<?php

declare(strict_types=1);

namespace App\Controller\Booking\Create;

use App\BusProNet\Model\Travel;
use App\Entity\User;
use App\Exception\BookingSessionNotFoundException;
use App\Exception\HotelNotInTravelException;
use App\Exception\TravelNotFoundException;
use App\Form\BookingCreateStep2Type;
use App\Form\Model\BookingDto;
use App\Form\Model\ParticipantDto;
use App\Form\Model\RoomSelectionDto;
use App\Service\BookingConfigurator;
use App\Service\BookingCreateContextFactory;
use App\Service\BookingSessionManager;
use App\Service\ParticipantDataPrefiller;
use App\Service\RoomAssigner;
use App\Service\TravelDataProvider;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Attribute\Route;

/**
 * Handles the second step of the booking creation process using card-based UI.
 *
 * This controller uses a card overview and lazy-loaded individual participant forms
 * for better performance and UX with large groups (50+ participants).
 */
class Step2Controller extends AbstractBookingCreateController
{
    public function __construct(
        private readonly BookingConfigurator $bookingService,
        private readonly BookingSessionManager $bookingSessionService,
        private readonly BookingCreateContextFactory $createContextFactory,
        private readonly TravelDataProvider $travelDataService,
        private readonly RoomAssigner $roomAssignmentService,
        private readonly ParticipantDataPrefiller $prepopulationService,
    ) {
    }

    /**
     * Display card grid for all participants.
     */
    #[Route('/bookings/create/participants', name: 'app_booking_create_step_2')]
    public function index(Request $request): Response
    {
        try {
            $bookingCreateDto = $this->loadBookingCreateDto($this->bookingSessionService, $request);
        } catch (BookingSessionNotFoundException|TravelNotFoundException|HotelNotInTravelException $exception) {
            return $this->createBookingCreateFailureResponse($exception, false);
        }

        // Validate step access
        if (null !== $redirect = $this->validateStepAccess($bookingCreateDto, 2)) {
            return $redirect;
        }

        // Enrich with fresh availability data
        $this->travelDataService->enrichWithFreshAvailabilities($bookingCreateDto->travel);

        // Ensure correct number of participants first, then prepopulate the applicant if needed.
        $this->ensureCorrectNumberOfParticipants($bookingCreateDto);

        $user = $this->getUser();
        if ($user instanceof User
            && isset($bookingCreateDto->participants[0])
            && $this->prepopulationService->shouldPrefillApplicant($bookingCreateDto->participants[0])) {
            $bookingCreateDto->participants[0] = $this->prepopulationService->prefillApplicantFromUser(
                $user,
                $bookingCreateDto->participants[0]
            );
        }

        // Validate room assignments against current selection (handles back-navigation from step 2 to step 1)
        $this->roomAssignmentService->validateAndResetInvalidAssignments($bookingCreateDto);

        // Auto-assign rooms if needed
        $this->roomAssignmentService->assignRoomsIfNeeded($bookingCreateDto);

        // Preselect mandatory services
        $this->bookingService->preselectDefaultServices($bookingCreateDto);
        $this->bookingService->applyCreateBookingStatusRules($bookingCreateDto);

        // Save BookingDto to session
        $this->bookingSessionService->saveBookingDto($request, $bookingCreateDto, BookingDto::MODE_CREATE);

        // Create validation form
        $form = $this->createForm(BookingCreateStep2Type::class, $bookingCreateDto);
        $form->handleRequest($request);

        // Handle form submission
        if (true === $form->isSubmitted() && true === $form->isValid()) {
            // All participants validated successfully, update current step
            $bookingCreateDto->currentStep = 3;
            $this->bookingSessionService->saveBookingDto($request, $bookingCreateDto, BookingDto::MODE_CREATE);

            // Proceed to Step 3
            return $this->redirectToRoute('app_booking_create_step_3');
        }

        $context = $this->createContextFactory->createWithParticipantCards($bookingCreateDto, $form->isSubmitted());

        $templateData = [
            'form' => $form->createView(),
            'bookingCreateContext' => $context,
        ];

        return $this->render('booking/create/step_2.html.twig', $templateData);
    }

    /**
     * Ensures the booking DTO has the expected number of participant objects based on room selections.
     */
    private function ensureCorrectNumberOfParticipants(BookingDto $bookingDto): void
    {
        $participantsCount = $this->calculateParticipantsCount($bookingDto->roomSelections, $bookingDto->travel);

        $existingParticipants = $bookingDto->participants;
        $bookingDto->participants = [];

        for ($i = 0; $i < $participantsCount; ++$i) {
            $participant = $existingParticipants[$i] ?? new ParticipantDto();
            $participant->index = $i;

            $bookingDto->participants[$i] = $participant;
        }
    }

    /**
     * @param array<int, RoomSelectionDto> $roomSelections
     */
    private function calculateParticipantsCount(array $roomSelections, Travel $travelData): int
    {
        $participantsCount = 0;
        $rooms = $travelData->getAvailableRooms();

        foreach ($roomSelections as $roomSelection) {
            $room = $rooms[$roomSelection->id];
            $participantsCount += $room->minPax * $roomSelection->quantity;
        }

        return $participantsCount;
    }
}