/**
  * Get name replacement for a filename
  *
  * @param $folder_row
  * @param $file_name
  * @return mixed|void
  */
 public function get_name_replacement($folder_row, $file_name)
 {
     $bucket_data = $this->get_source_settings($folder_row->source_id);
     $this->_s3_set_creds($bucket_data->access_key_id, $bucket_data->secret_access_key);
     $this->s3->setEndpoint(self::get_endpoint_by_location($bucket_data->location));
     $file_list = $this->s3->getBucket($bucket_data->bucket, $this->_get_path_prefix() . $folder_row->full_path);
     $file_name_parts = explode(".", $file_name);
     $extension = array_pop($file_name_parts);
     $file_name_start = join(".", $file_name_parts) . '_';
     $index = 1;
     while (isset($file_list[$folder_row->full_path . $file_name_start . $index . '.' . $extension]) || $this->EE->assets_lib->get_file_id_by_folder_id_and_name($folder_row->folder_id, $file_name_start . $index . '.' . $extension)) {
         $index++;
     }
     return $file_name_start . $index . '.' . $extension;
 }