FINERACT-2114: Interest rate modification

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/loanschedule/domain/LoanApplicationTerms.java

@@ -1890,8 +1890,4 @@ public void updateVariationDays(final long daysToAdd) {
         this.variationDays += daysToAdd;
     }
 
-    public LocalDate getLoanEndDate() {
-        return loanEndDate;
-    }
-
 }

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/rescheduleloan/data/LoanRescheduleRequestDataValidator.java

@@ -331,7 +331,10 @@ public void validateForApproveAction(final JsonCommand jsonCommand, LoanReschedu
             }
 
             if (rescheduleFromDate != null) {
-                installment = loan.getRepaymentScheduleInstallment(rescheduleFromDate);
+                final boolean isProgressiveLoanSchedule = loan.getLoanProductRelatedDetail()
+                        .getLoanScheduleType() == LoanScheduleType.PROGRESSIVE;
+                installment = isProgressiveLoanSchedule ? loan.getRelatedRepaymentScheduleInstallment(rescheduleFromDate)
+                        : loan.getRepaymentScheduleInstallment(rescheduleFromDate);
 
                 if (installment == null) {
                     dataValidatorBuilder.reset().failWithCodeNoParameterAddedToErrorCode(

fineract-progressive-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/loanschedule/data/ProgressiveLoanInterestRate.java

@@ -0,0 +1,32 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.fineract.portfolio.loanaccount.loanschedule.data;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+import org.jetbrains.annotations.NotNull;
+
+public record ProgressiveLoanInterestRate(LocalDate effectiveFrom, LocalDate validFrom,
+        BigDecimal interestRate) implements Comparable<ProgressiveLoanInterestRate> {
+
+    @Override
+    public int compareTo(@NotNull ProgressiveLoanInterestRate o) {
+        return this.effectiveFrom().compareTo(o.effectiveFrom());
+    }
+}

fineract-progressive-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/loanschedule/data/ProgressiveLoanInterestScheduleModel.java

@@ -18,13 +18,40 @@
  */
 package org.apache.fineract.portfolio.loanaccount.loanschedule.data;
 
+import java.math.BigDecimal;
 import java.math.MathContext;
+import java.time.LocalDate;
 import java.time.temporal.ChronoUnit;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import org.apache.fineract.portfolio.loanproduct.domain.LoanProductRelatedDetail;
 
-public record ProgressiveLoanInterestScheduleModel(List<ProgressiveLoanInterestRepaymentModel> repayments,
-        LoanProductRelatedDetail loanProductRelatedDetail, Integer installmentAmountInMultiplesOf, MathContext mc) {
+public record ProgressiveLoanInterestScheduleModel(List<ProgressiveLoanInterestRepaymentModel> repayments, //
+        List<ProgressiveLoanInterestRate> interestRates, //
+        LoanProductRelatedDetail loanProductRelatedDetail, //
+        Integer installmentAmountInMultiplesOf, //
+        MathContext mc) {
+
+    public ProgressiveLoanInterestScheduleModel(List<ProgressiveLoanInterestRepaymentModel> repayments,
+            LoanProductRelatedDetail loanProductRelatedDetail, Integer installmentAmountInMultiplesOf, MathContext mc) {
+        this(repayments, new ArrayList<>(1), loanProductRelatedDetail, installmentAmountInMultiplesOf, mc);
+    }
+
+    public void addInterestRate(final LocalDate newInterestDueDate, final BigDecimal newInterestRate) {
+        interestRates.add(new ProgressiveLoanInterestRate(newInterestDueDate, newInterestDueDate.plusDays(1), newInterestRate));
+        interestRates.sort(Collections.reverseOrder());
+    }
+
+    public BigDecimal getInterestRate(final LocalDate effectiveDate) {
+        return interestRates.isEmpty() ? loanProductRelatedDetail.getNominalInterestRatePerPeriod() : findInterestRate(effectiveDate);
+    }
+
+    private BigDecimal findInterestRate(final LocalDate effectiveDate) {
+        return interestRates.stream().filter(ir -> !ir.effectiveFrom().isAfter(effectiveDate))
+                .map(ProgressiveLoanInterestRate::interestRate).findFirst()
+                .orElse(loanProductRelatedDetail.getNominalInterestRatePerPeriod());
+    }
 
     public int getLoanTermInDays() {
         if (repayments.isEmpty()) {

fineract-progressive-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/loanschedule/domain/ProgressiveLoanScheduleGenerator.java

@@ -75,7 +75,6 @@ public LoanScheduleModel generate(final MathContext mc, final LoanApplicationTer
         if (lastDueDateVariation != null) {
             loanEndDate = lastDueDateVariation.getDateValue();
         }
-        loanApplicationTerms.updateLoanEndDate(loanEndDate);
 
         // determine the total charges due at time of disbursement
         final BigDecimal chargesDueAtTimeOfDisbursement = deriveTotalChargesDueAtTimeOfDisbursement(loanCharges);
@@ -111,6 +110,15 @@ public LoanScheduleModel generate(final MathContext mc, final LoanApplicationTer
             processDisbursements(loanApplicationTerms, scheduleParams, interestScheduleModel, periods, chargesDueAtTimeOfDisbursement);
             repaymentPeriod.setPeriodNumber(scheduleParams.getInstalmentNumber());
 
+            for (var interestRateChange : loanApplicationTerms.getLoanTermVariations().getInterestRateFromInstallment()) {
+                final LocalDate interestRateChangeEffectiveDate = interestRateChange.getTermVariationApplicableFrom().minusDays(1);
+                final BigDecimal newInterestRate = interestRateChange.getDecimalValue();
+                if (interestRateChangeEffectiveDate.isAfter(repaymentPeriod.getFromDate())
+                        && !interestRateChangeEffectiveDate.isAfter(repaymentPeriod.getDueDate())) {
+                    emiCalculator.changeInterestRate(interestScheduleModel, interestRateChangeEffectiveDate, newInterestRate);
+                }
+            }
+
             emiCalculator.findInterestRepaymentPeriod(interestScheduleModel, repaymentPeriod.getDueDate())
                     .ifPresent(interestRepaymentPeriod -> {
                         final Money principalDue = interestRepaymentPeriod.getPrincipalDue();

fineract-progressive-loan/src/main/java/org/apache/fineract/portfolio/loanproduct/calc/EMICalculator.java

@@ -18,6 +18,7 @@
  */
 package org.apache.fineract.portfolio.loanproduct.calc;
 
+import java.math.BigDecimal;
 import java.math.MathContext;
 import java.time.LocalDate;
 import java.util.List;
@@ -42,6 +43,9 @@ Optional<ProgressiveLoanInterestRepaymentModel> findInterestRepaymentPeriod(Prog
 
     void addDisbursement(ProgressiveLoanInterestScheduleModel scheduleModel, LocalDate disbursementDueDate, Money disbursedAmount);
 
+    void changeInterestRate(ProgressiveLoanInterestScheduleModel scheduleModel, LocalDate newInterestEffectiveDate,
+            BigDecimal newInterestRate);
+
     ProgressiveLoanInterestScheduleModel makeScheduleModelDeepCopy(ProgressiveLoanInterestScheduleModel scheduleModel);
 
     ProgressiveLoanInterestScheduleModel makeScheduleModelDeepCopy(ProgressiveLoanInterestScheduleModel scheduleModel,

fineract-progressive-loan/src/main/java/org/apache/fineract/portfolio/loanproduct/calc/ProgressiveEMICalculator.java

@@ -97,6 +97,27 @@ Optional<ProgressiveLoanInterestRepaymentInterestPeriod> findInterestPeriodForDi
                 .findFirst();
     }
 
+    Optional<ProgressiveLoanInterestRepaymentInterestPeriod> findInterestPeriodForInterestChange(
+            final ProgressiveLoanInterestRepaymentModel repaymentPeriod, final LocalDate interestRateChangeEffectiveDate) {
+        if (repaymentPeriod == null || interestRateChangeEffectiveDate == null) {
+            return Optional.empty();
+        }
+        return repaymentPeriod.getInterestPeriods().stream()//
+                .filter(interestPeriod -> interestRateChangeEffectiveDate.isEqual(interestPeriod.getFromDate()))//
+                .findFirst();
+    }
+
+    Optional<ProgressiveLoanInterestRepaymentModel> findInterestRepaymentPeriodForInterestChange(
+            final ProgressiveLoanInterestScheduleModel scheduleModel, final LocalDate interestChangeEffectiveDate) {
+        if (scheduleModel == null || interestChangeEffectiveDate == null) {
+            return Optional.empty();
+        }
+        return scheduleModel.repayments().stream()//
+                .filter(repaymentPeriod -> !interestChangeEffectiveDate.isBefore(repaymentPeriod.getFromDate())
+                        && interestChangeEffectiveDate.isBefore(repaymentPeriod.getDueDate()))//
+                .findFirst();
+    }
+
     /**
      * Add disbursement to Interest Period
      */
@@ -154,6 +175,42 @@ public ProgressiveLoanInterestScheduleModel makeScheduleModelDeepCopy(final Prog
         return new ProgressiveLoanInterestScheduleModel(repayments, loanProductRelatedDetail, installmentAmountInMultiplesOf, mc);
     }
 
+    @Override
+    public void changeInterestRate(final ProgressiveLoanInterestScheduleModel scheduleModel, LocalDate newInterestEffectiveDate,
+            final BigDecimal newInterestRate) {
+        final ProgressiveLoanInterestRepaymentModel repaymentPeriod = findInterestRepaymentPeriodForInterestChange(scheduleModel,
+                newInterestEffectiveDate).orElse(null);
+        if (repaymentPeriod == null) {
+            return;
+        }
+        scheduleModel.addInterestRate(newInterestEffectiveDate, newInterestRate);
+        var interestPeriodOptional = findInterestPeriodForInterestChange(repaymentPeriod, newInterestEffectiveDate);
+        if (interestPeriodOptional.isEmpty()) {
+            insertInterestPeriod(scheduleModel, repaymentPeriod, newInterestEffectiveDate);
+        }
+
+        calculateEMIValueAndRateFactors(repaymentPeriod.getDueDate(), scheduleModel);
+    }
+
+    void insertInterestPeriod(final ProgressiveLoanInterestScheduleModel scheduleModel,
+            final ProgressiveLoanInterestRepaymentModel repaymentPeriod, final LocalDate interestChangeDueDate) {
+        // period start date
+        final ProgressiveLoanInterestRepaymentInterestPeriod previousInterestPeriod = repaymentPeriod.getInterestPeriods().stream()
+                .filter(interestPeriod -> interestChangeDueDate.isAfter(interestPeriod.getFromDate())
+                        && interestChangeDueDate.isBefore(interestPeriod.getDueDate()))//
+                .findFirst()//
+                .get();//
+
+        final Money zeroAmount = Money.zero(scheduleModel.loanProductRelatedDetail().getCurrency());
+        final var interestPeriod = new ProgressiveLoanInterestRepaymentInterestPeriod(interestChangeDueDate,
+                previousInterestPeriod.getDueDate(), BigDecimal.ZERO, zeroAmount, zeroAmount);
+
+        previousInterestPeriod.setDueDate(interestChangeDueDate);
+
+        repaymentPeriod.getInterestPeriods().add(interestPeriod);
+        Collections.sort(repaymentPeriod.getInterestPeriods());
+    }
+
     /**
      * Calculate Equal Monthly Installment value and Rate Factor -1 values for calculate Interest
      */
@@ -259,7 +316,7 @@ BigDecimal calculateRateFactorMinus1PerPeriod(final ProgressiveLoanInterestRepay
             final ProgressiveLoanInterestRepaymentInterestPeriod interestPeriod, final ProgressiveLoanInterestScheduleModel scheduleModel) {
         final MathContext mc = scheduleModel.mc();
         final LoanProductRelatedDetail loanProductRelatedDetail = scheduleModel.loanProductRelatedDetail();
-        final BigDecimal interestRate = calcNominalInterestRatePercentage(loanProductRelatedDetail.getNominalInterestRatePerPeriod(), mc);
+        final BigDecimal interestRate = calcNominalInterestRatePercentage(scheduleModel.getInterestRate(interestPeriod.getFromDate()), mc);
         final DaysInYearType daysInYearType = DaysInYearType.fromInt(loanProductRelatedDetail.getDaysInYearType());
         final DaysInMonthType daysInMonthType = DaysInMonthType.fromInt(loanProductRelatedDetail.getDaysInMonthType());
         final PeriodFrequencyType repaymentFrequency = loanProductRelatedDetail.getRepaymentPeriodFrequencyType();

fineract-progressive-loan/src/test/java/org/apache/fineract/portfolio/loanproduct/calc/ProgressiveEMICalculatorTest.java

@@ -25,6 +25,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import org.apache.fineract.infrastructure.core.service.DateUtils;
+import org.apache.fineract.infrastructure.core.service.ThreadLocalContextUtil;
 import org.apache.fineract.organisation.monetary.domain.ApplicationCurrency;
 import org.apache.fineract.organisation.monetary.domain.MonetaryCurrency;
 import org.apache.fineract.organisation.monetary.domain.Money;
@@ -50,6 +51,7 @@ class ProgressiveEMICalculatorTest {
 
     private static final ProgressiveEMICalculator emiCalculator = new ProgressiveEMICalculator(null);
 
+    private static MockedStatic<ThreadLocalContextUtil> threadLocalContextUtil = Mockito.mockStatic(ThreadLocalContextUtil.class);
     private static MockedStatic<MoneyHelper> moneyHelper = Mockito.mockStatic(MoneyHelper.class);
     private static LoanProductRelatedDetail loanProductRelatedDetail = Mockito.mock(LoanProductRelatedDetail.class);
 
@@ -241,6 +243,95 @@ public void testEMICalculation_disbursedAmt100_dayInYears360_daysInMonth30_repay
         checkPeriod(interestSchedule, 5, 0, 17.13, 0.007901833333, 0.13, 17.00, 0.0);
     }
 
+    @Test
+    public void testEMICalculation_disbursedAmt100_dayInYears360_daysInMonth30_repayEvery1Month_reschedule_interest_on0201_4per() {
+        final MathContext mc = MoneyHelper.getMathContext();
+        final List<LoanScheduleModelRepaymentPeriod> expectedRepaymentPeriods = new ArrayList<>();
+
+        expectedRepaymentPeriods.add(repayment(1, LocalDate.of(2024, 1, 1), LocalDate.of(2024, 2, 1)));
+        expectedRepaymentPeriods.add(repayment(2, LocalDate.of(2024, 2, 1), LocalDate.of(2024, 3, 1)));
+        expectedRepaymentPeriods.add(repayment(3, LocalDate.of(2024, 3, 1), LocalDate.of(2024, 4, 1)));
+        expectedRepaymentPeriods.add(repayment(4, LocalDate.of(2024, 4, 1), LocalDate.of(2024, 5, 1)));
+        expectedRepaymentPeriods.add(repayment(5, LocalDate.of(2024, 5, 1), LocalDate.of(2024, 6, 1)));
+        expectedRepaymentPeriods.add(repayment(6, LocalDate.of(2024, 6, 1), LocalDate.of(2024, 7, 1)));
+
+        final BigDecimal interestRate = new BigDecimal("7");
+        final Integer installmentAmountInMultiplesOf = null;
+
+        Mockito.when(loanProductRelatedDetail.getNominalInterestRatePerPeriod()).thenReturn(interestRate);
+        Mockito.when(loanProductRelatedDetail.getDaysInYearType()).thenReturn(DaysInYearType.DAYS_360.getValue());
+        Mockito.when(loanProductRelatedDetail.getDaysInMonthType()).thenReturn(DaysInMonthType.DAYS_30.getValue());
+        Mockito.when(loanProductRelatedDetail.getRepaymentPeriodFrequencyType()).thenReturn(PeriodFrequencyType.MONTHS);
+        Mockito.when(loanProductRelatedDetail.getRepayEvery()).thenReturn(1);
+        Mockito.when(loanProductRelatedDetail.getCurrency()).thenReturn(monetaryCurrency);
+
+        threadLocalContextUtil.when(ThreadLocalContextUtil::getBusinessDate).thenReturn(LocalDate.of(2024, 2, 14));
+
+        final ProgressiveLoanInterestScheduleModel interestSchedule = emiCalculator.generateInterestScheduleModel(expectedRepaymentPeriods,
+                loanProductRelatedDetail, installmentAmountInMultiplesOf, mc);
+
+        final Money disbursedAmount = Money.of(monetaryCurrency, BigDecimal.valueOf(100));
+        emiCalculator.addDisbursement(interestSchedule, LocalDate.of(2024, 1, 1), disbursedAmount);
+
+        final BigDecimal interestRateNewValue = new BigDecimal("4");
+        final LocalDate interestChangeDate = LocalDate.of(2024, 2, 2);
+        final LocalDate interestEffectiveDate = interestChangeDate.minusDays(1);
+        emiCalculator.changeInterestRate(interestSchedule, interestEffectiveDate, interestRateNewValue);
+
+        checkDisbursementOnPeriod(interestSchedule, 0, disbursedAmount);
+        checkPeriod(interestSchedule, 0, 0, 17.01, 0.005833333333, 0.58, 16.43, 83.57);
+        checkPeriod(interestSchedule, 1, 0, 16.88, 0.003333333333, 0.28, 16.60, 66.97);
+        checkPeriod(interestSchedule, 2, 0, 16.88, 0.003333333333, 0.22, 16.66, 50.31);
+        checkPeriod(interestSchedule, 3, 0, 16.88, 0.003333333333, 0.17, 16.71, 33.60);
+        checkPeriod(interestSchedule, 4, 0, 16.88, 0.003333333333, 0.11, 16.77, 16.83);
+        checkPeriod(interestSchedule, 5, 0, 16.89, 0.003333333333, 0.06, 16.83, 0.0);
+    }
+
+    @Test
+    public void testEMICalculation_disbursedAmt100_dayInYears360_daysInMonth30_repayEvery1Month_reschedule_interest_on0215_4per() {
+        final MathContext mc = MoneyHelper.getMathContext();
+        final List<LoanScheduleModelRepaymentPeriod> expectedRepaymentPeriods = new ArrayList<>();
+
+        expectedRepaymentPeriods.add(repayment(1, LocalDate.of(2024, 1, 1), LocalDate.of(2024, 2, 1)));
+        expectedRepaymentPeriods.add(repayment(2, LocalDate.of(2024, 2, 1), LocalDate.of(2024, 3, 1)));
+        expectedRepaymentPeriods.add(repayment(3, LocalDate.of(2024, 3, 1), LocalDate.of(2024, 4, 1)));
+        expectedRepaymentPeriods.add(repayment(4, LocalDate.of(2024, 4, 1), LocalDate.of(2024, 5, 1)));
+        expectedRepaymentPeriods.add(repayment(5, LocalDate.of(2024, 5, 1), LocalDate.of(2024, 6, 1)));
+        expectedRepaymentPeriods.add(repayment(6, LocalDate.of(2024, 6, 1), LocalDate.of(2024, 7, 1)));
+
+        final BigDecimal interestRate = new BigDecimal("7");
+        final Integer installmentAmountInMultiplesOf = null;
+
+        Mockito.when(loanProductRelatedDetail.getNominalInterestRatePerPeriod()).thenReturn(interestRate);
+        Mockito.when(loanProductRelatedDetail.getDaysInYearType()).thenReturn(DaysInYearType.DAYS_360.getValue());
+        Mockito.when(loanProductRelatedDetail.getDaysInMonthType()).thenReturn(DaysInMonthType.DAYS_30.getValue());
+        Mockito.when(loanProductRelatedDetail.getRepaymentPeriodFrequencyType()).thenReturn(PeriodFrequencyType.MONTHS);
+        Mockito.when(loanProductRelatedDetail.getRepayEvery()).thenReturn(1);
+        Mockito.when(loanProductRelatedDetail.getCurrency()).thenReturn(monetaryCurrency);
+
+        threadLocalContextUtil.when(ThreadLocalContextUtil::getBusinessDate).thenReturn(LocalDate.of(2024, 2, 14));
+
+        final ProgressiveLoanInterestScheduleModel interestSchedule = emiCalculator.generateInterestScheduleModel(expectedRepaymentPeriods,
+                loanProductRelatedDetail, installmentAmountInMultiplesOf, mc);
+
+        final Money disbursedAmount = Money.of(monetaryCurrency, BigDecimal.valueOf(100));
+        emiCalculator.addDisbursement(interestSchedule, LocalDate.of(2024, 1, 1), disbursedAmount);
+
+        final BigDecimal interestRateNewValue = new BigDecimal("4");
+        final LocalDate interestChangeDate = LocalDate.of(2024, 2, 15);
+        final LocalDate interestEffectiveDate = interestChangeDate.minusDays(1);
+        emiCalculator.changeInterestRate(interestSchedule, interestEffectiveDate, interestRateNewValue);
+
+        checkDisbursementOnPeriod(interestSchedule, 0, disbursedAmount);
+        checkPeriod(interestSchedule, 0, 0, 17.01, 0.005833333333, 0.58, 16.43, 83.57);
+        checkPeriod(interestSchedule, 1, 0, 16.90, 0.002614942529, 0.22, 0.37, 16.53, 67.04);
+        checkPeriod(interestSchedule, 1, 1, 16.90, 0.001839080460, 0.15, 0.37, 16.53, 67.04);
+        checkPeriod(interestSchedule, 2, 0, 16.90, 0.003333333333, 0.22, 16.68, 50.36);
+        checkPeriod(interestSchedule, 3, 0, 16.90, 0.003333333333, 0.17, 16.73, 33.63);
+        checkPeriod(interestSchedule, 4, 0, 16.90, 0.003333333333, 0.11, 16.79, 16.84);
+        checkPeriod(interestSchedule, 5, 0, 16.90, 0.003333333333, 0.06, 16.84, 0.0);
+    }
+
     // @Test
     // public void testEMICalculation_disbursedAmt100_dayInYearsActual_daysInMonthActual_repayEvery1Month_reschedule() {
     // final MathContext mc = MoneyHelper.getMathContext();