🆕 程式碼實作

1. src/day8_speech_to_text.js（新增）
   // src/day8_speech_to_text.js
   import fs from "fs";
   import path from "path";
   import { openai } from "./aiClient.js";

/**

• 下載遠端檔到暫存目錄（Node 18+ 內建 fetch）
• @param {string} url
• @returns {Promise} 下載後的本機暫存檔路徑
  */
  async function downloadToTemp(url) {
  const res = await fetch(url);
  if (!res.ok) {
  throw new Error(下載失敗：${res.status} ${res.statusText});
  }
  const buf = Buffer.from(await res.arrayBuffer());
  const ext = guessExtFromContentType(res.headers.get("content-type")) || ".tmp";
  const tmpDir = path.join(process.cwd(), "outputs", "audio");
  if (!fs.existsSync(tmpDir)) fs.mkdirSync(tmpDir, { recursive: true });
  const filePath = path.join(tmpDir, audio_${Date.now()}${ext});
  fs.writeFileSync(filePath, buf);
  return filePath;
  }

function guessExtFromContentType(ct) {
if (!ct) return "";
if (ct.includes("audio/mpeg")) return ".mp3";
if (ct.includes("audio/mp4")) return ".m4a";
if (ct.includes("audio/x-m4a")) return ".m4a";
if (ct.includes("audio/wav")) return ".wav";
if (ct.includes("audio/webm")) return ".webm";
if (ct.includes("video/mp4")) return ".mp4"; // 有些錄音會是 mp4 容器
return "";
}

/**

• 將語音檔轉成文字
• @param {Object} opts
• @param {string} [opts.filePath] - 本地檔案路徑
• @param {string} [opts.url] - 遠端 URL（二擇一）
• @param {string} [opts.language] - 語言提示（如 "zh", "en", "ja"）
• @param {string} [opts.prompt] - 自訂詞彙/領域提示，例如專有名詞
• @param {boolean} [opts.detailed=false] - 是否需要詳細段落（若模型支援 verbose_json）
• @returns {Promise<{ text: string, raw?: any, saved: {txt: string, json: string} }>}
  */
  export async function transcribe(opts = {}) {
  let { filePath, url, language, prompt, detailed = false } = opts;
  if (!filePath && !url) {
  throw new Error("請提供 filePath（本地檔）或 url（遠端）其一。");
  }

// 若是 URL 先下載
let localPath = filePath;
if (!localPath && url) {
localPath = await downloadToTemp(url);
}
if (!fs.existsSync(localPath)) {
throw new Error(找不到檔案：${localPath});
}

// 以 Readable 方式傳入
const file = await fs.createReadStream(localPath);

// 模型：gpt-4o-transcribe（OpenAI 2025 推薦語音轉寫）
// 註：部分參數（如 response_format）依模型支援度而定
const baseReq = {
file,
model: "gpt-4o-transcribe",
// language 與 prompt 為可選，有助於專有名詞與口音辨識
...(language ? { language } : {}),
...(prompt ? { prompt } : {}),
};

let result;
try {
// 預設回傳純文字
result = await openai.audio.transcriptions.create(baseReq);
} catch (e) {
// 有些環境需要明確 mime 或副檔名提示；或 fallback whisper-1
// 你也可以在這裡實作重試/降級
throw e;
}

const text = (result?.text || "").trim();

// （可選）嘗試詳細段落（若模型支援 verbose_json）
let detailedJson = null;
if (detailed) {
try {
const verbose = await openai.audio.transcriptions.create({
...baseReq,
response_format: "verbose_json",
});
detailedJson = verbose || null;
} catch {
// 若不支援或失敗，忽略即可
detailedJson = null;
}
}

// 落檔 outputs/transcripts
const outDir = path.join(process.cwd(), "outputs", "transcripts");
if (!fs.existsSync(outDir)) fs.mkdirSync(outDir, { recursive: true });
const base = path.basename(localPath).replace(/.[^.]+$/, "");
const txtPath = path.join(outDir, ${base}.txt);
const jsonPath = path.join(outDir, ${base}.json);
fs.writeFileSync(txtPath, text, "utf-8");
fs.writeFileSync(
jsonPath,
JSON.stringify({ text, detailed: detailedJson }, null, 2),
"utf-8"
);

return { text, raw: detailedJson, saved: { txt: txtPath, json: jsonPath } };
}

2. index.js（修改：加入 STT 入口）
   // index.js
   import { englishTeacher, codeReview, sentimentClassify } from "./src/day3_prompt_engineering.js";
   import { newsToJson } from "./src/day4_text_to_json.js";
   import { chatOnce, resetSession } from "./src/day5_chat_history.js";
   import { textToImage } from "./src/day6_text_to_image.js";
   import { imageToJson } from "./src/day7_image_to_text.js";
   import { transcribe } from "./src/day8_speech_to_text.js";

const args = Object.fromEntries(
process.argv.slice(2).reduce((acc, cur, i, arr) => {
if (cur.startsWith("--")) {
const key = cur.replace(/^--/, "");
const val = arr[i + 1] && !arr[i + 1].startsWith("--") ? arr[i + 1] : true;
acc.push([key, val]);
}
return acc;
}, [])
);

async function main() {
const task = args.task || "chat";

if (task === "stt") {
const filePath = args.filePath || null;
const url = args.url || null;
const language = args.lang || ""; // 例："zh" | "en" | "ja"
const prompt = args.prompt || ""; // 專有名詞提示
const detailed = args.detailed === "true" || args.detailed === true;

const { text, saved } = await transcribe({ filePath, url, language, prompt, detailed });
console.log("\n=== 語音轉文字（STT） ===\n");
console.log(text);
console.log("\n已儲存：");
console.log("- TXT:", saved.txt);
console.log("- JSON:", saved.json);

} else if (task === "vision") {
const imagePath = args.imagePath || null;
const imageUrl = args.imageUrl || null;
const wantOCR = args.ocr === "true" || args.ocr === true;
const length = args.length || "medium";
const out = await imageToJson({ imagePath, imageUrl, wantOCR, length });
console.log("\n=== 圖片 → JSON 描述 ===\n");
console.log(JSON.stringify(out, null, 2));

} else if (task === "image") {
const prompt = args.text || "一隻戴著太空頭盔的柴犬，漂浮在月球上，插著台灣國旗";
const size = args.size || "512x512";
const n = args.n ? Number(args.n) : 1;
const urls = await textToImage(prompt, { size, n });
console.log("\n=== 生成圖片 ===\n");
urls.forEach((f) => console.log("已儲存：" + f));

} else if (task === "chat") {
const sessionId = args.session || "default";
if (args.reset) {
resetSession(sessionId);
console.log(已重設會話：${sessionId});
return;
}
const input = args.text || "嗨，我想規劃 3 天 2 夜的台中旅遊行程。";
const { reply } = await chatOnce(input, { sessionId });
console.log(\n[${sessionId}] AI：\n${reply}\n);

} else if (task === "teacher") {
const out = await englishTeacher(args.text || "He go to school every day.");
console.log("\n=== 英文老師 ===\n");
console.log(out);

} else if (task === "review") {
const out = await codeReview("function sum(arr){ return arr.reduce((a,b)=>a+b,0) }");
console.log("\n=== 程式碼審查 ===\n");
console.log(out);

} else if (task === "sentiment") {
const out = await sentimentClassify(args.text || "今天心情糟透了，事情一團亂。");
console.log("\n=== 情緒分類(JSON) ===\n");
console.log(out);

} else if (task === "json_summary") {
const out = await newsToJson(args.text || "OpenAI 發布新模型，效能大幅提升。");
console.log("\n=== 新聞 JSON 摘要 ===\n");
console.log(out);

} else {
console.log("未知任務，請使用 --task stt | vision | image | chat | teacher | review | sentiment | json_summary");
}
}

main().catch((e) => {
console.error("發生錯誤：", e.message);
process.exit(1);
});

3. package.json（新增 Script）
   {
   "scripts": {
   "day8:stt:file": "node index.js --task stt --filePath sample/audio_zh.mp3 --lang zh --detailed true",
   "day8:stt:url": "node index.js --task stt --url https://example.com/demo.m4a --lang zh"
   }
   }

▶️ CLI 操作範例

轉寫本地檔，中文，輸出詳細段落（若模型支援）

npm run day8:stt:file --silent

轉寫遠端 URL（下載到暫存再轉寫）

npm run day8:stt:url --silent

自定領域提示（提升專有名詞正確率）

node index.js --task stt --filePath sample/meeting.m4a --lang zh --prompt "專案名：SmartGo Plus；人名：小王、小美；術語：RAG、LIFF、IIS"

產出檔案示例：

outputs/transcripts/meeting.txt
outputs/transcripts/meeting.json // { text, detailed?: {...} }