feat: add TV show trailer downloads, episode trailers, and movie/TV trailer separation

- Download trailers for TV shows from TMDB with separate sources and an
  independent max-count cap (0 disables a category)
- Play trailers before TV episodes via IIntroProvider, limited to the first
  episode a user watches each day
- Tag TV show trailers in their NFO so movies only get movie trailers and
  episodes only get TV show trailers

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Jellyfin.Plugin.CinemaTrailers4Jellyfins/Services/TrailerIntroProvider.cs

@@ -8,6 +8,7 @@ using Jellyfin.Data.Enums;
 using Jellyfin.Database.Implementations.Entities;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Entities.Movies;
+using MediaBrowser.Controller.Entities.TV;
 using MediaBrowser.Controller.Library;
 using Microsoft.Extensions.Logging;
 
@@ -22,6 +23,10 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.Services
         private static readonly ConcurrentDictionary<Guid, HashSet<Guid>> _seenByUser = new();
         private static readonly object _seenLock = new();
 
+        // Per-user date of the last episode that received trailers, so only the
+        // first episode a user watches each day gets them.
+        private static readonly ConcurrentDictionary<Guid, DateTime> _lastEpisodeTrailerDateByUser = new();
+
         private readonly ILibraryManager _libraryManager;
         private readonly ILogger<TrailerIntroProvider> _logger;
 
@@ -39,8 +44,32 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.Services
             if (config == null || config.TrailersPerMovie <= 0)
                 return Task.FromResult(Enumerable.Empty<IntroInfo>());
 
-            if (item is not Movie)
-                return Task.FromResult(Enumerable.Empty<IntroInfo>());
+            // The item used for genre/rating filtering. For episodes this is the
+            // parent series, since episodes rarely carry their own genre metadata.
+            BaseItem feature;
+            bool isEpisode;
+
+            switch (item)
+            {
+                case Movie:
+                    feature = item;
+                    isEpisode = false;
+                    break;
+
+                case Episode episode:
+                    if (!config.TrailersForEpisodes)
+                        return Task.FromResult(Enumerable.Empty<IntroInfo>());
+
+                    if (!IsFirstEpisodeOfDay(user.Id))
+                        return Task.FromResult(Enumerable.Empty<IntroInfo>());
+
+                    feature = episode.Series ?? (BaseItem)episode;
+                    isEpisode = true;
+                    break;
+
+                default:
+                    return Task.FromResult(Enumerable.Empty<IntroInfo>());
+            }
 
             var outputFolder = config.DownloadFolder?.TrimEnd(
                 Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
@@ -62,21 +91,24 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.Services
                 .OfType<Movie>()
                 .Where(m =>
                     m.Path?.StartsWith(outputFolder, StringComparison.OrdinalIgnoreCase) == true
-                    && m.LocalTrailers.Count > 0)
+                    && m.LocalTrailers.Count > 0
+                    // Keep TV show trailers for episodes and movie trailers for movies separate.
+                    && m.Tags.Contains(TrailerTags.TvShow, StringComparer.OrdinalIgnoreCase) == isEpisode)
                 .SelectMany(m => m.LocalTrailers.Select(t => (Movie: m, Trailer: t)))
                 .ToList();
 
             if (pairs.Count == 0)
             {
                 _logger.LogDebug(
-                    "|CinemaTrailers4Jellyfins| No indexed trailers in {Folder}. "
+                    "|CinemaTrailers4Jellyfins| No indexed {Kind} trailers in {Folder}. "
                     + "Ensure the output folder is added as a Jellyfin Movies library and scanned.",
+                    isEpisode ? "TV show" : "movie",
                     outputFolder);
                 return Task.FromResult(Enumerable.Empty<IntroInfo>());
             }
 
             // Apply enabled filters. If nothing survives, fall back to the full pool.
-            var filtered = ApplyFilters(pairs, item, config);
+            var filtered = ApplyFilters(pairs, feature, config);
             var pool = filtered.Count > 0 ? filtered : pairs;
 
             // Prefer unseen trailers within the pool; reset the cycle when all have been shown.
@@ -149,6 +181,36 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.Services
             }
         }
 
+        /// <summary>
+        /// Returns true (and records today's date) only the first time this is called
+        /// for a given user on a given day.
+        /// </summary>
+        private static bool IsFirstEpisodeOfDay(Guid userId)
+        {
+            var today = DateTime.Now.Date;
+            var isFirst = false;
+
+            _lastEpisodeTrailerDateByUser.AddOrUpdate(
+                userId,
+                _ =>
+                {
+                    isFirst = true;
+                    return today;
+                },
+                (_, lastDate) =>
+                {
+                    if (lastDate < today)
+                    {
+                        isFirst = true;
+                        return today;
+                    }
+
+                    return lastDate;
+                });
+
+            return isFirst;
+        }
+
         private static void MarkSeen(Guid userId, IEnumerable<Guid> trailerIds)
         {
             lock (_seenLock)