<?php

declare(strict_types=1);

namespace App\Tests\Service;

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

class ParticipantEligibilityCheckerTest extends TestCase
{
    private ParticipantEligibilityChecker $service;

    protected function setUp(): void
    {
        $this->service = new ParticipantEligibilityChecker(
            new ServiceAgeEvaluator(),
            new ServiceAvailabilityCalculator()
        );
    }

    public function testBabyParticipantIsAlwaysEligible(): void
    {
        $travel = $this->createTravelWithNoSkiPasses();
        $bookingDto = new BookingDto($travel, 1);

        // Create a baby participant (1 year old at travel date)
        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom->modify('-1 year');
        $bookingDto->participants[0] = $participant;

        $result = $this->service->isParticipantEligible($bookingDto, 0);

        $this->assertTrue($result, 'Baby participant (1 year old) should be eligible regardless of ski pass availability');
    }

    public function testTwoYearOldParticipantIsEligibleAsBaby(): void
    {
        $travel = $this->createTravelWithNoSkiPasses();
        $bookingDto = new BookingDto($travel, 1);

        // Create a participant exactly at BABY_MAX_AGE (2 years old at travel date)
        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom->modify('-2 years');
        $bookingDto->participants[0] = $participant;

        $result = $this->service->isParticipantEligible($bookingDto, 0);

        $this->assertTrue($result, 'Participant at BABY_MAX_AGE (2 years) should be eligible');
    }

    public function testThreeYearOldParticipantIsNotExemptAsBaby(): void
    {
        $travel = $this->createTravelWithSkiPasses(ageFrom: 6);
        $bookingDto = new BookingDto($travel, 1);

        // Create a participant just over BABY_MAX_AGE (3 years old at travel date)
        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom->modify('-3 years');
        $bookingDto->participants[0] = $participant;

        $this->assertTrue(
            $this->service->isSkiPassRequired($bookingDto, 0),
            'Participant over BABY_MAX_AGE (3 years) should still need a ski pass'
        );
        $this->assertFalse(
            $this->service->isParticipantEligible($bookingDto, 0),
            'Participant over BABY_MAX_AGE (3 years) should not be eligible when no ski pass fits their age'
        );
    }

    public function testAdultParticipantWithSkiPassIsEligible(): void
    {
        $travel = $this->createTravelWithSkiPasses();
        $bookingDto = new BookingDto($travel, 1);

        // Create an adult participant (25 years old at travel date)
        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom->modify('-25 years');
        $bookingDto->participants[0] = $participant;

        $result = $this->service->isParticipantEligible($bookingDto, 0);

        $this->assertTrue($result, 'Adult participant with available ski passes should be eligible');
    }

    public function testParticipantWithoutDateOfBirthIsNotEligible(): void
    {
        $travel = $this->createTravelWithSkiPasses();
        $bookingDto = new BookingDto($travel, 1);

        // Create a participant without date of birth
        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = null;
        $bookingDto->participants[0] = $participant;

        $result = $this->service->isParticipantEligible($bookingDto, 0);

        $this->assertFalse($result, 'Participant without date of birth should not be eligible');
    }

    public function testNewbornBabyIsEligible(): void
    {
        $travel = $this->createTravelWithNoSkiPasses();
        $bookingDto = new BookingDto($travel, 1);

        // Create a newborn (born on travel date)
        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom;
        $bookingDto->participants[0] = $participant;

        $result = $this->service->isParticipantEligible($bookingDto, 0);

        $this->assertTrue($result, 'Newborn baby (0 years old) should be eligible');
    }

    public function testBabyAgeIsCalculatedAtTravelDate(): void
    {
        $travel = new Travel();
        $travel->dateFrom = new \DateTimeImmutable('2025-06-01');
        $travel->dateTo = new \DateTimeImmutable('2025-06-08');
        $travel->additionalServices = [];

        $bookingDto = new BookingDto($travel, 1);

        // Create a participant who will be 2 at travel date but 3 now
        // Born 2023-06-02, travel date 2025-06-01 = 1 year 364 days = 1 year old
        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = new \DateTimeImmutable('2023-06-02');
        $bookingDto->participants[0] = $participant;

        $result = $this->service->isParticipantEligible($bookingDto, 0);

        $this->assertTrue($result, 'Age should be calculated at travel date, not current date');
    }

    public function testAdultIsEligibleOnTravelWithoutSkiPasses(): void
    {
        $travel = $this->createTravelWithNoSkiPasses();
        $bookingDto = new BookingDto($travel, 1);

        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom->modify('-25 years');
        $bookingDto->participants[0] = $participant;

        $this->assertFalse(
            $this->service->isSkiPassRequired($bookingDto, 0),
            'A travel that offers no ski passes cannot require one'
        );
        $this->assertTrue(
            $this->service->isParticipantEligible($bookingDto, 0),
            'Adult should be eligible on a travel that offers no ski passes at all'
        );
    }

    public function testTeenagerIsEligibleOnTravelWithoutSkiPasses(): void
    {
        $travel = $this->createTravelWithNoSkiPasses();
        $bookingDto = new BookingDto($travel, 1);

        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom->modify('-14 years');
        $bookingDto->participants[0] = $participant;

        $this->assertFalse($this->service->isSkiPassRequired($bookingDto, 0));
        $this->assertTrue(
            $this->service->isParticipantEligible($bookingDto, 0),
            'Age must not be blamed when there is no ski pass to match against'
        );
    }

    public function testParticipantIsNotEligibleWhenNoSkiPassMatchesTheirAge(): void
    {
        $travel = $this->createTravelWithSkiPasses(ageFrom: 18);
        $bookingDto = new BookingDto($travel, 1);

        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom->modify('-14 years');
        $bookingDto->participants[0] = $participant;

        $this->assertTrue($this->service->isSkiPassRequired($bookingDto, 0));
        $this->assertFalse(
            $this->service->isParticipantEligible($bookingDto, 0),
            'Ski passes exist but none fits the age - the participant stays ineligible'
        );
    }

    public function testParticipantIsNotEligibleWhenSkiPassIsSoldOut(): void
    {
        $travel = $this->createTravelWithSkiPasses(available: 0);
        $bookingDto = new BookingDto($travel, 1);

        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom->modify('-25 years');
        $bookingDto->participants[0] = $participant;

        $this->assertTrue(
            $this->service->isSkiPassRequired($bookingDto, 0),
            'A sold out ski pass must not turn the requirement off'
        );
        $this->assertFalse($this->service->isParticipantEligible($bookingDto, 0));
    }

    public function testParticipantIsNotEligibleWhenSkiPassIsOnBookingStop(): void
    {
        $travel = $this->createTravelWithSkiPasses(status: Constants::STATUS_BLOCKED);
        $bookingDto = new BookingDto($travel, 1);

        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom->modify('-25 years');
        $bookingDto->participants[0] = $participant;

        $this->assertTrue($this->service->isSkiPassRequired($bookingDto, 0));
        $this->assertFalse($this->service->isParticipantEligible($bookingDto, 0));
    }

    public function testParticipantIsNotEligibleWhenLastSkiPassIsTakenByAnotherParticipant(): void
    {
        $travel = $this->createTravelWithSkiPasses(available: 1);
        $bookingDto = new BookingDto($travel, 2);

        $firstParticipant = new ParticipantDto();
        $firstParticipant->index = 0;
        $firstParticipant->dateOfBirth = $travel->dateFrom->modify('-25 years');
        $firstParticipant->skiPass = $travel->additionalServices[1];
        $bookingDto->participants[0] = $firstParticipant;

        $secondParticipant = new ParticipantDto();
        $secondParticipant->index = 1;
        $secondParticipant->dateOfBirth = $travel->dateFrom->modify('-25 years');
        $bookingDto->participants[1] = $secondParticipant;

        $this->assertTrue($this->service->isParticipantEligible($bookingDto, 0));
        $this->assertFalse(
            $this->service->isParticipantEligible($bookingDto, 1),
            'The only ski pass is consumed by the first participant'
        );
    }

    public function testBabyNeedsNoSkiPassEvenWhenTravelOffersThem(): void
    {
        $travel = $this->createTravelWithSkiPasses();
        $bookingDto = new BookingDto($travel, 1);

        $participant = new ParticipantDto();
        $participant->index = 0;
        $participant->dateOfBirth = $travel->dateFrom->modify('-1 year');
        $bookingDto->participants[0] = $participant;

        $this->assertFalse($this->service->isSkiPassRequired($bookingDto, 0));
        $this->assertTrue($this->service->isParticipantEligible($bookingDto, 0));
    }

    private function createTravelWithNoSkiPasses(): Travel
    {
        $travel = new Travel();
        $travel->dateFrom = new \DateTimeImmutable('+30 days');
        $travel->dateTo = new \DateTimeImmutable('+37 days');
        $travel->additionalServices = [];

        return $travel;
    }

    private function createTravelWithSkiPasses(?int $ageFrom = null, ?int $available = 10, ?string $status = null): Travel
    {
        $travel = new Travel();
        $travel->dateFrom = new \DateTimeImmutable('+30 days');
        $travel->dateTo = new \DateTimeImmutable('+37 days');

        // Create a ski pass service, by default available for all ages
        $skiPass = new Service();
        $skiPass->id = 1;
        $skiPass->label = 'Test Ski Pass';
        $skiPass->subType = Constants::TOKEN_SKI_PASS;
        $skiPass->available = $available;
        $skiPass->status = $status;
        $skiPass->price = 100.0;
        $skiPass->ageConstraintType = null === $ageFrom ? null : 'absolute_age';
        $skiPass->ageFrom = $ageFrom;
        $skiPass->dateFrom = $travel->dateFrom;
        $skiPass->dateTo = $travel->dateTo;

        $travel->additionalServices = [1 => $skiPass];

        return $travel;
    }
}