Fix Windows mpv logging and add log export (#88)

src/main/runtime/mpv-track-diagnostics.ts

@@ -0,0 +1,113 @@
+type MpvTrackDiagnosticEntry = {
+  id: number | null;
+  type: string | null;
+  selected: boolean;
+  external: boolean;
+  lang: string | null;
+  title: string | null;
+  codec: string | null;
+};
+
+export type SubtitleTrackDiagnostics = {
+  trackListReadable: boolean;
+  trackCount: number;
+  subtitleTrackCount: number;
+  activePrimarySid: number | null;
+  selectedSubtitleIds: number[];
+  externalSubtitleCount: number;
+  internalSubtitleCount: number;
+  languages: string[];
+  selectedSubtitleLabels: string[];
+};
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return Boolean(value && typeof value === 'object');
+}
+
+function parseTrackId(value: unknown): number | null {
+  if (typeof value === 'number' && Number.isInteger(value)) {
+    return value;
+  }
+  if (typeof value === 'string') {
+    const trimmed = value.trim();
+    if (!trimmed.length || trimmed === 'no' || trimmed === 'auto') {
+      return null;
+    }
+    const parsed = Number(trimmed);
+    if (Number.isInteger(parsed)) {
+      return parsed;
+    }
+  }
+  return null;
+}
+
+function readString(value: unknown): string | null {
+  return typeof value === 'string' && value.trim().length > 0 ? value.trim() : null;
+}
+
+function normalizeTrack(track: unknown): MpvTrackDiagnosticEntry | null {
+  if (!isRecord(track)) {
+    return null;
+  }
+
+  return {
+    id: parseTrackId(track.id),
+    type: readString(track.type),
+    selected: track.selected === true,
+    external: track.external === true,
+    lang: readString(track.lang),
+    title: readString(track.title),
+    codec: readString(track.codec),
+  };
+}
+
+function formatSubtitleTrackLabel(track: MpvTrackDiagnosticEntry): string {
+  const id = track.id === null ? '?' : String(track.id);
+  const source = track.external ? 'external' : 'internal';
+  const label = track.lang ?? track.title ?? track.codec ?? 'unknown';
+  return `${source}#${id}:${label}`;
+}
+
+export function buildSubtitleTrackDiagnostics(
+  activePrimarySid: number | null,
+  trackList: unknown[] | null,
+): SubtitleTrackDiagnostics {
+  if (!Array.isArray(trackList)) {
+    return {
+      trackListReadable: false,
+      trackCount: 0,
+      subtitleTrackCount: 0,
+      activePrimarySid,
+      selectedSubtitleIds: [],
+      externalSubtitleCount: 0,
+      internalSubtitleCount: 0,
+      languages: [],
+      selectedSubtitleLabels: [],
+    };
+  }
+
+  const normalizedTracks = trackList.map(normalizeTrack).filter((track) => track !== null);
+  const subtitleTracks = normalizedTracks.filter((track) => track.type === 'sub');
+  const selectedSubtitleTracks = subtitleTracks.filter((track) => track.selected);
+  const languages = Array.from(
+    new Set(
+      subtitleTracks
+        .map((track) => track.lang)
+        .filter((language): language is string => language !== null),
+    ),
+  ).sort((left, right) => left.localeCompare(right));
+
+  return {
+    trackListReadable: true,
+    trackCount: normalizedTracks.length,
+    subtitleTrackCount: subtitleTracks.length,
+    activePrimarySid,
+    selectedSubtitleIds: selectedSubtitleTracks
+      .map((track) => track.id)
+      .filter((id): id is number => id !== null),
+    externalSubtitleCount: subtitleTracks.filter((track) => track.external).length,
+    internalSubtitleCount: subtitleTracks.filter((track) => !track.external).length,
+    languages,
+    selectedSubtitleLabels: selectedSubtitleTracks.map(formatSubtitleTrackLabel),
+  };
+}