<?php

/*
 * Created on Sep 27, 2008
 *
 * API for MediaWiki 1.8+
 *
 * Copyright (C) 2008 Roan Kattow <Firstname>,<Lastname>@home.nl
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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.,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 * http://www.gnu.org/copyleft/gpl.html
 */

if (!defined('MEDIAWIKI')) {
	// Eclipse helper - will be ignored in production
	require_once ("ApiQueryBase.php");
}

/**
 * A query module to list duplicates of the given file(s)
 *
 * @ingroup API
 */
class ApiQueryDuplicateFiles extends ApiQueryGeneratorBase {

	public function __construct($query, $moduleName) {
		parent :: __construct($query, $moduleName, 'df');
	}

	public function execute() {
		$this->run();
	}

	public function executeGenerator($resultPageSet) {
		$this->run($resultPageSet);
	}

	private function run($resultPageSet = null) {
		$params = $this->extractRequestParams();
		$namespaces = $this->getPageSet()->getAllTitlesByNamespace();
		if ( empty( $namespaces[NS_FILE] ) ) {
			return;
		}
		$images = $namespaces[NS_FILE];
		
		$this->addTables('image', 'i1');
		$this->addTables('image', 'i2');
		$this->addFields(array(
			'i1.img_name AS orig_name',
			'i2.img_name AS dup_name',
			'i2.img_user_text AS dup_user_text',
			'i2.img_timestamp AS dup_timestamp'
		));
		$this->addWhere(array(
			'i1.img_name' => array_keys($images),
			'i1.img_sha1 = i2.img_sha1',
			'i1.img_name != i2.img_name',
		));
		if(isset($params['continue']))
		{
			$cont = explode('|', $params['continue']);
			if(count($cont) != 2)
				$this->dieUsage("Invalid continue param. You should pass the " .
					"original value returned by the previous query", "_badcontinue");
			$orig = $this->getDB()->strencode($this->titleTokey($cont[0]));
			$dup = $this->getDB()->strencode($this->titleToKey($cont[1]));
			$this->addWhere("i1.img_name > '$orig' OR ".
					"(i1.img_name = '$orig' AND ".
					"i2.img_name >= '$dup')");
		}
		$this->addOption('ORDER BY', 'i1.img_name');
		$this->addOption('LIMIT', $params['limit'] + 1);

		$res = $this->select(__METHOD__);
		$db = $this->getDB();
		$count = 0;
		$data = array();
		$titles = array();
		$lastName = '';
		while($row = $db->fetchObject($res))
		{
			if(++$count > $params['limit'])
			{
				// We've reached the one extra which shows that
				// there are additional pages to be had. Stop here...
				$this->setContinueEnumParameter('continue',
					$this->keyToTitle($row->orig_name) . '|' .
					$this->keyToTitle($row->dup_name));
				break;
			}
			if(!is_null($resultPageSet))
				$titles[] = Title::makeTitle(NS_FILE, $row->dup_name);
			else
			{
				if($row->orig_name != $lastName)
				{
					if($lastName != '')
					{
						$this->addPageSubItems($images[$lastName], $data);
						$data = array();
					}
					$lastName = $row->orig_name;
				}
						
				$data[] = array(
					'name' => $row->dup_name,
					'user' => $row->dup_user_text,
					'timestamp' => wfTimestamp(TS_ISO_8601, $row->dup_timestamp)
				);
			}
		}
		if(!is_null($resultPageSet))
			$resultPageSet->populateFromTitles($titles);
		else if($lastName != '')
			$this->addPageSubItems($images[$lastName], $data);
		$db->freeResult($res);
	}

	public function getAllowedParams() {
		return array (
			'limit' => array(
				ApiBase :: PARAM_DFLT => 10,
				ApiBase :: PARAM_TYPE => 'limit',
				ApiBase :: PARAM_MIN => 1,
				ApiBase :: PARAM_MAX => ApiBase :: LIMIT_BIG1,
				ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
			),
			'continue' => null,
		);
	}

	public function getParamDescription() {
		return array (
			'limit' => 'How many files to return',
			'continue' => 'When more results are available, use this to continue',
		);
	}

	public function getDescription() {
		return 'List all files that are duplicates of the given file(s).';
	}

	protected function getExamples() {
		return array (	'api.php?action=query&titles=Image:Albert_Einstein_Head.jpg&prop=duplicatefiles',
				'api.php?action=query&generator=allimages&prop=duplicatefiles',
			);
	}

	public function getVersion() {
		return __CLASS__ . ': $Id: ApiQueryDuplicateFiles.php 44121 2008-12-01 17:14:30Z vyznev $';
	}
}
