feat: sync animated anki images to sentence audio

src/anki-integration/animated-image-sync.ts

@@ -0,0 +1,133 @@
+import { execFile as nodeExecFile } from 'node:child_process';
+import * as fs from 'node:fs';
+import * as os from 'node:os';
+import * as path from 'node:path';
+
+import { DEFAULT_ANKI_CONNECT_CONFIG } from '../config';
+import type { AnkiConnectConfig } from '../types';
+
+type NoteInfoLike = {
+  noteId: number;
+  fields: Record<string, { value: string }>;
+};
+
+interface ResolveAnimatedImageLeadInSecondsArgs<TNoteInfo extends NoteInfoLike> {
+  config: Pick<AnkiConnectConfig, 'fields' | 'media'>;
+  noteInfo: TNoteInfo;
+  resolveConfiguredFieldName: (
+    noteInfo: TNoteInfo,
+    ...preferredNames: (string | undefined)[]
+  ) => string | null;
+  retrieveMediaFileBase64: (filename: string) => Promise<string>;
+  probeAudioDurationSeconds?: (buffer: Buffer, filename: string) => Promise<number | null>;
+  logWarn?: (message: string, ...args: unknown[]) => void;
+}
+
+interface ProbeAudioDurationDeps {
+  execFile?: typeof nodeExecFile;
+  mkdtempSync?: typeof fs.mkdtempSync;
+  writeFileSync?: typeof fs.writeFileSync;
+  rmSync?: typeof fs.rmSync;
+}
+
+export function extractSoundFilenames(value: string): string[] {
+  const matches = value.matchAll(/\[sound:([^\]]+)\]/gi);
+  return Array.from(matches, (match) => match[1]?.trim() || '').filter((value) => value.length > 0);
+}
+
+function shouldSyncAnimatedImageToWordAudio(config: Pick<AnkiConnectConfig, 'media'>): boolean {
+  return (
+    config.media?.imageType === 'avif' && config.media?.syncAnimatedImageToWordAudio !== false
+  );
+}
+
+export async function probeAudioDurationSeconds(
+  buffer: Buffer,
+  filename: string,
+  deps: ProbeAudioDurationDeps = {},
+): Promise<number | null> {
+  const execFile = deps.execFile ?? nodeExecFile;
+  const mkdtempSync = deps.mkdtempSync ?? fs.mkdtempSync;
+  const writeFileSync = deps.writeFileSync ?? fs.writeFileSync;
+  const rmSync = deps.rmSync ?? fs.rmSync;
+
+  const tempDir = mkdtempSync(path.join(os.tmpdir(), 'subminer-audio-probe-'));
+  const ext = path.extname(filename) || '.bin';
+  const tempPath = path.join(tempDir, `probe${ext}`);
+  writeFileSync(tempPath, buffer);
+
+  return new Promise((resolve) => {
+    execFile(
+      'ffprobe',
+      [
+        '-v',
+        'error',
+        '-show_entries',
+        'format=duration',
+        '-of',
+        'default=noprint_wrappers=1:nokey=1',
+        tempPath,
+      ],
+      (error, stdout) => {
+        try {
+          if (error) {
+            resolve(null);
+            return;
+          }
+
+          const durationSeconds = Number.parseFloat((stdout || '').trim());
+          resolve(Number.isFinite(durationSeconds) && durationSeconds > 0 ? durationSeconds : null);
+        } finally {
+          rmSync(tempDir, { recursive: true, force: true });
+        }
+      },
+    );
+  });
+}
+
+export async function resolveAnimatedImageLeadInSeconds<TNoteInfo extends NoteInfoLike>({
+  config,
+  noteInfo,
+  resolveConfiguredFieldName,
+  retrieveMediaFileBase64,
+  probeAudioDurationSeconds: probeDuration = probeAudioDurationSeconds,
+  logWarn,
+}: ResolveAnimatedImageLeadInSecondsArgs<TNoteInfo>): Promise<number> {
+  if (!shouldSyncAnimatedImageToWordAudio(config)) {
+    return 0;
+  }
+
+  const wordAudioFieldName = resolveConfiguredFieldName(
+    noteInfo,
+    config.fields?.audio,
+    DEFAULT_ANKI_CONNECT_CONFIG.fields.audio,
+  );
+  if (!wordAudioFieldName) {
+    return 0;
+  }
+
+  const wordAudioValue = noteInfo.fields[wordAudioFieldName]?.value || '';
+  const filenames = extractSoundFilenames(wordAudioValue);
+  if (filenames.length === 0) {
+    return 0;
+  }
+
+  let totalLeadInSeconds = 0;
+  for (const filename of filenames) {
+    const encoded = await retrieveMediaFileBase64(filename);
+    if (!encoded) {
+      logWarn?.('Animated image sync skipped: failed to retrieve word audio', filename);
+      return 0;
+    }
+
+    const durationSeconds = await probeDuration(Buffer.from(encoded, 'base64'), filename);
+    if (!(typeof durationSeconds === 'number' && Number.isFinite(durationSeconds))) {
+      logWarn?.('Animated image sync skipped: failed to probe word audio duration', filename);
+      return 0;
+    }
+
+    totalLeadInSeconds += durationSeconds;
+  }
+
+  return totalLeadInSeconds;
+}