wikimedia/mediawiki-extensions-MobileFrontend

<?php

namespace MobileFrontend;

use MediaWiki\MediaWikiServices;

/**
 * Utility class to find base domain for given host.
 *
 * This class contains a hardcoded list of all WMF hosts and WMF specific domain logic. As we never
 * experienced any bug requests from users and we do not change domains too often there is no need
 * to put that hosts list into settings.
 *
 * @see T148975
 */
class WMFBaseDomainExtractor implements BaseDomainExtractorInterface {
    /**
     * @var string[]
     */
    private $wmfWikiHosts = [
        'wikipedia.org',
        'wikibooks.org',
        'wikiversity.org',
        'wikinews.org',
        'wiktionary.org',
        'wikisource.org',
        'wikiquote.org',
        'wikivoyage.org',
        'wikidata.org',
        'mediawiki.org',
        // local vagrant instances
        'local.wmftest.net'
    ];
    /**
     * @var string[]
     */
    private $wmfMultiDomainWikiHosts = [
        // commons, office, meta, outreach, wikimania, incubator, etc...
        '.wikimedia.org',
        // beta cluster
        '.beta.wmflabs.org',
        // all other labs
        '.wmflabs.org'
    ];

    /**
     * Although some browsers will accept cookies without the initial . in domain
     * RFC 2109 requires it to be included.
     *
     * $server must be a valid URL (i.e. with the scheme included, http or https
     * or protocol-relative e.g. //en.m.wikipedia.org'). NULL and empty strings
     * can also be taken but will return NULL or empty string respectively.
     *
     * @inheritDoc
     */
    public function getCookieDomain( $server ) {
        // Per http://php.net/manual/en/function.parse-url.php,
        // If the requested component doesn't exist within the given
        // URL, NULL will be returned. So UrlUtils::parse() will return
        // null as it calls parse_url() if a valid server URL is not
        // given except it's an empty string.
        $services = MediaWikiServices::getInstance();
        $urlUtils = $services->getUrlUtils();
        $host = $urlUtils->parse( (string)$server )['host'] ?? '';

        $wikiHost = $this->matchBaseHostname( $host, $this->wmfWikiHosts );
        if ( $wikiHost !== false ) {
            return '.' . $wikiHost;
        }

        $multiWikiHost = $this->matchBaseHostname( $host, $this->wmfMultiDomainWikiHosts );
        if ( $multiWikiHost !== false ) {
            return '.' . $this->extractSubdomain( $host, $multiWikiHost );
        }
        return $host;
    }

    /**
     * Find out whether $hostname matches or is subdomain of any host from $hosts array
     *
     * @param string|null $hostname Visited host
     * @param string[] $hosts Array of all wikimedia hosts
     * @return bool|string Returns wikimedia host base domain, false when not found
     */
    private function matchBaseHostname( $hostname, array $hosts ) {
        if ( $hostname === null ) {
            return false;
        }
        foreach ( $hosts as $wmfHost ) {
            if ( str_ends_with( $hostname, $wmfHost ) ) {
                return $wmfHost;
            }
        }
        return false;
    }

    /**
     * Parse $host and return $baseDomain with first subdomain
     * ex: extractSubdomain('en.commons.wikimedia.org', '.wikimedia.org') => 'commons.wikimedia.org'
     *
     * This function assumes that $fullHostname is a subdomain of $baseDomain. Please
     * do the str_ends_with() check first before calling this function
     *
     * @param string $fullHostname
     * @param string $baseDomain
     * @return string
     */
    private function extractSubdomain( $fullHostname, $baseDomain ) {
        $length = strlen( $baseDomain );

        $subdomains = explode( '.', substr( $fullHostname, 0, -$length ) );
        $subdomain = array_pop( $subdomains );
        return $subdomain . $baseDomain;
    }

}