FINERACT-2114: Interest rate modification

2024-08-22 13:37:02 +02:00
parent 80f4627623
commit 1286b1e72f
8 changed files with 227 additions and 9 deletions
@@ -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());
+    }
+}
@@ -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()) {
@@ -75,7 +75,6 @@ public class ProgressiveLoanScheduleGenerator implements LoanScheduleGenerator {
        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 class ProgressiveLoanScheduleGenerator implements LoanScheduleGenerator {
            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();
@@ -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 @@ public interface EMICalculator {

    void addDisbursement(ProgressiveLoanInterestScheduleModel scheduleModel, LocalDate disbursementDueDate, Money disbursedAmount);

+    void changeInterestRate(ProgressiveLoanInterestScheduleModel scheduleModel, LocalDate newInterestEffectiveDate,
+            BigDecimal newInterestRate);
+
    ProgressiveLoanInterestScheduleModel makeScheduleModelDeepCopy(ProgressiveLoanInterestScheduleModel scheduleModel);

    ProgressiveLoanInterestScheduleModel makeScheduleModelDeepCopy(ProgressiveLoanInterestScheduleModel scheduleModel,
@@ -97,6 +97,27 @@ public final class ProgressiveEMICalculator implements EMICalculator {
                .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 final class ProgressiveEMICalculator implements EMICalculator {
        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 @@ public final class ProgressiveEMICalculator implements EMICalculator {
            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();