<?php
namespace TYPO3\CMS\Core\Resource\Index;

/*
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */

use TYPO3\CMS\Core\Resource;

/**
 * An Interface for MetaData extractors the FAL Indexer uses
 */
interface ExtractorInterface
{
    /**
     * Returns an array of supported file types;
     * An empty array indicates all filetypes
     *
     * @return array
     */
    public function getFileTypeRestrictions();

    /**
     * Get all supported DriverClasses
     *
     * Since some extractors may only work for local files, and other extractors
     * are especially made for grabbing data from remote.
     *
     * Returns array of string with driver names of Drivers which are supported,
     * If the driver did not register a name, it's the classname.
     * empty array indicates no restrictions
     *
     * @return array
     */
    public function getDriverRestrictions();

    /**
     * Returns the data priority of the extraction Service.
     * Defines the precedence of Data if several extractors
     * extracted the same property.
     *
     * Should be between 1 and 100, 100 is more important than 1
     *
     * @return int
     */
    public function getPriority();

    /**
     * Returns the execution priority of the extraction Service
     * Should be between 1 and 100, 100 means runs as first service, 1 runs at last service
     *
     * @return int
     */
    public function getExecutionPriority();

    /**
     * Checks if the given file can be processed by this Extractor
     *
     * @param Resource\File $file
     * @return bool
     */
    public function canProcess(Resource\File $file);

    /**
     * The actual processing TASK
     *
     * Should return an array with database properties for sys_file_metadata to write
     *
     * @param Resource\File $file
     * @param array $previousExtractedData optional, contains the array of already extracted data
     * @return array
     */
    public function extractMetaData(Resource\File $file, array $previousExtractedData = []);
}
