public function actionLogin($params = [])
 {
     $student = new Student();
     if (isset($_POST) && !empty($_POST)) {
         // TODO: validate user input
         if ($student->login($_POST['email'], $_POST['password'])) {
             Router::redirect('/student/profile');
         } else {
             Router::error('401');
         }
     }
     $this->render('login.php');
 }