FINERACT-2114: EMI Calculator outstanding balance correction

2024-09-04 15:30:13 +01:00
parent a6e35170a7
commit 803a575b04
5 changed files with 233 additions and 57 deletions
@@ -35,10 +35,11 @@ public class ProgressiveLoanInterestRepaymentInterestPeriod implements Comparabl
    private BigDecimal rateFactorMinus1;

    private Money disbursedAmount;
+    private Money correctionAmount;
    private Money interestDue;

    public ProgressiveLoanInterestRepaymentInterestPeriod(final ProgressiveLoanInterestRepaymentInterestPeriod period) {
-        this(period.fromDate, period.dueDate, period.rateFactorMinus1, period.disbursedAmount, period.interestDue);
+        this(period.fromDate, period.dueDate, period.rateFactorMinus1, period.disbursedAmount, period.correctionAmount, period.interestDue);
    }

    @Override
@@ -47,6 +48,14 @@ public class ProgressiveLoanInterestRepaymentInterestPeriod implements Comparabl
    }

    public void addDisbursedAmount(final Money outstandingBalance) {
-        this.disbursedAmount = this.disbursedAmount.add(outstandingBalance);
+        if (outstandingBalance != null && !outstandingBalance.isZero()) {
+            this.disbursedAmount = this.disbursedAmount.add(outstandingBalance);
+        }
+    }
+
+    public void addCorrectionAmount(final Money correctionAmount) {
+        if (correctionAmount != null && !correctionAmount.isZero()) {
+            this.correctionAmount = this.correctionAmount.add(correctionAmount);
+        }
    }
 }
@@ -32,27 +32,34 @@ public class ProgressiveLoanInterestRepaymentModel {

    private LinkedList<ProgressiveLoanInterestRepaymentInterestPeriod> interestPeriods;

+    private boolean isLastPeriod;
+
    private Money equalMonthlyInstallment;
    private Money principalDue;
    private Money remainingBalance;
+    private Money outstandingBalance;

    public ProgressiveLoanInterestRepaymentModel(final LocalDate fromDate, final LocalDate dueDate, final Money equalMonthlyInstallment) {
        this.fromDate = fromDate;
        this.dueDate = dueDate;
        this.equalMonthlyInstallment = equalMonthlyInstallment;
+        this.isLastPeriod = false;

        final Money zeroAmount = Money.zero(equalMonthlyInstallment.getCurrency());
+        this.outstandingBalance = zeroAmount;
        this.remainingBalance = zeroAmount;
        this.principalDue = zeroAmount;
        this.interestPeriods = new LinkedList<>();
-        this.interestPeriods
-                .add(new ProgressiveLoanInterestRepaymentInterestPeriod(fromDate, dueDate, BigDecimal.ZERO, zeroAmount, zeroAmount));
+        this.interestPeriods.add(
+                new ProgressiveLoanInterestRepaymentInterestPeriod(fromDate, dueDate, BigDecimal.ZERO, zeroAmount, zeroAmount, zeroAmount));
    }

    public ProgressiveLoanInterestRepaymentModel(ProgressiveLoanInterestRepaymentModel repaymentModel) {
        this.fromDate = repaymentModel.fromDate;
        this.dueDate = repaymentModel.dueDate;
+        this.isLastPeriod = repaymentModel.isLastPeriod;
        this.equalMonthlyInstallment = repaymentModel.equalMonthlyInstallment;
+        this.outstandingBalance = repaymentModel.outstandingBalance;
        this.remainingBalance = repaymentModel.remainingBalance;
        this.principalDue = repaymentModel.principalDue;
        this.interestPeriods = new LinkedList<>();
@@ -76,7 +83,12 @@ public class ProgressiveLoanInterestRepaymentModel {
                .reduce(Money.zero(equalMonthlyInstallment.getCurrency()), Money::plus);
    }

-    public Money getOutstandingBalance() {
-        return remainingBalance.plus(principalDue);
+    public Money getCorrectionAmount() {
+        return interestPeriods.stream().map(ProgressiveLoanInterestRepaymentInterestPeriod::getCorrectionAmount)
+                .reduce(Money.zero(equalMonthlyInstallment.getCurrency()), Money::plus);
+    }
+
+    public Money getCorrectedOutstandingBalance() {
+        return outstandingBalance.plus(getCorrectionAmount());
    }
 }
@@ -46,6 +46,11 @@ public interface EMICalculator {
    void changeInterestRate(ProgressiveLoanInterestScheduleModel scheduleModel, LocalDate newInterestEffectiveDate,
            BigDecimal newInterestRate);

+    void addBalanceCorrection(ProgressiveLoanInterestScheduleModel scheduleModel, LocalDate balanceCorrectionDate,
+            Money balanceCorrectionAmount);
+
+    Optional<ProgressiveLoanInterestRepaymentModel> getPayableDetails(ProgressiveLoanInterestScheduleModel scheduleModel, LocalDate date);
+
    ProgressiveLoanInterestScheduleModel makeScheduleModelDeepCopy(ProgressiveLoanInterestScheduleModel scheduleModel);

    ProgressiveLoanInterestScheduleModel makeScheduleModelDeepCopy(ProgressiveLoanInterestScheduleModel scheduleModel,
@@ -27,6 +27,7 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Optional;
+import java.util.function.Predicate;
 import lombok.RequiredArgsConstructor;
 import org.apache.fineract.infrastructure.core.service.DateUtils;
 import org.apache.fineract.infrastructure.core.service.MathUtil;
@@ -41,6 +42,7 @@ import org.apache.fineract.portfolio.loanaccount.loanschedule.data.ProgressiveLo
 import org.apache.fineract.portfolio.loanaccount.loanschedule.domain.LoanScheduleModelRepaymentPeriod;
 import org.apache.fineract.portfolio.loanproduct.domain.LoanProductRelatedDetail;
 import org.apache.fineract.portfolio.loanproduct.mapper.ProgressiveLoanInterestRepaymentModelMapper;
+import org.jetbrains.annotations.NotNull;
 import org.springframework.stereotype.Component;

@Component
@@ -61,6 +63,9 @@ public final class ProgressiveEMICalculator implements EMICalculator {
            interestRepaymentModelList
                    .add(new ProgressiveLoanInterestRepaymentModel(period.periodFromDate(), period.periodDueDate(), zeroAmount));
        }
+        if (!interestRepaymentModelList.isEmpty()) {
+            interestRepaymentModelList.get(interestRepaymentModelList.size() - 1).setLastPeriod(true);
+        }
        return new ProgressiveLoanInterestScheduleModel(interestRepaymentModelList, loanProductRelatedDetail,
                installmentAmountInMultiplesOf, mc);
    }
@@ -76,24 +81,24 @@ public final class ProgressiveEMICalculator implements EMICalculator {
                .findFirst();
    }

-    Optional<ProgressiveLoanInterestRepaymentModel> findInterestRepaymentPeriodForDisbursement(
-            final ProgressiveLoanInterestScheduleModel scheduleModel, final LocalDate disbursementDueDate) {
-        if (scheduleModel == null || disbursementDueDate == null) {
+    Optional<ProgressiveLoanInterestRepaymentModel> findInterestRepaymentPeriodForBalanceChange(
+            final ProgressiveLoanInterestScheduleModel scheduleModel, final LocalDate balanceChangeDate) {
+        if (scheduleModel == null || balanceChangeDate == null) {
            return Optional.empty();
        }
        return scheduleModel.repayments().stream()//
-                .filter(repaymentPeriod -> !disbursementDueDate.isBefore(repaymentPeriod.getFromDate())
-                        && disbursementDueDate.isBefore(repaymentPeriod.getDueDate()))//
+                .filter(repaymentPeriod -> !balanceChangeDate.isBefore(repaymentPeriod.getFromDate())
+                        && (repaymentPeriod.isLastPeriod() || balanceChangeDate.isBefore(repaymentPeriod.getDueDate())))//
                .findFirst();
    }

-    Optional<ProgressiveLoanInterestRepaymentInterestPeriod> findInterestPeriodForDisbursement(
-            final ProgressiveLoanInterestRepaymentModel repaymentPeriod, final LocalDate disbursementDueDate) {
-        if (repaymentPeriod == null || disbursementDueDate == null) {
+    Optional<ProgressiveLoanInterestRepaymentInterestPeriod> findInterestPeriodForBalanceChange(
+            final ProgressiveLoanInterestRepaymentModel repaymentPeriod, final LocalDate balanceChangeDate) {
+        if (repaymentPeriod == null || balanceChangeDate == null) {
            return Optional.empty();
        }
        return repaymentPeriod.getInterestPeriods().stream()//
-                .filter(interestPeriod -> disbursementDueDate.isEqual(interestPeriod.getFromDate()))//
+                .filter(interestPeriod -> balanceChangeDate.isEqual(interestPeriod.getFromDate()))//
                .findFirst();
    }

@@ -124,41 +129,54 @@ public final class ProgressiveEMICalculator implements EMICalculator {
    @Override
    public void addDisbursement(final ProgressiveLoanInterestScheduleModel scheduleModel, final LocalDate disbursementDueDate,
            final Money disbursedAmount) {
-        final ProgressiveLoanInterestRepaymentModel repaymentPeriod = findInterestRepaymentPeriodForDisbursement(scheduleModel,
-                disbursementDueDate).orElse(null);
-        if (repaymentPeriod == null) {
-            return;
-        }
-
-        var interestPeriodOptional = findInterestPeriodForDisbursement(repaymentPeriod, disbursementDueDate);
-        if (interestPeriodOptional.isPresent()) {
-            interestPeriodOptional.get().addDisbursedAmount(disbursedAmount);
-        } else {
-            insertInterestPeriod(repaymentPeriod, disbursementDueDate, disbursedAmount);
-        }
-
-        calculateEMIValueAndRateFactors(repaymentPeriod.getDueDate(), scheduleModel);
+        changeOutstandingBalanceAndUpdateInterestPeriods(scheduleModel, disbursementDueDate, disbursedAmount,
+                Money.zero(disbursedAmount.getCurrency()))
+                .ifPresent((repaymentPeriod) -> calculateEMIValueAndRateFactors(repaymentPeriod.getDueDate(), scheduleModel));
    }

-    void insertInterestPeriod(final ProgressiveLoanInterestRepaymentModel repaymentPeriod, final LocalDate disbursementDueDate,
-            final Money disbursedAmount) {
-        // disbursementDueDate is after disb.date because this case when disbursement date is different than interest
+    Optional<ProgressiveLoanInterestRepaymentModel> changeOutstandingBalanceAndUpdateInterestPeriods(
+            final ProgressiveLoanInterestScheduleModel scheduleModel, final LocalDate balanceChangeDate, final Money disbursedAmount,
+            final Money correctionAmount) {
+        return findInterestRepaymentPeriodForBalanceChange(scheduleModel, balanceChangeDate).stream().peek(repaymentPeriod -> {
+            var interestPeriodOptional = findInterestPeriodForBalanceChange(repaymentPeriod, balanceChangeDate);
+            if (interestPeriodOptional.isPresent()) {
+                interestPeriodOptional.get().addDisbursedAmount(disbursedAmount);
+                interestPeriodOptional.get().addCorrectionAmount(correctionAmount);
+            } else {
+                insertInterestPeriod(repaymentPeriod, balanceChangeDate, disbursedAmount, correctionAmount);
+            }
+        }).findFirst();
+    }
+
+    void insertInterestPeriod(final ProgressiveLoanInterestRepaymentModel repaymentPeriod, final LocalDate balanceChangeDate,
+            final Money disbursedAmount, final Money correctionAmount) {
+        // balanceChangeDate is after disb.date because this case when disbursement date is different then interest
        // period start date
        final ProgressiveLoanInterestRepaymentInterestPeriod previousInterestPeriod = repaymentPeriod.getInterestPeriods().stream()
-                .filter(interestPeriod -> disbursementDueDate.isAfter(interestPeriod.getFromDate())
-                        && disbursementDueDate.isBefore(interestPeriod.getDueDate()))//
+                .filter(balanceChangeRelatedPreviousInterestPeriod(repaymentPeriod, balanceChangeDate))//
                .findFirst()//
                .get();//

-        final var interestPeriod = new ProgressiveLoanInterestRepaymentInterestPeriod(disbursementDueDate,
-                previousInterestPeriod.getDueDate(), BigDecimal.ZERO, disbursedAmount, Money.zero(disbursedAmount.getCurrency()));
+        final boolean changeAfterLastRepaymentPeriod = repaymentPeriod.isLastPeriod()
+                && previousInterestPeriod.getDueDate().isEqual(repaymentPeriod.getDueDate());
+        final LocalDate interestPeriodDueDate = changeAfterLastRepaymentPeriod ? balanceChangeDate.plusDays(1)
+                : previousInterestPeriod.getDueDate();
+        final var interestPeriod = new ProgressiveLoanInterestRepaymentInterestPeriod(balanceChangeDate, interestPeriodDueDate,
+                BigDecimal.ZERO, disbursedAmount, correctionAmount, Money.zero(disbursedAmount.getCurrency()));

-        previousInterestPeriod.setDueDate(disbursementDueDate);
+        previousInterestPeriod.setDueDate(balanceChangeDate);

        repaymentPeriod.getInterestPeriods().add(interestPeriod);
        Collections.sort(repaymentPeriod.getInterestPeriods());
    }

+    private static @NotNull Predicate<ProgressiveLoanInterestRepaymentInterestPeriod> balanceChangeRelatedPreviousInterestPeriod(
+            ProgressiveLoanInterestRepaymentModel repaymentPeriod, LocalDate balanceChangeDate) {
+        return interestPeriod -> balanceChangeDate.isAfter(interestPeriod.getFromDate())
+                && (balanceChangeDate.isBefore(interestPeriod.getDueDate())
+                        || (repaymentPeriod.isLastPeriod() && !balanceChangeDate.isBefore(repaymentPeriod.getDueDate())));
+    }
+
    @Override
    public ProgressiveLoanInterestScheduleModel makeScheduleModelDeepCopy(final ProgressiveLoanInterestScheduleModel scheduleModel) {
        return makeScheduleModelDeepCopy(scheduleModel, scheduleModel.loanProductRelatedDetail(),
@@ -203,7 +221,7 @@ public final class ProgressiveEMICalculator implements EMICalculator {

        final Money zeroAmount = Money.zero(scheduleModel.loanProductRelatedDetail().getCurrency());
        final var interestPeriod = new ProgressiveLoanInterestRepaymentInterestPeriod(interestChangeDueDate,
-                previousInterestPeriod.getDueDate(), BigDecimal.ZERO, zeroAmount, zeroAmount);
+                previousInterestPeriod.getDueDate(), BigDecimal.ZERO, zeroAmount, zeroAmount, zeroAmount);

        previousInterestPeriod.setDueDate(interestChangeDueDate);

@@ -211,6 +229,30 @@ public final class ProgressiveEMICalculator implements EMICalculator {
        Collections.sort(repaymentPeriod.getInterestPeriods());
    }

+    @Override
+    public void addBalanceCorrection(ProgressiveLoanInterestScheduleModel scheduleModel, LocalDate balanceCorrectionDate,
+            Money balanceCorrectionAmount) {
+        final Money zeroAmount = Money.zero(balanceCorrectionAmount.getCurrency());
+        changeOutstandingBalanceAndUpdateInterestPeriods(scheduleModel, balanceCorrectionDate, zeroAmount, balanceCorrectionAmount)
+                .ifPresent(repaymentPeriod -> {
+                    calculateRateFactorMinus1ForRepaymentPeriod(repaymentPeriod, scheduleModel);
+                    calculatePrincipalInterestComponentsForPeriods(scheduleModel);
+                });
+    }
+
+    @Override
+    public Optional<ProgressiveLoanInterestRepaymentModel> getPayableDetails(ProgressiveLoanInterestScheduleModel scheduleModel,
+            LocalDate date) {
+        final var newScheduleModel = makeScheduleModelDeepCopy(scheduleModel);
+        final var zeroAmount = Money.zero(scheduleModel.loanProductRelatedDetail().getCurrency());
+
+        return changeOutstandingBalanceAndUpdateInterestPeriods(newScheduleModel, date, zeroAmount, zeroAmount).stream()
+                .peek(repaymentPeriod -> {
+                    calculateRateFactorMinus1ForRepaymentPeriod(repaymentPeriod, scheduleModel);
+                    calculatePrincipalInterestComponentsForPeriod(repaymentPeriod, date);
+                }).findFirst();
+    }
+
    /**
     * Calculate Equal Monthly Installment value and Rate Factor -1 values for calculate Interest
     */
@@ -302,11 +344,13 @@ public final class ProgressiveEMICalculator implements EMICalculator {
     */
    void calculateRateFactorMinus1ForPeriods(final List<ProgressiveLoanInterestRepaymentModel> repaymentPeriods,
            final ProgressiveLoanInterestScheduleModel scheduleModel) {
-        for (var repaymentPeriod : repaymentPeriods) {
-            for (var interestPeriod : repaymentPeriod.getInterestPeriods()) {
-                interestPeriod.setRateFactorMinus1(calculateRateFactorMinus1PerPeriod(repaymentPeriod, interestPeriod, scheduleModel));
-            }
-        }
+        repaymentPeriods.forEach(repaymentPeriod -> calculateRateFactorMinus1ForRepaymentPeriod(repaymentPeriod, scheduleModel));
+    }
+
+    void calculateRateFactorMinus1ForRepaymentPeriod(final ProgressiveLoanInterestRepaymentModel repaymentPeriod,
+            final ProgressiveLoanInterestScheduleModel scheduleModel) {
+        repaymentPeriod.getInterestPeriods().forEach(interestPeriod -> interestPeriod
+                .setRateFactorMinus1(calculateRateFactorMinus1PerPeriod(repaymentPeriod, interestPeriod, scheduleModel)));
    }

    /**
@@ -636,35 +680,45 @@ public final class ProgressiveEMICalculator implements EMICalculator {

    void calculatePrincipalInterestComponentsForPeriods(final ProgressiveLoanInterestScheduleModel scheduleModel) {
        Money outstandingBalance = Money.zero(scheduleModel.loanProductRelatedDetail().getCurrency());
-        int numberOfPeriods = scheduleModel.repayments().size();
-        int period = 0;
        for (var repaymentPeriod : scheduleModel.repayments()) {
-            final boolean isLastPeriod = ++period == numberOfPeriods;
-            outstandingBalance = calculatePrincipalInterestComponentsForPeriod(repaymentPeriod, outstandingBalance, isLastPeriod);
+            repaymentPeriod.setOutstandingBalance(outstandingBalance);
+            calculatePrincipalInterestComponentsForPeriod(repaymentPeriod, null);
+            outstandingBalance = repaymentPeriod.getRemainingBalance();
        }
    }

-    Money calculatePrincipalInterestComponentsForPeriod(final ProgressiveLoanInterestRepaymentModel repaymentPeriod,
-            final Money initBalance, final boolean isLastPeriod) {
-        Money outstandingBalance = initBalance;
+    void calculatePrincipalInterestComponentsForPeriod(final ProgressiveLoanInterestRepaymentModel repaymentPeriod,
+            final LocalDate calculateTill) {
+        final Money zeroAmount = Money.zero(repaymentPeriod.getOutstandingBalance().getCurrency());
+        Money outstandingBalance = repaymentPeriod.getOutstandingBalance();
+        Money balanceCorrection = zeroAmount;
+        Money cumulatedInterest = zeroAmount;
+
        for (ProgressiveLoanInterestRepaymentInterestPeriod interestPeriod : repaymentPeriod.getInterestPeriods()) {
+            final boolean shouldInvalidateInterestPeriod = calculateTill != null && interestPeriod.getDueDate().isAfter(calculateTill);
+            if (shouldInvalidateInterestPeriod) {
+                interestPeriod.setInterestDue(zeroAmount);
+                interestPeriod.setDisbursedAmount(zeroAmount);
+                interestPeriod.setCorrectionAmount(zeroAmount);
+                continue;
+            }
            outstandingBalance = outstandingBalance.plus(interestPeriod.getDisbursedAmount());
-            final Money calculatedInterest = outstandingBalance.multipliedBy(interestPeriod.getRateFactorMinus1());
+            balanceCorrection = balanceCorrection.plus(interestPeriod.getCorrectionAmount());
+            final Money calculatedInterest = outstandingBalance.plus(balanceCorrection).multipliedBy(interestPeriod.getRateFactorMinus1());
            interestPeriod.setInterestDue(calculatedInterest);
+            cumulatedInterest = cumulatedInterest.plus(calculatedInterest);
        }

-        final Money cumulatedInterest = repaymentPeriod.getInterestDue();
-        final Money calculatedPrincipal = isLastPeriod ? outstandingBalance
+        final Money calculatedPrincipal = repaymentPeriod.isLastPeriod() ? outstandingBalance
                : repaymentPeriod.getEqualMonthlyInstallment().minus(cumulatedInterest);

-        if (isLastPeriod) {
+        if (repaymentPeriod.isLastPeriod()) {
            repaymentPeriod.setEqualMonthlyInstallment(calculatedPrincipal.add(cumulatedInterest));
        }

+        final Money remainingBalance = outstandingBalance.minus(calculatedPrincipal);
        repaymentPeriod.setPrincipalDue(calculatedPrincipal);
-        repaymentPeriod.setRemainingBalance(outstandingBalance.minus(calculatedPrincipal));
-
-        return repaymentPeriod.getRemainingBalance();
+        repaymentPeriod.setRemainingBalance(remainingBalance);
    }

    @Override
@@ -674,6 +728,10 @@ public final class ProgressiveEMICalculator implements EMICalculator {
                .filter(period -> !period.isDownPayment() && !period.isAdditional()).toList();
        List<ProgressiveLoanInterestRepaymentModel> repaymentModels = progressiveLoanInterestRepaymentModelMapper
                .map(repaymentModelsWithoutDownPayment);
+
+        if (!repaymentModels.isEmpty()) {
+            repaymentModels.get(repaymentModels.size() - 1).setLastPeriod(true);
+        }
        return new ProgressiveLoanInterestScheduleModel(repaymentModels, loanProductRelatedDetail, installmentAmountInMultiplesOf, mc);
    }
 }