<?php

namespace App\Domains\Event\Services;

use App\Domains\Event\Models\EventDate;

class EffectiveEventDateResolver
{
    public function resolve(EventDate $eventDate): ?EventDate
    {
        $current = $eventDate;
        $visited = [];

        while (true) {
            $identity = $current->getKey() === null
                ? 'object:'.spl_object_id($current)
                : 'key:'.$current->getKey();

            if (isset($visited[$identity])) {
                return null;
            }

            $visited[$identity] = true;

            if ($current->rescheduled_to_event_date_id === null) {
                return $current->cancelled_at === null ? $current : null;
            }

            $current->loadMissing('rescheduledTo');
            $current = $current->rescheduledTo;

            if ($current === null) {
                return null;
            }
        }
    }
}