public string Dispense(CommonUtility.productType product)
        {
            string _dispenseMsg = string.Empty;

            if (isInStock(product))
            {
                var productPrice = getProductPrice(product);
                if (_currentCoinsAmount >= productPrice)
                {
                    _currentCoinsAmount -= productPrice;
                    updateProductStock(product);

                    _dispenseMsg = "THANK YOU";
                    //_dispenseMsg += returnCoins(_currentCoinsAmount);
                }
                else if (_currentCoinsAmount < productPrice)
                {
                    _dispenseMsg = $"PRICE {productPrice}, Current Amount {_currentCoinsAmount}";
                }
            }
            else
            {
                _dispenseMsg = "SOLD OUT";
            }
            return(_dispenseMsg);
        }
 private void updateProductStock(CommonUtility.productType product)
 {
     if (product == CommonUtility.productType.Cola)
     {
         _cola_stock -= 1;
     }
     else if (product == CommonUtility.productType.Candy)
     {
         _candy_stock -= 1;
     }
     else if (product == CommonUtility.productType.Chips)
     {
         _chips_stock -= 1;
     }
 }
        private bool isInStock(CommonUtility.productType product)
        {
            var inStock = false;

            if (product == CommonUtility.productType.Cola && _cola_stock > 0)
            {
                inStock = true;
            }
            else if (product == CommonUtility.productType.Chips && _chips_stock > 0)
            {
                inStock = true;
            }
            else if (product == CommonUtility.productType.Candy && _candy_stock > 0)
            {
                inStock = true;
            }

            return(inStock);
        }
        private decimal getProductPrice(CommonUtility.productType product)
        {
            var productPrice = 0m;

            if (product == CommonUtility.productType.Cola)
            {
                productPrice = _colaPrice;
            }
            else if (product == CommonUtility.productType.Chips)
            {
                productPrice = _chipsPrice;
            }
            else if (product == CommonUtility.productType.Candy)
            {
                productPrice = _candyPrice;
            }

            return(productPrice);
        }