<?php

declare(strict_types=1);

namespace App\Tests\Service;

use App\BusProNet\Constants;
use App\BusProNet\Model\Booking;
use App\BusProNet\Model\Service;
use App\BusProNet\Model\Travel;
use App\Form\Model\BookingDto;
use App\Form\Model\ParticipantDto;
use App\Service\ServiceAvailabilityCalculator;
use PHPUnit\Framework\TestCase;

class ServiceAvailabilityCalculatorTest extends TestCase
{
    private ServiceAvailabilityCalculator $calculator;

    protected function setUp(): void
    {
        $this->calculator = new ServiceAvailabilityCalculator();
    }

    public function testParkingServiceIsUnavailableWhenSoldOut(): void
    {
        $parkingService = $this->createParkingService(id: 1, available: 0);
        $bookingDto = $this->createBookingDtoWithServices([$parkingService]);

        $this->assertTrue($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testParkingServiceIsAvailableWhenQuotaRemains(): void
    {
        $parkingService = $this->createParkingService(id: 1, available: 5);
        $bookingDto = $this->createBookingDtoWithServices([$parkingService]);

        $this->assertFalse($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testParkingSelectedByOtherParticipantCountsTowardUsage(): void
    {
        $parkingService = $this->createParkingService(id: 1, available: 1);
        $bookingDto = $this->createBookingDtoWithServices([$parkingService]);

        $otherParticipant = new ParticipantDto();
        $otherParticipant->parkingService = $parkingService;
        $bookingDto->participants[1] = $otherParticipant;

        // Only one parking slot remains, and another participant already claimed it,
        // so it must show unavailable for the current participant (index 0)
        $this->assertTrue($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testServiceOnBookingStopIsUnavailableDespiteUnlimitedQuota(): void
    {
        $skiPass = $this->createSkiPass(id: 1, available: null, status: Constants::STATUS_BLOCKED);
        $bookingDto = $this->createBookingDtoWithServices([$skiPass]);

        $this->assertTrue($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testServiceOnBookingStopIsUnavailableDespiteRemainingQuota(): void
    {
        $skiPass = $this->createSkiPass(id: 1, available: 10, status: Constants::STATUS_BLOCKED);
        $bookingDto = $this->createBookingDtoWithServices([$skiPass]);

        $this->assertTrue($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testFilterAvailableServicesRemovesSoldOutAndBlockedServices(): void
    {
        $bookable = $this->createSkiPass(id: 1, available: 5);
        $soldOut = $this->createSkiPass(id: 2, available: 0);
        $blocked = $this->createSkiPass(id: 3, available: null, status: Constants::STATUS_BLOCKED);
        $unlimited = $this->createSkiPass(id: 4, available: null);

        $bookingDto = $this->createBookingDtoWithServices([$bookable, $soldOut, $blocked, $unlimited]);

        $filtered = $this->calculator->filterAvailableServices(
            $bookingDto->travel->additionalServices,
            $bookingDto,
            0
        );

        $this->assertSame([1, 4], array_keys($filtered));
    }

    public function testOnRequestServiceStaysAvailableInCreateMode(): void
    {
        $skiPass = $this->createSkiPass(id: 1, available: 10, status: Constants::STATUS_ON_REQUEST);
        $bookingDto = $this->createBookingDtoWithServices([$skiPass]);

        // Create may still move the whole booking to status 'A', so on request is bookable there
        $this->assertFalse($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testOnRequestServiceIsUnavailableInEditMode(): void
    {
        $skiPass = $this->createSkiPass(id: 1, available: 10, status: Constants::STATUS_ON_REQUEST);
        $bookingDto = $this->createEditBookingDtoWithServices([$skiPass]);

        $this->assertTrue($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testOnRequestServiceAlreadyHeldStaysAvailableInEditMode(): void
    {
        $skiPass = $this->createSkiPass(id: 1, available: 0, status: Constants::STATUS_ON_REQUEST);
        $bookingDto = $this->createEditBookingDtoWithServices([$skiPass], heldServiceIds: [1]);

        // Withdrawing a booked service breaks the Leistung/Teilnehmer counts, so it must be keepable
        $this->assertFalse($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testSeatsHeldByOtherParticipantsDoNotCountTowardUsageInEditMode(): void
    {
        // BusPro reports frei="3" after deducting the seats this booking already holds
        $parkingService = $this->createParkingService(id: 1, available: 3);
        $bookingDto = $this->createEditBookingDtoWithServices([$parkingService]);
        $this->holdParkingForOtherParticipants($bookingDto, $parkingService, [1, 2, 3, 4, 5, 6, 7, 8]);

        $this->assertFalse($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
        $this->assertSame(3, $this->calculator->calculateRemainingAvailability($bookingDto, 0)[1]);
    }

    public function testNewSelectionByOtherParticipantStillCountsTowardUsageInEditMode(): void
    {
        $parkingService = $this->createParkingService(id: 1, available: 1);
        $bookingDto = $this->createEditBookingDtoWithServices([$parkingService]);

        $otherParticipant = new ParticipantDto();
        $otherParticipant->parkingService = $parkingService;
        $bookingDto->participants[1] = $otherParticipant;

        // Participant 1 picks the last slot in this edit without holding it in the booking
        $this->assertTrue($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testAutoBookedOnRequestServiceStaysAvailableInEditMode(): void
    {
        $service = $this->createSkiPass(id: 1, available: 10, status: Constants::STATUS_ON_REQUEST);
        $service->autoBook = true;
        $bookingDto = $this->createEditBookingDtoWithServices([$service]);

        $this->assertFalse($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testMandatoryNonTransportOnRequestServiceStaysAvailableInEditMode(): void
    {
        $service = $this->createSkiPass(id: 1, available: 10, status: Constants::STATUS_ON_REQUEST);
        $service->mandatory = true;
        $service->category = Constants::CATEGORY_ADDITIONAL;
        $bookingDto = $this->createEditBookingDtoWithServices([$service]);

        // Blocking a service the mandatory-services validator requires makes the form unsatisfiable
        $this->assertFalse($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testMandatoryTransportOnRequestServiceIsStillUnavailableInEditMode(): void
    {
        $service = $this->createSkiPass(id: 1, available: 10, status: Constants::STATUS_ON_REQUEST);
        $service->mandatory = true;
        $service->category = Constants::CATEGORY_TRANSPORTATION;
        $bookingDto = $this->createEditBookingDtoWithServices([$service]);

        // pflicht on a transport leg means "pick one of this group", not "compulsory"
        $this->assertTrue($this->calculator->isServiceUnavailable(1, $bookingDto, 0));
    }

    public function testFilterAvailableServicesNeverEmptiesAGroupOnTheOnRequestRuleAlone(): void
    {
        $first = $this->createSkiPass(id: 1, available: 10, status: Constants::STATUS_ON_REQUEST);
        $second = $this->createSkiPass(id: 2, available: 10, status: Constants::STATUS_ON_REQUEST);

        $bookingDto = $this->createEditBookingDtoWithServices([$first, $second]);

        $filtered = $this->calculator->filterAvailableServices(
            $bookingDto->travel->additionalServices,
            $bookingDto,
            0
        );

        $this->assertSame([1, 2], array_keys($filtered));
    }

    public function testFilterAvailableServicesStillEmptiesAGroupThatIsSoldOutOrBlocked(): void
    {
        $soldOut = $this->createSkiPass(id: 1, available: 0, status: Constants::STATUS_ON_REQUEST);
        $blocked = $this->createSkiPass(id: 2, available: null, status: Constants::STATUS_BLOCKED);

        $bookingDto = $this->createEditBookingDtoWithServices([$soldOut, $blocked]);

        $filtered = $this->calculator->filterAvailableServices(
            $bookingDto->travel->additionalServices,
            $bookingDto,
            0
        );

        $this->assertSame([], array_keys($filtered));
    }

    private function createParkingService(int $id, int $available): Service
    {
        $service = new Service();
        $service->id = $id;
        $service->label = 'Parkplatz';
        $service->subType = Constants::TOKEN_PARKING;
        $service->available = $available;

        return $service;
    }

    private function createSkiPass(int $id, ?int $available, string $status = Constants::STATUS_AVAILABLE): Service
    {
        $service = new Service();
        $service->id = $id;
        $service->label = sprintf('Skipass %d', $id);
        $service->subType = Constants::TOKEN_SKI_PASS;
        $service->available = $available;
        $service->status = $status;

        return $service;
    }

    private function createBookingDtoWithServices(array $services): BookingDto
    {
        $travel = new Travel();

        $indexed = [];
        foreach ($services as $service) {
            $indexed[$service->id] = $service;
        }
        $travel->additionalServices = $indexed;

        $bookingDto = new BookingDto($travel, 1);
        $bookingDto->participants[0] = new ParticipantDto();

        return $bookingDto;
    }

    /**
     * @param array<int, Service> $services
     * @param list<int>           $heldServiceIds IDs participant 0 already holds in the booking
     */
    private function createEditBookingDtoWithServices(array $services, array $heldServiceIds = []): BookingDto
    {
        $bookingDto = $this->createBookingDtoWithServices($services);

        $heldServices = [];
        foreach ($heldServiceIds as $serviceId) {
            $held = clone $bookingDto->travel->additionalServices[$serviceId];
            $held->mapping = [0];
            $heldServices[$serviceId] = $held;
        }

        // A non-null booking is what puts the DTO into edit mode
        $booking = new Booking();
        $booking->additionalServices = $heldServices;
        $bookingDto->booking = $booking;

        return $bookingDto;
    }

    /**
     * Prefills the given participants with the parking service, as the edit form does for a
     * service they hold in the live booking.
     *
     * @param list<int> $participantIndexes
     */
    private function holdParkingForOtherParticipants(BookingDto $bookingDto, Service $parkingService, array $participantIndexes): void
    {
        $held = clone $parkingService;
        $held->mapping = $participantIndexes;
        $bookingDto->booking->additionalServices[$parkingService->id] = $held;

        foreach ($participantIndexes as $index) {
            $participant = new ParticipantDto();
            $participant->parkingService = $parkingService;
            $bookingDto->participants[$index] = $participant;
        }
    }
}