<?php
/**
 * Script will find all rows in the categorylinks table whose collation is
 * out-of-date (cl_collation != $wgCategoryCollation) and repopulate cl_sortkey
 * using the page title and cl_sortkey_prefix.
 *
 * 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
 * @author Aryeh Gregor (Simetrical)
 */

#$optionsWithArgs = array( 'begin', 'max-slave-lag' );

require_once( dirname( __FILE__ ) . '/Maintenance.php' );

class UpdateCollation extends Maintenance {
	const BATCH_SIZE = 50; // Number of rows to process in one batch
	const SYNC_INTERVAL = 20; // Wait for slaves after this many batches

	public function __construct() {
		parent::__construct();

		global $wgCategoryCollation;
		$this->mDescription = <<<TEXT
This script will find all rows in the categorylinks table whose collation is
out-of-date (cl_collation != '$wgCategoryCollation') and repopulate cl_sortkey
using the page title and cl_sortkey_prefix.  If everything's collation is
up-to-date, it will do nothing.
TEXT;

		$this->addOption( 'force', 'Run on all rows, even if the collation is ' .
			'supposed to be up-to-date.' );
		$this->addOption( 'previous-collation', 'Set the previous value of ' .
			'$wgCategoryCollation here to speed up this script, especially if your ' .
			'categorylinks table is large. This will only update rows with that ' .
			'collation, though, so it may miss out-of-date rows with a different, ' .
			'even older collation.', false, true );
	}

	public function execute() {
		global $wgCategoryCollation, $wgMiserMode;

		$dbw = $this->getDB( DB_MASTER );
		$force = $this->getOption( 'force' );

		$options = array( 'LIMIT' => self::BATCH_SIZE, 'STRAIGHT_JOIN' );

		if ( $force ) {
			$options['ORDER BY'] = 'cl_from, cl_to';
			$collationConds = array();
		} else {
			if ( $this->hasOption( 'previous-collation' ) ) {
				$collationConds['cl_collation'] = $this->getOption( 'previous-collation' );
			} else {
				$collationConds = array( 0 =>
					'cl_collation != ' . $dbw->addQuotes( $wgCategoryCollation )
				);
			}

			if ( !$wgMiserMode ) {
				$count = $dbw->selectField(
					'categorylinks',
					'COUNT(*)',
					$collationConds,
					__METHOD__
				);

				if ( $count == 0 ) {
					$this->output( "Collations up-to-date.\n" );
					return;
				}
				$this->output( "Fixing collation for $count rows.\n" );
			}
		}

		$count = 0;
		$batchCount = 0;
		$batchConds = array();
		do {
			$this->output( "Selecting next " . self::BATCH_SIZE . " rows..." );
			$res = $dbw->select(
				array( 'categorylinks', 'page' ),
				array( 'cl_from', 'cl_to', 'cl_sortkey_prefix', 'cl_collation',
					'cl_sortkey', 'page_namespace', 'page_title'
				),
				array_merge( $collationConds, $batchConds, array( 'cl_from = page_id' ) ),
				__METHOD__,
				$options
			);
			$this->output( " processing..." );

			$dbw->begin();
			foreach ( $res as $row ) {
				$title = Title::newFromRow( $row );
				if ( !$row->cl_collation ) {
					# This is an old-style row, so the sortkey needs to be
					# converted.
					if ( $row->cl_sortkey == $title->getText()
						|| $row->cl_sortkey == $title->getPrefixedText() ) {
						$prefix = '';
					} else {
						# Custom sortkey, use it as a prefix
						$prefix = $row->cl_sortkey;
					}
				} else {
					$prefix = $row->cl_sortkey_prefix;
				}
				# cl_type will be wrong for lots of pages if cl_collation is 0,
				# so let's update it while we're here.
				if ( $title->getNamespace() == NS_CATEGORY ) {
					$type = 'subcat';
				} elseif ( $title->getNamespace() == NS_FILE ) {
					$type = 'file';
				} else {
					$type = 'page';
				}
				$dbw->update(
					'categorylinks',
					array(
						'cl_sortkey' => Collation::singleton()->getSortKey(
							$title->getCategorySortkey( $prefix ) ),
						'cl_sortkey_prefix' => $prefix,
						'cl_collation' => $wgCategoryCollation,
						'cl_type' => $type,
						'cl_timestamp = cl_timestamp',
					),
					array( 'cl_from' => $row->cl_from, 'cl_to' => $row->cl_to ),
					__METHOD__
				);
			}
			$dbw->commit();

			if ( $force && $row ) {
				$encFrom = $dbw->addQuotes( $row->cl_from );
				$encTo = $dbw->addQuotes( $row->cl_to );
				$batchConds = array(
					"(cl_from = $encFrom AND cl_to > $encTo) " .
					" OR cl_from > $encFrom" );
			}

			$count += $res->numRows();
			$this->output( "$count done.\n" );

			if ( ++$batchCount % self::SYNC_INTERVAL == 0 ) {
				$this->output( "Waiting for slaves ... " );
				wfWaitForSlaves();
				$this->output( "done\n" );
			}
		} while ( $res->numRows() == self::BATCH_SIZE );
	}
}

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