<?php
/**
 * API for MediaWiki 1.8+
 *
 * Created on May 13, 2007
 *
 * Copyright © 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

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

/**
 * A query module to list all external URLs found on a given set of pages.
 *
 * @ingroup API
 */
class ApiQueryExternalLinks extends ApiQueryBase {

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

	public function execute() {
		if ( $this->getPageSet()->getGoodTitleCount() == 0 ) {
			return;
		}

		$params = $this->extractRequestParams();
		$this->addFields( array(
			'el_from',
			'el_to'
		) );

		$this->addTables( 'externallinks' );
		$this->addWhereFld( 'el_from', array_keys( $this->getPageSet()->getGoodTitles() ) );

		// Don't order by el_from if it's constant in the WHERE clause
		if ( count( $this->getPageSet()->getGoodTitles() ) != 1 ) {
			$this->addOption( 'ORDER BY', 'el_from' );
		}

		$this->addOption( 'LIMIT', $params['limit'] + 1 );
		if ( !is_null( $params['offset'] ) ) {
			$this->addOption( 'OFFSET', $params['offset'] );
		}

		$res = $this->select( __METHOD__ );

		$count = 0;
		foreach ( $res as $row ) {
			if ( ++$count > $params['limit'] ) {
				// We've reached the one extra which shows that
				// there are additional pages to be had. Stop here...
				$this->setContinueEnumParameter( 'offset', @$params['offset'] + $params['limit'] );
				break;
			}
			$entry = array();
			ApiResult::setContent( $entry, $row->el_to );
			$fit = $this->addPageSubItem( $row->el_from, $entry );
			if ( !$fit ) {
				$this->setContinueEnumParameter( 'offset', @$params['offset'] + $count - 1 );
				break;
			}
		}
	}

	public function getCacheMode( $params ) {
		return 'public';
	}

	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
			),
			'offset' => null,
		);
	}

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

	public function getDescription() {
		return 'Returns all external urls (not interwikies) from the given page(s)';
	}

	protected function getExamples() {
		return array(
			'Get a list of external links on the [[Main Page]]:',
			'  api.php?action=query&prop=extlinks&titles=Main%20Page',
		);
	}

	public function getVersion() {
		return __CLASS__ . ': $Id: ApiQueryExternalLinks.php 70647 2010-08-07 19:59:42Z ialex $';
	}
}