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

const PORT = process.env.PORT || 3000;

const server = http.createServer((req, res) => {
  let filePath = req.url.split('?')[0];
  if (filePath === '/') filePath = '/index.html';
  const safePath = path.join(__dirname, filePath);

  if (!safePath.startsWith(__dirname)) {
    res.writeHead(403);
    return res.end('Forbidden');
  }

  fs.readFile(safePath, (err, data) => {
    if (err) {
      res.writeHead(404);
      return res.end('Not Found');
    }
    const ext = path.extname(safePath);
    const contentType = ext === '.css' ? 'text/css' : ext === '.js' ? 'application/javascript' : 'text/html';
    res.writeHead(200, { 'Content-Type': contentType });
    res.end(data);
  });
});

server.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});