public function get_reference_details($reference, $filestatus = 0) {
        if (empty($reference)) {
            return get_string('unknownsource', 'repository');
        }
        $source = json_decode($reference);
        if (empty($source->usesystem)) {
            return '';
        }
        $systemauth = \core\oauth2\api::get_system_oauth_client($this->issuer);

        if ($systemauth === false) {
            return '';
        }
        $systemservice = new repository_onedrive\rest($systemauth);
        $info = $this->get_file_summary($systemservice, $source->id);

        $owner = '';
        if (!empty($info->createdByUser->displayName)) {
            $owner = $info->createdByUser->displayName;
        }
        if ($owner) {
            return get_string('owner', 'repository_onedrive', $owner);
        } else {
            return $info->name;
        }
    }