/// <summary>
/// Calculates manual line discount sent from cashier.
/// Should be called only after other discounts are calculated.
/// </summary>
/// <param name="transaction">Transaction to calculate manual total discounts on.</param>
public void CalculateLineManualDiscount(SalesTransaction transaction)
{
if (transaction == null)
{
throw new ArgumentNullException("transaction");
}
// Consider calculable lines only. Ignore voided or return-by-receipt lines.
foreach (var salesLine in transaction.PriceCalculableSalesLines)
{
Discount.ClearManualDiscountLinesOfType(salesLine, ManualDiscountType.LineDiscountAmount);
Discount.ClearManualDiscountLinesOfType(salesLine, ManualDiscountType.LineDiscountPercent);
DiscountLine lineDiscountItem = null;
if (salesLine.LineManualDiscountPercentage != 0)
{
// Add a new line discount
lineDiscountItem = new DiscountLine
{
DiscountLineType = DiscountLineType.ManualDiscount,
ManualDiscountType = ManualDiscountType.LineDiscountPercent,
Percentage = salesLine.LineManualDiscountPercentage,
};
this.AddLineDiscount(transaction, salesLine, lineDiscountItem);
}
if (salesLine.LineManualDiscountAmount != 0)
{
// Add a new line discount
lineDiscountItem = new DiscountLine
{
DiscountLineType = DiscountLineType.ManualDiscount,
ManualDiscountType = ManualDiscountType.LineDiscountAmount,
Amount = salesLine.Quantity != decimal.Zero ? salesLine.LineManualDiscountAmount / salesLine.Quantity : decimal.Zero,
};
this.AddLineDiscount(transaction, salesLine, lineDiscountItem);
}
}
}
/// <summary>
/// Calculates distribution of manual total discounts across the transaction.
/// Should be called only after other discounts are calculated.
/// </summary>
/// <param name="transaction">Transaction to calculate manual total discounts on.</param>
public void CalculateTotalManualDiscount(SalesTransaction transaction)
{
if (transaction == null)
{
throw new ArgumentNullException("transaction");
}
Discount.ClearManualDiscountLinesOfType(transaction, ManualDiscountType.TotalDiscountPercent);
Discount.ClearManualDiscountLinesOfType(transaction, ManualDiscountType.TotalDiscountAmount);
// It's either $ off or % off, not both. In case of a bug where both are present, $ off wins.
if (transaction.TotalManualDiscountAmount != 0)
{
this.AddTotalDiscAmountLines(transaction, DiscountLineType.ManualDiscount, transaction.TotalManualDiscountAmount);
}
else if (transaction.TotalManualDiscountPercentage != 0)
{
this.AddTotalDiscPctLines(transaction);
}
}
/// <summary>
/// This method will distribute the amountToDiscount across all the sale items in the transaction
/// proportionally except for the line item with the largest amount. The remainder will be distributed
/// to the line item with the largest amount to ensure the amount to discount is exactly applied.
/// This method currently works for either the customer discount or when the total discount button is applied.
/// </summary>
/// <param name="transaction">The transaction receiving total discount lines.</param>
/// <param name="discountType">Whether this discount is for a customer or for the total discount item.</param>
/// <param name="amountToDiscount">The amount to discount the transaction.</param>
private void AddTotalDiscAmountLines(
SalesTransaction transaction,
DiscountLineType discountType,
decimal amountToDiscount)
{
decimal totalAmtAvailableForDiscount = decimal.Zero;
// Build a list of the discountable items with the largest value item last.
// Consider calculable lines only. Ignore voided or return-by-receipt lines.
var discountableSaleItems = (from s in transaction.PriceCalculableSalesLines
where s.IsEligibleForDiscount() && s.Quantity > 0 &&
PriceContextHelper.IsDiscountAllowed(this.priceContext, s.ItemId)
orderby Math.Abs(s.NetAmount), s.LineId
select s).ToList();
// Iterate through all non voided items whether we are going to discount or not so that they get added
// back to the totals
// Consider calculable lines only. Ignore voided or return-by-receipt lines.
foreach (var saleItem in transaction.PriceCalculableSalesLines)
{
// We can clear the discount line for total discount because a total manual amount discount
// will override a total manual percent discount, whereas customer discount can have both
// amount and percentage applied simultaneously.
if (discountType == DiscountLineType.ManualDiscount)
{
Discount.ClearManualDiscountLinesOfType(saleItem, ManualDiscountType.TotalDiscountAmount);
Discount.ClearManualDiscountLinesOfType(saleItem, ManualDiscountType.TotalDiscountPercent);
}
SalesLineTotaller.CalculateLine(transaction, saleItem, d => this.priceContext.CurrencyAndRoundingHelper.Round(d));
if (saleItem.IsEligibleForDiscount() && saleItem.Quantity > 0)
{
// Calculate the total amount that is available for discount
totalAmtAvailableForDiscount += Math.Abs(saleItem.NetAmountWithAllInclusiveTax);
}
}
// Calculate the percentage (as a fraction) that we should attempt to discount each discountable item
// to reach the total.
decimal discountFactor = totalAmtAvailableForDiscount != decimal.Zero ? (amountToDiscount / totalAmtAvailableForDiscount) : decimal.Zero;
decimal totalAmtDistributed = decimal.Zero;
// Iterate through all discountable items.
foreach (var saleItem in discountableSaleItems)
{
decimal amountToDiscountForThisItem = decimal.Zero;
if (saleItem != discountableSaleItems.Last())
{
// for every item except for the last in the list (which will have the largest value)
// discount by the rounded amount that is closest to the percentage desired for the transaction
decimal itemPrice = saleItem.NetAmount;
amountToDiscountForThisItem = this.priceContext.CurrencyAndRoundingHelper.Round(discountFactor * Math.Abs(itemPrice));
totalAmtDistributed += amountToDiscountForThisItem;
}
else
{
// Discount the last item by the remainder to ensure that the exact desired discount is applied
amountToDiscountForThisItem = amountToDiscount - totalAmtDistributed;
}
DiscountLine discountItem;
if (amountToDiscountForThisItem != decimal.Zero)
{
if (discountType == DiscountLineType.ManualDiscount)
{
// Add a new total discount item
discountItem = new DiscountLine();
discountItem.DiscountLineType = DiscountLineType.ManualDiscount;
discountItem.ManualDiscountType = ManualDiscountType.TotalDiscountAmount;
saleItem.DiscountLines.Add(discountItem);
}
else
{
// for customer discounts we need to either update the existing one, or add a new one.
discountItem = GetCustomerDiscountItem(saleItem, CustomerDiscountType.TotalDiscount, DiscountLineType.CustomerDiscount);
}
discountItem.Amount = saleItem.Quantity != 0 ? amountToDiscountForThisItem / saleItem.Quantity : amountToDiscountForThisItem;
}
SalesLineTotaller.CalculateLine(transaction, saleItem, d => this.priceContext.CurrencyAndRoundingHelper.Round(d));
}
}