public function set_assets_path($path, $fs_dir = null)
    {
        if (empty($path)) {
            return;
        }

        $path = rtrim($path, '/') . '/';

        // handle relative assets path
        if (!preg_match('|^https?://|', $path) && $path[0] != '/') {
            // save the path to search for asset files later
            $this->assets_dir = $path;

            $base = preg_replace('/[?#&].*$/', '', $_SERVER['REQUEST_URI']);
            $base = rtrim($base, '/');

            // remove url token if exists
            if ($len = intval($this->config->get('use_secure_urls'))) {
                $_base  = explode('/', $base);
                $last   = count($_base) - 1;
                $length = $len > 1 ? $len : 16; // as in rcube::get_secure_url_token()

                // we can't use real token here because it
                // does not exists in unauthenticated state,
                // hope this will not produce false-positive matches
                if ($last > -1 && preg_match('/^[a-f0-9]{' . $length . '}$/', $_base[$last])) {
                    $path = '../' . $path;
                }
            }
        }

        // set filesystem path for assets
        if ($fs_dir) {
            if ($fs_dir[0] != '/') {
                $fs_dir = realpath(RCUBE_INSTALL_PATH . $fs_dir);
            }
            // ensure the path ends with a slash
            $this->assets_dir = rtrim($fs_dir, '/') . '/';
        }

        $this->assets_path = $path;
        $this->set_env('assets_path', $path);
    }