Search credits from the end of episode

ConfusedPolarBear.Plugin.IntroSkipper/Analyzers/ChapterAnalyzer.cs

@@ -96,6 +96,11 @@ public class ChapterAnalyzer : IMediaFileAnalyzer
             config.MaximumIntroDuration :
             config.MaximumEpisodeCreditsDuration;
 
+        if (chapters.Count == 0)
+        {
+            return null;
+        }
+
         if (mode == AnalysisMode.Credits)
         {
             // Since the ending credits chapter may be the last chapter in the file, append a virtual
@@ -104,8 +109,57 @@ public class ChapterAnalyzer : IMediaFileAnalyzer
             {
                 StartPositionTicks = TimeSpan.FromSeconds(episode.Duration).Ticks
             });
+
+            // Check all chapters in reverse order, skipping the virtual chapter
+            for (int i = chapters.Count - 2; i >= 0; i--)
+            {
+                var current = chapters[i];
+                var next = chapters[i + 1];
+
+                if (string.IsNullOrWhiteSpace(current.Name))
+                {
+                    continue;
                 }
 
+                var currentRange = new TimeRange(
+                    TimeSpan.FromTicks(current.StartPositionTicks).TotalSeconds,
+                    TimeSpan.FromTicks(next.StartPositionTicks).TotalSeconds);
+
+                var baseMessage = string.Format(
+                    CultureInfo.InvariantCulture,
+                    "{0}: Chapter \"{1}\" ({2} - {3})",
+                    episode.Path,
+                    current.Name,
+                    currentRange.Start,
+                    currentRange.End);
+
+                if (currentRange.Duration < minDuration || currentRange.Duration > maxDuration)
+                {
+                    _logger.LogTrace("{Base}: ignoring (invalid duration)", baseMessage);
+                    continue;
+                }
+
+                // Regex.IsMatch() is used here in order to allow the runtime to cache the compiled regex
+                // between function invocations.
+                var match = Regex.IsMatch(
+                    current.Name,
+                    expression,
+                    RegexOptions.None,
+                    TimeSpan.FromSeconds(1));
+
+                if (!match)
+                {
+                    _logger.LogTrace("{Base}: ignoring (does not match regular expression)", baseMessage);
+                    continue;
+                }
+
+                matchingChapter = new(episode.EpisodeId, currentRange);
+                _logger.LogTrace("{Base}: okay", baseMessage);
+                break;
+            }
+        }
+        else
+        {
             // Check all chapters
             for (int i = 0; i < chapters.Count - 1; i++)
             {
@@ -168,6 +222,7 @@ public class ChapterAnalyzer : IMediaFileAnalyzer
                 _logger.LogTrace("{Base}: okay", baseMessage);
                 break;
             }
+        }
 
         return matchingChapter;
     }

ConfusedPolarBear.Plugin.IntroSkipper/Configuration/PluginConfiguration.cs

@@ -103,7 +103,7 @@ public class PluginConfiguration : BasePluginConfiguration
     /// Gets or sets the regular expression used to detect ending credit chapters.
     /// </summary>
     public string ChapterAnalyzerEndCreditsPattern { get; set; } =
-        @"(^|\s)(Credits?|Ending)(\s|$)";
+        @"(^|\s)(Credits?|ED|Ending)(\s|$)";
 
     // ===== Playback settings =====