import http from 'node:http';
import { createReadStream, existsSync, statSync } from 'node:fs';
import { extname, join, normalize, resolve } from 'node:path';

// 这是 mini-desktop RC 部署的轻量静态服务：同时把前端相对 API 路径反代到 muse-server。
// 生产化部署应换成 Nginx/Caddy；RC smoke 用 Node 单文件可减少额外系统依赖和端口冲突。
const args = Object.fromEntries(
  process.argv.slice(2).map((arg) => {
    const [key, ...rest] = arg.replace(/^--/, '').split('=');
    return [key, rest.join('=') || ''];
  }),
);

const root = resolve(args.root || '.');
const port = Number(args.port || 4175);
const backend = new URL(args.backend || 'http://127.0.0.1:48081');
const proxyPrefixes = (args.proxy || '/app-api,/admin-api,/sse').split(',').filter(Boolean);

const contentTypes = new Map([
  ['.html', 'text/html; charset=utf-8'],
  ['.js', 'text/javascript; charset=utf-8'],
  ['.mjs', 'text/javascript; charset=utf-8'],
  ['.css', 'text/css; charset=utf-8'],
  ['.json', 'application/json; charset=utf-8'],
  ['.png', 'image/png'],
  ['.jpg', 'image/jpeg'],
  ['.jpeg', 'image/jpeg'],
  ['.svg', 'image/svg+xml'],
  ['.ico', 'image/x-icon'],
  ['.woff', 'font/woff'],
  ['.woff2', 'font/woff2'],
  ['.ttf', 'font/ttf'],
  ['.eot', 'application/vnd.ms-fontobject'],
]);

function sendNotFound(res) {
  res.writeHead(404, { 'content-type': 'text/plain; charset=utf-8' });
  res.end('Not Found');
}

function proxy(req, res) {
  const target = new URL(req.url || '/', backend);
  const headers = { ...req.headers, host: backend.host };
  const upstream = http.request(target, { method: req.method, headers }, (proxyRes) => {
    res.writeHead(proxyRes.statusCode || 502, proxyRes.headers);
    proxyRes.pipe(res);
  });

  upstream.on('error', (error) => {
    res.writeHead(502, { 'content-type': 'application/json; charset=utf-8' });
    res.end(JSON.stringify({ code: 502, msg: `backend unavailable: ${error.code || error.message}` }));
  });

  req.pipe(upstream);
}

function serve(req, res) {
  const url = new URL(req.url || '/', `http://${req.headers.host || 'localhost'}`);
  if (proxyPrefixes.some((prefix) => url.pathname === prefix || url.pathname.startsWith(`${prefix}/`))) {
    proxy(req, res);
    return;
  }

  const decodedPath = decodeURIComponent(url.pathname);
  const relative = normalize(decodedPath).replace(/^\/+/, '');
  let file = resolve(join(root, relative));
  if (!file.startsWith(root)) {
    sendNotFound(res);
    return;
  }

  // SPA 深链统一回落到 index.html，避免刷新路由时 404。
  if (!existsSync(file) || statSync(file).isDirectory()) {
    file = join(root, 'index.html');
  }
  if (!existsSync(file) || statSync(file).isDirectory()) {
    sendNotFound(res);
    return;
  }

  const type = contentTypes.get(extname(file).toLowerCase()) || 'application/octet-stream';
  res.writeHead(200, { 'content-type': type });
  createReadStream(file).pipe(res);
}

http.createServer(serve).listen(port, '0.0.0.0', () => {
  console.log(`static proxy listening on ${port}, root=${root}, backend=${backend.origin}`);
});