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

const PORT = 3000;
const PUBLIC_DIR = __dirname;

const MIME_TYPES = {
  '.html': 'text/html; charset=UTF-8',
  '.css': 'text/css; charset=UTF-8',
  '.js': 'application/javascript; 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'
};

const server = http.createServer((req, res) => {
  let reqUrl = req.url.split('?')[0];
  let safePath = path.normalize(decodeURIComponent(reqUrl));
  if (safePath === '/' || safePath === '\\') {
    safePath = '/index.html';
  }

  let filePath = path.join(PUBLIC_DIR, safePath);

  fs.stat(filePath, (err, stats) => {
    if (err || !stats.isFile()) {
      res.writeHead(404, { 'Content-Type': 'text/html' });
      res.end('<h1>404 Not Found</h1><p><a href="/">Return to Home</a></p>');
      return;
    }

    const ext = path.extname(filePath).toLowerCase();
    const contentType = MIME_TYPES[ext] || 'application/octet-stream';

    res.writeHead(200, { 'Content-Type': contentType });
    fs.createReadStream(filePath).pipe(res);
  });
});

server.listen(PORT, () => {
  console.log(`CurcuVance BioSciences server running at http://localhost:${PORT}`);
});