// 本地预览：node server.mjs  →  http://localhost:4173
// 仅用于演示与截图，不参与任何构建。
import { createServer } from 'node:http';
import { readFile, stat } from 'node:fs/promises';
import { extname, join, normalize } from 'node:path';

const ROOT = new URL('.', import.meta.url).pathname.replace(/^\/([A-Za-z]:)/, '$1');
const PORT = Number(process.env.PORT || 4173);
const TYPES = {
  '.html': 'text/html; charset=utf-8', '.css': 'text/css; charset=utf-8',
  '.js': 'text/javascript; charset=utf-8', '.svg': 'image/svg+xml',
  '.woff2': 'font/woff2', '.json': 'application/json',
};

createServer(async (req, res) => {
  const url = decodeURIComponent((req.url || '/').split('?')[0]);
  let path = normalize(join(ROOT, url === '/' ? 'index.html' : url));
  if (!path.startsWith(normalize(ROOT))) { res.writeHead(403).end(); return; }
  try {
    const info = await stat(path);
    if (info.isDirectory()) path = join(path, 'index.html');
    const body = await readFile(path);
    res.writeHead(200, { 'content-type': TYPES[extname(path)] || 'application/octet-stream', 'cache-control': 'no-store' });
    res.end(body);
  } catch {
    const body = await readFile(join(ROOT, '404.html')).catch(() => 'Not found');
    res.writeHead(404, { 'content-type': 'text/html; charset=utf-8' }).end(body);
  }
}).listen(PORT, () => console.log(`Fmode 落地页预览: http://localhost:${PORT}`));