WikiMap.php

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<?php
use MediaWiki\MediaWikiServices;
use Wikimedia\Rdbms\DatabaseDomain;

class WikiMap {

    public static function getWiki( $wikiID ) {
        $wikiReference = self::getWikiReferenceFromWgConf( $wikiID );
        if ( $wikiReference ) {
            return $wikiReference;
        }

        // Try sites, if $wgConf failed
        return self::getWikiWikiReferenceFromSites( $wikiID );
    }

    private static function getWikiReferenceFromWgConf( $wikiID ) {
        global $wgConf;

        $wgConf->loadFullData();

        list( $major, $minor ) = $wgConf->siteFromDB( $wikiID );
        if ( $major === null ) {
            return null;
        }
        $server = $wgConf->get( 'wgServer', $wikiID, $major,
            [ 'lang' => $minor, 'site' => $major ] );

        $canonicalServer = $wgConf->get( 'wgCanonicalServer', $wikiID, $major,
            [ 'lang' => $minor, 'site' => $major ] );
        if ( $canonicalServer === false || $canonicalServer === null ) {
            $canonicalServer = $server;
        }

        $path = $wgConf->get( 'wgArticlePath', $wikiID, $major,
            [ 'lang' => $minor, 'site' => $major ] );

        // If we don't have a canonical server or a path containing $1, the
        // WikiReference isn't going to function properly. Just return null in
        // that case.
        if ( !is_string( $canonicalServer ) || !is_string( $path ) || strpos( $path, '$1' ) === false ) {
            return null;
        }

        return new WikiReference( $canonicalServer, $path, $server );
    }

    private static function getWikiWikiReferenceFromSites( $wikiID ) {
        $siteLookup = MediaWikiServices::getInstance()->getSiteLookup();
        $site = $siteLookup->getSite( $wikiID );

        if ( !$site instanceof MediaWikiSite ) {
            // Abort if not a MediaWikiSite, as this is about Wikis
            return null;
        }

        $urlParts = wfParseUrl( $site->getPageUrl() );
        if ( $urlParts === false || !isset( $urlParts['path'] ) || !isset( $urlParts['host'] ) ) {
            // We can't create a meaningful WikiReference without URLs
            return null;
        }

        // XXX: Check whether path contains a $1?
        $path = $urlParts['path'];
        if ( isset( $urlParts['query'] ) ) {
            $path .= '?' . $urlParts['query'];
        }

        $canonicalServer = $urlParts['scheme'] ?? 'http';
        $canonicalServer .= '://' . $urlParts['host'];

        return new WikiReference( $canonicalServer, $path );
    }

    public static function getWikiName( $wikiID ) {
        $wiki = self::getWiki( $wikiID );

        if ( $wiki ) {
            return $wiki->getDisplayName();
        }
        return $wikiID;
    }

    public static function foreignUserLink( $wikiID, $user, $text = null ) {
        return self::makeForeignLink( $wikiID, "User:$user", $text );
    }

    public static function makeForeignLink( $wikiID, $page, $text = null ) {
        if ( !$text ) {
            $text = $page;
        }

        $url = self::getForeignURL( $wikiID, $page );
        if ( $url === false ) {
            return false;
        }

        return Linker::makeExternalLink( $url, $text );
    }

    public static function getForeignURL( $wikiID, $page, $fragmentId = null ) {
        $wiki = self::getWiki( $wikiID );

        if ( $wiki ) {
            return $wiki->getFullUrl( $page, $fragmentId );
        }

        return false;
    }

    public static function getCanonicalServerInfoForAllWikis() {
        $cache = MediaWikiServices::getInstance()->getLocalServerObjectCache();

        return $cache->getWithSetCallback(
            $cache->makeGlobalKey( 'wikimap', 'canonical-urls' ),
            $cache::TTL_DAY,
            function () {
                global $wgLocalDatabases, $wgCanonicalServer;

                $infoMap = [];
                // Make sure at least the current wiki is set, for simple configurations.
                // This also makes it the first in the map, which is useful for common cases.
                $wikiId = self::getWikiIdFromDbDomain( self::getCurrentWikiDbDomain() );
                $infoMap[$wikiId] = [
                    'url' => $wgCanonicalServer,
                    'parts' => wfParseUrl( $wgCanonicalServer )
                ];

                foreach ( $wgLocalDatabases as $wikiId ) {
                    $wikiReference = self::getWiki( $wikiId );
                    if ( $wikiReference ) {
                        $url = $wikiReference->getCanonicalServer();
                        $infoMap[$wikiId] = [ 'url' => $url, 'parts' => wfParseUrl( $url ) ];
                    }
                }

                return $infoMap;
            }
        );
    }

    public static function getWikiFromUrl( $url ) {
        global $wgCanonicalServer;

        if ( strpos( $url, "$wgCanonicalServer/" ) === 0 ) {
            // Optimisation: Handle the the common case.
            // (Duplicates self::getCanonicalServerInfoForAllWikis)
            return self::getWikiIdFromDbDomain( self::getCurrentWikiDbDomain() );
        }

        $urlPartsCheck = wfParseUrl( $url );
        if ( $urlPartsCheck === false ) {
            return false;
        }

        static $relevantKeys = [ 'host' => 1, 'port' => 1 ];
        $urlPartsCheck = array_intersect_key( $urlPartsCheck, $relevantKeys );

        foreach ( self::getCanonicalServerInfoForAllWikis() as $wikiId => $info ) {
            $urlParts = $info['parts'];
            if ( $urlParts === false ) {
                continue; // sanity
            }

            $urlParts = array_intersect_key( $urlParts, $relevantKeys );
            if ( $urlParts == $urlPartsCheck ) {
                return $wikiId;
            }
        }

        return false;
    }

    public static function getWikiIdFromDbDomain( $domain ) {
        $domain = DatabaseDomain::newFromId( $domain );
        // Since the schema was not always part of the wiki ID, try to maintain backwards
        // compatibility with some common cases. Assume that if the DB domain schema is just
        // the installer default then it is probably the case that the schema is the same for
        // all wikis in the farm. Historically, any wiki farm had to make the database/prefix
        // combination unique per wiki. Ommit the schema if it does not seem wiki specific.
        if ( !in_array( $domain->getSchema(), [ null, 'mediawiki' ], true ) ) {
            // This means a site admin may have specifically taylored the schemas.
            // Domain IDs might use the form <DB>-<project>- or <DB>-<project>-<language>_,
            // meaning that the schema portion must be accounted for to disambiguate wikis.
            return "{$domain->getDatabase()}-{$domain->getSchema()}-{$domain->getTablePrefix()}";
        }
        // Note that if this wiki ID is passed a a domain ID to LoadBalancer, then it can
        // handle the schema by assuming the generic "mediawiki" schema if needed.
        return strlen( $domain->getTablePrefix() )
            ? "{$domain->getDatabase()}-{$domain->getTablePrefix()}"
            : (string)$domain->getDatabase();
    }

    public static function getCurrentWikiDbDomain() {
        global $wgDBname, $wgDBmwschema, $wgDBprefix;
        // Avoid invoking LBFactory to avoid any chance of recursion
        return new DatabaseDomain( $wgDBname, $wgDBmwschema, (string)$wgDBprefix );
    }

    public static function isCurrentWikiDbDomain( $domain ) {
        return self::getCurrentWikiDbDomain()->equals( $domain );
    }

    public static function isCurrentWikiId( $wikiId ) {
        return ( self::getWikiIdFromDbDomain( self::getCurrentWikiDbDomain() ) === $wikiId );
    }
}