private static DateTime GetTempEndDate(InterestCalculationInput input)
{
DateTime startDate = input.StartDate;
DateTime tempEndDate = new DateTime(startDate.Year, startDate.Month, daysOfMonth[startDate.Month]);
if (input.IsMonthly.HasValue && input.IsMonthly.Value)
{
if (startDate.Month == 2 && tempEndDate.Year % 4 == 0)
{
tempEndDate = new DateTime(startDate.Year, startDate.Month, 29);
}
}
else if (input.IsQuarterly.HasValue && input.IsQuarterly.Value)
{
if (startDate.Month <= 3)
{
tempEndDate = new DateTime(startDate.Year, 3, daysOfMonth[3]);
}
else if (startDate.Month <= 6)
{
tempEndDate = new DateTime(startDate.Year, 6, daysOfMonth[6]);
}
else if (startDate.Month <= 9)
{
tempEndDate = new DateTime(startDate.Year, 9, daysOfMonth[9]);
}
else if (startDate.Month <= 12)
{
tempEndDate = new DateTime(startDate.Year, 12, daysOfMonth[12]);
}
}
else if (input.IsHalfYearly.HasValue && input.IsHalfYearly.Value)
{
if (startDate.Month <= 3)
{
tempEndDate = new DateTime(startDate.Year, 3, daysOfMonth[3]);
}
else if (startDate.Month <= 9)
{
tempEndDate = new DateTime(startDate.Year, 9, daysOfMonth[9]);
}
}
else if (input.IsAnnual.HasValue && input.IsAnnual.Value)
{
tempEndDate = new DateTime(startDate.Year, 12, daysOfMonth[12]);
}
return(tempEndDate);
}
public static double GetSimpleInterest(InterestCalculationInput input)
{
int daydiff, monthdiff, yeardiff;
GetDurationBreakup(input.StartDate, input.EndDate, out daydiff, out monthdiff, out yeardiff);
double interestamount = input.Principal * input.InterestRate / 100;
double yearsinterest = (yeardiff * interestamount);
double monthsinterest = monthdiff * interestamount / 12;
double daysinterest = daydiff * interestamount / 366;
double totalinterest = yearsinterest + monthsinterest + daysinterest;
return(totalinterest);
}
public static List <InterestInfo> CreateInterestDetails(InterestCalculationInput input)
{
List <InterestInfo> interestInfoList = new List <InterestInfo>();
DateTime tempEndDate = GetTempEndDate(input);
DateTime startDate = input.StartDate;
DateTime tempStartDate = startDate;
double interestRate = input.InterestRate;
double principal = input.Principal;
List <InterestRateChange> interestChangeList = input.InterestChangeList.ToList();
List <TransactionInfo> transactionList = input.TransactionList.ToList();
InterestInfo info = new InterestInfo {
TransactionDate = tempStartDate, HasTransaction = true, TransactionAmount = 0.0, InterestRate = 0.0, IsCredit = true, Principal = principal
};;
interestInfoList.Add(info);
do
{
if (tempEndDate > input.EndDate)
{
tempEndDate = input.EndDate;
}
List <InterestRateChange> changesForTheCurrentPeriod =
interestChangeList
.Where(irc => irc.StartDate >= tempStartDate && irc.StartDate <= tempEndDate)
.OrderBy(irc => irc.StartDate).ToList();
var datesList = changesForTheCurrentPeriod.Select(irc => new { Date = irc.StartDate, IsTransaction = false }).ToList();
List <TransactionInfo> transactionsForTheCurrentPeriod =
transactionList
.Where(txn => txn.TransactionDate >= tempStartDate && txn.TransactionDate <= tempEndDate)
.OrderBy(txn => txn.TransactionDate).ToList();
datesList.AddRange(transactionsForTheCurrentPeriod.Distinct(new TransactionInfoEqualityComparer()).Select(ti => new { Date = ti.TransactionDate, IsTransaction = true }));
datesList.OrderBy(di => di.Date).ToList().ForEach(
di =>
{
if (di.IsTransaction)
{
List <TransactionInfo> transactionOnThisDate = transactionsForTheCurrentPeriod.Where(ti => ti.TransactionDate == di.Date)
.ToList();
if (transactionOnThisDate.Any())
{
DateTime transDate = transactionOnThisDate.First().TransactionDate.AddDays(-1);
if (tempStartDate == transactionOnThisDate.First().TransactionDate)
{
transDate = tempStartDate;
}
info = new InterestInfo {
StartDate = tempStartDate, EndDate = transDate, InterestRate = interestRate, Principal = principal
};
interestInfoList.Add(info);
principal = info.TotalWithInterest;
transactionOnThisDate.ForEach(ti
=>
{
info = new InterestInfo {
TransactionDate = ti.TransactionDate, Principal = info.TotalWithInterest, HasTransaction = true, IsCredit = ti.IsCredit, TransactionAmount = ti.TransactionAmount
};
interestInfoList.Add(info);
principal = info.TotalWithInterest;
tempStartDate = ti.TransactionDate;
});
if (tempStartDate == transactionOnThisDate.First().TransactionDate&& transactionOnThisDate.First().IsCredit)
{
tempStartDate = tempStartDate.AddDays(1);
}
}
}
else
{
changesForTheCurrentPeriod
.Where(irc => irc.StartDate == di.Date)
.OrderBy(irc => irc.StartDate)
.ToList()
.ForEach(
irc =>
{
if (tempStartDate < irc.StartDate)
{
info = new InterestInfo {
StartDate = tempStartDate, EndDate = irc.StartDate.AddDays(-1), InterestRate = interestRate, Principal = principal
};
interestInfoList.Add(info);
principal = info.TotalWithInterest;
tempStartDate = irc.StartDate;
}
interestRate = irc.InterestRate;
}
);
}
}
);
if (tempStartDate <= tempEndDate)
{
info = new InterestInfo {
StartDate = tempStartDate, EndDate = tempEndDate, InterestRate = interestRate, Principal = principal
};
interestInfoList.Add(info);
principal = info.TotalWithInterest;
tempStartDate = tempEndDate.AddDays(1);
}
if (input.IsMonthly.HasValue && input.IsMonthly.Value)
{
tempEndDate = tempEndDate.AddMonths(1);
tempEndDate = new DateTime(tempEndDate.Year, tempEndDate.Month, (tempEndDate.Month == 2 && isLeapYear(tempEndDate.Year)) ? 29 : daysOfMonth[tempEndDate.Month]);
}
else if (input.IsQuarterly.HasValue && input.IsQuarterly.Value)
{
tempEndDate = tempEndDate.AddMonths(3);
tempEndDate = new DateTime(tempEndDate.Year, tempEndDate.Month, (tempEndDate.Month == 2 && isLeapYear(tempEndDate.Year)) ? 29 : daysOfMonth[tempEndDate.Month]);
}
else if (input.IsHalfYearly.HasValue && input.IsHalfYearly.Value)
{
tempEndDate = tempEndDate.AddMonths(6);
tempEndDate = new DateTime(tempEndDate.Year, tempEndDate.Month, (tempEndDate.Month == 2 && isLeapYear(tempEndDate.Year)) ? 29 : daysOfMonth[tempEndDate.Month]);
}
else if (input.IsAnnual.HasValue && input.IsAnnual.Value)
{
tempEndDate = tempEndDate.AddYears(1);
tempEndDate = new DateTime(tempEndDate.Year, tempEndDate.Month, (tempEndDate.Month == 2 && isLeapYear(tempEndDate.Year)) ? 29 : daysOfMonth[tempEndDate.Month]);
}
}while (tempStartDate <= input.EndDate || tempEndDate <= input.EndDate);
//transactionList
//.Where(txn => txn.IsCredit == false)
//.OrderBy(txn => txn.TransactionDate)
//.ToList()
//.ForEach(txn =>
//{
// info = new InterestInfo { TransactionDate = txn.TransactionDate, Principal = principal, HasTransaction = true, IsCredit = txn.IsCredit, TransactionAmount = txn.TransactionAmount };
// interestInfoList.Add(info);
// principal += txn.TransactionAmount;
//}
//);
return(interestInfoList);
}
public static double GetInterest(string interestType, string principal, string startDate, string endDate, string interestRate)
{
InterestCalculationInput input = new InterestCalculationInput();
try
{
interestType = interestType.Trim().ToUpper();
char interestIdentifier = interestType[0];
switch (interestIdentifier)
{
case 'S':
input.IsSimple = true;
break;
case 'M':
input.IsCompound = true;
input.IsMonthly = true;
break;
case 'Q':
input.IsCompound = true;
input.IsQuarterly = true;
break;
case 'H':
input.IsCompound = true;
input.IsHalfYearly = true;
break;
case 'Y':
input.IsCompound = true;
input.IsAnnual = true;
break;
}
input.StartDate = DateTime.Parse(startDate);
input.EndDate = DateTime.Parse(endDate);
input.InterestRate = Math.Round(Single.Parse(interestRate), 2);
input.Principal = double.Parse(principal);
if (interestIdentifier == 'S')
{
return(GetSimpleInterest(input));
}
else
{
List <InterestInfo> interestInfoList = CreateInterestDetails(input);
return(interestInfoList.Last().TotalWithInterest - input.Principal);
}
}
catch
{
}
return(0.0);
}