// Assumption: Subtotal and Discount have been calculated for each line item
static void calculateCommission(Invoice inv)
{
decimal commission;
commission = inv.LineItems.Sum(x => getCommissionForItem(x, COMMISSION_RATE));
// This rounding looks odd... This is to round to the nearest 50 cents, so I double it, round to the nearest whole dollar, then cut it back in half. Simple
inv.Commission = Math.Round(commission * 2.0m, 0) / 2.0m;
}
public static void ExerciseOne(Invoice inv)
{
foreach (InvoiceItem item in inv.LineItems)
{
calculateSubTotalForItem(item);
calculateTotalForItem(item, inv.TaxRate);
}
}
//invoice item Total
public void CalculateTotal(Invoice inv)
{
Total = Taxable ? ((SubTotal - getDiscount(SubTotal)) * inv.TaxRate) + (SubTotal - getDiscount(SubTotal)) : (SubTotal - getDiscount(SubTotal));
}
public void assignInvoiceNumber(Invoice inv)
{
InvoiceId = inv.Id;
}
public void PerformCalculations(IInvoice item, Invoice inv)
{
item.CalculateSubTotal();
item.CalculateTotal(inv);
item.CalculateCommission();
}
// Assumption: Total has been calculated
static void calculateTotal(Invoice inv)
{
inv.Total = inv.SubTotal + inv.Shipping;// +inv.Commission;
}
// Assumption: Line item totals have been calculated
static void calculateSubTotal(Invoice inv)
{
inv.SubTotal = inv.LineItems.Sum(x => { calculateTotalForItem(x, inv.TaxRate); return x.Total; });
}
public static void ExerciseTwo(Invoice inv)
{
calculateSubTotal(inv);
calculateTotal(inv);
}
public static void ExerciseThree(Invoice inv)
{
calculateCommission(inv);
}
