示例#1
0
        protected void DisplayBalance(IReadOnlyCashTransaction balance)
        {
            Console.WriteLine("Machine Balance:");
            var ordered = UnitedStatesTender.GetAllDefinedTenders().OrderByDescending(tender => tender.Value);

            foreach (var bill in ordered)
            {
                Console.WriteLine($"${bill.Value} - {balance.BillCount(bill)}");
            }
        }
        public IWithdrawalResult Withdraw(int amount, IAtmInventory inventory)
        {
            var withdrawTransaction           = CashTransaction.Start();
            var descendingUnitedStatesTenders = UnitedStatesTender.GetAllDefinedTenders().OrderByDescending(tender => tender.Value);

            var transactionAmount = amount;

            foreach (var tender in descendingUnitedStatesTenders)
            {
                var numberOfBills = transactionAmount / tender.Value;
                if (numberOfBills > 0)
                {
                    withdrawTransaction.Add(tender, numberOfBills);
                    transactionAmount = transactionAmount - tender.GetValue(numberOfBills);
                }
                if (transactionAmount == 0)
                {
                    break;
                }
                if (transactionAmount < 0)
                {
                    throw new ApplicationException($"transaction amount has gone below zero!");
                }
            }

            // Does inventory support transaction
            var isPossible = inventory.Withdraw(withdrawTransaction);

            if (isPossible)
            {
                return(WithdrawalResult.CreateSuccessResult(withdrawTransaction));
            }
            else
            {
                return(WithdrawalResult.CreateFailureResult("insufficient funds", withdrawTransaction));
            }
        }