public decimal TotalMoneySpent(string id)
        {
            var customer = _customerRepository
                           .Set()
                           .FirstOrDefault(c => c.CustomerID == id);

            if (customer == null)
            {
                return(0);
            }

            var orderDetailServices = new OrderDetailServices();

            decimal grandTotal = 0;

            foreach (var o in customer.Orders)
            {
                grandTotal += orderDetailServices.Total(o.OrderID);
            }

            return(grandTotal);
        }