<?php
/**
 * Send purge requests for listed pages to squid
 *
 * 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
 * @ingroup Maintenance
 */

require_once( __DIR__ . '/Maintenance.php' );

/**
 * Maintenance script that sends purge requests for listed pages to squid.
 *
 * @ingroup Maintenance
 */
class PurgeList extends Maintenance {
	public function __construct() {
		parent::__construct();
		$this->mDescription = "Send purge requests for listed pages to squid";
		$this->addOption( 'purge', 'Whether to update page_touched.' , false, false );
		$this->addOption( 'namespace', 'Namespace number', false, true );
		$this->setBatchSize( 100 );
	}

	public function execute() {
		if( $this->hasOption( 'namespace' ) ) {
			$this->purgeNamespace();
		} else {
			$this->purgeList();
		}
		$this->output( "Done!\n" );
	}

	/** Purge URL coming from stdin */
	private function purgeList() {
		$stdin = $this->getStdin();
		$urls = array();

		while ( !feof( $stdin ) ) {
			$page = trim( fgets( $stdin ) );
			if ( preg_match( '%^https?://%', $page ) ) {
				$urls[] = $page;
			} elseif ( $page !== '' ) {
				$title = Title::newFromText( $page );
				if ( $title ) {
					$url = $title->getInternalUrl();
					$this->output( "$url\n" );
					$urls[] = $url;
					if ( $this->getOption( 'purge' ) ) {
						$title->invalidateCache();
					}
				} else {
					$this->output( "(Invalid title '$page')\n" );
				}
			}
		}
		$this->sendPurgeRequest( $urls );
	}

	/** Purge a namespace given by --namespace */
	private function purgeNamespace() {
		$dbr = wfGetDB( DB_SLAVE );
		$ns = $dbr->addQuotes( $this->getOption( 'namespace') );

		$result = $dbr->select(
			array( 'page' ),
			array( 'page_namespace', 'page_title' ),
			array( "page_namespace = $ns" ),
			__METHOD__,
			array( 'ORDER BY' => 'page_id' )
		);

		$start   = 0;
		$end = $dbr->numRows( $result );
		$this->output( "Will purge $end pages from namespace $ns\n" );

		# Do remaining chunk
		$end += $this->mBatchSize - 1;
		$blockStart = $start;
		$blockEnd = $start + $this->mBatchSize - 1;

		while( $blockEnd <= $end ) {
			# Select pages we will purge:
			$result = $dbr->select(
				array( 'page' ),
				array( 'page_namespace', 'page_title' ),
				array( "page_namespace = $ns" ),
				__METHOD__,
				array( # conditions
					'ORDER BY' => 'page_id',
					'LIMIT'    => $this->mBatchSize,
					'OFFSET'   => $blockStart,
				)
			);
			# Initialize/reset URLs to be purged
			$urls = array();
			foreach( $result as $row ) {
				$title = Title::makeTitle( $row->page_namespace, $row->page_title );
				$url = $title->getInternalUrl();
				$urls[] = $url;
			}

			$this->sendPurgeRequest( $urls );

			$blockStart += $this->mBatchSize;
			$blockEnd   += $this->mBatchSize;
		}
	}

	/**
	 * Helper to purge an array of $urls
	 * @param $urls array List of URLS to purge from squids
	 */
	private function sendPurgeRequest( $urls ) {
		$this->output( "Purging " . count( $urls ). " urls\n" );
		$u = new SquidUpdate( $urls );
		$u->doUpdate();
	}

}

$maintClass = "PurgeList";
require_once( RUN_MAINTENANCE_IF_MAIN );