<?php

/**
 * This program 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; under version 2
 * of the License (non-upgradable).
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2016 (original work) Open Assessment Technologies SA (under the project TAO-PRODUCT);
 *
 */

use oat\tao\model\search\tokenizer\ResourceTokenizer;
use oat\taoItems\model\search\IndexableItemModel;

/**
 * Item content tokenizer.
 *
 * @author Joel Bout <joel@taotesting.com>
 * @author Jérôme Bogaerts <jerome@taotesting.com>
 * @author Camille Moyon <camille@taotesting.com>
 */
class taoItems_models_classes_search_ItemContentTokenizer implements ResourceTokenizer
{
    use \oat\generis\model\OntologyAwareTrait;

    /**
     * Find item model tokenizer and send request to it to extract tokens
     *
     * @param core_kernel_classes_Resource $resource
     * @return array
     */
    public function getStrings(\core_kernel_classes_Resource $resource)
    {
        $tokenizer = $this->getItemContentTokenizer($resource);
        if (is_null($tokenizer)) {
            return [];
        }
        return $tokenizer->getStrings($resource);
    }

    /**
     * Get item content tokenizer associated to $resource e.q. item model
     * If not return null
     *
     * @param core_kernel_classes_Resource $resource
     * @return null|taoItems_models_classes_itemModel
     */
    protected function getItemContentTokenizer(core_kernel_classes_Resource $resource)
    {
        $itemService = taoItems_models_classes_ItemsService::singleton();
        $model = $itemService->getItemModel($resource);
        if (! is_null($model)) {
            $impl = $itemService->getItemModelImplementation($model);
            if (! is_null($impl)) {
                if ($impl instanceof IndexableItemModel) {
                    return $impl->getItemContentTokenizer();
                }
            }
        }
        return null;
    }
}