public BaseResponse <Drink> AddDrink(Drink drink) { if (drink == null || drink.Id == Guid.Empty) { return(new BaseResponse <Drink>(ResultCodeEnum.InvalidData)); } var drinkInDb = dataLayer.GetDrinksByIdOrName(id: drink.Id, name: drink.Name).FirstOrDefault(); if (drinkInDb == null) { dataLayer.Insert(drink); } else { return(new BaseResponse <Drink>(ResultCodeEnum.Fail)); } return(new BaseResponse <Drink>(ResultCodeEnum.Success, resultItem: drink)); }