import { createServer } from 'node:http';
import { parse } from 'url'; // Required for extracting method from incoming request


// Enhanced router supporting all HTTP verbs
function createRouter() {
  const methods = new Map(); // Map to store different handlers for different methods

  function addRoute(method, path, handler) {
    const segments = path.split('/').filter(Boolean);
    methods.set(method, methods.get(method) || [],
      (existingHandlers, index) => {
        existingHandlers.unshift({ segments, handler });
        return existingHandlers;
      }
    ); // Using index to ensure handler order
  }

  function matchRoute(req) {
    const urlSegments = parse(req.url, true).pathname.split('/').filter(Boolean);
    let methodHandlers = methods.get(req.method);
    if (!methodHandlers) {
      return null; // Method not registered
    }

    for (const route of methodHandlers) {
      const { segments, handler } = route;
      if (segments.length !== urlSegments.length) continue;
      const params = {};
      let match = true;
      for (let i = 0; i < segments.length; i++) {
        const routeSegment = segments[i];
        const urlSegment = urlSegments[i];
        if (routeSegment.startsWith(':')) {
          params[routeSegment.slice(1)] = urlSegment;
        } else if (routeSegment !== urlSegment) {
          match = false;
          break;
        }
      }
      if (match) {
        req.params = params;
        return { handler, params };
      }
    }
    return null;
  }

  return {
    get: (path, handler) => addRoute('GET', path, handler),
    post: (path, handler) => addRoute('POST', path, handler),
    put: (path, handler) => addRoute('PUT', path, handler),
    delete: (path, handler) => addRoute('DELETE', path, handler),
    patch: (path, handler) => addRoute('PATCH', path, handler),
    options: (path, handler) => addRoute('OPTIONS', path, handler),
    // You can add more here for other HTTP verbs

    handle: (req, res) => {
      const match = matchRoute(req);
      if (match) {
        req.params = match.params;
        match.handler.call(null, req, res);
      } else {
        res.writeHead(404, { 'Content-Type': 'text/plain' });
        res.end('Not Found\n');
      }
    },
  };
}


const router = createRouter();

// Example routes
router.get('/users/:userId/books/:bookId', (req, res) => {
  res.writeHead(200, { 'Content-Type': 'application/json' });
  res.end(JSON.stringify(req.params));
});

router.post('/users', (req, res) => {
  // POST handler implementation
  res.writeHead(201, { 'Content-Type': 'application/json' });
  res.end('User created\n');
});


const server = createServer((req, res) => {
  router.handle(req, res);
});

server.listen(3000, '127.0.0.1', () => {
  console.log('Listening on 127.0.0.1:3000');
});