export function isLocalhost(
  req: Request,
  connInfo?: Deno.ServeHandlerInfo,
): boolean {
  if (connInfo?.remoteAddr) {
    const remoteAddr = connInfo.remoteAddr;
    if (remoteAddr.transport === 'tcp') {
      const hostname = remoteAddr.hostname;
      return hostname === '127.0.0.1' || hostname === '::1';
    }
    if (remoteAddr.transport === 'unix') {
      return true;
    }
  }
  const url = new URL(req.url);
  const hostname = url.hostname;
  if (hostname === '127.0.0.1' || hostname === '::1') {
    return true;
  }
  if (hostname === 'localhost') {
    const suspiciousHeaders = [
      'x-forwarded-for',
      'x-forwarded-host',
      'x-real-ip',
      'cf-connecting-ip',
      'x-cluster-client-ip',
    ];

    for (const header of suspiciousHeaders) {
      if (req.headers.get(header)) {
        return false;
      }
    }

    return true;
  }

  return false;
}