<?php

declare(strict_types=1);

namespace App\Form\Service\Condition;

use App\Form\Model\BookingDto;
use App\Form\Service\Contract\FieldConditionInterface;

/**
 * Condition that evaluates whether a participant has provided their date of birth.
 *
 * This condition checks if a participant has a valid date of birth set, which is
 * required for evaluating age-based service constraints and showing age-dependent
 * form fields. When no birth date is provided, age-restricted fields should be
 * hidden until this prerequisite is met.
 *
 * The condition is commonly used to control field visibility, ensuring that
 * age-dependent services and options are only displayed when the participant's
 * age can be calculated.
 */
class DateOfBirthProvidedCondition implements FieldConditionInterface
{
    /**
     * Evaluates if the participant has provided their date of birth.
     *
     * Checks if the participant exists and has a non-null dateOfBirth property.
     * This is a prerequisite for showing age-dependent form fields and services.
     *
     * @param BookingDto  $bookingDto       The current booking data
     * @param int                  $participantIndex The index of the participant being evaluated
     * @param array<string, mixed> $formData         Current form data (unused for this condition)
     *
     * @return bool True if the participant has provided their date of birth, false otherwise
     */
    public function evaluate(BookingDto $bookingDto, int $participantIndex, array $formData): bool
    {
        $participant = $bookingDto->getParticipant($participantIndex);
        $result = null !== $participant && null !== $participant->dateOfBirth;

        error_log(sprintf('[DOB Condition] Participant %d: dateOfBirth=%s, result=%s',
            $participantIndex,
            $participant?->dateOfBirth?->format('Y-m-d') ?? 'NULL',
            $result ? 'TRUE' : 'FALSE'
        ));

        return $result;
    }

    /**
     * Returns field names that this condition depends on.
     *
     * The date of birth condition depends on the participant's dateOfBirth field.
     * When this field changes, any conditions based on birth date availability
     * should be re-evaluated.
     *
     * @return string[] Array containing 'dateOfBirth' field name
     */
    public function getDependentFields(): array
    {
        return ['dateOfBirth'];
    }

    /**
     * Returns a human-readable description of this condition.
     *
     * Provides a clear description of what this condition checks for,
     * useful for debugging and understanding field state logic.
     *
     * @return string Description of the date of birth requirement
     */
    public function getDescription(): string
    {
        return 'Participant must provide their date of birth';
    }
}