<?php
/**
 * Copyright since 2007 PrestaShop SA and Contributors
 * PrestaShop is an International Registered Trademark & Property of PrestaShop SA
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.md.
 * It is also available through the world-wide-web at this URL:
 * https://opensource.org/licenses/OSL-3.0
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@prestashop.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
 * versions in the future. If you wish to customize PrestaShop for your
 * needs please refer to https://devdocs.prestashop.com/ for more information.
 *
 * @author    PrestaShop SA and Contributors <contact@prestashop.com>
 * @copyright Since 2007 PrestaShop SA and Contributors
 * @license   https://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
 */

declare(strict_types=1);

namespace PrestaShopBundle\Utils;

class Tree
{
    /**
     * @param array $elementlist
     * @param callable $getChildren; must return an array of children for the given element; signature function($element): array
     * @param callable $getId; must return the id of the given element; signature function($element): int
     * @param array $idStorage; store found ids (ensure recursion optimisation and avoiding infinite loop)
     *
     * @return array [ (int) 'id' => (int) 'id'] (make array construction easier)
     */
    public static function extractChildrenId(array $elementlist, callable $getChildren, callable $getId, array &$idStorage = []): array
    {
        foreach ($elementlist as $child) {
            $childId = $getId($child);
            // Test made to ensure avoiding unecessary recursive call
            if (!isset($idStorage[$childId])) {
                $idStorage[$childId] = $childId;
                static::extractChildrenId($getChildren($child), $getChildren, $getId, $idStorage);
            }
        }

        return $idStorage;
    }
}