const fs = require('fs');
const path = require('path');
const http = require('http');
const { pipeline } = require('stream');
const { URL } = require('url');

const ROOT_DIR = path.resolve(__dirname, '..', 'dist');
const UI_PORT = Number(process.env.CRANK_E2E_UI_PORT || 3300);
const ADMIN_PORT = Number(process.env.CRANK_E2E_ADMIN_PORT || 3301);
const ADMIN_BASE = new URL(`http://127.0.0.1:${ADMIN_PORT}`);

const MIME_TYPES = {
  '.css': 'text/css; charset=utf-8',
  '.html': 'text/html; charset=utf-8',
  '.js': 'application/javascript; charset=utf-8',
  '.json': 'application/json; charset=utf-8',
  '.png': 'image/png',
  '.svg': 'image/svg+xml',
  '.ico': 'image/x-icon',
  '.woff2': 'font/woff2',
  '.txt': 'text/plain; charset=utf-8',
};

function sendNotFound(response) {
  response.writeHead(404, { 'Content-Type': 'text/plain; charset=utf-8' });
  response.end('Not Found');
}

function redirect(response, location) {
  response.writeHead(302, { Location: location });
  response.end();
}

function mapRoute(urlPath) {
  if (urlPath === '/' || urlPath === '/index.html') {
    return path.join(ROOT_DIR, 'index.html');
  }
  if (urlPath === '/login' || urlPath === '/login.html') {
    return path.join(ROOT_DIR, 'html', 'login.html');
  }
  if (urlPath === '/agents') {
    return path.join(ROOT_DIR, 'html', 'agents.html');
  }
  if (urlPath === '/api-keys') {
    return path.join(ROOT_DIR, 'html', 'api-keys.html');
  }
  if (urlPath === '/secrets') {
    return path.join(ROOT_DIR, 'html', 'secrets.html');
  }
  if (urlPath === '/logs') {
    return path.join(ROOT_DIR, 'html', 'logs.html');
  }
  if (urlPath === '/usage') {
    return path.join(ROOT_DIR, 'html', 'usage.html');
  }
  if (urlPath === '/settings') {
    return path.join(ROOT_DIR, 'html', 'settings.html');
  }
  if (urlPath === '/workspace-setup') {
    return path.join(ROOT_DIR, 'html', 'workspace-setup.html');
  }
  if (urlPath === '/wizard/') {
    return path.join(ROOT_DIR, 'html', 'wizard', 'index.html');
  }
  if (urlPath.startsWith('/wizard/')) {
    return path.join(ROOT_DIR, 'html', 'wizard', urlPath.slice('/wizard/'.length));
  }
  if (urlPath.startsWith('/css/')) {
    return path.join(ROOT_DIR, urlPath.slice(1));
  }
  if (urlPath.startsWith('/js/')) {
    return path.join(ROOT_DIR, urlPath.slice(1));
  }
  if (urlPath.startsWith('/icons/')) {
    return path.join(ROOT_DIR, urlPath.slice(1));
  }
  if (urlPath.startsWith('/data/')) {
    return path.join(ROOT_DIR, urlPath.slice(1));
  }
  if (urlPath === '/Crank.png') {
    return path.resolve(ROOT_DIR, '..', '..', 'crank-community.png');
  }
  return null;
}

function serveFile(filePath, response) {
  const normalized = path.normalize(filePath);
  if (!normalized.startsWith(ROOT_DIR) && !normalized.endsWith(path.sep + 'crank-community.png')) {
    sendNotFound(response);
    return;
  }

  fs.stat(normalized, (error, stats) => {
    if (error || !stats.isFile()) {
      sendNotFound(response);
      return;
    }

    const extension = path.extname(normalized).toLowerCase();
    response.writeHead(200, {
      'Content-Length': stats.size,
      'Content-Type': MIME_TYPES[extension] || 'application/octet-stream',
      'Cache-Control': 'no-store',
    });

    pipeline(fs.createReadStream(normalized), response, () => {});
  });
}

function proxyRequest(request, response) {
  const target = new URL(request.url, ADMIN_BASE);
  const proxy = http.request(
    target,
    {
      method: request.method,
      headers: {
        ...request.headers,
        host: `127.0.0.1:${ADMIN_PORT}`,
      },
    },
    (proxyResponse) => {
      if (response.destroyed || response.writableEnded) {
        proxyResponse.resume();
        return;
      }
      response.writeHead(proxyResponse.statusCode || 502, proxyResponse.headers);
      proxyResponse.on('error', function() {
        if (!response.destroyed) response.destroy();
      });
      response.on('close', function() {
        if (!proxyResponse.destroyed) proxyResponse.destroy();
      });
      proxyResponse.pipe(response);
    },
  );

  proxy.on('error', () => {
    response.writeHead(502, { 'Content-Type': 'text/plain; charset=utf-8' });
    response.end('Bad Gateway');
  });

  pipeline(request, proxy, () => {});
}

const server = http.createServer((request, response) => {
  const requestUrl = new URL(request.url, `http://127.0.0.1:${UI_PORT}`);
  const urlPath = requestUrl.pathname;

  if (urlPath === '/wizard') {
    redirect(response, '/wizard/');
    return;
  }

  if (urlPath === '/html/login.html') {
    redirect(response, '/login');
    return;
  }
  if (urlPath === '/html/agents.html') {
    redirect(response, '/agents');
    return;
  }
  if (urlPath === '/html/api-keys.html') {
    redirect(response, '/api-keys');
    return;
  }
  if (urlPath === '/html/secrets.html') {
    redirect(response, '/secrets');
    return;
  }
  if (urlPath === '/html/logs.html') {
    redirect(response, '/logs');
    return;
  }
  if (urlPath === '/html/usage.html') {
    redirect(response, '/usage');
    return;
  }
  if (urlPath === '/html/settings.html') {
    redirect(response, '/settings');
    return;
  }
  if (urlPath === '/html/workspace-setup.html') {
    redirect(response, '/workspace-setup');
    return;
  }
  if (urlPath === '/html/wizard' || urlPath === '/html/wizard/') {
    redirect(response, '/wizard/');
    return;
  }

  if (urlPath.startsWith('/api/auth/') || urlPath.startsWith('/api/admin/')) {
    proxyRequest(request, response);
    return;
  }

  const filePath = mapRoute(urlPath);
  if (!filePath) {
    sendNotFound(response);
    return;
  }

  serveFile(filePath, response);
});

server.listen(UI_PORT, '127.0.0.1', () => {
  console.log(`Playwright UI server listening on http://127.0.0.1:${UI_PORT}`);
});