const express = require('express');
const axios = require('axios');
const authMiddleware = require('../middleware/auth');
const { buildInternalHeaders } = require('../middleware/internalSign');

const router = express.Router();

const PYTHON_URL = () => process.env.PYTHON_BACKEND_URL || 'http://localhost:3001';

/**
 * 通用代理函数：带 HMAC 签名转发到 Python
 */
async function forwardToPython(pythonPath, queryString, body, userId, res, userInfo = {}) {
  const url = `${PYTHON_URL()}${pythonPath}${queryString ? `?${queryString}` : ''}`;
  const headers = {
    'Content-Type': 'application/json',
    ...buildInternalHeaders(userId, userInfo),
  };

  console.log('[→ Python]', url);
  console.log('[→ Headers]', JSON.stringify(headers, null, 2));
  console.log('[→ Body]', JSON.stringify(body, null, 2));

  try {
    const resp = await axios.post(url, body, { headers, timeout: 30000 });
    return res.status(resp.status).json(resp.data);
  } catch (err) {
    if (err.response) {
      return res.status(err.response.status).json(err.response.data);
    }
    console.error('[aiProxy] 转发失败:', err.message);
    return res.status(502).json({ code: 502, message: `无法连接 Python 后端: ${err.message}` });
  }
}

// POST /api/ai/getScenes
router.post('/getScenes', authMiddleware, async (req, res) => {
  await forwardToPython('/getScenes', 'Action=getScenes', req.body, req.user.userId, res, req.user);
});

// POST /api/ai/proxy?Action=StartVoiceChat|StopVoiceChat
router.post('/proxy', authMiddleware, async (req, res) => {
  const action = req.query.Action;
  if (!action) {
    return res.status(400).json({ code: 400, message: 'Action 参数不能为空' });
  }
  await forwardToPython('/proxy', `Action=${action}`, req.body, req.user.userId, res, req.user);
});

// POST /api/ai/session/history — 存储历史对话上下文到 Python（start 前调用）
router.post('/session/history', authMiddleware, async (req, res) => {
  await forwardToPython('/api/session/history', '', req.body, req.user.userId, res, req.user);
});

module.exports = router;