wikimedia/mediawiki-extensions-CirrusSearch

<?php

namespace CirrusSearch\Query;

use CirrusSearch\CrossSearchStrategy;
use CirrusSearch\Parser\AST\KeywordFeatureNode;
use CirrusSearch\Query\Builder\QueryBuildingContext;
use CirrusSearch\Search\Filters;
use CirrusSearch\Search\SearchContext;
use CirrusSearch\WarningCollector;
use Elastica\Query\AbstractQuery;

/**
 * Filters the result set based on pages labeled with the provided language.
 * More than one language can be specified with commas and they will be
 * generated as an OR query.
 *
 * Examples:
 *   inlanguage:en
 *   inlanguage:fr,en
 */
class LanguageFeature extends SimpleKeywordFeature implements FilterQueryFeature {
    /**
     * Limit search to 20 languages. Arbitrarily chosen, but should be more
     * than enough and some sort of limit has to be enforced.
     */
    public const QUERY_LIMIT = 20;

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

    /**
     * @param KeywordFeatureNode $node
     * @return CrossSearchStrategy
     */
    public function getCrossSearchStrategy( KeywordFeatureNode $node ) {
        return CrossSearchStrategy::allWikisStrategy();
    }

    /**
     * @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 );
        return [ $this->doGetFilterQuery( $parsedValue ), 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 ) {
        if ( strpos( $value, ',' ) !== false ) {
            $langs = explode( ',', $value );
            $warningCollector->addWarning( 'cirrussearch-inlanguage-deprecate-comma' );
        } else {
            $langs = explode( '|', $value );
        }
        if ( count( $langs ) > self::QUERY_LIMIT ) {
            $warningCollector->addWarning(
                'cirrussearch-feature-too-many-conditions',
                $key,
                self::QUERY_LIMIT
            );
            $langs = array_slice( $langs, 0, self::QUERY_LIMIT );
        }
        return [ 'langs' => $langs ];
    }

    /**
     * @param array[] $parsedValue
     * @return \Elastica\Query\AbstractQuery|\Elastica\Query\MatchQuery|null
     */
    private function doGetFilterQuery( $parsedValue ) {
        $queries = [];
        foreach ( $parsedValue['langs'] as $lang ) {
            if ( strlen( trim( $lang ) ) > 0 ) {
                $query = new \Elastica\Query\MatchQuery();
                $query->setFieldQuery( 'language', $lang );
                $queries[] = $query;
            }
        }
        $query = Filters::booleanOr( $queries, false );

        return $query;
    }

    /**
     * @param KeywordFeatureNode $node
     * @param QueryBuildingContext $context
     * @return AbstractQuery|null
     */
    public function getFilterQuery( KeywordFeatureNode $node, QueryBuildingContext $context ) {
        return $this->doGetFilterQuery( $node->getParsedValue() );
    }
}