private string GetDocumentSavingPath(HttpPostedFileBase file, int documentId) { if (file == null) { throw new ArgumentNullException(ErrorMessagesConstants.CannotSaveNullFile); } var savingDirName = documentId % 100; var filesHelper = new FilesHelper(); var fileExtension = filesHelper.GetFileExtension(file.FileName); var saveDirPath = $"~/Files/Documents/{savingDirName}"; if (!Directory.Exists(saveDirPath)) { Directory.CreateDirectory(Server.MapPath(saveDirPath)); } return($"{saveDirPath}/{documentId}{fileExtension}"); }