 1000;
+export const GUIDE_WINDOW_MS = 13 * 60 * 60 * 1000;
+
+export function defaultGuideWindowStart(now = new Date()): Date {
+  return new Date(now.getTime() - GUIDE_PAST_MS);
+}
+
+export function getGuide(start: Date, end: Date): Promise<ChannelGuide> {
+  const query = new URLSearchParams({
+    start: start.toISOString(),
+    end: end.toISOString()
+  });
+
+  return request<ChannelGuide>(`/api/guide?${query.toString()}`);
+}
+
+export async function getGuideScreenData(start: Date, end: Date): Promise<GuideScreenData> {
+  const guide = await getGuide(start, end);
+  const channelStates = await getChannelStates().catch(() => []);
+
+  return { channelStates, guide };
+}
+
+export function useGuideScreenQuery(channelStatePollMs = 30000): GuideScreenQueryState {
+  const [windowStart, setWindowStartState] = useState(() => defaultGuideWindowStart());
+  const windowStartRef = useRef(windowStart);
+  const [state, setState] = useState<GuideScreenState>({
+    data: null,
+    error: null,
+    status: 'loading'
+  });
+  const activeRef = useRef(true);
+  const requestIdRef = useRef(0);
+
+  useEffect(() => {
+    activeRef.current = true;
+
+    return () => {
+      activeRef.current = false;
+    };
+  }, []);
+
+  const windowEnd = new Date(windowStart.getTime() + GUIDE_WINDOW_MS);
+
+  const load = useCallback((start = windowStartRef.current) => {
+    const end = new Date(start.getTime() + GUIDE_WINDOW_MS);
+    const requestId = requestIdRef.current + 1;
+    requestIdRef.current = requestId;
+
+    getGuideScreenData(start, end)
+      .then((data) => {
+        if (
+          activeRef.current &&
+          requestIdRef.current === requestId &&
+          windowStartRef.current.getTime() === start.getTime()
+        ) {
+          setState({ data, error: null, status: 'success' });
+        }
+      })
+      .catch((error: unknown) => {
+        if (
+          activeRef.current &&
+          requestIdRef.current === requestId &&
+          windowStartRef.current.getTime() === start.getTime()
+        ) {
+          setState({ data: null, error: messageFromError(error), status: 'error' });
+        }
+      });
+  }, []);
+
+  const loadChannelStates = useCallback(() => {
+    getChannelStates()
+      .then((channelStates) => {
+        if (!activeRef.current) {
+          return;
+        }
+
+        setState((current) => {
+          if (current.status !== 'success') {
+            return current;
+          }
+
+          return {
+            data: { ...current.data, channelStates },
+            error: null,
+            status: 'success'
+          };
+        });
+      })
+      .catch(() => {
+        // Keep the guide visible when the optional live-state refresh fails.
+      });
+  }, []);
+
+  useEffect(() => {
+    load(windowStart);
+  }, [load, windowStart]);
+
+  useEffect(() => {
+    const intervalId = window.setInterval(loadChannelStates, Math.max(channelStatePollMs, 30000));
+
+    return () => {
+      window.clearInterval(intervalId);
+    };
+  }, [channelStatePollMs, loadChannelStates]);
+
+  const setWindowStart = useCallback((start: Date) => {
+    windowStartRef.current = start;
+    setState({ data: null, error: null, status: 'loading' });
+    setWindowStartState(start);
+  }, []);
+
+  const refresh = useCallback(() => {
+    setState({ data: null, error: null, status: 'loading' });
+    load(windowStartRef.current);
+  }, [load]);
+
+  if (state.status === 'success') {
+    return { data: state.data, error: null, refresh, setWindowStart, status: 'success', windowEnd, windowStart };
+  }
+
+  if (state.status === 'error') {
+    return { data: null, error: state.error, refresh, status: 'error', windowEnd, windowStart };
+  }
+
+  return { data: null, error: null, refresh, status: 'loading', windowEnd, windowStart };
+}

web/src/api/index.ts

@@ -2,4 +2,8 @@ export * from './auth';
 export * from './channels';
 export * from './client';
 export * from './dashboard';
+export * from './guide';
+export * from './libraries';
+export * from './playouts';
+export * from './schedules';
 export * from './useChannelsQuery';

web/src/api/libraries.ts

@@ -0,0 +1,337 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+import { ApiError, request } from './client';
+import type { components } from './generated/v1';
+
+export type MediaSource = components['schemas']['MediaSourceResponseModel'];
+export type MediaSourceLibrary = components['schemas']['MediaSourceLibraryResponseModel'];
+export type LibraryScanStatus = components['schemas']['LibraryScanStatusResponseModel'];
+
+export interface LibrariesScreenData {
+  scanStatuses: LibraryScanStatus[];
+  sources: MediaSource[];
+}
+
+export type LibrariesScreenQueryState =
+  | {
+      data: LibrariesScreenData;
+      error: string | null;
+      refresh: () => void;
+      scanLibrary: (libraryId: number) => Promise<void>;
+      scanningLibraryIds: Set<number>;
+      status: 'success';
+    }
+  | { data: null; error: string; refresh: () => void; status: 'error' }
+  | { data: null; error: null; refresh: () => void; status: 'loading' };
+
+type LibrariesScreenState =
+  | { data: LibrariesScreenData; error: string | null; pendingLibraryIds: Set<number>; status: 'success' }
+  | { data: null; error: string; status: 'error' }
+  | { data: null; error: null; status: 'loading' };
+
+// A trigger'd scan disappears from the button-disabled set once either: it has been
+// observed at least once in scan-status (promoted to "active"), or this many poll
+// ticks pass without ever appearing (the scanner never picked it up / it failed silently).
+const PENDING_GRACE_TICKS = 3;
+
+export function getMediaSources(): Promise<MediaSource[]> {
+  return request<MediaSource[]>('/api/media-sources');
+}
+
+export function getLibraryScanStatus(): Promise<LibraryScanStatus[]> {
+  // Wire contract: `percent` is a 0-1 FRACTION despite the field name - the backend
+  // never multiplies by 100 (known backend wart, tracked in the handoff backlog).
+  // Normalize to a 0-100 percentage once, here at the API boundary, so every
+  // consumer (ProgressBar, percent labels) works in ordinary percentage terms.
+  return request<LibraryScanStatus[]>('/api/libraries/scan-status').then((scanStatuses) =>
+    scanStatuses.map((scanStatus) => ({ ...scanStatus, percent: scanStatus.percent * 100 }))
+  );
+}
+
+export function scanLibrary(libraryId: number): Promise<void> {
+  return request<void>(`/api/libraries/${libraryId}/scan`, { method: 'POST' });
+}
+
+// Pure: computes the surviving pending-id set for one poll tick (success or failure) and
+// mutates the grace-ticks map in place (delete on promote/expire, set on decrement) -
+// callers must still write pendingIdsRef.current with the returned set themselves, and
+// must call this exactly once per tick before that write to keep it a single, ref-free
+// computation that's safe to run under StrictMode double-invocation.
+function pruneGraceExpiredPending(
+  pendingIds: Set<number>,
+  graceTicks: Map<number, number>,
+  isSeenActive: (libraryId: number) => boolean
+): Set<number> {
+  const nextPending = new Set<number>();
+
+  pendingIds.forEach((libraryId) => {
+    if (isSeenActive(libraryId)) {
+      // Seen active at least once - normal active/inactive pruning takes over.
+      graceTicks.delete(libraryId);
+      return;
+    }
+
+    const ticksRemaining = (graceTicks.get(libraryId) ?? PENDING_GRACE_TICKS) - 1;
+
+    if (ticksRemaining <= 0) {
+      // Grace window expired without ever appearing in scan-status - give up on it.
+      graceTicks.delete(libraryId);
+      return;
+    }
+
+    graceTicks.set(libraryId, ticksRemaining);
+    nextPending.add(libraryId);
+  });
+
+  return nextPending;
+}
+
+export function useLibrariesScreenQuery(pollMs = 10000): LibrariesScreenQueryState {
+  const [state, setState] = useState<LibrariesScreenState>({
+    data: null,
+    error: null,
+    status: 'loading'
+  });
+  const activeRef = useRef(true);
+  const hadScanInProgressRef = useRef(false);
+  // Mirrors of the corresponding state, kept in sync synchronously so triggerScan can
+  // guard against double-submits without waiting for a render.
+  const pendingIdsRef = useRef<Set<number>>(new Set());
+  const activeIdsRef = useRef<Set<number>>(new Set());
+  const pendingGraceTicksRef = useRef<Map<number, number>>(new Map());
+
+  useEffect(() => {
+    activeRef.current = true;
+
+    return () => {
+      activeRef.current = false;
+    };
+  }, []);
+
+  const loadSources = useCallback(() => {
+    getMediaSources()
+      .then((sources) => {
+        if (!activeRef.current) {
+          return;
+        }
+
+        setState((current) => {
+          if (current.status !== 'success') {
+            return current;
+          }
+
+          return {
+            data: { scanStatuses: current.data.scanStatuses, sources },
+            error: null,
+            pendingLibraryIds: current.pendingLibraryIds,
+            status: 'success'
+          };
+        });
+      })
+      .catch(() => {
+        // A completion refresh should not hide the screen if the source reload fails.
+      });
+  }, []);
+
+  const loadScanStatuses = useCallback(() => {
+    return getLibraryScanStatus()
+      .then((scanStatuses) => {
+        if (!activeRef.current) {
+          return;
+        }
+
+        const activeScanIds = new Set(scanStatuses.map((scan) => scan.libraryId));
+        activeIdsRef.current = activeScanIds;
+
+        const hadScanInProgress = hadScanInProgressRef.current;
+        hadScanInProgressRef.current = scanStatuses.length > 0;
+
+        // Compute the pruned/promoted pending set - and write the grace-tick and pending
+        // refs - OUTSIDE the setState updater. Updaters must be pure: StrictMode double-
+        // invokes them (which would double-decrement grace ticks) and concurrent rendering
+        // may invoke-and-discard one. Mirrors how activeIdsRef is written above.
+        const nextPending = pruneGraceExpiredPending(pendingIdsRef.current, pendingGraceTicksRef.current, (libraryId) =>
+          activeScanIds.has(libraryId)
+        );
+
+        pendingIdsRef.current = nextPending;
+
+        setState((current) => {
+          if (current.status !== 'success') {
+            return current;
+          }
+
+          return {
+            data: { scanStatuses, sources: current.data.sources },
+            error: null,
+            pendingLibraryIds: nextPending,
+            status: 'success'
+          };
+        });
+
+        if (hadScanInProgress && scanStatuses.length === 0) {
+          loadSources();
+        }
+      })
+      .catch(() => {
+        if (!activeRef.current) {
+          return;
+        }
+
+        // A status-fetch failure never promotes a pending id to active, so it never
+        // survives via "seen active" - it just burns down the same grace budget as a
+        // successful poll that never saw it. This keeps a persistently-erroring endpoint
+        // from leaving the scan button disabled and the poll interval running forever.
+        // Active-scan state (activeIdsRef / scanStatuses) is left untouched: a transient
+        // failure must not kill an in-progress scan's UI.
+        const nextPending = pruneGraceExpiredPending(pendingIdsRef.current, pendingGraceTicksRef.current, () => false);
+
+        pendingIdsRef.current = nextPending;
+
+        setState((current) => {
+          if (current.status !== 'success') {
+            return current;
+          }
+
+          return {
+            data: current.data,
+            error: current.error,
+            pendingLibraryIds: nextPending,
+            status: 'success'
+          };
+        });
+      });
+  }, [loadSources]);
+
+  const load = useCallback(() => {
+    Promise.all([getMediaSources(), getLibraryScanStatus()])
+      .then(([sources, scanStatuses]) => {
+        if (!activeRef.current) {
+          return;
+        }
+
+        hadScanInProgressRef.current = scanStatuses.length > 0;
+        pendingIdsRef.current = new Set();
+        activeIdsRef.current = new Set(scanStatuses.map((scan) => scan.libraryId));
+        pendingGraceTicksRef.current = new Map();
+        setState({
+          data: { scanStatuses, sources },
+          error: null,
+          pendingLibraryIds: new Set(),
+          status: 'success'
+        });
+      })
+      .catch((error: unknown) => {
+        if (activeRef.current) {
+          setState({ data: null, error: messageFromLibrariesError(error, 'Unable to load libraries'), status: 'error' });
+        }
+      });
+  }, []);
+
+  useEffect(() => {
+    load();
+  }, [load]);
+
+  const hasActiveScans =
+    state.status === 'success' && (state.pendingLibraryIds.size > 0 || state.data.scanStatuses.length > 0);
+
+  useEffect(() => {
+    if (!hasActiveScans) {
+      return undefined;
+    }
+
+    const intervalId = window.setInterval(loadScanStatuses, Math.max(pollMs, 10000));
+
+    return () => {
+      window.clearInterval(intervalId);
+    };
+  }, [hasActiveScans, loadScanStatuses, pollMs]);
+
+  const refresh = useCallback(() => {
+    setState({ data: null, error: null, status: 'loading' });
+    load();
+  }, [load]);
+
+  const triggerScan = useCallback((libraryId: number): Promise<void> => {
+    if (pendingIdsRef.current.has(libraryId) || activeIdsRef.current.has(libraryId)) {
+      // Already pending or active - ignore the duplicate submission.
+      return Promise.resolve();
+    }
+
+    pendingIdsRef.current = new Set(pendingIdsRef.current).add(libraryId);
+    pendingGraceTicksRef.current.set(libraryId, PENDING_GRACE_TICKS);
+
+    setState((current) => {
+      if (current.status !== 'success') {
+        return current;
+      }
+
+      return {
+        data: current.data,
+        error: null,
+        pendingLibraryIds: new Set(current.pendingLibraryIds).add(libraryId),
+        status: 'success'
+      };
+    });
+
+    return scanLibrary(libraryId)
+      .then(() => loadScanStatuses())
+      .catch((error: unknown) => {
+        const pendingIds = new Set(pendingIdsRef.current);
+        pendingIds.delete(libraryId);
+        pendingIdsRef.current = pendingIds;
+        pendingGraceTicksRef.current.delete(libraryId);
+
+        if (!activeRef.current) {
+          return;
+        }
+
+        setState((current) => {
+          if (current.status !== 'success') {
+            return current;
+          }
+
+          const pendingLibraryIds = new Set(current.pendingLibraryIds);
+          pendingLibraryIds.delete(libraryId);
+
+          return {
+            data: current.data,
+            error: messageFromLibrariesError(error, 'Unable to scan library'),
+            pendingLibraryIds,
+            status: 'success'
+          };
+        });
+      });
+  }, [loadScanStatuses]);
+
+  if (state.status === 'success') {
+    const activeLibraryIds = new Set(state.data.scanStatuses.map((scan) => scan.libraryId));
+    const scanningLibraryIds = new Set([...state.pendingLibraryIds, ...activeLibraryIds]);
+
+    return {
+      data: state.data,
+      error: state.error,
+      refresh,
+      scanLibrary: triggerScan,
+      scanningLibraryIds,
+      status: 'success'
+    };
+  }
+
+  if (state.status === 'error') {
+    return { data: null, error: state.error, refresh, status: 'error' };
+  }
+
+  return { data: null, error: null, refresh, status: 'loading' };
+}
+
+function messageFromLibrariesError(error: unknown, fallback = 'Unable to load libraries'): string {
+  if (error instanceof ApiError) {
+    return error.detail ?? error.message;
+  }
+
+  if (error instanceof Error) {
+    return error.message;
+  }
+
+  return fallback;
+}

web/src/api/playouts.ts

@@ -0,0 +1,321 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+import { ApiError, request } from './client';
+import type { components } from './generated/v1';
+
+export type PlayoutSummary = components['schemas']['PlayoutListItemResponseModel'];
+export type PlayoutDetail = components['schemas']['PlayoutResponseModel'];
+export type PlayoutItem = components['schemas']['PlayoutItemResponseModel'];
+export type PlayoutsPage = components['schemas']['PagedPlayoutsResponseModel'];
+export type PlayoutItemsPage = components['schemas']['PagedPlayoutItemsResponseModel'];
+export type PlayoutChannelState = components['schemas']['ChannelStateResponseModel'];
+
+export interface PlayoutsScreenData {
+  channelStates: PlayoutChannelState[];
+  items: PlayoutItem[];
+  playout: PlayoutDetail | null;
+  playouts: PlayoutSummary[];
+  selectedPlayoutId: number | null;
+  totalCount: number;
+  warningsCount: number;
+}
+
+type PlayoutsScreenBase = Omit<PlayoutsScreenData, 'items' | 'playout'>;
+
+export type PlayoutsScreenQueryState =
+  | {
+      data: PlayoutsScreenData;
+      error: null;
+      itemsLoading: boolean;
+      refresh: () => void;
+      setActivePlayout: (playoutId: number) => void;
+      setShowFiller: (showFiller: boolean) => void;
+      showFiller: boolean;
+      status: 'success';
+    }
+  | { data: null; error: string; refresh: () => void; status: 'error' }
+  | { data: null; error: null; refresh: () => void; status: 'loading' };
+
+type PlayoutsScreenState =
+  | { data: PlayoutsScreenData; error: null; itemsLoading: boolean; status: 'success' }
+  | { data: null; error: string; status: 'error' }
+  | { data: null; error: null; status: 'loading' };
+
+export function getPlayouts(): Promise<PlayoutsPage> {
+  return request<PlayoutsPage>('/api/playouts');
+}
+
+export function getPlayout(playoutId: number): Promise<PlayoutDetail> {
+  return request<PlayoutDetail>(`/api/playouts/${playoutId}`);
+}
+
+export function getPlayoutItems(playoutId: number, showFiller = false): Promise<PlayoutItemsPage> {
+  return request<PlayoutItemsPage>(`/api/playouts/${playoutId}/items${showFiller ? '?showFiller=true' : ''}`);
+}
+
+export function getPlayoutWarningsCount(): Promise<number> {
+  return request<number>('/api/playouts/warnings/count');
+}
+
+export function getPlayoutChannelStates(): Promise<PlayoutChannelState[]> {
+  return request<PlayoutChannelState[]>('/api/channels/state');
+}
+
+export function resetAllPlayouts(): Promise<void> {
+  return request<void>('/api/playouts/reset-all', { method: 'POST' });
+}
+
+export function usePlayoutsScreenQuery(pollMs = 30000): PlayoutsScreenQueryState {
+  const [state, setState] = useState<PlayoutsScreenState>({
+    data: null,
+    error: null,
+    status: 'loading'
+  });
+  const [showFiller, setShowFillerState] = useState(false);
+  const activeRef = useRef(true);
+  const selectedPlayoutIdRef = useRef<number | null>(null);
+  const showFillerRef = useRef(false);
+  // Snapshot of the last-known base fields (everything but the selected playout's
+  // detail/items), kept in sync whenever load()/loadChannelStates() succeed. Reading
+  // this lets setActivePlayout/setShowFiller kick off their fetch without doing the
+  // fetch from inside a setState updater (impure; StrictMode double-invokes updaters).
+  const baseRef = useRef<PlayoutsScreenBase>({
+    channelStates: [],
+    playouts: [],
+    selectedPlayoutId: null,
+    totalCount: 0,
+    warningsCount: 0
+  });
+
+  useEffect(() => {
+    activeRef.current = true;
+
+    return () => {
+      activeRef.current = false;
+    };
+  }, []);
+
+  const loadSelectedPlayout = useCallback((playoutId: number, base: PlayoutsScreenBase) => {
+    baseRef.current = base;
+
+    Promise.all([getPlayout(playoutId), getPlayoutItems(playoutId, showFillerRef.current)])
+      .then(([playout, itemsPage]) => {
+        if (!activeRef.current || selectedPlayoutIdRef.current !== playoutId) {
+          return;
+        }
+
+        setState((current) => {
+          // Merge onto whatever channel state the background poll may have landed
+          // while this request was in flight, rather than clobbering it with the
+          // snapshot captured when the request started.
+          const channelStates = current.status === 'success' ? current.data.channelStates : base.channelStates;
+
+          return {
+            data: {
+              ...base,
+              channelStates,
+              items: itemsPage.page ?? [],
+              playout,
+              selectedPlayoutId: playoutId
+            },
+            error: null,
+            itemsLoading: false,
+            status: 'success'
+          };
+        });
+      })
+      .catch((error: unknown) => {
+        if (activeRef.current && selectedPlayoutIdRef.current === playoutId) {
+          setState({ data: null, error: messageFromPlayoutError(error), status: 'error' });
+        }
+      });
+  }, []);
+
+  const load = useCallback(() => {
+    Promise.all([getPlayouts(), getPlayoutWarningsCount(), getPlayoutChannelStates()])
+      .then(([playoutsPage, warningsCount, channelStates]) => {
+        if (!activeRef.current) {
+          return;
+        }
+
+        const playouts = playoutsPage.page ?? [];
+        const selectedPlayoutId = selectedPlayoutIdRef.current && playouts.some((playout) => playout.id === selectedPlayoutIdRef.current)
+          ? selectedPlayoutIdRef.current
+          : playouts[0]?.id ?? null;
+        selectedPlayoutIdRef.current = selectedPlayoutId;
+
+        const base: PlayoutsScreenBase = {
+          channelStates,
+          playouts,
+          selectedPlayoutId,
+          totalCount: playoutsPage.totalCount,
+          warningsCount
+        };
+        baseRef.current = base;
+
+        if (selectedPlayoutId == null) {
+          setState({
+            data: {
+              ...base,
+              items: [],
+              playout: null
+            },
+            error: null,
+            itemsLoading: false,
+            status: 'success'
+          });
+          return;
+        }
+
+        loadSelectedPlayout(selectedPlayoutId, base);
+      })
+      .catch((error: unknown) => {
+        if (activeRef.current) {
+          setState({ data: null, error: messageFromPlayoutError(error), status: 'error' });
+        }
+      });
+  }, [loadSelectedPlayout]);
+
+  const loadChannelStates = useCallback(() => {
+    getPlayoutChannelStates()
+      .then((channelStates) => {
+        if (!activeRef.current) {
+          return;
+        }
+
+        baseRef.current = { ...baseRef.current, channelStates };
+
+        setState((current) => {
+          if (current.status !== 'success') {
+            return current;
+          }
+
+          return {
+            data: { ...current.data, channelStates },
+            error: null,
+            itemsLoading: current.itemsLoading,
+            status: 'success'
+          };
+        });
+      })
+      .catch(() => {
+        // Keep the monitor visible on background polling failures.
+      });
+  }, []);
+
+  useEffect(() => {
+    load();
+
+    const intervalId = window.setInterval(loadChannelStates, pollMs);
+
+    return () => {
+      window.clearInterval(intervalId);
+    };
+  }, [load, loadChannelStates, pollMs]);
+
+  const refresh = useCallback(() => {
+    setState({ data: null, error: null, status: 'loading' });
+    load();
+  }, [load]);
+
+  const setActivePlayout = useCallback((playoutId: number) => {
+    selectedPlayoutIdRef.current = playoutId;
+
+    setState((current) => {
+      if (current.status !== 'success') {
+        return current;
+      }
+
+      return {
+        data: {
+          ...current.data,
+          items: [],
+          playout: null,
+          selectedPlayoutId: playoutId
+        },
+        error: null,
+        itemsLoading: true,
+        status: 'success'
+      };
+    });
+
+    const base: PlayoutsScreenBase = { ...baseRef.current, selectedPlayoutId: playoutId };
+    loadSelectedPlayout(playoutId, base);
+  }, [loadSelectedPlayout]);
+
+  const setShowFiller = useCallback((next: boolean) => {
+    showFillerRef.current = next;
+    setShowFillerState(next);
+
+    const playoutId = selectedPlayoutIdRef.current;
+
+    if (playoutId == null) {
+      return;
+    }
+
+    setState((current) => {
+      if (current.status !== 'success') {
+        return current;
+      }
+
+      return { ...current, itemsLoading: true };
+    });
+
+    getPlayoutItems(playoutId, next)
+      .then((itemsPage) => {
+        if (!activeRef.current || selectedPlayoutIdRef.current !== playoutId) {
+          return;
+        }
+
+        setState((current) => {
+          if (current.status !== 'success') {
+            return current;
+          }
+
+          return {
+            data: { ...current.data, items: itemsPage.page ?? [] },
+            error: null,
+            itemsLoading: false,
+            status: 'success'
+          };
+        });
+      })
+      .catch((error: unknown) => {
+        if (!activeRef.current || selectedPlayoutIdRef.current !== playoutId) {
+          return;
+        }
+
+        setState({ data: null, error: messageFromPlayoutError(error), status: 'error' });
+      });
+  }, []);
+
+  if (state.status === 'success') {
+    return {
+      data: state.data,
+      error: null,
+      itemsLoading: state.itemsLoading,
+      refresh,
+      setActivePlayout,
+      setShowFiller,
+      showFiller,
+      status: 'success'
+    };
+  }
+
+  if (state.status === 'error') {
+    return { data: null, error: state.error, refresh, status: 'error' };
+  }
+
+  return { data: null, error: null, refresh, status: 'loading' };
+}
+
+function messageFromPlayoutError(error: unknown, fallback = 'Unable to load playouts'): string {
+  if (error instanceof ApiError) {
+    return error.detail ?? error.message;
+  }
+
+  if (error instanceof Error) {
+    return error.message;
+  }
+
+  return fallback;
+}

web/src/api/schedules.ts

@@ -0,0 +1,304 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+import { ApiError, request } from './client';
+import type { components } from './generated/v1';
+
+export type ProgramSchedule = components['schemas']['ProgramScheduleViewModel'];
+// These fields are real on the wire (the backend serializes ProgramScheduleItemViewModel
+// subtypes with Newtonsoft using the runtime type), but the OpenAPI schema doesn't declare
+// them: ProgramScheduleItemViewModel is an abstract base with no polymorphism annotation, so
+// the generator only sees the base shape. Tracked in Gitea issue #126 — remove this widening
+// once the schema is fixed to describe the concrete subtypes.
+export type ProgramScheduleItem = components['schemas']['ProgramScheduleItemViewModel'] & {
+  count?: null | string;
+  discardToFillAttempts?: null | number;
+  multipleCount?: null | string;
+  multipleMode?: components['schemas']['MultipleMode'];
+  playoutDuration?: null | string;
+  tailMode?: components['schemas']['TailMode'];
+};
+export type ProgramScheduleItemsWithDuration = components['schemas']['ProgramScheduleItemsWithDurationViewModel'];
+export type ScheduleItemRequest = components['schemas']['ScheduleItemRequest'];
+export type ReplaceScheduleItemsRequest = components['schemas']['ReplaceScheduleItemsRequest'];
+export type MediaCollection = components['schemas']['MediaCollectionViewModel'];
+export type SmartCollection = components['schemas']['SmartCollectionViewModel'];
+export type FillerPreset = components['schemas']['FillerPresetResponseModel'];
+export type Watermark = components['schemas']['WatermarkResponseModel'];
+
+export interface SchedulePickerData {
+  collections: MediaCollection[];
+  fillerPresets: FillerPreset[];
+  smartCollections: SmartCollection[];
+  watermarks: Watermark[];
+}
+
+export interface ScheduleScreenData {
+  activeSchedule: ProgramSchedule | null;
+  items: ProgramScheduleItem[];
+  pickers: SchedulePickerData;
+  schedules: ProgramSchedule[];
+  totalDurationEstimate: string | null;
+}
+
+export type ScheduleScreenQueryState =
+  | {
+      data: ScheduleScreenData;
+      error: null;
+      itemsLoading: boolean;
+      refresh: () => void;
+      setActiveSchedule: (scheduleId: number) => void;
+      setItems: (items: ProgramScheduleItem[]) => void;
+      status: 'success';
+    }
+  | { data: null; error: string; refresh: () => void; status: 'error' }
+  | { data: null; error: null; refresh: () => void; status: 'loading' };
+
+type ScheduleScreenState =
+  | { data: ScheduleScreenData; error: null; itemsLoading: boolean; status: 'success' }
+  | { data: null; error: string; status: 'error' }
+  | { data: null; error: null; status: 'loading' };
+
+export function getSchedules(): Promise<ProgramSchedule[]> {
+  return request<ProgramSchedule[]>('/api/schedules');
+}
+
+export function getScheduleItems(scheduleId: number): Promise<ProgramScheduleItemsWithDuration> {
+  return request<ProgramScheduleItemsWithDuration>(`/api/schedules/${scheduleId}/items`);
+}
+
+export function getCollections(): Promise<MediaCollection[]> {
+  return request<MediaCollection[]>('/api/collections');
+}
+
+export function getSmartCollections(): Promise<SmartCollection[]> {
+  return request<SmartCollection[]>('/api/smart-collections');
+}
+
+export function getFillerPresets(): Promise<FillerPreset[]> {
+  return request<FillerPreset[]>('/api/filler-presets');
+}
+
+export function getWatermarks(): Promise<Watermark[]> {
+  return request<Watermark[]>('/api/watermarks');
+}
+
+export function addScheduleItem(scheduleId: number, body: ScheduleItemRequest): Promise<ProgramScheduleItem> {
+  return request<ProgramScheduleItem>(`/api/schedules/${scheduleId}/items`, {
+    body,
+    method: 'POST'
+  });
+}
+
+export function replaceScheduleItems(
+  scheduleId: number,
+  body: ReplaceScheduleItemsRequest
+): Promise<ProgramScheduleItem[]> {
+  return request<ProgramScheduleItem[]>(`/api/schedules/${scheduleId}/items`, {
+    body,
+    method: 'PUT'
+  });
+}
+
+export function deleteScheduleItem(scheduleId: number, itemId: number): Promise<void> {
+  return request<void>(`/api/schedules/${scheduleId}/items/${itemId}`, {
+    method: 'DELETE'
+  });
+}
+
+export async function getScheduleScreenData(): Promise<ScheduleScreenData> {
+  const schedules = await getSchedules();
+  const activeSchedule = schedules[0] ?? null;
+
+  if (!activeSchedule) {
+    return {
+      activeSchedule: null,
+      items: [],
+      pickers: emptyPickerData(),
+      schedules,
+      totalDurationEstimate: null
+    };
+  }
+
+  const [itemsEnvelope, pickers] = await Promise.all([
+    getScheduleItems(activeSchedule.id),
+    getSchedulePickerData()
+  ]);
+
+  return {
+    activeSchedule,
+    items: (itemsEnvelope.items ?? []) as ProgramScheduleItem[],
+    pickers,
+    schedules,
+    totalDurationEstimate: itemsEnvelope.totalDurationEstimate
+  };
+}
+
+export function useScheduleScreenQuery(): ScheduleScreenQueryState {
+  const [state, setState] = useState<ScheduleScreenState>({
+    data: null,
+    error: null,
+    status: 'loading'
+  });
+  const activeRef = useRef(true);
+  const activeScheduleIdRef = useRef<number | null>(null);
+
+  useEffect(() => {
+    activeRef.current = true;
+
+    return () => {
+      activeRef.current = false;
+    };
+  }, []);
+
+  const load = useCallback(() => {
+    getScheduleScreenData()
+      .then((data) => {
+        if (activeRef.current) {
+          activeScheduleIdRef.current = data.activeSchedule?.id ?? null;
+          setState({ data, error: null, itemsLoading: false, status: 'success' });
+        }
+      })
+      .catch((error: unknown) => {
+        if (activeRef.current) {
+          setState({ data: null, error: messageFromScheduleError(error, 'Unable to load schedules'), status: 'error' });
+        }
+      });
+  }, []);
+
+  useEffect(() => {
+    load();
+  }, [load]);
+
+  const refresh = useCallback(() => {
+    setState({ data: null, error: null, status: 'loading' });
+    load();
+  }, [load]);
+
+  const setActiveSchedule = useCallback((scheduleId: number) => {
+    activeScheduleIdRef.current = scheduleId;
+
+    setState((current) => {
+      if (current.status !== 'success') {
+        return current;
+      }
+
+      const nextActiveSchedule = current.data.schedules.find((schedule) => schedule.id === scheduleId)
+        ?? current.data.activeSchedule;
+
+      return {
+        data: { ...current.data, activeSchedule: nextActiveSchedule },
+        error: null,
+        itemsLoading: true,
+        status: 'success'
+      };
+    });
+
+    getScheduleItems(scheduleId)
+      .then((itemsEnvelope) => {
+        if (!activeRef.current || activeScheduleIdRef.current !== scheduleId) {
+          return;
+        }
+
+        setState((current) => {
+          if (current.status !== 'success') {
+            return current;
+          }
+
+          return {
+            data: {
+              ...current.data,
+              items: (itemsEnvelope.items ?? []) as ProgramScheduleItem[],
+              totalDurationEstimate: itemsEnvelope.totalDurationEstimate
+            },
+            error: null,
+            itemsLoading: false,
+            status: 'success'
+          };
+        });
+      })
+      .catch((error: unknown) => {
+        if (!activeRef.current || activeScheduleIdRef.current !== scheduleId) {
+          return;
+        }
+
+        setState({
+          data: null,
+          error: messageFromScheduleError(error, 'Unable to load schedule items'),
+          status: 'error'
+        });
+      });
+  }, []);
+
+  const setItems = useCallback((items: ProgramScheduleItem[]) => {
+    setState((current) => {
+      if (current.status !== 'success') {
+        return current;
+      }
+
+      return {
+        data: { ...current.data, items },
+        error: null,
+        itemsLoading: false,
+        status: 'success'
+      };
+    });
+  }, []);
+
+  if (state.status === 'success') {
+    return {
+      data: state.data,
+      error: null,
+      itemsLoading: state.itemsLoading,
+      refresh,
+      setActiveSchedule,
+      setItems,
+      status: 'success'
+    };
+  }
+
+  if (state.status === 'error') {
+    return { data: null, error: state.error, refresh, status: 'error' };
+  }
+
+  return { data: null, error: null, refresh, status: 'loading' };
+}
+
+async function getSchedulePickerData(): Promise<SchedulePickerData> {
+  const [collections, smartCollections, fillerPresets, watermarks] = await Promise.all([
+    getCollections(),
+    getSmartCollections(),
+    getFillerPresets(),
+    getWatermarks()
+  ]);
+
+  return {
+    collections,
+    fillerPresets: sortByName(fillerPresets),
+    smartCollections,
+    watermarks: sortByName(watermarks)
+  };
+}
+
+function emptyPickerData(): SchedulePickerData {
+  return {
+    collections: [],
+    fillerPresets: [],
+    smartCollections: [],
+    watermarks: []
+  };
+}
+
+function sortByName<T extends { name: null | string }>(items: T[]): T[] {
+  return [...items].sort((left, right) => (left.name ?? '').localeCompare(right.name ?? ''));
+}
+
+function messageFromScheduleError(error: unknown, fallback = 'Unable to load schedules'): string {
+  if (error instanceof ApiError) {
+    return error.detail ?? error.message;
+  }
+
+  if (error instanceof Error) {
+    return error.message;
+  }
+
+  return fallback;
+}