230 lines
7.5 KiB
TypeScript
230 lines
7.5 KiB
TypeScript
import type {IncomingMessage, ServerResponse} from 'node:http';
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import type {Plugin} from 'vite';
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const BAIDU_APP_ID = '8077750';
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const BAIDU_API_KEY = '7TTNPHbh3bBuKY5gX7vNS2Mp';
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const BAIDU_SECRET_KEY = 'jjvoStfvqGlvlp06P0zvuQynSGRJn9Xq';
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const BAIDU_TOKEN_URL = 'https://aip.baidubce.com/oauth/2.0/token';
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const BAIDU_ASR_URL = 'https://vop.baidu.com/pro_api';
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const MAX_AUDIO_BYTES = 2 * 1024 * 1024;
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const MIN_AUDIO_BYTES = 3_200;
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const REQUEST_TIMEOUT_MS = 20_000;
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type BaiduTokenResponse = {
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access_token?: string;
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expires_in?: number;
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error?: string;
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error_description?: string;
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};
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type BaiduAsrResponse = {
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err_no?: number;
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err_msg?: string;
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result?: string[];
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};
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let cachedToken = '';
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let cachedTokenExpiresAt = 0;
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let pendingTokenRequest: Promise<string> | null = null;
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class HttpError extends Error {
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statusCode: number;
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constructor(statusCode: number, message: string) {
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super(message);
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this.statusCode = statusCode;
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}
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}
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const sendJson = (res: ServerResponse, statusCode: number, payload: object) => {
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if (res.writableEnded || res.destroyed) return;
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res.statusCode = statusCode;
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res.setHeader('Content-Type', 'application/json; charset=utf-8');
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res.setHeader('Cache-Control', 'no-store');
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res.end(JSON.stringify(payload));
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};
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const readAudioBody = (req: IncomingMessage) => new Promise<Buffer>((resolve, reject) => {
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const chunks: Buffer[] = [];
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let size = 0;
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let tooLarge = false;
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req.on('data', (chunk: Buffer) => {
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size += chunk.length;
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if (size > MAX_AUDIO_BYTES) {
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tooLarge = true;
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return;
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}
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chunks.push(chunk);
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});
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req.on('end', () => {
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if (tooLarge) {
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reject(new HttpError(413, '录音超过60秒，请缩短问题后重试'));
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return;
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}
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const audio = Buffer.concat(chunks);
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if (audio.length < MIN_AUDIO_BYTES) {
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reject(new HttpError(400, '录音时间太短，请重新说一遍'));
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return;
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}
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resolve(audio);
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});
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req.on('error', () => reject(new HttpError(400, '读取录音失败')));
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});
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const fetchWithTimeout = async (url: string, init: RequestInit, timeoutMs = REQUEST_TIMEOUT_MS) => {
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const controller = new AbortController();
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const timeoutId = setTimeout(() => controller.abort(), timeoutMs);
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try {
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return await fetch(url, {...init, signal: controller.signal});
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} finally {
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clearTimeout(timeoutId);
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}
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};
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const requestAccessToken = async () => {
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const body = new URLSearchParams({
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grant_type: 'client_credentials',
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client_id: BAIDU_API_KEY,
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client_secret: BAIDU_SECRET_KEY,
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});
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let response: Response;
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try {
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response = await fetchWithTimeout(BAIDU_TOKEN_URL, {
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method: 'POST',
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headers: {'Content-Type': 'application/x-www-form-urlencoded'},
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body,
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});
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} catch (error) {
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if (error instanceof Error && error.name === 'AbortError') {
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throw new HttpError(504, '百度语音鉴权超时，请稍后重试');
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}
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throw new HttpError(502, '无法连接百度语音鉴权服务');
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}
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const data = await response.json().catch(() => ({})) as BaiduTokenResponse;
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if (!response.ok || !data.access_token) {
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console.error('Baidu token request failed:', data.error, data.error_description);
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throw new HttpError(502, '百度语音应用鉴权失败，请检查API Key和Secret Key');
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}
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cachedToken = data.access_token;
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const expiresInSeconds = Math.max(300, Number(data.expires_in) || 2_592_000);
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cachedTokenExpiresAt = Date.now() + Math.max(60, expiresInSeconds - 300) * 1000;
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return cachedToken;
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};
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const getAccessToken = async (forceRefresh = false) => {
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if (!forceRefresh && cachedToken && Date.now() < cachedTokenExpiresAt) return cachedToken;
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if (!forceRefresh && pendingTokenRequest) return pendingTokenRequest;
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pendingTokenRequest = requestAccessToken().finally(() => {
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pendingTokenRequest = null;
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});
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return pendingTokenRequest;
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};
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const mapBaiduError = (data: BaiduAsrResponse) => {
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switch (data.err_no) {
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case 3301:
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return new HttpError(422, '没有识别到清晰语音，请靠近麦克风重新说一遍');
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case 3302:
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case 110:
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case 111:
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return new HttpError(502, '百度语音鉴权已失效，请重新获取凭证');
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case 3303:
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return new HttpError(503, '百度语音服务繁忙，请稍后重试');
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case 3304:
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return new HttpError(429, '语音识别请求过于频繁，请稍后重试');
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case 3305:
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return new HttpError(402, '百度语音识别额度已用完，请购买资源包');
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case 3310:
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return new HttpError(413, '录音超过60秒，请缩短问题后重试');
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case 3311:
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return new HttpError(400, '录音格式不正确，请重新录制');
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default:
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return new HttpError(502, `百度语音识别失败（${data.err_no ?? '未知错误'}）`);
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}
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};
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const recognizeAudio = async (audio: Buffer, forceRefresh = false): Promise<string> => {
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const token = await getAccessToken(forceRefresh);
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const query = new URLSearchParams({
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cuid: `digital-human-${BAIDU_APP_ID}`,
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token,
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dev_pid: '80001',
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});
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let response: Response;
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try {
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response = await fetchWithTimeout(`${BAIDU_ASR_URL}?${query.toString()}`, {
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method: 'POST',
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headers: {
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'Content-Type': 'audio/pcm;rate=16000',
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'Content-Length': String(audio.length),
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},
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body: audio,
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});
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} catch (error) {
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if (error instanceof Error && error.name === 'AbortError') {
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throw new HttpError(504, '百度语音识别超时，请稍后重试');
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}
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throw new HttpError(502, '无法连接百度语音识别服务');
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}
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const data = await response.json().catch(() => ({})) as BaiduAsrResponse;
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if ((data.err_no === 110 || data.err_no === 111 || data.err_no === 3302) && !forceRefresh) {
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cachedToken = '';
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cachedTokenExpiresAt = 0;
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return recognizeAudio(audio, true);
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}
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if (!response.ok || data.err_no !== 0) throw mapBaiduError(data);
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const text = data.result?.[0]?.trim() || '';
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if (!text) throw new HttpError(422, '没有识别到清晰语音，请重新说一遍');
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return text;
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};
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export const createBaiduAsrMiddleware = () => async (
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req: IncomingMessage,
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res: ServerResponse,
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) => {
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if (req.method !== 'POST') {
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res.setHeader('Allow', 'POST');
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sendJson(res, 405, {error: '仅支持 POST 请求'});
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return;
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}
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if (!req.headers['content-type']?.toLowerCase().startsWith('audio/pcm')) {
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sendJson(res, 415, {error: '录音格式必须是16kHz单声道PCM'});
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return;
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}
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try {
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const audio = await readAudioBody(req);
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const requestStartedAt = Date.now();
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const audioDurationMs = Math.round(audio.length / 2 / 16_000 * 1000);
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console.info(`[Baidu ASR] start bytes=${audio.length} durationMs=${audioDurationMs}`);
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const text = await recognizeAudio(audio);
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console.info(`[Baidu ASR] success durationMs=${audioDurationMs} elapsedMs=${Date.now() - requestStartedAt}`);
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sendJson(res, 200, {text});
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} catch (error) {
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if (error instanceof HttpError) {
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console.warn(`[Baidu ASR] failed status=${error.statusCode} message=${error.message}`);
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sendJson(res, error.statusCode, {error: error.message});
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return;
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}
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console.error('Baidu ASR request failed:', error);
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sendJson(res, 500, {error: '服务端处理语音失败'});
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}
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};
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export default function baiduAsrProxy(): Plugin {
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const middleware = createBaiduAsrMiddleware();
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return {
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name: 'baidu-asr-server-proxy',
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configureServer(server) {
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server.middlewares.use('/api/baidu/asr', middleware);
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},
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configurePreviewServer(server) {
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server.middlewares.use('/api/baidu/asr', middleware);
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},
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};
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}
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