public function loginAction(Request $request)
    {
        if(!$request->hasSession())
        {
            if($request->getMethod() == 'POST')
            {
                $username = $request->get('username');
                $password = $request->get('password');
                if((!empty($username)) && (!empty($password)))
                {
                    $username = filter_var($username, FILTER_SANITIZE_STRING);
                    $password = filter_var($password, FILTER_SANITIZE_STRING);
                    $account = \AccountsQuery::create()
                        ->filterByCuenta($username)
                        ->filterByPass($password)
                        ->findOne();
                    if($account)
                    {
                        $this->session->set('user_id', $account->getGuid());
                        $request->setSession($this->session);
                        $this->render('success.html.twig', array(
                            'message' => 'Vous êtes désormais connecté !',
                        ));
                    }
                    else {
                        $this->render('error.html.twig', array(
                            'message' => 'Le nom de compte ou le mot de passe est incorrect.',
                        ));
                    }
                }
                else {
                    $this->render('error.html.twig', array(
                        'message' => 'Veuillez remplir tout les champs.',
                    ));
                }
            } else {
                $this->render('error.html.twig', array(
                    'message' => 'Veuillez soumettre le formulaire de connexion.',
                ));
            }
        }
        else {
            $this->render('error.html.twig', array(
                'message' => 'Vous êtes déjà connecté !',
            ));
        }
        return $this->response;
    }