const express = require('express');
const multer = require('multer');
const FormData = require('form-data');
const axios = require('axios'); // 使用 axios 替换 node-fetch
const fetch = require('node-fetch'); // 保留用于翻译接口

const app = express();
const port = 3000;

const storage = multer.memoryStorage();
const upload = multer({ storage: storage });

app.use(express.json());
app.use(express.urlencoded({ extended: true }));
app.use((req, res, next) => {
    res.header('Access-Control-Allow-Origin', '*');
    res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
    next();
});

const PYTHON_ASR_SERVICE_URL = 'http://localhost:5001/transcribe';

// ASR Endpoint: 使用 axios 重写，确保超时正确生效
app.post('/asr', upload.single('audio'), async (req, res) => {
    console.log("Received ASR request, proxying to Python service with axios...");

    if (!req.file) {
        return res.status(400).json({ error: 'No audio file uploaded.' });
    }

    try {
        const form = new FormData();
        form.append('audio', req.file.buffer, {
            filename: req.file.originalname,
            contentType: req.file.mimetype,
        });
        
        const langCode = req.body.sourceLang.split('-')[0];
        form.append('language', langCode);
        console.log(`Forwarding audio buffer with language '${langCode}'...`);

        // 使用 axios 发送请求，并设置一个可靠的60秒超时
        const asrResponse = await axios.post(PYTHON_ASR_SERVICE_URL, form, {
            headers: form.getHeaders(),
            timeout: 60000 // 60秒超时，作用于整个请求
        });

        const asrData = asrResponse.data;
        
        console.log(`Transcription result: "${asrData.transcript}"`);
        res.json({ transcript: asrData.transcript });

    } catch (error) {
        if (error.code === 'ECONNABORTED') {
            console.error("Failed to process ASR request: Axios request timed out.");
            res.status(504).json({ error: 'Request to ASR service timed out.' });
        } else {
            console.error("Failed to process ASR request:", error.message);
            res.status(500).json({ error: error.message });
        }
    }
});

// Translate Endpoint (保持不变)
app.post('/translate', async (req, res) => {
    const { text, sourceLang, targetLang } = req.body;
    if (!text || !sourceLang || !targetLang) {
        return res.status(400).json({ error: 'Missing text, sourceLang, or targetLang' });
    }
    const source = sourceLang.split('-')[0];
    const target = targetLang.split('-')[0];
    if (source === target) {
        return res.json({ translatedText: text });
    }
    const apiUrl = `https://translate.googleapis.com/translate_a/single?client=gtx&sl=${source}&tl=${target}&dt=t&q=${encodeURIComponent(text)}`;
    try {
        const response = await fetch(apiUrl);
        const data = await response.json();
        if (data && data[0] && data[0][0] && data[0][0][0]) {
            const translatedText = data[0].map(segment => segment[0]).join('');
            res.json({ translatedText });
        } else {
            throw new Error('Unexpected API response from translation service');
        }
    } catch (error) {
        console.error('Translation request error:', error.message);
        res.status(500).json({ error: 'Translation failed' });
    }
});

app.get('/', (req, res) => {
    res.status(200).send('Node.js server is running and healthy!');
});

app.listen(port, () => {
    console.log(`Node.js proxy server listening at http://localhost:${port}`);
});