<?php

declare(strict_types=1);

namespace App\Form\Service;

use App\BusProNet\Constants;
use App\BusProNet\Model\Service;
use App\Form\Model\BookingDto;
use App\Form\Service\Abstract\AbstractParticipantFieldHandler;

/**
 * Handles processing of the veg (vegetarian/vegan) field for booking participants.
 *
 * This handler manages dietary preference selection for participants in the booking
 * process. It processes the veg field from form submissions, validates age-appropriate
 * options if constraints exist, and updates the participant DTO with the valid selection.
 *
 * The field is rendered as radio buttons (mutually exclusive single selection) since
 * vegetarian and vegan options should not be combined.
 *
 * Dependencies: dateOfBirth (for potential future age constraints)
 */
class ParticipantVegFieldHandler extends AbstractParticipantFieldHandler
{
    /**
     * Returns the form field name this handler processes.
     *
     * @return string The field name 'veg'
     */
    public function getFieldName(): string
    {
        return 'veg';
    }

    /**
     * Returns the field dependencies for proper processing order.
     *
     * This handler depends on dateOfBirth being processed first because
     * age evaluation requires the participant's birth date to be available.
     *
     * @return string[] Array containing 'dateOfBirth' dependency
     */
    public function getDependencies(): array
    {
        return ['dateOfBirth'];
    }

    /**
     * Determines if this handler should process the field based on submitted data.
     *
     * For service selection fields, we always need to process to handle cases where
     * the selection is cleared (field not present in data). This ensures the participant
     * DTO is updated with null when no option is selected.
     *
     * @param array<string, mixed> $submittedData    The submitted participant form data
     * @param string               $mode             The booking mode (BookingDto::MODE_CREATE or MODE_EDIT)
     * @param int                  $participantIndex The index of the participant being processed
     *
     * @return bool Always returns true for service selection fields
     */
    public function shouldProcess(array $submittedData, string $mode, int $participantIndex): bool
    {
        return true;
    }

    /**
     * Processes the veg field for a specific participant.
     *
     * This method extracts the dietary preference selection from submitted form data,
     * validates the selection against any age constraints if present, and updates the
     * participant DTO with the valid selection.
     *
     * @param array<string, mixed> $submittedData    The submitted participant form data
     * @param BookingDto           $bookingDto       The booking DTO to update (create or edit)
     * @param int                  $participantIndex The index of the participant being processed
     */
    public function processField(array $submittedData, BookingDto $bookingDto, int $participantIndex): void
    {
        $participant = $this->getParticipant($bookingDto, $participantIndex);
        if (null === $participant) {
            return;
        }

        $selectedVeg = $this->getFieldValue($submittedData, $this->getFieldName());

        // Get available veg options from travel data (includes booked options in edit mode)
        $availableVegOptions = $this->getAvailableServicesWithBooked(
            $bookingDto,
            $participantIndex,
            Constants::TOKEN_VEG,
            true
        );

        $validSelection = null;
        if (null !== $selectedVeg) {
            if ($this->isServiceValidForParticipant($selectedVeg, $availableVegOptions, $bookingDto, $participantIndex)) {
                $validSelection = $this->findServiceInAvailableServices($selectedVeg, $availableVegOptions);
            }
        }

        $participant->veg = $validSelection;
    }

    /**
     * Validates if a selected veg option is still valid for the participant.
     *
     * This method checks age constraints if they exist for the service.
     *
     * @param mixed               $selectedService   The selected veg option to validate
     * @param array<int, Service> $availableServices Array of available veg options
     * @param BookingDto          $bookingDto        The booking DTO for context
     * @param int                 $participantIndex  The participant index for age evaluation
     *
     * @return bool True if the option is valid for the participant, false otherwise
     */
    private function isServiceValidForParticipant(
        mixed $selectedService,
        array $availableServices,
        BookingDto $bookingDto,
        int $participantIndex,
    ): bool {
        $service = $this->findServiceInAvailableServices($selectedService, $availableServices);

        if (null === $service) {
            return false;
        }

        $ageEvaluator = new ServiceAgeEvaluator();
        if ($ageEvaluator->canEvaluate($service)) {
            if (false === $ageEvaluator->isServiceAvailableForParticipant($service, $bookingDto, $participantIndex)) {
                return false;
            }
        }

        return true;
    }
}