TV Series playback from episode list does not require mediaSourceId

CinemaJellyfin/CinemaMediaSourceManager.cs

@@ -247,6 +247,10 @@ sealed class CinemaMediaSourceManager : IMediaSourceManager
 						// We need to directly inspect the video file and therefore need to know which
 						// version to specifically return. For free accounts it is not possible to just
 						// read files at random, for VIP accounts that would slow playback startup also.
+						// Warning: We assume GetVideoVersionsEnumerate keeps the order between its input and output collections
+						Video? videoVer;
+						int idxVer;
+						if (!sortByPrefs) {
 							Guid mediaSourceId;
 							if (ctx == null
 								|| !ctx.Items.TryGetValue(ContextItemsMediaSourceIdKey, out object? mediaSourceIdO)
@@ -254,18 +258,17 @@ sealed class CinemaMediaSourceManager : IMediaSourceManager
 								|| (!Guid.TryParse(mediaSourceIdS, out mediaSourceId)))
 								throw new InvalidOperationException("For precise stream indexing knowing mediaSourceId is required.");
 							
-						// Warning: We assume GetVideoVersionsEnumerate keeps the order between its input and output collections
-						int idxVer = 0;
-						Video? videoVer = null;
-						foreach (Video i in items)
-							if ((!sortByPrefs && i.Id == mediaSourceId)
-									|| (sortByPrefs && idxVer == bestIdx))
-							{
-								videoVer = i;
-								break;
+							idxVer = -1;
+							videoVer = items.Where((x, idx) => { 
+								bool isMatch = x.Id == mediaSourceId;
+								if (isMatch)
+									idxVer = idx;
+								return isMatch;
+							}).FirstOrDefault();
+						} else {
+							idxVer = bestIdx;
+							videoVer = items.Skip(bestIdx).FirstOrDefault();
 						}
-							else
-								idxVer++;
 						if (videoVer == null)
 							// Version not found, return empty set
 							break;

CinemaJellyfin/CinemaServiceRegistrator.cs

@@ -104,7 +104,9 @@ public class CinemaServiceRegistrator : IPluginServiceRegistrator
 				// Fallback to the obsolete query argument
 				if (!context.ActionArguments.TryGetValue("mediaSourceId", out object? mediaSourceIdO)
 				|| (mediaSourceId = mediaSourceIdO as string) == null)
-					throw new InvalidOperationException("Cannot extract MediaSourceId from the Jellyfin's action MediaInfo.GetPostedPlaybackInfo.");
+					// It is optional in certain situations
+					return;
+					//throw new InvalidOperationException("Cannot extract MediaSourceId from the Jellyfin's action MediaInfo.GetPostedPlaybackInfo.");
 			}
 
 			context.HttpContext.Items.Add(CinemaMediaSourceManager.ContextItemsMediaSourceIdKey, mediaSourceId);