using ErsatzTV.Core.Domain;

namespace ErsatzTV.Application.Channels;

/// <summary>
///     Shared programme-metadata projection for guide output. Both the XMLTV cache builder
///     (<see cref="RefreshChannelDataHandler" />) and the JSON guide query
///     (<see cref="GetChannelGuideDataHandler" />) resolve the display title/subtitle/category from a
///     <see cref="PlayoutItem" /> here so the two representations stay consistent.
/// </summary>
public static class ChannelGuideMetadata
{
    public static string GetTitle(PlayoutItem playoutItem)
    {
        if (!string.IsNullOrWhiteSpace(playoutItem.CustomTitle))
        {
            return playoutItem.CustomTitle;
        }

        return playoutItem.MediaItem switch
        {
            Movie m => m.MovieMetadata.HeadOrNone().Map(mm => mm.Title ?? string.Empty)
                .IfNone("[unknown movie]"),
            Episode e => e.Season.Show.ShowMetadata.HeadOrNone().Map(em => em.Title ?? string.Empty)
                .IfNone("[unknown show]"),
            MusicVideo mv => mv.Artist.ArtistMetadata.HeadOrNone().Map(am => am.Title ?? string.Empty)
                .IfNone("[unknown artist]"),
            OtherVideo ov => ov.OtherVideoMetadata.HeadOrNone().Map(vm => vm.Title ?? string.Empty)
                .IfNone("[unknown video]"),
            RemoteStream rs => rs.RemoteStreamMetadata.HeadOrNone().Map(vm => vm.Title ?? string.Empty)
                .IfNone("[unknown remote stream]"),
            _ => "[unknown]"
        };
    }

    public static string GetSubtitle(PlayoutItem playoutItem)
    {
        if (!string.IsNullOrWhiteSpace(playoutItem.CustomTitle))
        {
            return string.Empty;
        }

        return playoutItem.MediaItem switch
        {
            Episode e => e.EpisodeMetadata.HeadOrNone().Match(
                em => em.Title ?? string.Empty,
                () => string.Empty),
            MusicVideo mv => mv.MusicVideoMetadata.HeadOrNone().Match(
                mvm => mvm.Title ?? string.Empty,
                () => string.Empty),
            Song s => s.SongMetadata.HeadOrNone().Match(
                mvm => mvm.Title ?? string.Empty,
                () => string.Empty),
            _ => string.Empty
        };
    }

    /// <summary>
    ///     The primary guide category, mirroring the fixed <c>&lt;category&gt;</c> the XMLTV templates
    ///     emit per media kind (Movie / Series / Music). Media kinds without a fixed category return null.
    /// </summary>
    public static string GetCategory(PlayoutItem playoutItem) =>
        playoutItem.MediaItem switch
        {
            Movie => "Movie",
            Episode => "Series",
            MusicVideo => "Music",
            Song => "Music",
            _ => null
        };
}