<?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 getCacheMode( $params ) {
		return 'public';
	}

	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;
		$titles = array();
		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
			{
				$r = array(
					'name' => $row->dup_name,
					'user' => $row->dup_user_text,
					'timestamp' => wfTimestamp( TS_ISO_8601, $row->dup_timestamp )
				);
				$fit = $this->addPageSubItem( $images[$row->orig_name], $r );
				if ( !$fit )
				{
					$this->setContinueEnumParameter( 'continue',
							$this->keyToTitle( $row->orig_name ) . '|' .
							$this->keyToTitle( $row->dup_name ) );
					break;
				}
			}
		}
		if ( !is_null( $resultPageSet ) )
			$resultPageSet->populateFromTitles( $titles );
		$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).';
	}
	
	public function getPossibleErrors() {
		return array_merge( parent::getPossibleErrors(), array(
			array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
		) );
	}

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

	public function getVersion() {
		return __CLASS__ . ': $Id: ApiQueryDuplicateFiles.php 69932 2010-07-26 08:03:21Z tstarling $';
	}
}