public void AddChangeTransaction(ChangeTransaction changeTransaction)
{
if (State == SaleState.Completed || State == SaleState.Cancelled)
{
throw new InvalidOperationException("Change cannot be given on a Completed or Cancelled sale.");
}
if (Balance >= 0)
{
throw new InvalidOperationException("Change can only be given on a sale with a negative balance.");
}
if (changeTransaction.Amount > Math.Abs(Balance))
{
throw new InvalidOperationException("Change amount cannot exceed change due amount.");
}
_changeTransactions.Add(changeTransaction);
calculateBalance();
}
public static StateTransitionResult <SaleState, SaleEvent> Fire(Sale sale, SaleEvent saleEvent, ChangeTransaction change)
{
return(_saleStateManager.FireTrigger(sale, saleEvent, change));
}