using System;
using System.Linq;
using ErsatzTV.Core.Domain;

namespace ErsatzTV.Application.Playouts
{
    internal static class Mapper
    {
        internal static PlayoutItemViewModel ProjectToViewModel(PlayoutItem playoutItem) =>
            new(
                GetDisplayTitle(playoutItem.MediaItem),
                playoutItem.StartOffset,
                GetDisplayDuration(playoutItem.MediaItem));

        private static string GetDisplayTitle(MediaItem mediaItem)
        {
            switch (mediaItem)
            {
                case Episode e:
                    string showTitle = e.Season.Show.ShowMetadata.HeadOrNone()
                        .Map(sm => $"{sm.Title} - ").IfNone(string.Empty);
                    var episodeNumbers = e.EpisodeMetadata.Map(em => em.EpisodeNumber).ToList();
                    var episodeTitles = e.EpisodeMetadata.Map(em => em.Title).ToList();
                    if (episodeNumbers.Count == 0 || episodeTitles.Count == 0)
                    {
                        return "[unknown episode]";
                    }

                    var numbersString = $"e{string.Join('e', episodeNumbers.Map(n => $"{n:00}"))}";
                    var titlesString = $"{string.Join('/', episodeTitles)}";
                    return $"{showTitle}s{e.Season.SeasonNumber:00}{numbersString} - {titlesString}";
                case Movie m:
                    return m.MovieMetadata.HeadOrNone().Map(mm => mm.Title).IfNone("[unknown movie]");
                case MusicVideo mv:
                    string artistName = mv.Artist.ArtistMetadata.HeadOrNone()
                        .Map(am => $"{am.Title} - ").IfNone(string.Empty);
                    return mv.MusicVideoMetadata.HeadOrNone()
                        .Map(mvm => $"{artistName}{mvm.Title}")
                        .IfNone("[unknown music video]");
                default:
                    return string.Empty;
            }
        }

        private static string GetDisplayDuration(MediaItem mediaItem)
        {
            MediaVersion version = mediaItem switch
            {
                Movie m => m.MediaVersions.Head(),
                Episode e => e.MediaVersions.Head(),
                MusicVideo mv => mv.MediaVersions.Head(),
                _ => throw new ArgumentOutOfRangeException(nameof(mediaItem))
            };

            return string.Format(
                version.Duration.TotalHours >= 1 ? @"{0:h\:mm\:ss}" : @"{0:mm\:ss}",
                version.Duration);
        }
    }
}