public void AddReverseRate(ReverseRate reverseRate) => _reverseRates.Add(reverseRate);
public void Calculate(Order order)
{
foreach (var item in order.OrderItems)
{
// Loop through each of the charges that this charge type is to be calculated on top of.
foreach (var baseChargeName in _baseCharges)
{
var baseChargeAmount = item.GetChargeAmount(baseChargeName, order.Currency);
// Check to see if a charge has been calculated for this charge type.
// If so, do a forward calculation - the calculated charges can be removed from the
// inclusive price before applying the reverse rate as they are known.
if (baseChargeAmount.Value != 0)
{
var chargeAmount = baseChargeAmount * _getRate(item).AsDecimal;
var chargeName = ChargeName.FromBaseChargeName(_chargeName, baseChargeName);
item.AddCharge(new OrderCharge(chargeName, chargeAmount, _chargeName));
}
// If the charge that we need to calculate on top of has not already been calculated,
// and is therefore unknown - we need to calculate the reverse rate.
else
{
// If the base charge is item or delivery (not a calculated rate), just add the rate
// for this item to the calculation rates collection. There might be a better way of
// identifying these 'non calculated' rates types of charges that would be more flexible.
if (baseChargeName.Value == "Item" || baseChargeName.Value == "Delivery")
{
item.AddReverseRate(new ReverseRate(
name: ChargeName.FromBaseChargeName(_chargeName, baseChargeName),
parentChargeName: _chargeName,
rate: _getRate(item)));
}
// If the base charge is a calculated rate, we need to calculate a new rate and add it
// to the calculated rates collection. All of these rates combined will be used to reverse
// back to the item price.
else
{
// Get the current list of rates
var reverseRates = item.ReverseRates.ToList();
// Get all of the reverse rates related to the current base charge. For example, if we're
// calculating a fee, which was calculated on top of duty and vat, we'll need the base
// fee rate, the fee on duty rate and the fee on vat rate. This is done by querying the
// rates collection by 'parent' charge. In this example, all rates would have a parent charge
// of fee.
foreach (var reverseRate in reverseRates.Where(x => x.BaseChargeName == baseChargeName))
{
var rate = _getRate(item).AsDecimal *reverseRate.Rate.AsDecimal * 100;
var calculatedRate = new ReverseRate(
name: ChargeName.FromBaseChargeName(_chargeName, reverseRate.ChargeName),
parentChargeName: _chargeName,
rate: new Rate(rate));
item.AddReverseRate(calculatedRate);
}
}
}
}
}
}
