feat: 新增歌詞翻譯模組和 OpenCC 翻譯引擎

src/renderer/services/lyricTranslation.ts

@@ -0,0 +1,28 @@
+import { useSettingsStore } from '@/store/modules/settings';
+import type { ILyricText } from '@/types/music';
+
+/**
+ * Translate lyric lines according to selected engine.
+ * Supports runtime-loading `opencc-rust` from CDN and caches the converter.
+ */
+export async function translateLyrics(lines: ILyricText[] | undefined) {
+  if (!lines || lines.length === 0) return lines || [];
+
+  const settingsStore = useSettingsStore();
+  const engine = settingsStore.setData?.lyricTranslationEngine || 'none';
+
+  switch (engine) {
+    case 'opencc': {
+      const mod: any = await import('./translation-engines/opencc');
+      const engineMod = await mod.ensureOpenccConverter();
+      return engineMod.translateLines(lines);
+    }
+    default: {
+      return lines.map((l) => ({ ...l, trText: l.trText || '' }));
+    }
+  }
+}
+
+export default {
+  translateLyrics
+};

src/renderer/services/translation-engines/index.ts

@@ -0,0 +1,3 @@
+// Re-export available translation engines from this folder.
+// Add more engines here as separate files and re-export them.
+export * from './opencc';

src/renderer/services/translation-engines/opencc.ts

@@ -0,0 +1,94 @@
+import type { ILyricText } from '@/types/music';
+
+let _inited = false;
+let _converter: any = null;
+
+export async function init(): Promise<void> {
+  if (_inited) return;
+  const mod: any = await import('https://cdn.jsdelivr.net/npm/opencc-rust/dist/opencc-rust.mjs');
+  if (!mod?.initOpenccRust || !mod?.getConverter) {
+    throw new Error('opencc-rust module missing expected exports');
+  }
+  await mod.initOpenccRust();
+  _converter = mod.getConverter();
+  _inited = true;
+}
+
+export async function convert(text: string): Promise<string> {
+  await init();
+  if (!_converter) return text;
+  return _converter.convert(text);
+}
+
+export async function convertLines(lines: string[]) {
+  await init();
+  if (!_converter) return lines.slice();
+
+  const cjkRe = /[\u4e00-\u9fff]/;
+
+  const convertOne = async (s: string) => {
+    const src = (s || '').trim();
+    if (!src || !cjkRe.test(src)) return '';
+    try {
+      return await _converter.convert(src);
+    } catch (e) {
+      console.warn('opencc convertLines item failed:', e);
+      return '';
+    }
+  };
+
+  const results = await Promise.all(lines.map((s) => convertOne(s)));
+  return results;
+}
+
+export async function translateLines(lines: ILyricText[]) {
+  if (!lines || lines.length === 0) return lines.slice();
+  const srcInfo = lines.map((l) => {
+    const hasTr = !!(l.trText && l.trText.trim() !== '');
+    return {
+      src: hasTr ? (l.trText || '').trim() : (l.text || '').trim(),
+      targetIsTr: hasTr
+    };
+  });
+
+  const srcLines = srcInfo.map((s) => s.src);
+  const converted = await convertLines(srcLines);
+
+  return lines.map((l, i) => {
+    const { targetIsTr } = srcInfo[i];
+    const conv = converted[i] || '';
+    if (targetIsTr) {
+      const tr = conv || l.trText || l.text || '';
+      return { ...l, trText: tr };
+    }
+    const txt = conv || l.text || '';
+    return { ...l, text: txt };
+  });
+}
+
+export default {
+  init,
+  convert,
+  convertLines,
+  translateLines
+};
+
+// Ensure the engine is initialized and return public API.
+let _ensurePromise: Promise<any> | null = null;
+export async function ensureOpenccConverter() {
+  if (_ensurePromise) return _ensurePromise;
+  _ensurePromise = (async () => {
+    try {
+      await init();
+    } catch (e) {
+      console.warn('opencc ensureOpenccConverter init failed:', e);
+    }
+    return {
+      init,
+      convert,
+      convertLines,
+      translateLines
+    };
+  })();
+  return _ensurePromise;
+}