/**
 * 开发环境代理服务器
 * 用于解决跨域问题和统一 API 请求
 */

const express = require('express');
const { createProxyMiddleware } = require('http-proxy-middleware');
const cors = require('cors');

const app = express();
const PORT = 8086;

// 启用 CORS
app.use(cors({
  origin: '*', // 允许所有源，开发环境使用
  credentials: true,
  methods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS', 'PATCH'],
  allowedHeaders: [
    'Content-Type',
    'Authorization',
    'X-Requested-With',
    'Accept',
    // 自定义请求头
    'cmdId',
    'datetime',
    'pwds',
    'aseqId',
    'nc',
    'apiName',
    'tid',
    'custId',
    'reqId',
    'isMobileOpen',
    'languageNum',
    'project',
    'platform',
    'checkOr',
    'tbc',
    'reqKey',
    'signature',
    'authorization',
  ],
  exposedHeaders: ['cmdId', 'datetime', 'pwds', 'aseqId', 'nc', 'checkOr', 'checkor'],
}));

// 目标 API 服务器地址
const API_TARGET = process.env.API_TARGET || 'https://51zhh5.notbug.org';

// 代理路径列表
const PROXY_PATHS = ['/api/v1', '/api/v2', '/api/v3'];

// 为每个路径配置代理
PROXY_PATHS.forEach((path) => {
  app.use(
    path,
    createProxyMiddleware({
      target: API_TARGET,
      changeOrigin: true,
      secure: false, // 如果目标服务器使用自签名证书，设置为 false
      pathRewrite: (pathStr, req) => {
        // Express 会自动去掉匹配的前缀，所以需要加回来
        const fullPath = path + pathStr;
        console.log(`[Proxy] Path rewrite: ${pathStr} → ${fullPath}`);
        return fullPath;
      },
      onProxyReq: (proxyReq, req, res) => {
        const fullPath = path + req.url;
        console.log(`[Proxy] ${req.method} ${fullPath} → ${API_TARGET}${fullPath}`);
      },
      onProxyRes: (proxyRes, req, res) => {
        const fullPath = path + req.url;
        console.log(`[Proxy] ${req.method} ${fullPath} ← ${proxyRes.statusCode}`);

        // 确保 CORS 头被正确设置
        res.setHeader('Access-Control-Allow-Origin', '*');
        res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS, PATCH');
        res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization, X-Requested-With, Accept, cmdId, datetime, pwds, aseqId, nc, apiName, tid, custId, reqId, isMobileOpen, languageNum, project, platform, checkOr, tbc, reqKey, signature, authorization');
        res.setHeader('Access-Control-Expose-Headers', 'cmdId, datetime, pwds, aseqId, nc, checkOr, checkor');
        res.setHeader('Access-Control-Allow-Credentials', 'true');
      },
      onError: (err, req, res) => {
        console.error('[Proxy Error]', err.message);
        res.status(500).json({
          error: 'Proxy Error',
          message: err.message,
        });
      },
    })
  );
});

// 健康检查
app.get('/health', (req, res) => {
  res.json({
    status: 'ok',
    proxy: API_TARGET,
    timestamp: new Date().toISOString(),
  });
});

app.listen(PORT, () => {
  console.log(`
╔════════════════════════════════════════════════════════╗
║  🚀 Proxy Server Running                              ║
╠════════════════════════════════════════════════════════╣
║  Local:   http://localhost:${PORT}                       ║
║  Target:  ${API_TARGET.padEnd(40)} ║
║  Health:  http://localhost:${PORT}/health                ║
╚════════════════════════════════════════════════════════╝
  `);
});