internal void Generate(Settings.InstalmentPolicyDetail instalmentPolicyDetail, decimal instalmentAmount, int totalPeriod, DateTime tradeDay, int sequenceOffset = 1)
{
decimal monthRate = this.CalculateMonthRate(instalmentPolicyDetail.InterestRate, _instalment.Frequence);
decimal remainAmount = instalmentAmount;
decimal principle;
decimal interest;
for (int period = 0; period < totalPeriod; period++)
{
if (this.IsInstalmentDetailExist(period + 1))
{
continue;
}
if (_instalment.InstalmentType == InstalmentType.EqualPrincipal || monthRate == 0m)
{
principle = InstalmentDetailCalculator.Round(instalmentAmount / totalPeriod);
interest = InstalmentDetailCalculator.Round(remainAmount * monthRate);
}
else
{
var item = this.CalculateEqualInstalmentPrincipleAndInterest(monthRate, period, totalPeriod, instalmentAmount, remainAmount);
principle = item.Item1;
interest = item.Item2;
}
remainAmount -= principle;
if (period == totalPeriod - 1 && remainAmount != 0)
{
principle += remainAmount;
remainAmount = 0m;
}
DateTime dateTimeOnPlan = this.CalculateDateTimeOnPlan(tradeDay, _instalment.Frequence, period);
_order.AddInstalmentDetail(new InstalmentDetail(_order, (sequenceOffset - 1) + period + 1, principle, interest, 0m, dateTimeOnPlan, null), OperationType.AsNewRecord);
}
}
private Tuple <decimal, decimal> CalculateEqualInstalmentPrincipleAndInterest(decimal monthRate, int period, int totalPeriod, decimal amount, decimal remainAmount)
{
double x = 1 + (double)monthRate;
decimal p1 = (decimal)Math.Pow(x, (period + 1));
decimal p2 = (decimal)Math.Pow(x, period);
decimal p3 = (decimal)Math.Pow(x, totalPeriod) - 1;
decimal principle = InstalmentDetailCalculator.Round((p1 - p2) / p3 * amount);
decimal interest = InstalmentDetailCalculator.Round(remainAmount * monthRate);
return(Tuple.Create(principle, interest));
}
