<?php
/************************************************************************
 * This file is part of EspoCRM.
 *
 * EspoCRM - Open Source CRM application.
 * Copyright (C) 2014-2022 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
 * Website: https://www.espocrm.com
 *
 * EspoCRM is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * EspoCRM is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU General Public License version 3.
 *
 * In accordance with Section 7(b) of the GNU General Public License version 3,
 * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
 ************************************************************************/

namespace Espo\Core\Formula;

use Espo\ORM\Entity;
use Espo\Core\ORM\Entity as CoreEntity;

/**
 * Fetches attributes from an entity.
 */
class AttributeFetcher
{
    /**
     * @var array<string,mixed>
     */
    private $relatedEntitiesCacheMap = [];

    /**
     * @return mixed
     */
    public function fetch(Entity $entity, string $attribute, bool $getFetchedAttribute = false)
    {
        if (strpos($attribute, '.') !== false) {
            $arr = explode('.', $attribute);

            $key = $this->buildKey($entity, $arr[0]);

            if (!array_key_exists($key, $this->relatedEntitiesCacheMap)) {
                // @todo Use getRelation.
                $this->relatedEntitiesCacheMap[$key] = $entity->get($arr[0]);
            }

            $relatedEntity = $this->relatedEntitiesCacheMap[$key];

            if (
                $relatedEntity &&
                ($relatedEntity instanceof Entity) &&
                count($arr) > 1
            ) {
                return $this->fetch($relatedEntity, $arr[1]);
            }

            return null;
        }

        $methodName = 'get';

        if ($getFetchedAttribute) {
            $methodName = 'getFetched';
        }

        if (
            $entity instanceof CoreEntity &&
            $entity->getAttributeParam($attribute, 'isParentName') &&
            $methodName == 'get'
        ) {
            $relationName = $entity->getAttributeParam($attribute, 'relation');

            $parent = $parent = $entity->get($relationName);

            if ($parent) {
                return $parent->get('name');
            }
        }
        else if (
            $entity instanceof CoreEntity &&
            $entity->getAttributeParam($attribute, 'isLinkMultipleIdList') &&
            $methodName == 'get'
        ) {
            $relationName = $entity->getAttributeParam($attribute, 'relation');

            if (!$entity->has($attribute)) {
                $entity->loadLinkMultipleField($relationName);
            }
        }

        if ($methodName === 'getFetched') {
            return $entity->getFetched($attribute);
        }

        return $entity->get($attribute);
    }

    public function resetRuntimeCache(): void
    {
        $this->relatedEntitiesCacheMap = [];
    }

    private function buildKey(Entity $entity, string $link): string
    {
        return spl_object_hash($entity) . '-' . $link;
    }
}