private function downloadFile($countryCode)
    {
        $tempname = sys_get_temp_dir() . '/elcodi-locator-geonames-' . $countryCode . '.zip';
        if (!file_exists($tempname)) {
            $dirname = dirname($tempname);
            if (!file_exists($dirname)) {
                mkdir($dirname, 0777, true);
            }
            $downloadUrl = 'http://download.geonames.org/export/zip/' . $countryCode . '.zip';
            copy($downloadUrl, $tempname);
        }

        return $tempname;
    }