wikimedia/mediawiki-extensions-CirrusSearch

<?php

namespace CirrusSearch;

use MediaWiki\Extension\SiteMatrix\SiteMatrix;
use MediaWiki\Interwiki\InterwikiLookup;
use MediaWiki\Registration\ExtensionRegistry;
use MediaWiki\WikiMap\WikiMap;
use Wikimedia\Http\MultiHttpClient;
use Wikimedia\ObjectCache\WANObjectCache;

/**
 * InterwikiResolver suited for WMF context and uses SiteMatrix.
 */
class SiteMatrixInterwikiResolver extends BaseInterwikiResolver {

    private const MATRIX_CACHE_TTL = 600;

    public function __construct(
        SearchConfig $config,
        MultiHttpClient $client,
        WANObjectCache $wanCache,
        InterwikiLookup $iwLookup
    ) {
        parent::__construct( $config, $client, $wanCache, $iwLookup );
        if ( $config->getWikiId() !== WikiMap::getCurrentWikiId() ) {
            throw new \RuntimeException( "This resolver cannot with an external wiki config. (config: " .
                $config->getWikiId() . ", global: " . WikiMap::getCurrentWikiId() );
        }
    }

    /**
     * @param SearchConfig $config
     * @param ExtensionRegistry|null $extensionRegistry
     * @return bool true if this resolver can run with the specified config
     */
    public static function accepts( SearchConfig $config, ExtensionRegistry $extensionRegistry = null ) {
        $extensionRegistry = $extensionRegistry ?: ExtensionRegistry::getInstance();
        return $config->getWikiId() === WikiMap::getCurrentWikiId()
            && $extensionRegistry->isLoaded( 'SiteMatrix' )
            && $config->has( 'SiteMatrixSites' );
    }

    protected function loadMatrix() {
        $cacheKey = $this->wanCache->makeKey( 'cirrussearch-interwiki-matrix', 'v1' );
        $matrix = $this->wanCache->getWithSetCallback(
            $cacheKey,
            self::MATRIX_CACHE_TTL,
            $this->siteMatrixLoader()
        );
        if ( !is_array( $matrix ) ) {
            // Should we log something if we failed?
            return [];
        }
        return $matrix;
    }

    /**
     * @return callable
     */
    private function siteMatrixLoader() {
        return function () {
            global $wgConf;

            $matrix = new SiteMatrix;
            $wikiDBname = $this->config->get( 'DBname' );
            [ , $myLang ] = $wgConf->siteFromDB( $wikiDBname );
            $siteConf = $this->config->get( 'SiteMatrixSites' );
            $prefixOverrides = $this->config->get( 'CirrusSearchInterwikiPrefixOverrides' );
            $sisterProjects = [];
            $crossLanguage = [];
            $prefixesByWiki = [];
            $languageMap = [];
            $myProject = null;

            if ( !in_array( $myLang, $matrix->getLangList() ) ) {
                return [];
            }

            foreach ( $matrix->getSites() as $site ) {
                if ( $matrix->getDBName( $myLang, $site ) === $wikiDBname ) {
                    $myProject = $site;
                    break;
                }
            }

            if ( $myProject === null ) {
                // This is not a "project"
                return [];
            }

            foreach ( $matrix->getSites() as $site ) {
                if ( $site === $myProject ) {
                    continue;
                }
                if ( !$matrix->exist( $myLang, $site ) ) {
                    continue;
                }
                if ( $matrix->isClosed( $myLang, $site ) ) {
                    continue;
                }
                if ( !isset( $siteConf[$site]['prefix'] ) ) {
                    continue;
                }
                $dbName = $matrix->getDBName( $myLang, $site );
                $prefix = $siteConf[$site]['prefix'];

                if ( isset( $prefixOverrides[$prefix] ) ) {
                    $prefix = $prefixOverrides[$prefix];
                }

                if ( !in_array( $prefix, $this->config->get( 'CirrusSearchCrossProjectSearchBlockList' ) ) ) {
                    $sisterProjects[$prefix] = $dbName;
                }
                $prefixesByWiki[$dbName] = $prefix;
            }

            foreach ( $matrix->getLangList() as $lang ) {
                if ( $lang === $myLang ) {
                    continue;
                }

                $dbname = $matrix->getDBName( $lang, $myProject );
                if ( !$matrix->exist( $lang, $myProject ) ) {
                    continue;
                }
                if ( $matrix->isClosed( $lang, $myProject ) ) {
                    continue;
                }
                // Bold assumption that the interwiki prefix is equal
                // to the language.
                $iw = $this->interwikiLookup->fetch( $lang );
                // Not a valid interwiki prefix...
                if ( !$iw ) {
                    continue;
                }

                $url = $matrix->getCanonicalUrl( $lang, $myProject );
                $iwurl = $iw->getURL();
                if ( strlen( $url ) > strlen( $iwurl ) ) {
                    continue;
                }
                if ( substr_compare( $iwurl, $url, 0, strlen( $url ) ) !== 0 ) {
                    continue;
                }

                $crossLanguage[$lang] = $dbname;
                // In theory it's impossible to override something here
                // should we log something if the case?
                $prefixesByWiki[$dbname] = $lang;
                $wikiLangCode = $wgConf->get( 'wgLanguageCode', $dbname, $myProject,
                    [ 'lang' => $lang, 'site' => $myProject ] );
                $languageMap[$wikiLangCode][] = $lang;
            }
            // Cleanup unambiguous languages
            $cleanLanguageMap = [];
            foreach ( $languageMap as $lang => $dbprefixes ) {
                if ( array_key_exists( $lang, $dbprefixes )
                    && ( $dbprefixes === [ $lang ] )
                ) {
                    continue;
                }
                // if lang is equals to one of the dbprefixes then
                if ( in_array( $lang, $dbprefixes ) ) {
                    continue;
                }
                if ( count( $dbprefixes ) > 1 ) {
                    // TODO: Log this ambiguous entry
                }
                $cleanLanguageMap[$lang] = reset( $dbprefixes );
            }
            return [
                'sister_projects' => $sisterProjects,
                'language_map' => $cleanLanguageMap,
                'cross_language' => $crossLanguage,
                'prefixes_by_wiki' => $prefixesByWiki,
            ];
        };
    }

}