From 5f597ef56704042fdd0649c345a6ae09c57e1b9a Mon Sep 17 00:00:00 2001
From: edde746 <86283021+edde746@users.noreply.github.com>
Date: Sun, 15 Mar 2026 11:40:45 +0100
Subject: [PATCH] fix: prefer exact language code match in track selection

Fixes #703
---
 lib/services/track_selection_service.dart | 26 +++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/lib/services/track_selection_service.dart b/lib/services/track_selection_service.dart
index da557a11..2c6aca92 100644
--- a/lib/services/track_selection_service.dart
+++ b/lib/services/track_selection_service.dart
@@ -39,9 +39,12 @@ SubtitleTrack? findMpvTrackForPlexSubtitle(PlexSubtitleTrack plexTrack, List<Sub
 
     int score = 0;
 
-    // Language match is most important (+10)
+    // Language match is most important (+10, +1 bonus for exact code match)
     if (_languagesMatch(mpvTrack.language, plexTrack.languageCode)) {
       score += 10;
+      if (_languageCodesExactMatch(mpvTrack.language, plexTrack.languageCode)) {
+        score += 1;
+      }
     }
 
     // Codec match (+5)
@@ -94,9 +97,12 @@ PlexSubtitleTrack? findPlexTrackForMpvSubtitle(SubtitleTrack mpvTrack, List<Plex
 
     int score = 0;
 
-    // Language match is most important (+10)
+    // Language match is most important (+10, +1 bonus for exact code match)
     if (_languagesMatch(mpvTrack.language, plexTrack.languageCode)) {
       score += 10;
+      if (_languageCodesExactMatch(mpvTrack.language, plexTrack.languageCode)) {
+        score += 1;
+      }
     }
 
     // Codec match (+5)
@@ -134,9 +140,12 @@ AudioTrack? findMpvTrackForPlexAudio(PlexAudioTrack plexTrack, List<AudioTrack>
   for (final mpvTrack in mpvTracks) {
     int score = 0;
 
-    // Language match is most important (+10)
+    // Language match is most important (+10, +1 bonus for exact code match)
     if (_languagesMatch(mpvTrack.language, plexTrack.languageCode)) {
       score += 10;
+      if (_languageCodesExactMatch(mpvTrack.language, plexTrack.languageCode)) {
+        score += 1;
+      }
     }
 
     // Codec match (+5)
@@ -176,9 +185,12 @@ PlexAudioTrack? findPlexTrackForMpvAudio(AudioTrack mpvTrack, List<PlexAudioTrac
   for (final plexTrack in plexTracks) {
     int score = 0;
 
-    // Language match is most important (+10)
+    // Language match is most important (+10, +1 bonus for exact code match)
     if (_languagesMatch(mpvTrack.language, plexTrack.languageCode)) {
       score += 10;
+      if (_languageCodesExactMatch(mpvTrack.language, plexTrack.languageCode)) {
+        score += 1;
+      }
     }
 
     // Codec match (+5)
@@ -208,6 +220,12 @@ PlexAudioTrack? findPlexTrackForMpvAudio(AudioTrack mpvTrack, List<PlexAudioTrac
   return bestScore >= 10 ? bestMatch : null;
 }
 
+/// Check if two language codes match exactly (after normalizing case and stripping region suffixes)
+bool _languageCodesExactMatch(String? a, String? b) {
+  if (a == null || b == null) return false;
+  return a.toLowerCase().split('-').first == b.toLowerCase().split('-').first;
+}
+
 /// Check if two language codes refer to the same language
 /// Handles both ISO 639-1 (2-letter) and ISO 639-2 (3-letter) codes
 bool _languagesMatch(String? mpvLang, String? plexLang) {