while file exists update the file revision number

gistfile1.txt

        $path = public_path() . '/directory/' . $file_name;

        $i = 0;
        while(file_exists($path)) {
            $i++;
            if($i == 1) {
                $file_name = pathinfo($path, PATHINFO_FILENAME);
                $file_extension = pathinfo($path, PATHINFO_EXTENSION);
                $file_name = $file_name . '-r' . $i . '.' . $file_extension;
                $path = public_path() . '/directory'/' . $file_name;
            } else {
                $test = $i-1;
                $file_name =str_replace('-r' . $test . '.pdf', '-r' . $i, $file_name . '.pdf');
                $path = public_path() . '/directory/' . $file_name;
            }
        }