private $groupsManager;

    private $trainingsManager;

    private $walletsManager;

    public function __construct(GroupsManager $groupsManager, TrainingsManager $trainingsManager, WalletsManager $walletsManager)
    {
        $this->groupsManager = $groupsManager;
        $this->trainingsManager = $trainingsManager;
        $this->walletsManager = $walletsManager;
    }

    public function group(Request $request, string $slug = null, TranslatorInterface $translator): Response
    {
//        if (null === $slug) {
//            $group = new Group();
//        } else {
//            $group = $this->getDoctrine()->getRepository(Group::class)->findOneBy(['slug' => $slug]);
//            if (!$group) {
//                throw new Exception($translator->trans('Invalid group slug'));
//            }
//        }

        $group = $this->groupsManager->getGroupBySlug($slug);

        if(!$group) {
            throw new Exception($translator->trans('Invalid group slug'));
        }

        $form = $this->createForm(GroupType::class, $group);
        $form->handleRequest($request);

        if ($form->isSubmitted() && $form->isValid()) {
//            if (empty($group->getSlug())) {
//                $group->setSlug($group->getName());
//            }
//            $em = $this->getDoctrine()->getManager();
//            $em->persist($group);
//            $em->flush();
            $group = $this->groupsManager->updateGroup($group);

            if (null === $slug) {
                // Tworzenie treningów do grupy
//                $startDateGroup = $group->getStartDate();
//                $endDateGroup = $group->getEndDate();
//
//                $endDateTraining = new \DateTime($group->getStartDate()->format('Y-m-d H:i:s'));
//                $endDateTraining->modify('+45 minutes');
//
//                $trainingCount = 0;
//                while ($startDateGroup < $endDateGroup) {
//                    $training = new Training();
//                    $training->setStartDate($startDateGroup)
//                        ->setEndDate($endDateTraining);
//
//                    $training->setGroup($group);
//                    $training->setCoach($group->getCoach());
//
//                    foreach ($group->getStudents() as $student) {
//                        $training->addStudent($student);
//                    }
//
//                    $em->persist($training);
//                    $em->flush();
//
//                    $startDateGroup->modify('+7 day');
//                    $endDateTraining->modify('+7 day');
//
//                    ++$trainingCount;
//                }
                $this->trainingsManager->create($group);

                // Do każdego portfela studenta dodajemy koszt zajęć w grupie
                // portfel = portfel - (ilość_treningów * cena_jednych zajęć_w_grupie)
//                foreach ($group->getStudents() as $student) {
//                    $student->setWallet($student->getWallet() - ($trainingCount * $group->getPrice()));
//                    $em->persist($student);
//                    $em->flush();
//                }
                $this->walletsManager->updateForGroup($group);
            }

            $this->addFlash('success', $translator->trans('Changes have been saved'));

            return $this->redirectToRoute('panel_groups');
        }
//        elseif ($form->isSubmitted() && false === $form->isValid()) {
//            $this->addFlash('error', $translator->trans('Corrects form'));
//        }

        return $this->render('backend/group/group.html.twig', [
            'form' => $form->createView(),
            'group' => $group,
        ]);
    }