private void AddBillToStorage(Bill bill, int sellerLocation)
        {
            var storage = _context.SalePoints.Find(sellerLocation).Storage;

            foreach (var item in bill.Products)
            {
                SaleStorage saleStorage = new SaleStorage
                {
                    Count = item.Count,
                    ProductId = item.Product.Id,
                    SalePointId = sellerLocation
                };

                storage.Add(saleStorage);
            }
        }
        public ActionResult CreateBill()
        {
            // [HttpPost]
            if (Request.IsAjaxRequest())
            {
                int salePoint = GetSellerLocation();

                Bill bill = new Bill
                {
                    Amount = CalculateAmount(),
                    DateTime = DateTime.Now,
                    SalePointId = salePoint
                };

                _context.Bills.Add(bill);

                // записать елементы чека (продукт) в БД
                foreach (var item in _currentBill)
                {
                    ProductToBill productToBill = new ProductToBill();

                    productToBill.BillId = bill.Id;
                    productToBill.ProductId = item.Key.Id;
                    productToBill.Count = item.Value;

                    _context.ProductToBills.Add(productToBill);

                    #region Delete product count from storage

                    _recivedProducts[item.Key] -= item.Value;
                    _context.SalePoints
                        .Find(salePoint).Storage
                        .ToList()
                        .Find(p => p.ProductId == item.Key.Id)
                        .Count -= item.Value;

                    #endregion
                }

                _context.SaveChanges();

                _currentBill.Clear();

                return PartialView("AddProductToBill", _currentBill);
            }

            _recivedProducts = GetProducts();
            _currentBill.Clear();
            return View(_recivedProducts);
        }