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

const ROOT = __dirname;
const PORT = 8777;

const MIME = {
  '.html': 'text/html; charset=utf-8',
  '.js': 'text/javascript; charset=utf-8',
  '.css': 'text/css; charset=utf-8',
  '.json': 'application/json; charset=utf-8',
  '.png': 'image/png',
  '.jpg': 'image/jpeg',
  '.svg': 'image/svg+xml',
  '.ico': 'image/x-icon',
};

http.createServer((req, res) => {
  let urlPath = decodeURIComponent(req.url.split('?')[0]);
  if (urlPath === '/') urlPath = '/index.html';
  const filePath = path.join(ROOT, urlPath);
  if (!filePath.startsWith(ROOT)) {
    res.writeHead(403); res.end('Forbidden'); return;
  }
  fs.readFile(filePath, (err, data) => {
    if (err) {
      res.writeHead(404, { 'Content-Type': 'text/plain; charset=utf-8' });
      res.end('404 Not Found: ' + urlPath);
      return;
    }
    res.writeHead(200, { 'Content-Type': MIME[path.extname(filePath)] || 'application/octet-stream' });
    res.end(data);
  });
}).listen(PORT, () => {
  console.log(`Static server running at http://localhost:${PORT}`);
});