require('dotenv').config();

const express = require('express');
const cors = require('cors');
const https = require('https');
const signer = require('./APIGW-javascript-sdk-2.0.6/signer');

const app = express();
const PORT = 3001;

app.use(cors());
app.use(express.json());

const METASTUDIO_API_BASE = 'https://metastudio.cn-north-4.myhuaweicloud.com';

async function createOnceCodeWithAKSK() {
    const accessKey = process.env.HUAWEI_AK;
    const secretKey = process.env.HUAWEI_SK;
    const projectId = process.env.HUAWEI_PROJECT_ID;

    if (!accessKey || !secretKey) {
        throw new Error('请配置环境变量: HUAWEI_AK 和 HUAWEI_SK');
    }
    if (!projectId) {
        throw new Error('请配置环境变量: HUAWEI_PROJECT_ID');
    }

    const uri = `/v1/${projectId}/digital-human-chat/once-code`;

    const sig = new signer.Signer();
    sig.Key = accessKey;
    sig.Secret = secretKey;

    const req = new signer.HttpRequest(
        'POST',
        `${METASTUDIO_API_BASE}${uri}`,
        {
            'content-type': 'application/json',
            'x-project-id': projectId
        },
        '{}'
    );

    const options = sig.Sign(req);

    return new Promise((resolve, reject) => {
        const request = https.request(options, (res) => {
            let data = '';
            res.on('data', (chunk) => {
                data += chunk;
            });
            res.on('end', () => {
                if (res.statusCode !== 200) {
                    reject(new Error(`API调用失败: ${res.statusCode} - ${data}`));
                    return;
                }
                const response = JSON.parse(data);
                resolve(response.once_code);
            });
        });

        request.on('error', (e) => {
            reject(e);
        });

        request.write('{}');
        request.end();
    });
}

app.post('/api/once-code', async (req, res) => {
    try {
        console.log('使用 AK/SK 认证获取授权码...');
        const onceCode = await createOnceCodeWithAKSK();
        res.json({ once_code: onceCode });
    } catch (error) {
        console.error('获取授权码失败:', error);
        res.status(500).json({
            error_code: 'INTERNAL_ERROR',
            error_msg: error.message
        });
    }
});

app.get('/health', (req, res) => {
    res.json({ status: 'ok' });
});

app.listen(PORT, () => {
    console.log(`后端服务已启动: http://localhost:${PORT}`);
    console.log('使用 AK/SK 认证方式');
});