calculate total interest based on etered loan term.

mifosng-provider/src/main/java/org/mifosng/platform/api/LoansApiResource.java

@@ -147,10 +147,8 @@ public class LoansApiResource {
 		SubmitLoanApplicationCommand command = this.apiDataConversionService
 				.convertJsonToSubmitLoanApplicationCommand(jsonRequestBody);
 
-		CalculateLoanScheduleCommand calculateLoanScheduleCommand = command
+		CalculateLoanScheduleCommand calculateLoanScheduleCommand = command.toCalculateLoanScheduleCommand();
-				.toCalculateLoanScheduleCommand();
+		LoanSchedule loanSchedule = this.calculationPlatformService.calculateLoanSchedule(calculateLoanScheduleCommand);
-		LoanSchedule loanSchedule = this.calculationPlatformService
-				.calculateLoanSchedule(calculateLoanScheduleCommand);
 
 		// for now just auto generating the loan schedule and setting support
 		// for 'manual' loan schedule creation later.
@@ -160,8 +158,7 @@ public class LoansApiResource {
 			return Response.ok().entity(loanSchedule).build();
 		}
 
-		EntityIdentifier identifier = this.loanWritePlatformService
+		EntityIdentifier identifier = this.loanWritePlatformService.submitLoanApplication(command);
-				.submitLoanApplication(command);
 
 		return Response.ok().entity(identifier).build();
 	}

mifosng-provider/src/main/java/org/mifosng/platform/loan/domain/Loan.java

@@ -186,8 +186,7 @@ public class Loan extends AbstractAuditableCustom<AppUser, Long> {
 			LocalDate interestChargedFromDate,
 			LoanLifecycleStateMachine lifecycleStateMachine) {
 
-		this.loanStatus = lifecycleStateMachine.transition(
+		this.loanStatus = lifecycleStateMachine.transition(LoanEvent.LOAN_CREATED, this.loanStatus);
-				LoanEvent.LOAN_CREATED, this.loanStatus);
 
 		this.submittedOnDate = submittedOn.toDateTimeAtCurrentTime().toDate();
 

mifosng-provider/src/main/java/org/mifosng/platform/loan/service/CalculationPlatformServiceImpl.java

@@ -67,9 +67,14 @@ public class CalculationPlatformServiceImpl implements
 		final PeriodFrequencyType interestPeriodFrequencyType = PeriodFrequencyType.fromInt(command.getInterestRateFrequencyType());
 		final InterestMethod interestMethod = InterestMethod.fromInt(command.getInterestType());
 		final InterestCalculationPeriodMethod interestCalculationPeriodMethod = InterestCalculationPeriodMethod.fromInt(command.getInterestCalculationPeriodType());
+		
+		final Integer loanTermFrequency = command.getLoanTermFrequency();
+		final PeriodFrequencyType loanTermFrequencyType = PeriodFrequencyType.fromInt(command.getLoanTermFrequencyType());
+		
+		final Integer defaultNumberOfInstallments = command.getNumberOfRepayments();
 		final Integer repayEvery = command.getRepaymentEvery();
 		final PeriodFrequencyType repaymentFrequencyType = PeriodFrequencyType.fromInt(command.getRepaymentFrequencyType());
-		final Integer defaultNumberOfInstallments = command.getNumberOfRepayments();
+		
 		final AmortizationMethod amortizationMethod = AmortizationMethod.fromInt(command.getAmortizationType());
 		
 		final BigDecimal defaultAnnualNominalInterestRate = this.aprCalculator.calculateFrom(interestPeriodFrequencyType, defaultNominalInterestRatePerPeriod);
@@ -96,7 +101,7 @@ public class CalculationPlatformServiceImpl implements
 		CurrencyData currencyData = new CurrencyData(applicationCurrency.getCode(), applicationCurrency.getName(), currency.getDigitsAfterDecimal(),
 				applicationCurrency.getDisplaySymbol(), applicationCurrency.getNameCode());
 		
-		return loanScheduleGenerator.generate(loanScheduleInfo, command.getExpectedDisbursementDate(), command.getRepaymentsStartingFromDate(), 
+		return loanScheduleGenerator.generate(loanScheduleInfo, loanTermFrequency, loanTermFrequencyType, command.getExpectedDisbursementDate(), command.getRepaymentsStartingFromDate(), 
 				command.getInterestChargedFromDate(), currencyData);
 	}
 

mifosng-provider/src/main/java/org/mifosng/platform/loanschedule/domain/DecliningBalanceMethodLoanScheduleGenerator.java

@@ -14,6 +14,7 @@ import org.mifosng.platform.currency.domain.MonetaryCurrency;
 import org.mifosng.platform.currency.domain.Money;
 import org.mifosng.platform.loan.domain.AmortizationMethod;
 import org.mifosng.platform.loan.domain.LoanProductRelatedDetail;
+import org.mifosng.platform.loan.domain.PeriodFrequencyType;
 
 public class DecliningBalanceMethodLoanScheduleGenerator implements
 		LoanScheduleGenerator {
@@ -26,6 +27,8 @@ public class DecliningBalanceMethodLoanScheduleGenerator implements
 	@Override
 	public LoanSchedule generate(
 			final LoanProductRelatedDetail loanScheduleInfo,
+			final Integer loanTermFrequency, 
+			final PeriodFrequencyType loanTermFrequencyType, 
 			final LocalDate disbursementDate, 
 			final LocalDate firstRepaymentDate, 
 			final LocalDate interestCalculatedFrom, CurrencyData currencyData) {
@@ -43,6 +46,10 @@ public class DecliningBalanceMethodLoanScheduleGenerator implements
 		final Money totalDuePerInstallment = this.pmtCalculator.calculatePaymentForOnePeriodFrom(loanScheduleInfo, periodInterestRateForRepaymentPeriod, monetaryCurrency);
 		final Money totalDue = this.pmtCalculator.calculateTotalRepaymentFrom(loanScheduleInfo, periodInterestRateForRepaymentPeriod, monetaryCurrency);
 		
+		// REVIEW. calculate total interest due based on loan term settings
+		final BigDecimal periodInterestRateForLoanTermPeriod = this.periodicInterestRateCalculator.calculateFrom(loanTermFrequencyType, loanScheduleInfo.getAnnualNominalInterestRate());
+		final Money totalRepaymentDueForLoanTerm = this.pmtCalculator.calculateTotalRepaymentFrom(loanScheduleInfo.getPrincipal(), loanTermFrequency, periodInterestRateForLoanTermPeriod, monetaryCurrency);
+		
 		Money totalInterestDue = totalDue.minus(loanScheduleInfo.getPrincipal());
 		Money outstandingBalance = loanScheduleInfo.getPrincipal();
 		Money totalPrincipal = Money.zero(monetaryCurrency);

mifosng-provider/src/main/java/org/mifosng/platform/loanschedule/domain/FlatLoanScheduleGenerator.java

@@ -13,6 +13,7 @@ import org.mifosng.platform.api.data.MoneyData;
 import org.mifosng.platform.api.data.ScheduledLoanInstallment;
 import org.mifosng.platform.currency.domain.Money;
 import org.mifosng.platform.loan.domain.LoanProductRelatedDetail;
+import org.mifosng.platform.loan.domain.PeriodFrequencyType;
 
 public class FlatLoanScheduleGenerator implements LoanScheduleGenerator {
 
@@ -22,6 +23,8 @@ public class FlatLoanScheduleGenerator implements LoanScheduleGenerator {
 	@Override
 	public LoanSchedule generate(
 			final LoanProductRelatedDetail loanScheduleInfo,
+			final Integer loanTermFrequency, 
+			final PeriodFrequencyType loanTermFrequencyType, 
 			final LocalDate disbursementDate, final LocalDate firstRepaymentDate, 
 			final LocalDate interestCalculatedFrom, final CurrencyData currencyData) {
 
@@ -31,40 +34,57 @@ public class FlatLoanScheduleGenerator implements LoanScheduleGenerator {
 
 		MathContext mc = new MathContext(8, RoundingMode.HALF_EVEN);
 		
-		// FIXME - use the expected loan term to work out interest due
+		BigDecimal loanTermPeriodsInYear = BigDecimal.valueOf(this.paymentPeriodsInOneYearCalculator.calculate(loanTermFrequencyType));
-		// loan term = 9 months
+		BigDecimal interestRateForLoanTerm = loanScheduleInfo
+				.getAnnualNominalInterestRate()
+				.divide(loanTermPeriodsInYear, mc)
+				.divide(BigDecimal.valueOf(Double.valueOf("100.0")), mc)
+				.multiply(BigDecimal.valueOf(loanTermFrequency));
+		
+		Money totalInterestForLoanTerm = loanScheduleInfo.getPrincipal().multiplyRetainScale(interestRateForLoanTerm, RoundingMode.HALF_EVEN);
+
+		Money interestPerInstallment = totalInterestForLoanTerm.dividedBy(Long.valueOf(loanScheduleInfo.getNumberOfRepayments()), RoundingMode.HALF_EVEN);
 		
 		Money principalPerInstallment = loanScheduleInfo.getPrincipal()
 				.dividedBy(loanScheduleInfo.getNumberOfRepayments(),
 						RoundingMode.HALF_EVEN);
 
-		BigDecimal paymentPeriodsInYear = BigDecimal
+//		BigDecimal paymentPeriodsInYear = BigDecimal
-				.valueOf(this.paymentPeriodsInOneYearCalculator
+//				.valueOf(this.paymentPeriodsInOneYearCalculator
-						.calculate(loanScheduleInfo.getRepaymentPeriodFrequencyType()));
+//						.calculate(loanScheduleInfo.getRepaymentPeriodFrequencyType()));
 
-		BigDecimal periodicInterestRate = loanScheduleInfo
+//		BigDecimal periodicInterestRate = loanScheduleInfo
-				.getAnnualNominalInterestRate()
+//				.getAnnualNominalInterestRate()
-				.divide(paymentPeriodsInYear, mc)
+//				.divide(paymentPeriodsInYear, mc)
-				.divide(BigDecimal.valueOf(Double.valueOf("100.0")), mc)
+//				.divide(BigDecimal.valueOf(Double.valueOf("100.0")), mc)
-				.multiply(BigDecimal.valueOf(loanScheduleInfo.getRepayEvery()));
+//				.multiply(BigDecimal.valueOf(loanScheduleInfo.getRepayEvery()));
 
-		Money interestPerInstallment = loanScheduleInfo.getPrincipal().multiplyRetainScale(periodicInterestRate, RoundingMode.HALF_EVEN);
+//		Money interestPerInstallment = loanScheduleInfo.getPrincipal().multiplyRetainScale(periodicInterestRate, RoundingMode.HALF_EVEN);
 
 		Money outstandingBalance = loanScheduleInfo.getPrincipal();
 		Money totalPrincipal = Money.zero(outstandingBalance.getCurrency());
+		Money totalInterest = Money.zero(outstandingBalance.getCurrency());
 
 		LocalDate startDate = disbursementDate;
 		int installmentNumber = 1;
 		for (LocalDate scheduledDueDate : scheduledDates) {
 			totalPrincipal = totalPrincipal.plus(principalPerInstallment);
+			totalInterest = totalInterest.plus(interestPerInstallment);
 
 			if (installmentNumber == loanScheduleInfo.getNumberOfRepayments()) {
-				Money difference = totalPrincipal.minus(loanScheduleInfo.getPrincipal());
+				final Money difference = totalPrincipal.minus(loanScheduleInfo.getPrincipal());
 				if (difference.isLessThanZero()) {
 					principalPerInstallment = principalPerInstallment.plus(difference.abs());
 				} else if (difference.isGreaterThanZero()) {
 					principalPerInstallment = principalPerInstallment.minus(difference.abs());
 				}
+				
+				final Money interestDifference = totalInterest.minus(totalInterestForLoanTerm);
+				if (interestDifference.isLessThanZero()) {
+					interestPerInstallment = interestPerInstallment.plus(interestDifference.abs());
+				} else if (interestDifference.isGreaterThanZero()) {
+					interestPerInstallment = interestPerInstallment.minus(interestDifference.abs());
+				}
 			}
 
 			Money totalInstallmentDue = principalPerInstallment.plus(interestPerInstallment);

mifosng-provider/src/main/java/org/mifosng/platform/loanschedule/domain/LoanScheduleGenerator.java

@@ -4,10 +4,13 @@ import org.joda.time.LocalDate;
 import org.mifosng.platform.api.data.CurrencyData;
 import org.mifosng.platform.api.data.LoanSchedule;
 import org.mifosng.platform.loan.domain.LoanProductRelatedDetail;
+import org.mifosng.platform.loan.domain.PeriodFrequencyType;
 
 public interface LoanScheduleGenerator {
 
 	LoanSchedule generate(LoanProductRelatedDetail loanScheduleInfo,
+			Integer loanTermFrequency, 
+			PeriodFrequencyType loanTermFrequencyType, 
 			LocalDate disbursementDate, LocalDate firstRepaymentDate, LocalDate interestCalculatedFrom, 
 			CurrencyData currencyData);
 

mifosng-provider/src/main/java/org/mifosng/platform/loanschedule/domain/PeriodicInterestRateCalculator.java

@@ -6,12 +6,23 @@ import java.math.RoundingMode;
 
 import org.mifosng.platform.currency.domain.Money;
 import org.mifosng.platform.loan.domain.LoanProductRelatedDetail;
+import org.mifosng.platform.loan.domain.PeriodFrequencyType;
 
 public class PeriodicInterestRateCalculator {
 
 	private final PaymentPeriodsInOneYearCalculator paymentPeriodsInOneYearCalculator = new DefaultPaymentPeriodsInOneYearCalculator();
 	
-	public BigDecimal calculateFrom(LoanProductRelatedDetail loanScheduleInfo) {
+	public BigDecimal calculateFrom(final PeriodFrequencyType loanTermFrequencyType, final BigDecimal annualNominalInterestRate) {
+		
+		MathContext mc = new MathContext(8, RoundingMode.HALF_EVEN);
+		
+		Integer paymentPeriodsInOneYear = this.paymentPeriodsInOneYearCalculator.calculate(loanTermFrequencyType);
+		
+		BigDecimal divisor = BigDecimal.valueOf(paymentPeriodsInOneYear * 100);
+		return annualNominalInterestRate.divide(divisor, mc);
+	}
+	
+	public BigDecimal calculateFrom(final LoanProductRelatedDetail loanScheduleInfo) {
 		
 		MathContext mc = new MathContext(8, RoundingMode.HALF_EVEN);
 		

mifosng-provider/src/main/java/org/mifosng/platform/loanschedule/domain/PmtCalculator.java

@@ -8,7 +8,9 @@ import org.mifosng.platform.loan.domain.LoanProductRelatedDetail;
 
 public class PmtCalculator {
 
-	public Money calculatePaymentForOnePeriodFrom(LoanProductRelatedDetail loanScheduleInfo, BigDecimal periodInterestRateForRepaymentPeriod, MonetaryCurrency monetaryCurrency) {
+	public Money calculatePaymentForOnePeriodFrom(final LoanProductRelatedDetail loanScheduleInfo, 
+			final BigDecimal periodInterestRateForRepaymentPeriod, 
+			final MonetaryCurrency monetaryCurrency) {
 		double interestRateFraction = periodInterestRateForRepaymentPeriod.doubleValue();
 		
 		double futureValue = 0;
@@ -22,7 +24,9 @@ public class PmtCalculator {
 		return Money.of(monetaryCurrency, BigDecimal.valueOf(paymentPerInstallment));
 	}
 	
-	public Money calculateTotalRepaymentFrom(LoanProductRelatedDetail loanScheduleInfo, BigDecimal periodInterestRateForRepaymentPeriod, MonetaryCurrency monetaryCurrency) {
+	public Money calculateTotalRepaymentFrom(final LoanProductRelatedDetail loanScheduleInfo, 
+			final BigDecimal periodInterestRateForRepaymentPeriod, 
+			final MonetaryCurrency monetaryCurrency) {
 		double interestRateFraction = periodInterestRateForRepaymentPeriod.doubleValue();
 		
 		double futureValue = 0;
@@ -38,6 +42,27 @@ public class PmtCalculator {
 		return Money.of(monetaryCurrency, BigDecimal.valueOf(totalRepayment));
 	}
 	
+	public Money calculateTotalRepaymentFrom(
+			final Money principal, 
+			final Integer loanTermFrequency,
+			final BigDecimal periodInterestRateForLoanTermPeriod,
+			final MonetaryCurrency monetaryCurrency) {
+		
+		double interestRateFraction = periodInterestRateForLoanTermPeriod.doubleValue();
+		
+		double futureValue = 0;
+		double numberOfPeriods = loanTermFrequency;
+		double principalAmount = principal.getAmount().multiply(BigDecimal.valueOf(-1)).doubleValue();
+		
+		// work out the total payment (principal + interest components) for each installment due.
+		// use the period type and interest as expressed e.g. 2% per month or 24% per year even is 'daily' interest calculation is selected
+		double paymentPerInstallment = pmt(interestRateFraction, numberOfPeriods, principalAmount, futureValue, false);
+		
+		double totalRepayment = paymentPerInstallment * loanTermFrequency;
+		
+		return Money.of(monetaryCurrency, BigDecimal.valueOf(totalRepayment));
+	}
+
 	/**
 	 * PMT calculates a fixed monthly payment to be paid by borrower every 'period' to ensure loan is paid off in full (with interest).
 	 *