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

const root = __dirname;
const port = process.argv[2] ? parseInt(process.argv[2], 10) : 8181;

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',
  '.jpeg': 'image/jpeg',
  '.gif': 'image/gif',
  '.svg': 'image/svg+xml',
  '.webp': 'image/webp',
  '.mp4': 'video/mp4',
  '.woff': 'font/woff',
  '.woff2': 'font/woff2',
  '.ttf': 'font/ttf',
  '.ico': 'image/x-icon',
};

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

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

  fs.stat(filePath, (err, stats) => {
    if (err) {
      res.writeHead(404);
      res.end('Not found: ' + reqPath);
      return;
    }
    if (stats.isDirectory()) {
      filePath = path.join(filePath, 'index.html');
    }
    fs.readFile(filePath, (err2, data) => {
      if (err2) {
        res.writeHead(404);
        res.end('Not found: ' + reqPath);
        return;
      }
      const ext = path.extname(filePath).toLowerCase();
      res.writeHead(200, { 'Content-Type': mime[ext] || 'application/octet-stream' });
      res.end(data);
    });
  });
});

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