add experimental playout template system (#1808)

* add template playout kind

* add template scheduler count

* implement pad to next

* only allow resetting template playouts

* update changelog

CHANGELOG.md

@@ -22,6 +22,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   - Default filler will stop scheduling when the next item would extend into primary content
   - Alternatively, default filler can be configured to `Trim To Fit`
     - In this case, the last item that would extend into primary content is trimmed to end exactly when the primary content starts
+- Add **experimental** playout type `Template`
+  - This playout type uses a YAML file to declare content and describe how the playout should be built
+  - Content currently supports search queries
+  - Playout instructions currently include `count`, `pad to next`, and `repeat`
+    - `count`: add the specified number of items (from the referenced content) to the playout
+    - `pad to next`: add items from the referenced content until the wall clock is a multiple of the specified minutes value
+    - `repeat`: continue building the playout from the first instruction in the template
 
 ### Fixed
 - Add basic cache busting to XMLTV image URLs

ErsatzTV.Application/Playouts/Commands/BuildPlayoutHandler.cs

@@ -19,6 +19,7 @@ public class BuildPlayoutHandler : IRequestHandler<BuildPlayout, Either<BaseErro
 {
     private readonly IBlockPlayoutBuilder _blockPlayoutBuilder;
     private readonly IBlockPlayoutFillerBuilder _blockPlayoutFillerBuilder;
+    private readonly ITemplatePlayoutBuilder _templatePlayoutBuilder;
     private readonly IClient _client;
     private readonly IDbContextFactory<TvContext> _dbContextFactory;
     private readonly IEntityLocker _entityLocker;
@@ -33,6 +34,7 @@ public class BuildPlayoutHandler : IRequestHandler<BuildPlayout, Either<BaseErro
         IPlayoutBuilder playoutBuilder,
         IBlockPlayoutBuilder blockPlayoutBuilder,
         IBlockPlayoutFillerBuilder blockPlayoutFillerBuilder,
+        ITemplatePlayoutBuilder templatePlayoutBuilder,
         IExternalJsonPlayoutBuilder externalJsonPlayoutBuilder,
         IFFmpegSegmenterService ffmpegSegmenterService,
         IEntityLocker entityLocker,
@@ -43,6 +45,7 @@ public class BuildPlayoutHandler : IRequestHandler<BuildPlayout, Either<BaseErro
         _playoutBuilder = playoutBuilder;
         _blockPlayoutBuilder = blockPlayoutBuilder;
         _blockPlayoutFillerBuilder = blockPlayoutFillerBuilder;
+        _templatePlayoutBuilder = templatePlayoutBuilder;
         _externalJsonPlayoutBuilder = externalJsonPlayoutBuilder;
         _ffmpegSegmenterService = ffmpegSegmenterService;
         _entityLocker = entityLocker;
@@ -74,6 +77,9 @@ public class BuildPlayoutHandler : IRequestHandler<BuildPlayout, Either<BaseErro
                     await _blockPlayoutBuilder.Build(playout, request.Mode, cancellationToken);
                     await _blockPlayoutFillerBuilder.Build(playout, request.Mode, cancellationToken);
                     break;
+                case ProgramSchedulePlayoutType.Template:
+                    await _templatePlayoutBuilder.Build(playout, request.Mode, cancellationToken);
+                    break;
                 case ProgramSchedulePlayoutType.ExternalJson:
                     await _externalJsonPlayoutBuilder.Build(playout, request.Mode, cancellationToken);
                     break;

ErsatzTV.Application/Playouts/Commands/CreatePlayout.cs

@@ -12,5 +12,8 @@ public record CreateFloodPlayout(int ChannelId, int ProgramScheduleId)
 public record CreateBlockPlayout(int ChannelId)
     : CreatePlayout(ChannelId, ProgramSchedulePlayoutType.Block);
 
+public record CreateTemplatePlayout(int ChannelId, string TemplateFile)
+    : CreatePlayout(ChannelId, ProgramSchedulePlayoutType.Template);
+
 public record CreateExternalJsonPlayout(int ChannelId, string ExternalJsonFile)
     : CreatePlayout(ChannelId, ProgramSchedulePlayoutType.ExternalJson);

ErsatzTV.Application/Playouts/Commands/CreateTemplatePlayoutHandler.cs

@@ -0,0 +1,91 @@
+using System.Threading.Channels;
+using ErsatzTV.Application.Channels;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Metadata;
+using ErsatzTV.Core.Scheduling;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+using Channel = ErsatzTV.Core.Domain.Channel;
+
+namespace ErsatzTV.Application.Playouts;
+
+public class CreateTemplatePlayoutHandler
+    : IRequestHandler<CreateTemplatePlayout, Either<BaseError, CreatePlayoutResponse>>
+{
+    private readonly ChannelWriter<IBackgroundServiceRequest> _channel;
+    private readonly IDbContextFactory<TvContext> _dbContextFactory;
+    private readonly ILocalFileSystem _localFileSystem;
+
+    public CreateTemplatePlayoutHandler(
+        ILocalFileSystem localFileSystem,
+        ChannelWriter<IBackgroundServiceRequest> channel,
+        IDbContextFactory<TvContext> dbContextFactory)
+    {
+        _localFileSystem = localFileSystem;
+        _channel = channel;
+        _dbContextFactory = dbContextFactory;
+    }
+
+    public async Task<Either<BaseError, CreatePlayoutResponse>> Handle(
+        CreateTemplatePlayout request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Validation<BaseError, Playout> validation = await Validate(dbContext, request);
+        return await validation.Apply(playout => PersistPlayout(dbContext, playout));
+    }
+
+    private async Task<CreatePlayoutResponse> PersistPlayout(TvContext dbContext, Playout playout)
+    {
+        await dbContext.Playouts.AddAsync(playout);
+        await dbContext.SaveChangesAsync();
+        await _channel.WriteAsync(new BuildPlayout(playout.Id, PlayoutBuildMode.Reset));
+        await _channel.WriteAsync(new RefreshChannelList());
+        return new CreatePlayoutResponse(playout.Id);
+    }
+
+    private async Task<Validation<BaseError, Playout>> Validate(
+        TvContext dbContext,
+        CreateTemplatePlayout request) =>
+        (await ValidateChannel(dbContext, request), ValidateTemplateFile(request), ValidatePlayoutType(request))
+        .Apply(
+            (channel, externalJsonFile, playoutType) => new Playout
+            {
+                ChannelId = channel.Id,
+                TemplateFile = externalJsonFile,
+                ProgramSchedulePlayoutType = playoutType
+            });
+
+    private static Task<Validation<BaseError, Channel>> ValidateChannel(
+        TvContext dbContext,
+        CreateTemplatePlayout createTemplatePlayout) =>
+        dbContext.Channels
+            .Include(c => c.Playouts)
+            .SelectOneAsync(c => c.Id, c => c.Id == createTemplatePlayout.ChannelId)
+            .Map(o => o.ToValidation<BaseError>("Channel does not exist"))
+            .BindT(ChannelMustNotHavePlayouts);
+
+    private static Validation<BaseError, Channel> ChannelMustNotHavePlayouts(Channel channel) =>
+        Optional(channel.Playouts.Count)
+            .Filter(count => count == 0)
+            .Map(_ => channel)
+            .ToValidation<BaseError>("Channel already has one playout");
+
+    private Validation<BaseError, string> ValidateTemplateFile(CreateTemplatePlayout request)
+    {
+        if (!_localFileSystem.FileExists(request.TemplateFile))
+        {
+            return BaseError.New("Template file does not exist!");
+        }
+
+        return request.TemplateFile;
+    }
+
+    private static Validation<BaseError, ProgramSchedulePlayoutType> ValidatePlayoutType(
+        CreateTemplatePlayout createTemplatePlayout) =>
+        Optional(createTemplatePlayout.ProgramSchedulePlayoutType)
+            .Filter(playoutType => playoutType == ProgramSchedulePlayoutType.Template)
+            .ToValidation<BaseError>("[ProgramSchedulePlayoutType] must be Template");
+}

ErsatzTV.Application/Playouts/Commands/UpdateExternalJsonPlayoutHandler.cs

@@ -51,6 +51,7 @@ public class
             playout.Channel.Number,
             playout.Channel.ProgressMode,
             playout.ProgramSchedule?.Name ?? string.Empty,
+            playout.TemplateFile,
             playout.ExternalJsonFile,
             playout.DailyRebuildTime);
     }

ErsatzTV.Application/Playouts/Commands/UpdatePlayoutHandler.cs

@@ -43,6 +43,7 @@ public class UpdatePlayoutHandler : IRequestHandler<UpdatePlayout, Either<BaseEr
             playout.Channel.Number,
             playout.Channel.ProgressMode,
             playout.ProgramSchedule?.Name ?? string.Empty,
+            playout.TemplateFile,
             playout.ExternalJsonFile,
             playout.DailyRebuildTime);
     }

ErsatzTV.Application/Playouts/Commands/UpdateTemplatePlayout.cs

@@ -0,0 +1,6 @@
+using ErsatzTV.Core;
+
+namespace ErsatzTV.Application.Playouts;
+
+public record UpdateTemplatePlayout(int PlayoutId, string TemplateFile)
+    : IRequest<Either<BaseError, PlayoutNameViewModel>>;

ErsatzTV.Application/Playouts/Commands/UpdateTemplatePlayoutHandler.cs

@@ -0,0 +1,71 @@
+using System.Threading.Channels;
+using ErsatzTV.Application.Channels;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.Playouts;
+
+public class
+    UpdateTemplatePlayoutHandler : IRequestHandler<UpdateTemplatePlayout,
+    Either<BaseError, PlayoutNameViewModel>>
+{
+    private readonly IDbContextFactory<TvContext> _dbContextFactory;
+    private readonly ChannelWriter<IBackgroundServiceRequest> _workerChannel;
+
+    public UpdateTemplatePlayoutHandler(
+        IDbContextFactory<TvContext> dbContextFactory,
+        ChannelWriter<IBackgroundServiceRequest> workerChannel)
+    {
+        _dbContextFactory = dbContextFactory;
+        _workerChannel = workerChannel;
+    }
+
+    public async Task<Either<BaseError, PlayoutNameViewModel>> Handle(
+        UpdateTemplatePlayout request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Validation<BaseError, Playout> validation = await Validate(dbContext, request);
+        return await validation.Apply(playout => ApplyUpdateRequest(dbContext, request, playout));
+    }
+
+    private async Task<PlayoutNameViewModel> ApplyUpdateRequest(
+        TvContext dbContext,
+        UpdateTemplatePlayout request,
+        Playout playout)
+    {
+        playout.TemplateFile = request.TemplateFile;
+
+        if (await dbContext.SaveChangesAsync() > 0)
+        {
+            await _workerChannel.WriteAsync(new RefreshChannelData(playout.Channel.Number));
+        }
+
+        return new PlayoutNameViewModel(
+            playout.Id,
+            playout.ProgramSchedulePlayoutType,
+            playout.Channel.Name,
+            playout.Channel.Number,
+            playout.Channel.ProgressMode,
+            playout.ProgramSchedule?.Name ?? string.Empty,
+            playout.TemplateFile,
+            playout.ExternalJsonFile,
+            playout.DailyRebuildTime);
+    }
+
+    private static Task<Validation<BaseError, Playout>> Validate(
+        TvContext dbContext,
+        UpdateTemplatePlayout request) =>
+        PlayoutMustExist(dbContext, request);
+
+    private static Task<Validation<BaseError, Playout>> PlayoutMustExist(
+        TvContext dbContext,
+        UpdateTemplatePlayout updatePlayout) =>
+        dbContext.Playouts
+            .Include(p => p.Channel)
+            .SelectOneAsync(p => p.Id, p => p.Id == updatePlayout.PlayoutId)
+            .Map(o => o.ToValidation<BaseError>("Playout does not exist."));
+}

ErsatzTV.Application/Playouts/PlayoutNameViewModel.cs

@@ -9,6 +9,7 @@ public record PlayoutNameViewModel(
     string ChannelNumber,
     ChannelProgressMode ProgressMode,
     string ScheduleName,
+    string TemplateFile,
     string ExternalJsonFile,
     TimeSpan? DbDailyRebuildTime)
 {

ErsatzTV.Application/Playouts/Queries/GetAllPlayoutsHandler.cs

@@ -27,6 +27,7 @@ public class GetAllPlayoutsHandler : IRequestHandler<GetAllPlayouts, List<Playou
                     p.Channel.Number,
                     p.Channel.ProgressMode,
                     p.ProgramScheduleId == null ? string.Empty : p.ProgramSchedule.Name,
+                    p.TemplateFile,
                     p.ExternalJsonFile,
                     p.DailyRebuildTime))
             .ToListAsync(cancellationToken);

ErsatzTV.Core.Tests/Fakes/FakeMediaCollectionRepository.cs

@@ -22,6 +22,7 @@ public class FakeMediaCollectionRepository : IMediaCollectionRepository
     public Task<List<MediaItem>> GetItems(int id) => _data[id].ToList().AsTask();
     public Task<List<MediaItem>> GetMultiCollectionItems(int id) => throw new NotSupportedException();
     public Task<List<MediaItem>> GetSmartCollectionItems(int id) => _data[id].ToList().AsTask();
+    public Task<List<MediaItem>> GetSmartCollectionItems(string query) => throw new NotSupportedException();
     public Task<List<MediaItem>> GetPlaylistItems(int id) => throw new NotSupportedException();
     public Task<List<Movie>> GetMovie(int id) => throw new NotSupportedException();
     public Task<List<Episode>> GetEpisode(int id) => throw new NotSupportedException();

ErsatzTV.Core/Domain/Playout.cs

@@ -10,6 +10,7 @@ public class Playout
     public int? ProgramScheduleId { get; set; }
     public ProgramSchedule ProgramSchedule { get; set; }
     public string ExternalJsonFile { get; set; }
+    public string TemplateFile { get; set; }
     public List<ProgramScheduleAlternate> ProgramScheduleAlternates { get; set; }
     public ProgramSchedulePlayoutType ProgramSchedulePlayoutType { get; set; }
     public List<PlayoutItem> Items { get; set; }

ErsatzTV.Core/Domain/ProgramSchedulePlayoutType.cs

@@ -5,6 +5,7 @@ public enum ProgramSchedulePlayoutType
     None = 0,
     Flood = 1,
     Block = 2,
+    Template = 3,
 
     ExternalJson = 20
 }

ErsatzTV.Core/ErsatzTV.Core.csproj

@@ -27,6 +27,7 @@
       <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
       <PackageReference Include="Serilog" Version="4.0.0" />
       <PackageReference Include="Serilog.Sinks.Console" Version="6.0.0" />
+      <PackageReference Include="YamlDotNet" Version="16.0.0" />
     </ItemGroup>
     
     <ItemGroup>

ErsatzTV.Core/Interfaces/Repositories/IMediaCollectionRepository.cs

@@ -11,6 +11,7 @@ public interface IMediaCollectionRepository
     Task<List<MediaItem>> GetItems(int id);
     Task<List<MediaItem>> GetMultiCollectionItems(int id);
     Task<List<MediaItem>> GetSmartCollectionItems(int id);
+    Task<List<MediaItem>> GetSmartCollectionItems(string query);
     Task<List<MediaItem>> GetPlaylistItems(int id);
     Task<List<Movie>> GetMovie(int id);
     Task<List<Episode>> GetEpisode(int id);

ErsatzTV.Core/Interfaces/Scheduling/ITemplatePlayoutBuilder.cs

@@ -0,0 +1,9 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Scheduling;
+
+namespace ErsatzTV.Core.Interfaces.Scheduling;
+
+public interface ITemplatePlayoutBuilder
+{
+    Task<Playout> Build(Playout playout, PlayoutBuildMode mode, CancellationToken cancellationToken);
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplate.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplate
+{
+    public List<PlayoutTemplateContentSearchItem> Content { get; set; } = [];
+    public List<PlayoutTemplateItem> Playout { get; set; } = [];
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplateContent.cs

@@ -0,0 +1,6 @@
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplateContent
+{
+
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplateContentItem.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplateContentItem
+{
+    public string Key { get; set; }
+    public string Order { get; set; }
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplateContentSearchItem.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplateContentSearchItem : PlayoutTemplateContentItem
+{
+    public string Search { get; set; }
+    public string Query { get; set; }
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplateCountItem.cs

@@ -0,0 +1,6 @@
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplateCountItem : PlayoutTemplateItem
+{
+    public int Count { get; set; }
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplateItem.cs

@@ -0,0 +1,6 @@
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplateItem
+{
+    public string Content { get; set; }
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplatePadToNextItem.cs

@@ -0,0 +1,11 @@
+using YamlDotNet.Serialization;
+
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplatePadToNextItem : PlayoutTemplateItem
+{
+    [YamlMember(Alias = "pad_to_next", ApplyNamingConventions = false)]
+    public int PadToNext { get; set; }
+
+    public bool Trim { get; set; }
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplatePlayout.cs

@@ -0,0 +1,5 @@
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplatePlayout
+{
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplateRepeatItem.cs

@@ -0,0 +1,6 @@
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplateRepeatItem : PlayoutTemplateItem
+{
+    public bool Repeat { get; set; }
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplateScheduler.cs

@@ -0,0 +1,18 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Extensions;
+
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public abstract class PlayoutTemplateScheduler
+{
+    protected static TimeSpan DurationForMediaItem(MediaItem mediaItem)
+    {
+        if (mediaItem is Image image)
+        {
+            return TimeSpan.FromSeconds(image.ImageMetadata.Head().DurationSeconds ?? Image.DefaultSeconds);
+        }
+
+        MediaVersion version = mediaItem.GetHeadVersion();
+        return version.Duration;
+    }
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplateSchedulerCount.cs

@@ -0,0 +1,53 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Interfaces.Scheduling;
+
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplateSchedulerCount : PlayoutTemplateScheduler
+{
+    public static DateTimeOffset Schedule(
+        Playout playout,
+        DateTimeOffset currentTime,
+        PlayoutTemplateCountItem count,
+        IMediaCollectionEnumerator enumerator)
+    {
+        for (int i = 0; i < count.Count; i++)
+        {
+            foreach (MediaItem mediaItem in enumerator.Current)
+            {
+                TimeSpan itemDuration = DurationForMediaItem(mediaItem);
+
+                // create a playout item
+                var playoutItem = new PlayoutItem
+                {
+                    MediaItemId = mediaItem.Id,
+                    Start = currentTime.UtcDateTime,
+                    Finish = currentTime.UtcDateTime + itemDuration,
+                    InPoint = TimeSpan.Zero,
+                    OutPoint = itemDuration,
+                    FillerKind = FillerKind.None, //blockItem.IncludeInProgramGuide ? FillerKind.None : FillerKind.GuideMode,
+                    //CustomTitle = scheduleItem.CustomTitle,
+                    //WatermarkId = scheduleItem.WatermarkId,
+                    //PreferredAudioLanguageCode = scheduleItem.PreferredAudioLanguageCode,
+                    //PreferredAudioTitle = scheduleItem.PreferredAudioTitle,
+                    //PreferredSubtitleLanguageCode = scheduleItem.PreferredSubtitleLanguageCode,
+                    //SubtitleMode = scheduleItem.SubtitleMode
+                    //GuideGroup = effectiveBlock.TemplateItemId,
+                    //GuideStart = effectiveBlock.Start.UtcDateTime,
+                    //GuideFinish = blockFinish.UtcDateTime,
+                    //BlockKey = JsonConvert.SerializeObject(effectiveBlock.BlockKey),
+                    //CollectionKey = JsonConvert.SerializeObject(collectionKey, JsonSettings),
+                    //CollectionEtag = collectionEtags[collectionKey]
+                };
+
+                playout.Items.Add(playoutItem);
+
+                currentTime += itemDuration;
+                enumerator.MoveNext();
+            }
+        }
+
+        return currentTime;
+    }
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplateSchedulerPadToNext.cs

@@ -0,0 +1,80 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Scheduling;
+
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class PlayoutTemplateSchedulerPadToNext : PlayoutTemplateScheduler
+{
+    public static DateTimeOffset Schedule(
+        Playout playout,
+        DateTimeOffset currentTime,
+        PlayoutTemplatePadToNextItem padToNext,
+        IMediaCollectionEnumerator enumerator)
+    {
+        int currentMinute = currentTime.Minute;
+
+        int targetMinute = (currentMinute + padToNext.PadToNext - 1) / padToNext.PadToNext * padToNext.PadToNext;
+
+        DateTimeOffset almostTargetTime =
+            currentTime - TimeSpan.FromMinutes(currentMinute) + TimeSpan.FromMinutes(targetMinute);
+
+        var targetTime = new DateTimeOffset(
+            almostTargetTime.Year,
+            almostTargetTime.Month,
+            almostTargetTime.Day,
+            almostTargetTime.Hour,
+            almostTargetTime.Minute,
+            0,
+            almostTargetTime.Offset);
+
+        // ensure filler works for content less than one minute
+        if (targetTime <= currentTime)
+            targetTime = targetTime.AddMinutes(padToNext.PadToNext);
+
+        bool done = false;
+        TimeSpan remainingToFill = targetTime - currentTime;
+        while (!done && enumerator.Current.IsSome && remainingToFill > TimeSpan.Zero &&
+               remainingToFill >= enumerator.MinimumDuration)
+        {
+            foreach (MediaItem mediaItem in enumerator.Current)
+            {
+                TimeSpan itemDuration = DurationForMediaItem(mediaItem);
+
+                var playoutItem = new PlayoutItem
+                {
+                    MediaItemId = mediaItem.Id,
+                    Start = currentTime.UtcDateTime,
+                    Finish = currentTime.UtcDateTime + itemDuration,
+                    InPoint = TimeSpan.Zero,
+                    OutPoint = itemDuration,
+                    //GuideGroup = playoutBuilderState.NextGuideGroup,
+                    //FillerKind = fillerKind,
+                    //DisableWatermarks = !allowWatermarks
+                };
+
+                if (remainingToFill - itemDuration >= TimeSpan.Zero)
+                {
+                    remainingToFill -= itemDuration;
+                    playout.Items.Add(playoutItem);
+                    enumerator.MoveNext();
+                }
+                else if (padToNext.Trim)
+                {
+                    // trim item to exactly fit
+                    remainingToFill = TimeSpan.Zero;
+                    playoutItem.Finish = targetTime.UtcDateTime;
+                    playoutItem.OutPoint = playoutItem.Finish - playoutItem.Start;
+                    playout.Items.Add(playoutItem);
+                    enumerator.MoveNext();
+                }
+                else
+                {
+                    // item won't fit; we're done for now
+                    done = true;
+                }
+            }
+        }
+
+        return targetTime;
+    }
+}

ErsatzTV.Core/Scheduling/TemplateScheduling/TemplatePlayoutBuilder.cs

@@ -0,0 +1,161 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Metadata;
+using ErsatzTV.Core.Interfaces.Repositories;
+using ErsatzTV.Core.Interfaces.Scheduling;
+using LanguageExt.UnsafeValueAccess;
+using Microsoft.Extensions.Logging;
+using YamlDotNet.Serialization;
+using YamlDotNet.Serialization.NamingConventions;
+
+namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
+
+public class TemplatePlayoutBuilder(
+    ILocalFileSystem localFileSystem,
+    IConfigElementRepository configElementRepository,
+    IMediaCollectionRepository mediaCollectionRepository,
+    ILogger<TemplatePlayoutBuilder> logger)
+    : ITemplatePlayoutBuilder
+{
+    public async Task<Playout> Build(Playout playout, PlayoutBuildMode mode, CancellationToken cancellationToken)
+    {
+        if (!localFileSystem.FileExists(playout.TemplateFile))
+        {
+            logger.LogWarning("Playout template file {File} does not exist; aborting.", playout.TemplateFile);
+            return playout;
+        }
+
+        PlayoutTemplate playoutTemplate = await LoadTemplate(playout, cancellationToken);
+
+        DateTimeOffset start = DateTimeOffset.Now;
+        int daysToBuild = await GetDaysToBuild();
+        DateTimeOffset finish = start.AddDays(daysToBuild);
+
+        if (mode is not PlayoutBuildMode.Reset)
+        {
+            logger.LogWarning("Template playouts can only be reset; ignoring build mode {Mode}", mode.ToString());
+            return playout;
+        }
+
+        // these are only for reset
+        playout.Seed = new Random().Next();
+        playout.Items.Clear();
+
+        DateTimeOffset currentTime = start;
+
+        // load content and content enumerators on demand
+        Dictionary<string, IMediaCollectionEnumerator> enumerators = new();
+
+        var index = 0;
+        while (currentTime < finish)
+        {
+            if (index >= playoutTemplate.Playout.Count)
+            {
+                logger.LogInformation("Reached the end of the playout template; stopping");
+                break;
+            }
+
+            PlayoutTemplateItem playoutItem = playoutTemplate.Playout[index];
+
+            // repeat resets index into template playout
+            if (playoutItem is PlayoutTemplateRepeatItem)
+            {
+                index = 0;
+                continue;
+            }
+
+            if (!enumerators.TryGetValue(playoutItem.Content, out IMediaCollectionEnumerator enumerator))
+            {
+                Option<IMediaCollectionEnumerator> maybeEnumerator =
+                    await GetEnumeratorForContent(playout, playoutItem.Content, playoutTemplate, cancellationToken);
+
+                if (maybeEnumerator.IsNone)
+                {
+                    logger.LogWarning("Unable to locate content with key {Key}", playoutItem.Content);
+                    continue;
+                }
+
+                foreach (IMediaCollectionEnumerator e in maybeEnumerator)
+                {
+                    enumerator = maybeEnumerator.ValueUnsafe();
+                    enumerators.Add(playoutItem.Content, enumerator);
+                }
+            }
+
+            switch (playoutItem)
+            {
+                case PlayoutTemplateCountItem count:
+                    currentTime = PlayoutTemplateSchedulerCount.Schedule(playout, currentTime, count, enumerator);
+                    break;
+                case PlayoutTemplatePadToNextItem padToNext:
+                    currentTime = PlayoutTemplateSchedulerPadToNext.Schedule(
+                        playout,
+                        currentTime,
+                        padToNext,
+                        enumerator);
+                    break;
+            }
+
+            index++;
+        }
+
+        return playout;
+    }
+
+    private async Task<int> GetDaysToBuild() =>
+        await configElementRepository
+            .GetValue<int>(ConfigElementKey.PlayoutDaysToBuild)
+            .IfNoneAsync(2);
+
+    private async Task<Option<IMediaCollectionEnumerator>> GetEnumeratorForContent(
+        Playout playout,
+        string contentKey,
+        PlayoutTemplate playoutTemplate,
+        CancellationToken cancellationToken)
+    {
+        int index = playoutTemplate.Content.FindIndex(c => c.Key == contentKey);
+        if (index < 0)
+        {
+            return Option<IMediaCollectionEnumerator>.None;
+        }
+
+        PlayoutTemplateContentSearchItem content = playoutTemplate.Content[index];
+        List<MediaItem> items = await mediaCollectionRepository.GetSmartCollectionItems(content.Query);
+        var state = new CollectionEnumeratorState { Seed = playout.Seed + index, Index = 0 };
+        switch (Enum.Parse<PlaybackOrder>(content.Order, true))
+        {
+            case PlaybackOrder.Chronological:
+                return new ChronologicalMediaCollectionEnumerator(items, state);
+            case PlaybackOrder.Shuffle:
+                // TODO: fix this
+                var groupedMediaItems = items.Map(mi => new GroupedMediaItem(mi, null)).ToList();
+                return new ShuffledMediaCollectionEnumerator(groupedMediaItems, state, cancellationToken);
+        }
+
+        return Option<IMediaCollectionEnumerator>.None;
+    }
+
+    private static async Task<PlayoutTemplate> LoadTemplate(Playout playout, CancellationToken cancellationToken)
+    {
+        string yaml = await File.ReadAllTextAsync(playout.TemplateFile, cancellationToken);
+
+        IDeserializer deserializer = new DeserializerBuilder()
+            .WithNamingConvention(CamelCaseNamingConvention.Instance)
+            .WithTypeDiscriminatingNodeDeserializer(
+                o =>
+                {
+                    var keyMappings = new Dictionary<string, Type>
+                    {
+                        { "count", typeof(PlayoutTemplateCountItem) },
+                        { "pad_to_next", typeof(PlayoutTemplatePadToNextItem) },
+                        { "repeat", typeof(PlayoutTemplateRepeatItem) }
+                    };
+
+                    o.AddUniqueKeyTypeDiscriminator<PlayoutTemplateItem>(keyMappings);
+                })
+            .Build();
+
+        return deserializer.Deserialize<PlayoutTemplate>(yaml);
+    }
+
+
+}

ErsatzTV.Infrastructure.MySql/Migrations/20240726025833_Add_Playout_TemplateFile.cs

@@ -0,0 +1,29 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ErsatzTV.Infrastructure.MySql.Migrations
+{
+    /// <inheritdoc />
+    public partial class Add_Playout_TemplateFile : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "TemplateFile",
+                table: "Playout",
+                type: "longtext",
+                nullable: true)
+                .Annotation("MySql:CharSet", "utf8mb4");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "TemplateFile",
+                table: "Playout");
+        }
+    }
+}

ErsatzTV.Infrastructure.MySql/Migrations/TvContextModelSnapshot.cs

@@ -1714,6 +1714,9 @@ namespace ErsatzTV.Infrastructure.MySql.Migrations
                     b.Property<int>("Seed")
                         .HasColumnType("int");
 
+                    b.Property<string>("TemplateFile")
+                        .HasColumnType("longtext");
+
                     b.HasKey("Id");
 
                     b.HasIndex("ChannelId");

ErsatzTV.Infrastructure.Sqlite/Migrations/20240726020713_Add_Playout_TemplateFile.cs

@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ErsatzTV.Infrastructure.Sqlite.Migrations
+{
+    /// <inheritdoc />
+    public partial class Add_Playout_TemplateFile : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "TemplateFile",
+                table: "Playout",
+                type: "TEXT",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "TemplateFile",
+                table: "Playout");
+        }
+    }
+}

ErsatzTV.Infrastructure.Sqlite/Migrations/TvContextModelSnapshot.cs

@@ -1627,6 +1627,9 @@ namespace ErsatzTV.Infrastructure.Sqlite.Migrations
                     b.Property<int>("Seed")
                         .HasColumnType("INTEGER");
 
+                    b.Property<string>("TemplateFile")
+                        .HasColumnType("TEXT");
+
                     b.HasKey("Id");
 
                     b.HasIndex("ChannelId");

ErsatzTV.Infrastructure/Data/Repositories/MediaCollectionRepository.cs

@@ -346,15 +346,25 @@ public class MediaCollectionRepository : IMediaCollectionRepository
     {
         await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync();
 
-        var result = new List<MediaItem>();
-
         Option<SmartCollection> maybeCollection = await dbContext.SmartCollections
             .SelectOneAsync(sc => sc.Id, sc => sc.Id == id);
 
         foreach (SmartCollection collection in maybeCollection)
         {
+            return await GetSmartCollectionItems(collection.Query);
+        }
+
+        return [];
+    }
+
+    public async Task<List<MediaItem>> GetSmartCollectionItems(string query)
+    {
+        await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync();
+
+        var result = new List<MediaItem>();
+
         // elasticsearch doesn't like when we ask for a limit of zero, so use 10,000
-            SearchResult searchResults = await _searchIndex.Search(_client, collection.Query, 0, 10_000);
+        SearchResult searchResults = await _searchIndex.Search(_client, query, 0, 10_000);
 
         var movieIds = searchResults.Items
             .Filter(i => i.Type == LuceneSearchIndex.MovieType)
@@ -408,7 +418,6 @@ public class MediaCollectionRepository : IMediaCollectionRepository
             .Map(i => i.Id)
             .ToList();
         result.AddRange(await GetImageItems(dbContext, imageIds));
-        }
 
         return result.DistinctBy(x => x.Id).ToList();
     }

ErsatzTV/Pages/PlayoutEditor.razor

@@ -15,6 +15,9 @@
             case PlayoutKind.ExternalJson:
                 <span>Add External Json Playout</span>
                 break;
+            case PlayoutKind.Template:
+                <span>Add Template Playout</span>
+                break;
             case PlayoutKind.Block:
                 <span>Add Block Playout</span>
                 break;
@@ -39,12 +42,15 @@
                             </MudSelectItem>
                         }
                     </MudSelect>
-                    @if (Kind == PlayoutKind.ExternalJson)
+                    @switch (Kind)
                     {
+                        case PlayoutKind.ExternalJson:
                             <MudTextField Label="External Json File" @bind-Value="_model.ExternalJsonFile" For="@(() => _model.ExternalJsonFile)"/>
-                    }
-                    else if (string.IsNullOrWhiteSpace(Kind))
-                    {
+                            break;
+                        case PlayoutKind.Template:
+                            <MudTextField Label="Template File" @bind-Value="_model.TemplateFile" For="@(() => _model.TemplateFile)"/>
+                            break;
+                        default:
                             <MudSelect Class="mt-3"
                                        T="ProgramScheduleViewModel"
                                        Label="Schedule"
@@ -54,6 +60,7 @@
                                     <MudSelectItem Value="@schedule">@schedule.Name</MudSelectItem>
                                 }
                             </MudSelect>
+                            break;
                     }
                 </MudCardContent>
                 <MudCardActions>

ErsatzTV/Pages/Playouts.razor

@@ -18,6 +18,11 @@
                 Add Block Playout
             </MudButton>
         </MudTooltip>
+        <MudTooltip Text="This feature is experimental">
+            <MudButton Class="ml-3" Variant="Variant.Filled" Color="Color.Primary" StartIcon="@Icons.Material.Filled.Warning" Href="@($"playouts/add/{PlayoutKind.Template}")">
+                Add Template Playout
+            </MudButton>
+        </MudTooltip>
         <MudTooltip Text="This feature is experimental">
             <MudButton Class="ml-3" Variant="Variant.Filled" Color="Color.Primary" StartIcon="@Icons.Material.Filled.Warning" Href="@($"playouts/add/{PlayoutKind.ExternalJson}")">
                 Add External Json Playout
@@ -63,6 +68,9 @@
                     case ProgramSchedulePlayoutType.Block:
                         <span>Block</span>
                         break;
+                    case ProgramSchedulePlayoutType.Template:
+                        <span>Template</span>
+                        break;
                     case ProgramSchedulePlayoutType.ExternalJson:
                         <span>External Json</span>
                         break;
@@ -123,6 +131,22 @@
                         <div style="width: 48px"></div>
                         <div style="width: 48px"></div>
                     }
+                    else if (context.PlayoutType == ProgramSchedulePlayoutType.Template)
+                    {
+                        <MudTooltip Text="Edit Template File">
+                            <MudIconButton Icon="@Icons.Material.Filled.Edit"
+                                           Disabled="@EntityLocker.IsPlayoutLocked(context.PlayoutId)"
+                                           OnClick="@(_ => EditTemplateFile(context))">
+                            </MudIconButton>
+                        </MudTooltip>
+                        <MudTooltip Text="Reset Playout">
+                            <MudIconButton Icon="@Icons.Material.Filled.Refresh"
+                                           Disabled="@EntityLocker.IsPlayoutLocked(context.PlayoutId)"
+                                           OnClick="@(_ => ResetPlayout(context))">
+                            </MudIconButton>
+                        </MudTooltip>
+                        <div style="width: 48px"></div>
+                    }
                     else if (context.PlayoutType == ProgramSchedulePlayoutType.Block)
                     {
                         <MudTooltip Text="Edit Playout">
@@ -232,8 +256,8 @@
 
     private async Task PlayoutSelected(PlayoutNameViewModel playout)
     {
-        // only show details for flood and block playouts
-        _selectedPlayoutId = playout.PlayoutType is ProgramSchedulePlayoutType.Flood or ProgramSchedulePlayoutType.Block
+        // only show details for flood, block and template playouts
+        _selectedPlayoutId = playout.PlayoutType is ProgramSchedulePlayoutType.Flood or ProgramSchedulePlayoutType.Block or ProgramSchedulePlayoutType.Template
             ? playout.PlayoutId
             : null;
 
@@ -262,6 +286,25 @@
         }
     }
 
+    private async Task EditTemplateFile(PlayoutNameViewModel playout)
+    {
+        var parameters = new DialogParameters { { "TemplateFile", $"{playout.TemplateFile}" } };
+        var options = new DialogOptions { CloseButton = true, MaxWidth = MaxWidth.ExtraLarge };
+
+        IDialogReference dialog = await Dialog.ShowAsync<EditTemplateFileDialog>("Edit Template File", parameters, options);
+        DialogResult result = await dialog.Result;
+        if (!result.Canceled)
+        {
+            await Mediator.Send(new UpdateTemplatePlayout(playout.PlayoutId, result.Data as string ?? playout.TemplateFile), _cts.Token);
+            if (_table != null)
+            {
+                await _table.ReloadServerData();
+            }
+
+            _selectedPlayoutId = null;
+        }
+    }
+
     private async Task DeletePlayout(PlayoutNameViewModel playout)
     {
         var parameters = new DialogParameters { { "EntityType", "playout" }, { "EntityName", $"{playout.ScheduleName} on {playout.ChannelNumber} - {playout.ChannelName}" } };

ErsatzTV/PlayoutKind.cs

@@ -3,5 +3,6 @@ namespace ErsatzTV;
 public static class PlayoutKind
 {
     public const string ExternalJson = "externaljson";
+    public const string Template = "template";
     public const string Block = "block";
 }

ErsatzTV/Shared/EditTemplateFileDialog.razor

@@ -0,0 +1,42 @@
+@implements IDisposable
+
+<MudDialog>
+    <DialogContent>
+        <MudContainer Class="mb-6">
+            <MudText>
+                Edit the playout's template file
+            </MudText>
+        </MudContainer>
+        <MudTextField Label="Template File" @bind-Value="_templateFile"/>
+    </DialogContent>
+    <DialogActions>
+        <MudButton OnClick="Cancel" ButtonType="ButtonType.Reset">Cancel</MudButton>
+        <MudButton Color="Color.Primary" Variant="Variant.Filled" Disabled="@(string.IsNullOrWhiteSpace(_templateFile))" OnClick="Submit">
+            Save Changes
+        </MudButton>
+    </DialogActions>
+</MudDialog>
+
+@code {
+    private readonly CancellationTokenSource _cts = new();
+
+    [Parameter]
+    public string TemplateFile { get; set; }
+
+    [CascadingParameter]
+    MudDialogInstance MudDialog { get; set; }
+
+    private string _templateFile;
+
+    public void Dispose()
+    {
+        _cts.Cancel();
+        _cts.Dispose();
+    }
+
+    protected override void OnParametersSet() => _templateFile = TemplateFile;
+
+    private void Submit() => MudDialog.Close(DialogResult.Ok(_templateFile));
+
+    private void Cancel() => MudDialog.Cancel();
+}

ErsatzTV/Startup.cs

@@ -36,6 +36,7 @@ using ErsatzTV.Core.Metadata;
 using ErsatzTV.Core.Plex;
 using ErsatzTV.Core.Scheduling;
 using ErsatzTV.Core.Scheduling.BlockScheduling;
+using ErsatzTV.Core.Scheduling.TemplateScheduling;
 using ErsatzTV.Core.Trakt;
 using ErsatzTV.FFmpeg.Capabilities;
 using ErsatzTV.FFmpeg.Pipeline;
@@ -655,6 +656,7 @@ public class Startup
         services.AddScoped<IBlockPlayoutBuilder, BlockPlayoutBuilder>();
         services.AddScoped<IBlockPlayoutPreviewBuilder, BlockPlayoutPreviewBuilder>();
         services.AddScoped<IBlockPlayoutFillerBuilder, BlockPlayoutFillerBuilder>();
+        services.AddScoped<ITemplatePlayoutBuilder, TemplatePlayoutBuilder>();
         services.AddScoped<IExternalJsonPlayoutBuilder, ExternalJsonPlayoutBuilder>();
         services.AddScoped<IPlayoutTimeShifter, PlayoutTimeShifter>();
         services.AddScoped<IImageCache, ImageCache>();

ErsatzTV/ViewModels/PlayoutEditViewModel.cs

@@ -10,11 +10,13 @@ public class PlayoutEditViewModel
     public ChannelViewModel Channel { get; set; }
     public ProgramScheduleViewModel ProgramSchedule { get; set; }
     public string ExternalJsonFile { get; set; }
+    public string TemplateFile { get; set; }
 
     public CreatePlayout ToCreate() =>
         Kind switch
         {
             PlayoutKind.ExternalJson => new CreateExternalJsonPlayout(Channel.Id, ExternalJsonFile),
+            PlayoutKind.Template => new CreateTemplatePlayout(Channel.Id, TemplateFile),
             PlayoutKind.Block => new CreateBlockPlayout(Channel.Id),
             _ => new CreateFloodPlayout(Channel.Id, ProgramSchedule.Id)
         };