Fix Windows mpv shortcut launch and subtitle dedupe

src/core/services/mpv-protocol.test.ts

@@ -184,6 +184,39 @@ test('dispatchMpvProtocolMessage sets secondary subtitle track based on track li
   assert.deepEqual(state.commands, [{ command: ['set_property', 'secondary-sid', 2] }]);
 });
 
+test('dispatchMpvProtocolMessage prefers the already selected matching secondary track', async () => {
+  const { deps, state } = createDeps();
+
+  await dispatchMpvProtocolMessage(
+    {
+      request_id: MPV_REQUEST_ID_TRACK_LIST_SECONDARY,
+      data: [
+        {
+          type: 'sub',
+          id: 2,
+          lang: 'ja',
+          title: 'ja.srt',
+          selected: false,
+          external: true,
+          'external-filename': '/tmp/dupe.srt',
+        },
+        {
+          type: 'sub',
+          id: 3,
+          lang: 'ja',
+          title: 'ja.srt',
+          selected: true,
+          external: true,
+          'external-filename': '/tmp/dupe.srt',
+        },
+      ],
+    },
+    deps,
+  );
+
+  assert.deepEqual(state.commands, [{ command: ['set_property', 'secondary-sid', 3] }]);
+});
+
 test('dispatchMpvProtocolMessage restores secondary visibility on shutdown', async () => {
   const { deps, state } = createDeps();
 

src/core/services/mpv-protocol.ts

@@ -93,6 +93,97 @@ export interface MpvProtocolHandleMessageDeps {
   restorePreviousSecondarySubVisibility: () => void;
 }
 
+type SubtitleTrackCandidate = {
+  id: number;
+  lang: string;
+  title: string;
+  selected: boolean;
+  external: boolean;
+  externalFilename: string | null;
+};
+
+function normalizeSubtitleTrackCandidate(track: Record<string, unknown>): SubtitleTrackCandidate | null {
+  const id =
+    typeof track.id === 'number'
+      ? track.id
+      : typeof track.id === 'string'
+        ? Number(track.id.trim())
+        : Number.NaN;
+  if (!Number.isInteger(id)) {
+    return null;
+  }
+
+  const externalFilename =
+    typeof track['external-filename'] === 'string' && track['external-filename'].trim().length > 0
+      ? track['external-filename'].trim()
+      : typeof track.external_filename === 'string' && track.external_filename.trim().length > 0
+        ? track.external_filename.trim()
+        : null;
+
+  return {
+    id,
+    lang: String(track.lang || '').trim().toLowerCase(),
+    title: String(track.title || '').trim().toLowerCase(),
+    selected: track.selected === true,
+    external: track.external === true,
+    externalFilename,
+  };
+}
+
+function getSubtitleTrackIdentity(track: SubtitleTrackCandidate): string {
+  if (track.externalFilename) {
+    return `external:${track.externalFilename.toLowerCase()}`;
+  }
+  if (track.title.length > 0) {
+    return `title:${track.title}`;
+  }
+  return `id:${track.id}`;
+}
+
+function pickSecondarySubtitleTrackId(
+  tracks: Array<Record<string, unknown>>,
+  preferredLanguages: string[],
+): number | null {
+  const normalizedLanguages = preferredLanguages
+    .map((language) => language.trim().toLowerCase())
+    .filter((language) => language.length > 0);
+  if (normalizedLanguages.length === 0) {
+    return null;
+  }
+
+  const subtitleTracks = tracks
+    .filter((track) => track.type === 'sub')
+    .map(normalizeSubtitleTrackCandidate)
+    .filter((track): track is SubtitleTrackCandidate => track !== null);
+
+  const dedupedTracks = new Map<string, SubtitleTrackCandidate>();
+  for (const track of subtitleTracks) {
+    const identity = getSubtitleTrackIdentity(track);
+    const existing = dedupedTracks.get(identity);
+    if (!existing || (track.selected && !existing.selected)) {
+      dedupedTracks.set(identity, track);
+    }
+  }
+
+  const uniqueTracks = [...dedupedTracks.values()];
+
+  for (const language of normalizedLanguages) {
+    const selectedMatch = uniqueTracks.find(
+      (track) => track.selected && track.lang === language,
+    );
+    if (selectedMatch) {
+      return selectedMatch.id;
+    }
+
+    const match = uniqueTracks.find((track) => track.lang === language);
+    if (match) {
+      return match.id;
+    }
+  }
+
+  return null;
+}
+
 export function splitMpvMessagesFromBuffer(
   buffer: string,
   onMessage?: MpvMessageParser,
@@ -283,15 +374,11 @@ export async function dispatchMpvProtocolMessage(
       if (Array.isArray(tracks)) {
         const config = deps.getResolvedConfig();
         const languages = config.secondarySub?.secondarySubLanguages || [];
-        const subTracks = tracks.filter((track) => track.type === 'sub');
-        for (const language of languages) {
-          const match = subTracks.find((track) => track.lang === language);
-          if (match) {
-            deps.sendCommand({
-              command: ['set_property', 'secondary-sid', match.id],
-            });
-            break;
-          }
+        const secondaryTrackId = pickSecondarySubtitleTrackId(tracks, languages);
+        if (secondaryTrackId !== null) {
+          deps.sendCommand({
+            command: ['set_property', 'secondary-sid', secondaryTrackId],
+          });
         }
       }
     } else if (msg.request_id === MPV_REQUEST_ID_TRACK_LIST_AUDIO) {

src/core/services/subsync.test.ts

@@ -92,6 +92,52 @@ test('triggerSubsyncFromConfig opens manual picker in manual mode', async () =>
   assert.equal(inProgressState, false);
 });
 
+test('triggerSubsyncFromConfig dedupes repeated subtitle source tracks', async () => {
+  let payloadTrackCount = 0;
+
+  await triggerSubsyncFromConfig(
+    makeDeps({
+      getMpvClient: () => ({
+        connected: true,
+        currentAudioStreamIndex: null,
+        send: () => {},
+        requestProperty: async (name: string) => {
+          if (name === 'path') return '/tmp/video.mkv';
+          if (name === 'sid') return 1;
+          if (name === 'secondary-sid') return 2;
+          if (name === 'track-list') {
+            return [
+              { id: 1, type: 'sub', selected: true, lang: 'jpn' },
+              {
+                id: 2,
+                type: 'sub',
+                selected: true,
+                external: true,
+                lang: 'eng',
+                'external-filename': '/tmp/ref.srt',
+              },
+              {
+                id: 3,
+                type: 'sub',
+                selected: false,
+                external: true,
+                lang: 'eng',
+                'external-filename': '/tmp/ref.srt',
+              },
+            ];
+          }
+          return null;
+        },
+      }),
+      openManualPicker: (payload) => {
+        payloadTrackCount = payload.sourceTracks.length;
+      },
+    }),
+  );
+
+  assert.equal(payloadTrackCount, 1);
+});
+
 test('triggerSubsyncFromConfig reports failures to OSD', async () => {
   const osd: string[] = [];
   await triggerSubsyncFromConfig(

src/core/services/subsync.ts

@@ -76,6 +76,31 @@ function normalizeTrackIds(tracks: unknown[]): MpvTrack[] {
   });
 }
 
+function getSourceTrackIdentity(track: MpvTrack): string {
+  if (track.external && typeof track['external-filename'] === 'string' && track['external-filename'].length > 0) {
+    return `external:${track['external-filename'].toLowerCase()}`;
+  }
+  if (typeof track.id === 'number') {
+    return `id:${track.id}`;
+  }
+  if (typeof track.title === 'string' && track.title.length > 0) {
+    return `title:${track.title.toLowerCase()}`;
+  }
+  return 'unknown';
+}
+
+function dedupeSourceTracks(tracks: MpvTrack[]): MpvTrack[] {
+  const deduped = new Map<string, MpvTrack>();
+  for (const track of tracks) {
+    const identity = getSourceTrackIdentity(track);
+    const existing = deduped.get(identity);
+    if (!existing || (track.selected && !existing.selected)) {
+      deduped.set(identity, track);
+    }
+  }
+  return [...deduped.values()];
+}
+
 export interface TriggerSubsyncFromConfigDeps extends SubsyncCoreDeps {
   isSubsyncInProgress: () => boolean;
   setSubsyncInProgress: (inProgress: boolean) => void;
@@ -123,12 +148,13 @@ async function gatherSubsyncContext(client: MpvClientLike): Promise<SubsyncConte
       const filename = track['external-filename'];
       return typeof filename === 'string' && filename.length > 0;
     });
+  const uniqueSourceTracks = dedupeSourceTracks(sourceTracks);
 
   return {
     videoPath,
     primaryTrack,
     secondaryTrack,
-    sourceTracks,
+    sourceTracks: uniqueSourceTracks,
     audioStreamIndex: client.currentAudioStreamIndex,
   };
 }