wikimedia/mediawiki-extensions-CirrusSearch

<?php

namespace CirrusSearch\Query;

use CirrusSearch\CrossSearchStrategy;
use CirrusSearch\Parser\AST\KeywordFeatureNode;
use CirrusSearch\Query\Builder\QueryBuildingContext;
use CirrusSearch\Search\SearchContext;
use CirrusSearch\SearchConfig;
use CirrusSearch\WarningCollector;
use Elastica\Query\AbstractQuery;
use MediaWiki\Config\Config;
use MediaWiki\MediaWikiServices;
use MediaWiki\Page\PageRecord;
use MediaWiki\Page\PageStore;

/**
 * Filters by one or more categories, specified either by name or by category
 * id. Multiple categories are separated by |. Categories specified by id
 * must follow the syntax `id:<id>`.
 *
 * We emulate template syntax here as best as possible, so things in NS_MAIN
 * are prefixed with ":" and things in NS_TEMPLATE don't have a prefix at all.
 * Since we don't actually index templates like that, munge the query here.
 *
 * Examples:
 *   incategory:id:12345
 *   incategory:Music_by_genre
 *   incategory:Music_by_genre|Animals
 *   incategory:"Music by genre|Animals"
 *   incategory:Animals|id:54321
 *   incategory::Something_in_NS_MAIN
 */
class InCategoryFeature extends SimpleKeywordFeature implements FilterQueryFeature {
    /**
     * @var int
     */
    private $maxConditions;
    /**
     * @var PageStore|null
     */
    private $pageStore;

    /**
     * @param Config $config
     * @param PageStore|null $pageStore
     */
    public function __construct( Config $config, PageStore $pageStore = null ) {
        $this->maxConditions = $config->get( 'CirrusSearchMaxIncategoryOptions' );
        $this->pageStore = $pageStore;
    }

    /**
     * @return string[]
     */
    protected function getKeywords() {
        return [ 'incategory' ];
    }

    /**
     * @param KeywordFeatureNode $node
     * @return CrossSearchStrategy
     */
    public function getCrossSearchStrategy( KeywordFeatureNode $node ) {
        if ( empty( $node->getParsedValue()['pageIds'] ) ) {
            // We depend on the db to fetch the category by id
            return CrossSearchStrategy::allWikisStrategy();
        } else {
            return CrossSearchStrategy::hostWikiOnlyStrategy();
        }
    }

    /**
     * @param SearchContext $context
     * @param string $key The keyword
     * @param string $value The value attached to the keyword with quotes stripped
     * @param string $quotedValue The original value in the search string, including quotes if used
     * @param bool $negated Is the search negated? Not used to generate the returned AbstractQuery,
     *  that will be negated as necessary. Used for any other building/context necessary.
     * @return array Two element array, first an AbstractQuery or null to apply to the
     *  query. Second a boolean indicating if the quotedValue should be kept in the search
     *  string.
     */
    protected function doApply( SearchContext $context, $key, $value, $quotedValue, $negated ) {
        $parsedValue = $this->parseValue( $key, $value, $quotedValue, '', '', $context );
        if ( $parsedValue === null ) {
            $context->setResultsPossible( false );
            return [ null, false ];
        }

        $names = $this->doExpand( $key, $parsedValue, $context );

        if ( $names === [] ) {
            $context->setResultsPossible( false );
            return [ null, false ];
        }

        $filter = $this->matchPageCategories( $names );
        return [ $filter, false ];
    }

    /**
     * @param string $key
     * @param string $value
     * @param string $quotedValue
     * @param string $valueDelimiter
     * @param string $suffix
     * @param WarningCollector $warningCollector
     * @return array|false|null
     */
    public function parseValue( $key, $value, $quotedValue, $valueDelimiter, $suffix, WarningCollector $warningCollector ) {
        // en:Programming|id:3041512\
        $categories = explode( '|', $value );// en:programming
        if ( count( $categories ) > $this->maxConditions ) {
            $warningCollector->addWarning(
                'cirrussearch-feature-too-many-conditions',
                $key,
                $this->maxConditions
            );
            $categories = array_slice(
                $categories,
                0,
                $this->maxConditions
            );
        }

        $pageIds = [];
        $names = [];

        foreach ( $categories as $category ) {
            if ( str_starts_with( $category, 'id:' ) ) {
                $pageId = substr( $category, 3 );
                if ( ctype_digit( $pageId ) ) {
                    $pageIds[] = $pageId;
                }
            } else {
                $names[] = $category;// en:programming
            }
        }

        return [ 'names' => $names, 'pageIds' => $pageIds ];// en:programming
    }

    /**
     * @param KeywordFeatureNode $node
     * @param SearchConfig $config
     * @param WarningCollector $warningCollector
     * @return array
     */
    public function expand( KeywordFeatureNode $node, SearchConfig $config, WarningCollector $warningCollector ) {
        return $this->doExpand( $node->getKey(), $node->getParsedValue(), $warningCollector );
    }

    /**
     * @param string $key
     * @param array $parsedValue
     * @param WarningCollector $warningCollector
     * @return array
     */
    private function doExpand( $key, array $parsedValue, WarningCollector $warningCollector ) {
        $names = $parsedValue['names'];// en:programming
        $pageIds = $parsedValue['pageIds'];

        $pageStore = $this->pageStore ?? MediaWikiServices::getInstance()->getPageStore();
        $titles = $pageStore
            ->newSelectQueryBuilder()
            ->wherePageIds( $pageIds )
            ->caller( __METHOD__ )
            ->fetchPageRecords();

        $titleFormatter = MediaWikiServices::getInstance()->getTitleFormatter();

        /** @var PageRecord $title */
        foreach ( $titles as $title ) {
            $names[] = $titleFormatter->getText( $title );
        }

        if ( $names === [] ) {
            $warningCollector->addWarning( 'cirrussearch-incategory-feature-no-valid-categories', $key );
        }
        return $names;// en:programing
    }

    /**
     * Builds an or between many categories that the page could be in.
     *
     * @param string[] $names categories to match
     * @return \Elastica\Query\BoolQuery|null A null return value means all values are filtered
     *  and an empty result set should be returned.
     */
    private function matchPageCategories( array $names ) {
        $filter = new \Elastica\Query\BoolQuery();

        foreach ( $names as $name ) {
            $filter->addShould( QueryHelper::matchCategory( 'category.lowercase_keyword', $name ) );
        }

        return $filter;
    }

    /**
     * @param KeywordFeatureNode $node
     * @param QueryBuildingContext $context
     * @return AbstractQuery|null
     */
    public function getFilterQuery( KeywordFeatureNode $node, QueryBuildingContext $context ) {
        $names = $context->getKeywordExpandedData( $node );
        if ( $names === [] ) {
            return null;
        }
        return $this->matchPageCategories( $names );
    }
}