Merge "Set namespaces for dtp"

[mediawiki.git] / includes / api / ApiQueryBacklinksprop.php

<?php
/**
 * API module to handle links table back-queries
 *
 * Copyright © 2014 Wikimedia Foundation and contributors
 *
 * 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
 * @since 1.24
 */

namespace MediaWiki\Api;

use MediaWiki\Linker\LinksMigration;
use MediaWiki\MainConfigNames;
use MediaWiki\Title\Title;
use Wikimedia\ParamValidator\ParamValidator;
use Wikimedia\ParamValidator\TypeDef\IntegerDef;

/**
 * This implements prop=redirects, prop=linkshere, prop=catmembers,
 * prop=transcludedin, and prop=fileusage
 *
 * @ingroup API
 * @since 1.24
 */
class ApiQueryBacklinksprop extends ApiQueryGeneratorBase {

        /** @var array Data for the various modules implemented by this class */
        private static $settings = [
                'redirects' => [
                        'code' => 'rd',
                        'prefix' => 'rd',
                        'linktable' => 'redirect',
                        'props' => [
                                'fragment',
                        ],
                        'showredirects' => false,
                        'show' => [
                                'fragment',
                                '!fragment',
                        ],
                ],
                'linkshere' => [
                        'code' => 'lh',
                        'prefix' => 'pl',
                        'linktable' => 'pagelinks',
                        'indexes' => [ 'pl_namespace', 'pl_backlinks_namespace' ],
                        'from_namespace' => true,
                        'showredirects' => true,
                ],
                'transcludedin' => [
                        'code' => 'ti',
                        'prefix' => 'tl',
                        'linktable' => 'templatelinks',
                        'from_namespace' => true,
                        'showredirects' => true,
                ],
                'fileusage' => [
                        'code' => 'fu',
                        'prefix' => 'il',
                        'linktable' => 'imagelinks',
                        'indexes' => [ 'il_to', 'il_backlinks_namespace' ],
                        'from_namespace' => true,
                        'to_namespace' => NS_FILE,
                        'exampletitle' => 'File:Example.jpg',
                        'showredirects' => true,
                ],
        ];

        private LinksMigration $linksMigration;

        public function __construct(
                ApiQuery $query,
                string $moduleName,
                LinksMigration $linksMigration
        ) {
                parent::__construct( $query, $moduleName, self::$settings[$moduleName]['code'] );
                $this->linksMigration = $linksMigration;
        }

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

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

        /**
         * @param ApiPageSet|null $resultPageSet
         */
        private function run( ?ApiPageSet $resultPageSet = null ) {
                $settings = self::$settings[$this->getModuleName()];

                $db = $this->getDB();
                $params = $this->extractRequestParams();
                $prop = array_fill_keys( $params['prop'], true );

                $pageSet = $this->getPageSet();
                $titles = $pageSet->getGoodAndMissingPages();
                $map = $pageSet->getGoodAndMissingTitlesByNamespace();

                // Add in special pages, they can theoretically have backlinks too.
                // (although currently they only do for prop=redirects)
                foreach ( $pageSet->getSpecialPages() as $id => $title ) {
                        $titles[] = $title;
                        $map[$title->getNamespace()][$title->getDBkey()] = $id;
                }

                // Determine our fields to query on
                $p = $settings['prefix'];
                $hasNS = !isset( $settings['to_namespace'] );
                if ( $hasNS ) {
                        if ( isset( $this->linksMigration::$mapping[$settings['linktable']] ) ) {
                                [ $bl_namespace, $bl_title ] = $this->linksMigration->getTitleFields( $settings['linktable'] );
                        } else {
                                $bl_namespace = "{$p}_namespace";
                                $bl_title = "{$p}_title";
                        }
                } else {
                        // @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
                        $bl_namespace = $settings['to_namespace'];
                        $bl_title = "{$p}_to";

                        $titles = array_filter( $titles, static function ( $t ) use ( $bl_namespace ) {
                                return $t->getNamespace() === $bl_namespace;
                        } );
                        $map = array_intersect_key( $map, [ $bl_namespace => true ] );
                }
                $bl_from = "{$p}_from";

                if ( !$titles ) {
                        return; // nothing to do
                }
                if ( $params['namespace'] !== null && count( $params['namespace'] ) === 0 ) {
                        return; // nothing to do
                }

                // Figure out what we're sorting by, and add associated WHERE clauses.
                // MySQL's query planner screws up if we include a field in ORDER BY
                // when it's constant in WHERE, so we have to test that for each field.
                $sortby = [];
                if ( $hasNS && count( $map ) > 1 ) {
                        $sortby[$bl_namespace] = 'int';
                }
                $theTitle = null;
                foreach ( $map as $nsTitles ) {
                        $key = array_key_first( $nsTitles );
                        $theTitle ??= $key;
                        if ( count( $nsTitles ) > 1 || $key !== $theTitle ) {
                                $sortby[$bl_title] = 'string';
                                break;
                        }
                }
                $miser_ns = null;
                if ( $params['namespace'] !== null ) {
                        if ( empty( $settings['from_namespace'] ) ) {
                                if ( $this->getConfig()->get( MainConfigNames::MiserMode ) ) {
                                        $miser_ns = $params['namespace'];
                                } else {
                                        $this->addWhereFld( 'page_namespace', $params['namespace'] );
                                }
                        } else {
                                $this->addWhereFld( "{$p}_from_namespace", $params['namespace'] );
                                if ( !empty( $settings['from_namespace'] )
                                        && $params['namespace'] !== null && count( $params['namespace'] ) > 1
                                ) {
                                        $sortby["{$p}_from_namespace"] = 'int';
                                }
                        }
                }
                $sortby[$bl_from] = 'int';

                // Now use the $sortby to figure out the continuation
                $continueFields = array_keys( $sortby );
                $continueTypes = array_values( $sortby );
                if ( $params['continue'] !== null ) {
                        $continueValues = $this->parseContinueParamOrDie( $params['continue'], $continueTypes );
                        $conds = array_combine( $continueFields, $continueValues );
                        $this->addWhere( $db->buildComparison( '>=', $conds ) );
                }

                // Populate the rest of the query
                [ $idxNoFromNS, $idxWithFromNS ] = $settings['indexes'] ?? [ '', '' ];
                // @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
                if ( isset( $this->linksMigration::$mapping[$settings['linktable']] ) ) {
                        // @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
                        $queryInfo = $this->linksMigration->getQueryInfo( $settings['linktable'] );
                        $this->addTables( array_merge( [ 'page' ], $queryInfo['tables'] ) );
                        $this->addJoinConds( $queryInfo['joins'] );
                        // TODO: Move to links migration
                        if ( in_array( 'linktarget', $queryInfo['tables'] ) ) {
                                $idxWithFromNS .= '_target_id';
                        }
                } else {
                        // @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
                        $this->addTables( [ $settings['linktable'], 'page' ] );
                }
                $this->addWhere( "$bl_from = page_id" );

                if ( $this->getModuleName() === 'redirects' ) {
                        $this->addWhereFld( 'rd_interwiki', '' );
                }

                $this->addFields( array_keys( $sortby ) );
                $this->addFields( [ 'bl_namespace' => $bl_namespace, 'bl_title' => $bl_title ] );
                if ( $resultPageSet === null ) {
                        $fld_pageid = isset( $prop['pageid'] );
                        $fld_title = isset( $prop['title'] );
                        $fld_redirect = isset( $prop['redirect'] );

                        $this->addFieldsIf( 'page_id', $fld_pageid );
                        $this->addFieldsIf( [ 'page_title', 'page_namespace' ], $fld_title );
                        $this->addFieldsIf( 'page_is_redirect', $fld_redirect );

                        // prop=redirects
                        $fld_fragment = isset( $prop['fragment'] );
                        $this->addFieldsIf( 'rd_fragment', $fld_fragment );
                } else {
                        $this->addFields( $resultPageSet->getPageTableFields() );
                }

                $this->addFieldsIf( 'page_namespace', $miser_ns !== null );

                if ( $hasNS && $map ) {
                        // Can't use LinkBatch because it throws away Special titles.
                        // And we already have the needed data structure anyway.
                        $this->addWhere( $db->makeWhereFrom2d( $map, $bl_namespace, $bl_title ) );
                } else {
                        $where = [];
                        foreach ( $titles as $t ) {
                                if ( $t->getNamespace() == $bl_namespace ) {
                                        $where[] = $db->expr( $bl_title, '=', $t->getDBkey() );
                                }
                        }
                        $this->addWhere( $db->orExpr( $where ) );
                }

                if ( $params['show'] !== null ) {
                        // prop=redirects only
                        $show = array_fill_keys( $params['show'], true );
                        if ( ( isset( $show['fragment'] ) && isset( $show['!fragment'] ) ) ||
                                ( isset( $show['redirect'] ) && isset( $show['!redirect'] ) )
                        ) {
                                $this->dieWithError( 'apierror-show' );
                        }
                        $this->addWhereIf( $db->expr( 'rd_fragment', '!=', '' ), isset( $show['fragment'] ) );
                        $this->addWhereIf( [ 'rd_fragment' => '' ], isset( $show['!fragment'] ) );
                        $this->addWhereIf( [ 'page_is_redirect' => 1 ], isset( $show['redirect'] ) );
                        $this->addWhereIf( [ 'page_is_redirect' => 0 ], isset( $show['!redirect'] ) );
                }

                // Override any ORDER BY from above with what we calculated earlier.
                $this->addOption( 'ORDER BY', array_keys( $sortby ) );

                // MySQL's optimizer chokes if we have too many values in "$bl_title IN
                // (...)" and chooses the wrong index, so specify the correct index to
                // use for the query. See T139056 for details.
                if ( !empty( $settings['indexes'] ) ) {
                        if (
                                $params['namespace'] !== null &&
                                count( $params['namespace'] ) == 1 &&
                                !empty( $settings['from_namespace'] )
                        ) {
                                // @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
                                $this->addOption( 'USE INDEX', [ $settings['linktable'] => $idxWithFromNS ] );
                                // @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
                        } elseif ( !isset( $this->linksMigration::$mapping[$settings['linktable']] ) ) {
                                // @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
                                $this->addOption( 'USE INDEX', [ $settings['linktable'] => $idxNoFromNS ] );
                        }
                }

                $this->addOption( 'LIMIT', $params['limit'] + 1 );

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

                if ( $resultPageSet === null ) {
                        // @phan-suppress-next-line PhanPossiblyUndeclaredVariable set when used
                        if ( $fld_title ) {
                                $this->executeGenderCacheFromResultWrapper( $res, __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->setContinue( $row, $sortby );
                                        break;
                                }

                                if ( $miser_ns !== null && !in_array( $row->page_namespace, $miser_ns ) ) {
                                        // Miser mode namespace check
                                        continue;
                                }

                                // Get the ID of the current page
                                $id = $map[$row->bl_namespace][$row->bl_title];

                                $vals = [];
                                // @phan-suppress-next-line PhanPossiblyUndeclaredVariable set when used
                                if ( $fld_pageid ) {
                                        $vals['pageid'] = (int)$row->page_id;
                                }
                                if ( $fld_title ) {
                                        ApiQueryBase::addTitleInfo( $vals,
                                                Title::makeTitle( $row->page_namespace, $row->page_title )
                                        );
                                }
                                // @phan-suppress-next-line PhanPossiblyUndeclaredVariable set when used
                                if ( $fld_fragment && $row->rd_fragment !== '' ) {
                                        $vals['fragment'] = $row->rd_fragment;
                                }
                                // @phan-suppress-next-line PhanPossiblyUndeclaredVariable set when used
                                if ( $fld_redirect ) {
                                        $vals['redirect'] = (bool)$row->page_is_redirect;
                                }
                                $fit = $this->addPageSubItem( $id, $vals );
                                if ( !$fit ) {
                                        $this->setContinue( $row, $sortby );
                                        break;
                                }
                        }
                } else {
                        $titles = [];
                        $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->setContinue( $row, $sortby );
                                        break;
                                }

                                if ( $miser_ns !== null && !in_array( $row->page_namespace, $miser_ns ) ) {
                                        // Miser mode namespace check
                                        continue;
                                }

                                $titles[] = Title::makeTitle( $row->page_namespace, $row->page_title );
                        }
                        $resultPageSet->populateFromTitles( $titles );
                }
        }

        private function setContinue( $row, $sortby ) {
                $cont = [];
                foreach ( $sortby as $field => $v ) {
                        $cont[] = $row->$field;
                }
                $this->setContinueEnumParameter( 'continue', implode( '|', $cont ) );
        }

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

        public function getAllowedParams() {
                $settings = self::$settings[$this->getModuleName()];

                $ret = [
                        'prop' => [
                                ParamValidator::PARAM_TYPE => [
                                        'pageid',
                                        'title',
                                ],
                                ParamValidator::PARAM_ISMULTI => true,
                                ParamValidator::PARAM_DEFAULT => 'pageid|title',
                                ApiBase::PARAM_HELP_MSG_PER_VALUE => [],
                        ],
                        'namespace' => [
                                ParamValidator::PARAM_ISMULTI => true,
                                ParamValidator::PARAM_TYPE => 'namespace',
                        ],
                        'show' => null, // Will be filled/removed below
                        'limit' => [
                                ParamValidator::PARAM_DEFAULT => 10,
                                ParamValidator::PARAM_TYPE => 'limit',
                                IntegerDef::PARAM_MIN => 1,
                                IntegerDef::PARAM_MAX => ApiBase::LIMIT_BIG1,
                                IntegerDef::PARAM_MAX2 => ApiBase::LIMIT_BIG2
                        ],
                        'continue' => [
                                ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
                        ],
                ];

                if ( empty( $settings['from_namespace'] ) &&
                $this->getConfig()->get( MainConfigNames::MiserMode ) ) {
                        $ret['namespace'][ApiBase::PARAM_HELP_MSG_APPEND] = [
                                'api-help-param-limited-in-miser-mode',
                        ];
                }

                if ( !empty( $settings['showredirects'] ) ) {
                        $ret['prop'][ParamValidator::PARAM_TYPE][] = 'redirect';
                        $ret['prop'][ParamValidator::PARAM_DEFAULT] .= '|redirect';
                }
                if ( isset( $settings['props'] ) ) {
                        $ret['prop'][ParamValidator::PARAM_TYPE] = array_merge(
                                $ret['prop'][ParamValidator::PARAM_TYPE], $settings['props']
                        );
                }

                $show = [];
                if ( !empty( $settings['showredirects'] ) ) {
                        $show[] = 'redirect';
                        $show[] = '!redirect';
                }
                if ( isset( $settings['show'] ) ) {
                        $show = array_merge( $show, $settings['show'] );
                }
                if ( $show ) {
                        $ret['show'] = [
                                ParamValidator::PARAM_TYPE => $show,
                                ParamValidator::PARAM_ISMULTI => true,
                                ApiBase::PARAM_HELP_MSG_PER_VALUE => [],
                        ];
                } else {
                        unset( $ret['show'] );
                }

                return $ret;
        }

        protected function getExamplesMessages() {
                $settings = self::$settings[$this->getModuleName()];
                $name = $this->getModuleName();
                $path = $this->getModulePath();
                $title = $settings['exampletitle'] ?? Title::newMainPage()->getPrefixedText();
                $etitle = rawurlencode( $title );

                return [
                        "action=query&prop={$name}&titles={$etitle}"
                                => "apihelp-$path-example-simple",
                        "action=query&generator={$name}&titles={$etitle}&prop=info"
                                => "apihelp-$path-example-generator",
                ];
        }

        public function getHelpUrls() {
                $name = ucfirst( $this->getModuleName() );
                return "https://www.mediawiki.org/wiki/Special:MyLanguage/API:{$name}";
        }
}

/** @deprecated class alias since 1.43 */
class_alias( ApiQueryBacklinksprop::class, 'ApiQueryBacklinksprop' );