fix: restore app-owned youtube subtitle flow

src/main/runtime/youtube-primary-subtitle-notification.ts

@@ -0,0 +1,168 @@
+import { isYoutubeMediaPath } from './youtube-playback';
+import { normalizeYoutubeLangCode } from '../../core/services/youtube/labels';
+
+export type YoutubePrimarySubtitleNotificationTimer = ReturnType<typeof setTimeout> | { id: number };
+
+type SubtitleTrackEntry = {
+  id: number | null;
+  type: string;
+  lang: string;
+  external: boolean;
+};
+
+function parseTrackId(value: unknown): number | null {
+  if (typeof value === 'number' && Number.isInteger(value)) {
+    return value;
+  }
+  if (typeof value === 'string') {
+    const parsed = Number(value.trim());
+    return Number.isInteger(parsed) ? parsed : null;
+  }
+  return null;
+}
+
+function normalizeTrack(entry: unknown): SubtitleTrackEntry | null {
+  if (!entry || typeof entry !== 'object') {
+    return null;
+  }
+  const track = entry as Record<string, unknown>;
+  return {
+    id: parseTrackId(track.id),
+    type: String(track.type || '').trim(),
+    lang: String(track.lang || '').trim(),
+    external: track.external === true,
+  };
+}
+
+export function clearYoutubePrimarySubtitleNotificationTimer(
+  timer: YoutubePrimarySubtitleNotificationTimer | null,
+): void {
+  if (!timer) {
+    return;
+  }
+  if (typeof timer === 'object' && timer !== null && 'id' in timer) {
+    clearTimeout((timer as { id: number }).id);
+    return;
+  }
+  clearTimeout(timer);
+}
+
+function buildPreferredLanguageSet(values: string[]): Set<string> {
+  const normalized = values
+    .map((value) => normalizeYoutubeLangCode(value))
+    .filter((value) => value.length > 0);
+  return new Set(normalized);
+}
+
+function matchesPreferredLanguage(language: string, preferred: Set<string>): boolean {
+  if (preferred.size === 0) {
+    return false;
+  }
+  const normalized = normalizeYoutubeLangCode(language);
+  if (!normalized) {
+    return false;
+  }
+  if (preferred.has(normalized)) {
+    return true;
+  }
+  const base = normalized.split('-')[0] || normalized;
+  return preferred.has(base);
+}
+
+function hasSelectedPrimarySubtitle(
+  sid: number | null,
+  trackList: unknown[] | null,
+  preferredLanguages: Set<string>,
+): boolean {
+  if (sid === null || !Array.isArray(trackList)) {
+    return false;
+  }
+
+  const activeTrack =
+    trackList.map(normalizeTrack).find((track) => track?.type === 'sub' && track.id === sid) ?? null;
+  if (!activeTrack) {
+    return false;
+  }
+  if (activeTrack.external) {
+    return true;
+  }
+  return matchesPreferredLanguage(activeTrack.lang, preferredLanguages);
+}
+
+export function createYoutubePrimarySubtitleNotificationRuntime(deps: {
+  getPrimarySubtitleLanguages: () => string[];
+  notifyFailure: (message: string) => void;
+  schedule: (fn: () => void, delayMs: number) => YoutubePrimarySubtitleNotificationTimer;
+  clearSchedule: (timer: YoutubePrimarySubtitleNotificationTimer | null) => void;
+  delayMs?: number;
+}) {
+  const delayMs = deps.delayMs ?? 5000;
+  let currentMediaPath: string | null = null;
+  let currentSid: number | null = null;
+  let currentTrackList: unknown[] | null = null;
+  let pendingTimer: YoutubePrimarySubtitleNotificationTimer | null = null;
+  let lastReportedMediaPath: string | null = null;
+
+  const clearPendingTimer = (): void => {
+    deps.clearSchedule(pendingTimer);
+    pendingTimer = null;
+  };
+
+  const maybeReportFailure = (): void => {
+    const mediaPath = currentMediaPath?.trim() || '';
+    if (!mediaPath || !isYoutubeMediaPath(mediaPath)) {
+      return;
+    }
+    if (lastReportedMediaPath === mediaPath) {
+      return;
+    }
+    const preferredLanguages = buildPreferredLanguageSet(deps.getPrimarySubtitleLanguages());
+    if (preferredLanguages.size === 0) {
+      return;
+    }
+    if (hasSelectedPrimarySubtitle(currentSid, currentTrackList, preferredLanguages)) {
+      return;
+    }
+    lastReportedMediaPath = mediaPath;
+    deps.notifyFailure('Primary subtitle failed to download or load. Try again from the subtitle modal.');
+  };
+
+  const schedulePendingCheck = (): void => {
+    clearPendingTimer();
+    const mediaPath = currentMediaPath?.trim() || '';
+    if (!mediaPath || !isYoutubeMediaPath(mediaPath)) {
+      return;
+    }
+    pendingTimer = deps.schedule(() => {
+      pendingTimer = null;
+      maybeReportFailure();
+    }, delayMs);
+  };
+
+  return {
+    handleMediaPathChange: (path: string | null): void => {
+      const normalizedPath = typeof path === 'string' && path.trim().length > 0 ? path.trim() : null;
+      if (currentMediaPath !== normalizedPath) {
+        lastReportedMediaPath = null;
+      }
+      currentMediaPath = normalizedPath;
+      currentSid = null;
+      currentTrackList = null;
+      schedulePendingCheck();
+    },
+    handleSubtitleTrackChange: (sid: number | null): void => {
+      currentSid = sid;
+      const preferredLanguages = buildPreferredLanguageSet(deps.getPrimarySubtitleLanguages());
+      if (hasSelectedPrimarySubtitle(currentSid, currentTrackList, preferredLanguages)) {
+        clearPendingTimer();
+      }
+    },
+    handleSubtitleTrackListChange: (trackList: unknown[] | null): void => {
+      currentTrackList = trackList;
+      const preferredLanguages = buildPreferredLanguageSet(deps.getPrimarySubtitleLanguages());
+      if (hasSelectedPrimarySubtitle(currentSid, currentTrackList, preferredLanguages)) {
+        clearPendingTimer();
+      }
+    },
+  };
+}