public async Task <IActionResult> Post([FromBody] AddShoppingCartModel shoppingCartModel)
        {
            IIdentity fedIdentity = GetFederationIdentity(HttpContext.User.Identities);

            if (null == fedIdentity)
            {
                return(ResponseHelper.Forbidden());
            }

            // Get current user session id.
            string sessionID = string.Empty;

            if (fedIdentity.IsAuthenticated)
            {
                int count = await _cartItemRepository.AddAsync(
                    sessionID, shoppingCartModel.UserID,
                    shoppingCartModel.ProductID, shoppingCartModel.Amount);

                if (count > 0)
                {
                    return(Ok());
                }
            }

            return(ResponseHelper.NotAcceptable());
        }