wikimedia/mediawiki-extensions-CirrusSearch

<?php

namespace CirrusSearch;

/**
 * Defines support strategies regarding cross wiki searches.
 *
 * Cross wiki search techniques include:
 *  - extra indices searches (i.e. search media files on commons)
 *  - cross project searches
 *  - cross language searches (i.e. second try attempt)
 */
class CrossSearchStrategy {
    /**
     * @see InterwikiSearcher
     * @var bool
     */
    private $crossProjectSearchSupported;

    /**
     * @see \CirrusSearch::searchTextSecondTry()
     * @var bool
     */
    private $crossLanguageSearchSupported;

    /**
     * Controlled by $wgCirrusSearchExtraIndexes
     * (Usually used to search media files on commons from any host wikis)
     * @var bool
     */
    private $extraIndicesSearchSupported;

    /**
     * @var CrossSearchStrategy
     */
    private static $hostWikiOnly;

    /**
     * @var CrossSearchStrategy
     */
    private static $allWikisStrategy;

    /**
     * Only host wiki is supported
     * Applies to features that are probably not available on any
     * other target wiki cirrus may access.
     * @return CrossSearchStrategy
     */
    public static function hostWikiOnlyStrategy() {
        if ( self::$hostWikiOnly === null ) {
            self::$hostWikiOnly = new CrossSearchStrategy( false, false, false );
        }
        return self::$hostWikiOnly;
    }

    /**
     * Applies to features that must be available on any target wiki.
     *
     * @return CrossSearchStrategy
     */
    public static function allWikisStrategy() {
        if ( self::$allWikisStrategy === null ) {
            self::$allWikisStrategy = new CrossSearchStrategy( true, true, true );
        }
        return self::$allWikisStrategy;
    }

    /**
     * @param bool $crossProjectSearchSupported
     * @param bool $crossLanguageSearchSupported
     * @param bool $extraIndicesSupported
     */
    public function __construct( $crossProjectSearchSupported, $crossLanguageSearchSupported, $extraIndicesSupported ) {
        $this->crossProjectSearchSupported = $crossProjectSearchSupported;
        $this->crossLanguageSearchSupported = $crossLanguageSearchSupported;
        $this->extraIndicesSearchSupported = $extraIndicesSupported;
    }

    /**
     * Is cross project search supported (aka interwiki search)
     * @return bool
     */
    public function isCrossProjectSearchSupported() {
        return $this->crossProjectSearchSupported;
    }

    /**
     * Is cross language search supported (i.e. second try language search)
     * @return bool
     */
    public function isCrossLanguageSearchSupported() {
        return $this->crossLanguageSearchSupported;
    }

    /**
     * (in WMF context it's most commonly used to search media files
     * on commons from any wikis.)
     *
     * See wgCirrusSearchExtraIndexes
     * @return bool
     */
    public function isExtraIndicesSearchSupported() {
        return $this->extraIndicesSearchSupported;
    }

    /**
     * Intersect this strategy with other.
     * @param CrossSearchStrategy $other
     * @return CrossSearchStrategy
     */
    public function intersect( CrossSearchStrategy $other ) {
        if ( $other === self::hostWikiOnlyStrategy() || $this === self::hostWikiOnlyStrategy() ) {
            return self::hostWikiOnlyStrategy();
        }
        $crossL = $other->crossLanguageSearchSupported && $this->crossLanguageSearchSupported;
        $crossP = $other->crossProjectSearchSupported && $this->crossProjectSearchSupported;
        $otherI = $other->extraIndicesSearchSupported && $this->extraIndicesSearchSupported;
        if ( $crossL === $crossP && $crossP === $otherI ) {
            if ( $crossL ) {
                return self::allWikisStrategy();
            } else {
                return self::hostWikiOnlyStrategy();
            }
        }
        return new CrossSearchStrategy( $crossP, $crossL, $otherI );
    }
}