using System.Collections.Generic;
using System.Linq;
using ErsatzTV.Core.Api;
using ErsatzTV.Core.Api.Scheduling;
using ErsatzTV.Core.Domain;

namespace ErsatzTV.Application.ProgramSchedules;

/// <summary>
///     Maps the polymorphic <see cref="ProgramScheduleItemViewModel" /> hierarchy to the flat,
///     fully-described <see cref="ScheduleItemResponseModel" /> API DTO (issue #126). Subtype-specific
///     fields (Multiple's mode/count, Duration's playoutDuration/tailMode/discardToFillAttempts) are
///     read by pattern-matching the concrete VM type; they are null for other subtypes.
/// </summary>
public static class ScheduleItemResponseMapper
{
    public static ScheduleItemResponseModel ProjectToResponseModel(ProgramScheduleItemViewModel item)
    {
        MultipleMode? multipleMode = null;
        string multipleCount = null;
        TimeSpan? playoutDuration = null;
        TailMode? tailMode = null;
        int? discardToFillAttempts = null;

        switch (item)
        {
            case ProgramScheduleItemMultipleViewModel multiple:
                multipleMode = multiple.MultipleMode;
                multipleCount = multiple.Count;
                break;
            case ProgramScheduleItemDurationViewModel duration:
                playoutDuration = duration.PlayoutDuration;
                tailMode = duration.TailMode;
                discardToFillAttempts = duration.DiscardToFillAttempts;
                break;
        }

        List<int> watermarkIds = item.Watermarks?.Map(w => w.Id).ToList() ?? new List<int>();
        List<int> graphicsElementIds = item.GraphicsElements?.Map(g => g.Id).ToList() ?? new List<int>();
        List<NamedIdResponseModel> watermarks =
            item.Watermarks?.Map(w => new NamedIdResponseModel(w.Id, w.Name)).ToList()
            ?? new List<NamedIdResponseModel>();
        List<NamedIdResponseModel> graphicsElements =
            item.GraphicsElements?.Map(g => new NamedIdResponseModel(g.Id, g.Name)).ToList()
            ?? new List<NamedIdResponseModel>();

        return new ScheduleItemResponseModel(
            item.Id,
            item.Index,
            item.StartType,
            item.StartTime,
            item.FixedStartTimeBehavior,
            item.PlayoutMode,
            item.CollectionType,
            item.Collection?.Id,
            item.MultiCollection?.Id,
            item.SmartCollection?.Id,
            item.RerunCollection?.Id,
            item.MediaItem?.MediaItemId,
            item.Playlist?.Id,
            item.SearchTitle,
            item.SearchQuery,
            item.PlaybackOrder,
            item.MarathonGroupBy,
            item.MarathonShuffleGroups,
            item.MarathonShuffleItems,
            item.MarathonBatchSize,
            item.FillWithGroupMode,
            multipleMode,
            multipleCount,
            playoutDuration,
            tailMode,
            discardToFillAttempts,
            item.CustomTitle,
            item.GuideMode,
            item.PreRollFiller?.Id,
            item.MidRollFiller?.Id,
            item.PostRollFiller?.Id,
            item.TailFiller?.Id,
            item.FallbackFiller?.Id,
            watermarkIds,
            graphicsElementIds,
            item.PreferredAudioLanguageCode,
            item.PreferredAudioTitle,
            item.PreferredSubtitleLanguageCode,
            item.SubtitleMode,
            item.Collection?.Name,
            item.MultiCollection?.Name,
            item.SmartCollection?.Name,
            item.RerunCollection?.Name,
            item.Playlist?.Name,
            item.Playlist?.PlaylistGroupId,
            item.MediaItem?.Name,
            item.PreRollFiller?.Name,
            item.MidRollFiller?.Name,
            item.PostRollFiller?.Name,
            item.TailFiller?.Name,
            item.FallbackFiller?.Name,
            watermarks,
            graphicsElements,
            item.Name,
            item.DurationEstimate);
    }

    public static ScheduleItemsResponseModel ProjectToResponseModel(ProgramScheduleItemsWithDurationViewModel vm) =>
        new(
            vm.Items.Map(ProjectToResponseModel).ToList(),
            vm.TotalDurationEstimate);
}