<?php

declare(strict_types=1);

namespace App\Form\Service;

use App\BusProNet\Constants;
use App\BusProNet\Model\Pickup;
use App\BusProNet\Model\Service;
use App\BusProNet\Utility\DirectionMapper;
use App\Form\Model\BookingCreateDto;
use App\Form\Model\BookingDtoInterface;
use App\Form\Service\Abstract\AbstractFieldOptionsProvider;
use App\Form\Service\Factory\ParticipantRoomChoiceLoaderFactory;
use App\Service\ServiceAvailabilityCalculator;

/**
 * Provides dynamic field options for participant form fields.
 *
 * This service generates context-aware Symfony form field options for
 * dynamic fields in the participant form system. It handles fields that
 * require options to be calculated based on the current booking context,
 * participant data, and business logic.
 *
 * Key Responsibilities:
 * - Manages field option providers for dynamic fields
 * - Provides context-aware field configurations
 * - Handles interdependent field relationships
 * - Supports extensible field option generation
 *
 * The provider uses a callable pattern for field options, enabling
 * lazy evaluation and complex conditional field behavior.
 */
class ParticipantFieldOptionsProvider extends AbstractFieldOptionsProvider
{
    /**
     * Initializes the provider with required dependencies.
     *
     * The provider automatically registers all field option providers during
     * construction to ensure they're available for form building. This approach
     * keeps all field configuration logic centralized and makes it easy to add
     * new dynamic fields.
     *
     * @param ParticipantRoomChoiceLoaderFactory $roomChoiceLoaderFactory       Factory for creating room choice loaders
     * @param ServiceAvailabilityCalculator      $serviceAvailabilityCalculator Service for calculating dynamic availability
     */
    public function __construct(
        private readonly ParticipantRoomChoiceLoaderFactory $roomChoiceLoaderFactory,
        private readonly ServiceAvailabilityCalculator $serviceAvailabilityCalculator,
    ) {
        parent::__construct();
    }

    /**
     * Registers all field option providers during service initialization.
     *
     * This method defines the option generation logic for each supported dynamic field.
     * Each provider is a callable that receives the booking DTO and participant
     * index and returns appropriate Symfony form field options.
     *
     * Adding new fields:
     * To add support for a new dynamic field, simply add a new provider here:
     *
     * $this->fieldOptionProviders['newField'] = fn($bookingDto, $participantIndex) => [
     *     'label' => 'New Field Label',
     *     'choices' => $this->generateChoicesFor($bookingDto, $participantIndex),
     * ];
     *
     * Provider Pattern Benefits:
     * - Lazy evaluation (options only generated when needed)
     * - Context-aware configuration
     * - Easy to test individual field logic
     * - Supports complex interdependencies
     */
    protected function registerFieldOptionProviders(): void
    {
        // Room assignment field provider (only available for create workflow)
        $this->fieldOptionProviders['assignedRoomId'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Zimmer',
            'placeholder' => 'Bitte wählen',
            // Use factory to create context-aware choice loader that:
            // - Shows only available rooms for this participant
            // - Excludes rooms already assigned to other participants
            // - Respects room capacity and booking constraints
            'choice_loader' => $bookingDto instanceof BookingCreateDto
                ? $this->roomChoiceLoaderFactory->create(
                    $bookingDto->participants,
                    $bookingDto->getSelectedRooms(),
                    $participantIndex
                )
                : null,
        ];

        // Courses field provider - provides age-appropriate courses from travel data
        $this->fieldOptionProviders['courses'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Kurse',
            'multiple' => true,
            'expanded' => true,
            'required' => false,
            'choices' => $this->filterServicesByAvailability(
                $this->filterServicesByAgeConstraints(
                    $bookingDto->travel->getAdditionalServicesBySubTypes(Constants::TOKEN_COURSES),
                    $bookingDto,
                    $participantIndex
                ),
                $bookingDto,
                $participantIndex
            ),
            'choice_value' => 'id',
            'choice_label' => fn (?Service $service) => $this->formatServiceLabelWithPrice($service),
            'choice_attr' => function (?Service $service) {
                if (null === $service) {
                    return [];
                }

                $attributes = [];

                // Add service description as data attribute for frontend use
                if (null !== $service->description && '' !== trim($service->description)) {
                    $attributes['data-description'] = $service->description;
                }

                return $attributes;
            },
        ];

        // Additional services field provider - provides age-appropriate additional services with mandatory pre-selection
        $this->fieldOptionProviders['additionalServices'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Zusatzleistungen',
            'multiple' => true,
            'expanded' => true,
            'required' => false,
            'choices' => $this->filterServicesByAvailability(
                $this->filterServicesByAgeConstraints(
                    $bookingDto->travel->getAdditionalServicesBySubTypes(Constants::TOKEN_ADDITIONAL),
                    $bookingDto,
                    $participantIndex
                ),
                $bookingDto,
                $participantIndex
            ),
            'choice_value' => 'id',
            'choice_label' => fn (?Service $service) => $this->formatServiceLabelWithPrice($service),
            'choice_attr' => function (?Service $service) {
                if (null === $service) {
                    return [];
                }

                $attributes = [];

                // Make readonly for mandatory services (pre-selection handled by service layer)
                if (true === $service->mandatory) {
                    $attributes['readonly'] = true;
                    $attributes['class'] = 'text-pink';
                    $attributes['title'] = 'Diese Leistung ist nicht abwählbar';
                }

                // Add service description as data attribute for frontend use
                if (null !== $service->description && '' !== trim($service->description)) {
                    $attributes['data-description'] = $service->description;
                }

                return $attributes;
            },
        ];

        // Board field provider - provides age-appropriate board options from travel data
        $this->fieldOptionProviders['board'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Verpflegung',
            'multiple' => true,
            'expanded' => true,
            'required' => false,
            'choices' => $this->filterServicesByAvailability(
                $this->filterServicesByAgeConstraints(
                    $bookingDto->travel->getAdditionalServicesBySubTypes(Constants::TOKEN_BOARD),
                    $bookingDto,
                    $participantIndex
                ),
                $bookingDto,
                $participantIndex
            ),
            'choice_value' => 'id',
            'choice_label' => fn (?Service $service) => $this->formatServiceLabelWithPrice($service),
        ];

        // Rentals field provider - provides age-appropriate rental options filtered by selected skipass duration
        $this->fieldOptionProviders['rentals'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Leihmaterial',
            'multiple' => true,
            'expanded' => true,
            'required' => false,
            'choices' => $this->filterServicesByAvailability(
                $this->filterServicesByAgeConstraints(
                    $this->filterRentalsBySkiPassDuration(
                        $bookingDto->travel->getAdditionalServicesBySubTypes(Constants::TOKEN_RENTALS, true, true),
                        $bookingDto,
                        $participantIndex
                    ),
                    $bookingDto,
                    $participantIndex
                ),
                $bookingDto,
                $participantIndex
            ),
            'choice_value' => 'id',
            'choice_label' => fn (?Service $service) => $this->formatServiceLabelWithPrice($service),
            'choice_attr' => function (?Service $service) {
                if (null === $service) {
                    return [];
                }

                $attributes = [];

                // Add service description as data attribute for frontend use
                if (null !== $service->description && '' !== trim($service->description)) {
                    $attributes['data-description'] = $service->description;
                }

                return $attributes;
            },
        ];

        // Rental insurance field provider - provides rental insurance options when rental services are selected
        $this->fieldOptionProviders['rentalInsurance'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => $this->getRentalInsuranceCheckboxLabel($bookingDto->travel->getAdditionalServicesBySubTypes(Constants::TOKEN_RENTAL_INSURANCE, true, true)),
            'required' => false,
            'property_path' => 'rentalInsuranceSelected',
            'help' => $this->getRentalInsuranceDescription($bookingDto->travel->getAdditionalServicesBySubTypes(Constants::TOKEN_RENTAL_INSURANCE, true, true)),
        ];

        // License plate field provider - provides text input for vehicle license plate when parking is selected
        $this->fieldOptionProviders['licensePlate'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Kennzeichen',
            'required' => false,
            'attr' => [
                'placeholder' => 'z.B. AB-CD 123',
                'maxlength' => 20,
            ],
            'help' => 'Bitte gib das Kennzeichen deines Fahrzeugs an. Du kannst es aber auch später nachreichen.',
            'clean_xss' => true,
        ];

        // Skipass field provider - provides age-appropriate skipass options from travel data filtered by date range
        $this->fieldOptionProviders['skiPass'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Skipass',
            'multiple' => false,
            'expanded' => true,
            'required' => true,
            'choices' => $this->filterServicesByAvailability(
                $this->filterServicesByAgeConstraints(
                    $bookingDto->travel->getAdditionalServicesBySubTypes(Constants::TOKEN_SKI_PASS, true, true),
                    $bookingDto,
                    $participantIndex
                ),
                $bookingDto,
                $participantIndex
            ),
            'choice_value' => 'id',
            'choice_label' => fn (?Service $service) => $this->formatServiceLabelWithPrice($service),
            'choice_attr' => function (?Service $service) {
                if (null === $service) {
                    return [];
                }

                $attributes = [];

                // Add service description as data attribute for frontend use
                if (null !== $service->description && '' !== trim($service->description)) {
                    $attributes['data-description'] = $service->description;
                }

                return $attributes;
            },
        ];

        // Room remarks field provider - provides textarea for room-specific remarks (only for 'mbz' rooms)
        $this->fieldOptionProviders['remarksRoom'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Wünsche oder Anmerkungen zum Zimmer',
            'required' => false,
            'clean_xss' => true,
            'attr' => [
                'rows' => 2,
            ],
        ];

        // Transportation field providers - handles outbound/inbound transportation and pickup selection

        // Outbound Transportation
        $this->fieldOptionProviders['transportationOutbound'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Hinfahrt',
            'choices' => $this->filterServicesByAvailability(
                $bookingDto->travel->getTransportationServicesByDirection(DirectionMapper::OUTBOUND_TRAVEL),
                $bookingDto,
                $participantIndex
            ),
            'choice_label' => fn (Service $service) => $this->formatTransportationServiceLabel($service),
            'choice_value' => 'id',
            'expanded' => true,
            'multiple' => false,
            'required' => true,
            'attr' => [
                'hx-post' => '#',  // Will be configured when HTMX integration is implemented
                'hx-target' => '#booking-summary',
                'hx-trigger' => 'change',
            ],
        ];

        // Inbound Transportation
        $this->fieldOptionProviders['transportationInbound'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Rückfahrt',
            'choices' => $this->filterServicesByAvailability(
                $bookingDto->travel->getTransportationServicesByDirection(DirectionMapper::INBOUND_TRAVEL),
                $bookingDto,
                $participantIndex
            ),
            'choice_label' => fn (Service $service) => $this->formatTransportationServiceLabel($service),
            'choice_value' => 'id',
            'expanded' => true,
            'multiple' => false,
            'required' => true,
            'attr' => [
                'hx-post' => '#',  // Will be configured when HTMX integration is implemented
                'hx-target' => '#booking-summary',
                'hx-trigger' => 'change',
            ],
        ];

        // Outbound Pickup (conditional - only shown when outbound transportation is bus)
        $this->fieldOptionProviders['pickupOutbound'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Zustieg Hinfahrt',
            'choices' => $bookingDto->travel->pickupsTo,
            'choice_label' => fn (?Pickup $pickup) => $this->formatPickupLabelWithPrice($pickup),
            'choice_value' => 'id',
            'expanded' => false, // Dropdown for pickups
            'multiple' => false,
            'required' => true,
            'placeholder' => 'Zustieg auswählen',
        ];

        // Inbound Pickup (conditional - only shown when inbound transportation is bus)
        $this->fieldOptionProviders['pickupInbound'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => 'Ausstieg Rückfahrt',
            'choices' => $bookingDto->travel->pickupsFro,
            'choice_label' => fn (?Pickup $pickup) => $this->formatPickupLabelWithPrice($pickup),
            'choice_value' => 'id',
            'expanded' => false,
            'multiple' => false,
            'required' => true,
            'placeholder' => 'Ausstieg auswählen',
        ];

        // Parking (conditional - only shown when outbound transportation is PKW)
        // Simple checkbox since there's only ever one parking type
        $this->fieldOptionProviders['parking'] = fn (BookingDtoInterface $bookingDto, int $participantIndex, array $options = []) => [
            'label' => $this->getParkingCheckboxLabel($bookingDto->travel->getAdditionalServicesBySubTypes(Constants::TOKEN_PARKING, true)),
            'required' => false,
        ];

        // Future field providers would be added here, for example:
        //
        // $this->fieldOptionProviders['mealPreference'] = fn($bookingDto, $participantIndex) => [
        //     'label' => 'Meal Preference',
        //     'choices' => [
        //         'Standard' => 'standard',
        //         'Vegetarian' => 'vegetarian',
        //         'Vegan' => 'vegan',
        //     ],
        // ];
    }

    /**
     * Filters rental services by selected skipass duration.
     *
     * Only returns rentals that have exactly the same dateFrom and dateTo
     * as the participant's selected skipass. This ensures rental equipment
     * is only available for the exact duration of the skipass.
     *
     * @param array               $rentals          Array of rental Service objects to filter
     * @param BookingDtoInterface $bookingDto       The booking DTO containing participant data
     * @param int                 $participantIndex Index of the participant to evaluate
     *
     * @return array Filtered array of rentals matching skipass duration
     */
    private function filterRentalsBySkiPassDuration(array $rentals, BookingDtoInterface $bookingDto, int $participantIndex): array
    {
        $participant = $bookingDto->getParticipant($participantIndex);
        if (null === $participant || null === $participant->skiPass) {
            return []; // No skipass selected = no rentals available
        }

        $selectedSkiPass = $participant->skiPass;

        // If skipass has no valid dates, return empty rentals
        if (null === $selectedSkiPass->dateFrom || null === $selectedSkiPass->dateTo) {
            return [];
        }

        return array_filter($rentals, function (Service $rental) use ($selectedSkiPass) {
            // Rental must have valid dates to be considered
            if (null === $rental->dateFrom || null === $rental->dateTo) {
                return false;
            }

            // Exact date matching: rental dates must match skipass dates exactly
            return $rental->dateFrom->format('Y-m-d') === $selectedSkiPass->dateFrom->format('Y-m-d')
                && $rental->dateTo->format('Y-m-d') === $selectedSkiPass->dateTo->format('Y-m-d');
        });
    }

    /**
     * Formats service label with pricing information.
     *
     * @param Service|null $service The service to format
     *
     * @return string The formatted label
     */
    private function formatServiceLabelWithPrice(?Service $service): string
    {
        if (null === $service) {
            return '';
        }

        if (null === $service->price || 0.0 === $service->price) {
            return $service->label;
        }

        if ($service->price < 0) {
            // Negative prices are discounts
            return sprintf('%s (-%s€ Rabatt)', $service->label, number_format(abs($service->price), 2, ',', '.'));
        }

        return sprintf('%s (€%s)', $service->label, number_format($service->price, 2, ',', '.'));
    }

    /**
     * Format transportation service labels with type indicator and pricing.
     *
     * Creates user-friendly labels for transportation services that include:
     * - Transportation type icon (🚌 for bus, 🚗 for car)
     * - Service name
     * - Pricing (with discount indication for negative prices)
     * - Availability warning for limited services
     *
     * @param Service $service The transportation service to format
     *
     * @return string The formatted transportation service label
     */
    private function formatTransportationServiceLabel(Service $service): string
    {
        $label = $service->label;

        if (null === $service->price || 0.0 === $service->price) {
            return $service->label;
        }

        if ($service->price > 0) {
            $label .= sprintf(' (€%s)', number_format($service->price, 2, ',', '.'));
        } else {
            $label .= sprintf(' (-%s€ Rabatt)', number_format(abs($service->price), 2, ',', '.'));
        }

        // Add availability warning if limited
        if (null !== $service->available && $service->available <= 5) {
            $label .= sprintf(' (nur %d verfügbar)', $service->available);
        }

        return $label;
    }

    /**
     * Format pickup labels with city and street information.
     *
     * Creates user-friendly labels for pickup locations following the existing pattern:
     * - Primary format: "City (Street)" if street is available
     * - Fallback format: "City" if no street information
     *
     * @param Pickup $pickup The pickup location to format
     *
     * @return string The formatted pickup location label
     */
    private function formatPickupLabel(Pickup $pickup): string
    {
        $label = $pickup->city ?? '';

        if (null !== $pickup->street && '' !== trim($pickup->street)) {
            $label .= ' ('.$pickup->street.')';
        }

        return $label;
    }

    private function formatPickupLabelWithPrice(?Pickup $pickup): string
    {
        if (null === $pickup) {
            return '';
        }

        $label = $this->formatPickupLabel($pickup);

        if (null === $pickup->price || 0.0 === $pickup->price) {
            return $label;
        }

        if ($pickup->price < 0) {
            // Negative prices are discounts
            return sprintf('%s (-%s€ Rabatt)', $label, number_format(abs($pickup->price), 2, ',', '.'));
        }

        return sprintf('%s (€%s)', $label, number_format($pickup->price, 2, ',', '.'));
    }

    /**
     * Gets the parking checkbox label with pricing information.
     *
     * Creates a checkbox label for the single parking service including pricing.
     * Since there's only ever one parking type, we take the first available service.
     *
     * @param array $parkingServices Array of available parking services
     *
     * @return string The formatted checkbox label with pricing
     */
    private function getParkingCheckboxLabel(array $parkingServices): string
    {
        if (empty($parkingServices)) {
            return 'Parkplatz';
        }

        $parkingService = reset($parkingServices); // Get the first (and only) parking service

        return $this->formatServiceLabelWithPrice($parkingService);
    }

    /**
     * Filters services based on remaining availability in the current booking session.
     *
     * Removes services that have been fully booked by other participants in
     * the current booking session. This prevents overbooking within a single
     * booking workflow while maintaining accurate availability counts.
     *
     * @param array               $services         Array of Service objects to filter
     * @param BookingDtoInterface $bookingDto       The booking DTO containing participant data
     * @param int                 $participantIndex Index of the participant currently selecting services
     *
     * @return array Filtered array containing only services with remaining availability
     */
    private function filterServicesByAvailability(array $services, BookingDtoInterface $bookingDto, int $participantIndex): array
    {
        if (!$bookingDto instanceof BookingCreateDto) {
            // For non-create workflows, return all services (no availability tracking needed)
            return $services;
        }

        return $this->serviceAvailabilityCalculator->filterAvailableServices($services, $bookingDto, $participantIndex);
    }

    /**
     * Filters services based on participant's age constraints.
     *
     * Removes services that have age restrictions the participant doesn't meet.
     * If no age evaluator is configured or participant has no birth date,
     * returns empty array to be handled by field visibility conditions.
     *
     * @param array               $services         Array of Service objects to filter
     * @param BookingDtoInterface $bookingDto       The booking DTO containing participant data
     * @param int                 $participantIndex Index of the participant to evaluate
     *
     * @return array Filtered array of available services
     */
    private function filterServicesByAgeConstraints(array $services, BookingDtoInterface $bookingDto, int $participantIndex): array
    {
        $ageEvaluator = new ServiceAgeEvaluator();

        $participant = $bookingDto->getParticipant($participantIndex);

        // If no birthdate provided, return empty array (handled by field visibility conditions)
        if (null === $participant || null === $participant->dateOfBirth) {
            return [];
        }

        return array_filter($services, function (Service $service) use ($bookingDto, $participantIndex, $ageEvaluator) {
            // No age constraints = available to all
            if (false === $ageEvaluator->canEvaluate($service)) {
                return true;
            }

            return $ageEvaluator->isServiceAvailableForParticipant($service, $bookingDto, $participantIndex);
        });
    }

    /**
     * Generates label for rental insurance checkbox including pricing information.
     */
    private function getRentalInsuranceCheckboxLabel(array $rentalInsuranceServices): string
    {
        if (empty($rentalInsuranceServices)) {
            return 'Leihmaterial-Versicherung';
        }
        $rentalInsuranceService = reset($rentalInsuranceServices); // Get the first (and only) rental insurance service

        return $this->formatServiceLabelWithPrice($rentalInsuranceService);
    }

    /**
     * Gets the rental insurance description for help text.
     */
    private function getRentalInsuranceDescription(array $rentalInsuranceServices): ?string
    {
        if (empty($rentalInsuranceServices)) {
            return null;
        }
        $rentalInsuranceService = reset($rentalInsuranceServices); // Get the first (and only) rental insurance service

        return $rentalInsuranceService->description;
    }
}