const http = require('http');
const fs = require('fs');
const path = require('path');

const root = path.resolve(__dirname, '..', 'dist', 'frontend', 'browser');
const port = Number(process.env.PORT || 4301);

const types = {
  '.html': 'text/html; charset=utf-8',
  '.js': 'text/javascript; charset=utf-8',
  '.css': 'text/css; charset=utf-8',
  '.ico': 'image/x-icon'
};

http.createServer((req, res) => {
  const urlPath = decodeURIComponent((req.url || '/').split('?')[0]);
  const candidate = path.join(root, urlPath === '/' ? 'index.html' : urlPath);
  const safePath = candidate.startsWith(root) && fs.existsSync(candidate) && fs.statSync(candidate).isFile()
    ? candidate
    : path.join(root, 'index.html');

  res.setHeader('Content-Type', types[path.extname(safePath)] || 'application/octet-stream');
  fs.createReadStream(safePath).pipe(res);
}).listen(port, '127.0.0.1', () => {
  console.log(`Static preview ready: http://127.0.0.1:${port}`);
});