FINERACT-1981: Fix interest calculation when applies multi disbursement

2025-01-20 13:39:09 +01:00
parent 6e6ac8ffd6
commit 8ab9c9ea9a
6 changed files with 249 additions and 107 deletions
@@ -26,9 +26,12 @@ import java.math.MathContext;
 import java.time.LocalDate;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Optional;
 import java.util.TreeSet;
+import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import lombok.Data;
 import lombok.experimental.Accessors;
@@ -62,7 +65,8 @@ public class ProgressiveLoanInterestScheduleModel {
            final LoanProductMinimumRepaymentScheduleRelatedDetail loanProductRelatedDetail, final Integer installmentAmountInMultiplesOf,
            final MathContext mc) {
        this.mc = mc;
-        this.repaymentPeriods = copyRepaymentPeriods(repaymentPeriods);
+        this.repaymentPeriods = copyRepaymentPeriods(repaymentPeriods,
+                (previousPeriod, repaymentPeriod) -> new RepaymentPeriod(previousPeriod, repaymentPeriod, mc));
        this.interestRates = new TreeSet<>(interestRates);
        this.loanProductRelatedDetail = loanProductRelatedDetail;
        this.installmentAmountInMultiplesOf = installmentAmountInMultiplesOf;
@@ -74,11 +78,20 @@ public class ProgressiveLoanInterestScheduleModel {
                installmentAmountInMultiplesOf, mc);
    }

-    private List<RepaymentPeriod> copyRepaymentPeriods(final List<RepaymentPeriod> repaymentPeriods) {
+    public ProgressiveLoanInterestScheduleModel emptyCopy() {
+        final List<RepaymentPeriod> repaymentPeriodCopies = copyRepaymentPeriods(repaymentPeriods,
+                (previousPeriod, repaymentPeriod) -> new RepaymentPeriod(previousPeriod, repaymentPeriod.getFromDate(),
+                        repaymentPeriod.getDueDate(), repaymentPeriod.getEmi().zero(), mc));
+        return new ProgressiveLoanInterestScheduleModel(repaymentPeriodCopies, interestRates, loanProductRelatedDetail,
+                installmentAmountInMultiplesOf, mc);
+    }
+
+    private List<RepaymentPeriod> copyRepaymentPeriods(final List<RepaymentPeriod> repaymentPeriods,
+            final BiFunction<RepaymentPeriod, RepaymentPeriod, RepaymentPeriod> repaymentCopyFunction) {
        final List<RepaymentPeriod> repaymentCopies = new ArrayList<>(repaymentPeriods.size());
        RepaymentPeriod previousPeriod = null;
        for (RepaymentPeriod repaymentPeriod : repaymentPeriods) {
-            RepaymentPeriod currentPeriod = new RepaymentPeriod(previousPeriod, repaymentPeriod, mc);
+            RepaymentPeriod currentPeriod = repaymentCopyFunction.apply(previousPeriod, repaymentPeriod);
            previousPeriod = currentPeriod;
            repaymentCopies.add(currentPeriod);
        }
@@ -229,4 +242,40 @@ public class ProgressiveLoanInterestScheduleModel {
                .filter(period -> isInPeriod(transactionDate, period.getFromDate(), period.getDueDate(), period.isFirstRepaymentPeriod()))//
                .findFirst();
    }
+
+    public boolean isEmpty() {
+        return repaymentPeriods.stream() //
+                .filter(rp -> !rp.getEmi().isZero()) //
+                .findFirst() //
+                .isEmpty(); //
+    }
+
+    /**
+     * This method gives you repayment pairs to copy attributes.
+     *
+     * @param periodFromDueDate
+     *            Copy from this due periods.
+     * @param copyFromPeriods
+     *            Copy source
+     * @param copyConsumer
+     *            Consumer to copy attributes. Params: (from, to)
+     */
+    public void copyPeriodsFrom(final LocalDate periodFromDueDate, List<RepaymentPeriod> copyFromPeriods,
+            BiConsumer<RepaymentPeriod, RepaymentPeriod> copyConsumer) {
+        if (copyFromPeriods.isEmpty()) {
+            return;
+        }
+        final Iterator<RepaymentPeriod> actualIterator = repaymentPeriods.iterator();
+        final Iterator<RepaymentPeriod> copyFromIterator = copyFromPeriods.iterator();
+        while (actualIterator.hasNext()) {
+            final RepaymentPeriod copyFromPeriod = copyFromIterator.next();
+            RepaymentPeriod actualPeriod = actualIterator.next();
+            while (actualIterator.hasNext() && !copyFromPeriod.getDueDate().isEqual(actualPeriod.getDueDate())) {
+                actualPeriod = actualIterator.next();
+            }
+            if (!actualPeriod.getDueDate().isBefore(periodFromDueDate)) {
+                copyConsumer.accept(copyFromPeriod, actualPeriod);
+            }
+        }
+    }
 }
@@ -0,0 +1,49 @@
+/**
+ * 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.loanproduct.calc;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import org.apache.fineract.organisation.monetary.domain.Money;
+
+@Getter
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+public class EmiChangeOperation {
+
+    public enum Action {
+        DISBURSEMENT, INTEREST_RATE_CHANGE
+    }
+
+    private final Action action;
+    private final LocalDate submittedOnDate;
+
+    private final Money amount;
+    private final BigDecimal interestRate;
+
+    public static EmiChangeOperation disburse(final LocalDate disbursementDueDate, final Money disbursedAmount) {
+        return new EmiChangeOperation(EmiChangeOperation.Action.DISBURSEMENT, disbursementDueDate, disbursedAmount, null);
+    }
+
+    public static EmiChangeOperation changeInterestRate(final LocalDate newInterestSubmittedOnDate, final BigDecimal newInterestRate) {
+        return new EmiChangeOperation(EmiChangeOperation.Action.INTEREST_RATE_CHANGE, newInterestSubmittedOnDate, null, newInterestRate);
+    }
+}
@@ -102,9 +102,16 @@ public final class ProgressiveEMICalculator implements EMICalculator {
    @Override
    public void addDisbursement(final ProgressiveLoanInterestScheduleModel scheduleModel, final LocalDate disbursementDueDate,
            final Money disbursedAmount) {
-        scheduleModel.changeOutstandingBalanceAndUpdateInterestPeriods(disbursementDueDate, disbursedAmount, scheduleModel.zero())
+        addDisbursement(scheduleModel, EmiChangeOperation.disburse(disbursementDueDate, disbursedAmount));
+    }
+
+    private void addDisbursement(final ProgressiveLoanInterestScheduleModel scheduleModel, final EmiChangeOperation operation) {
+        scheduleModel
+                .changeOutstandingBalanceAndUpdateInterestPeriods(operation.getSubmittedOnDate(), operation.getAmount(),
+                        scheduleModel.zero())
                .ifPresent((repaymentPeriod) -> calculateEMIValueAndRateFactors(
-                        getEffectiveRepaymentDueDate(scheduleModel, repaymentPeriod, disbursementDueDate), scheduleModel));
+                        getEffectiveRepaymentDueDate(scheduleModel, repaymentPeriod, operation.getSubmittedOnDate()), scheduleModel,
+                        operation));
    }

    private LocalDate getEffectiveRepaymentDueDate(final ProgressiveLoanInterestScheduleModel scheduleModel,
@@ -125,13 +132,18 @@ public final class ProgressiveEMICalculator implements EMICalculator {
    @Override
    public void changeInterestRate(final ProgressiveLoanInterestScheduleModel scheduleModel, final LocalDate newInterestSubmittedOnDate,
            final BigDecimal newInterestRate) {
-        final LocalDate interestRateChangeEffectiveDate = newInterestSubmittedOnDate.minusDays(1);
-        scheduleModel.addInterestRate(interestRateChangeEffectiveDate, newInterestRate);
+        changeInterestRate(scheduleModel, EmiChangeOperation.changeInterestRate(newInterestSubmittedOnDate, newInterestRate));
+    }
+
+    private void changeInterestRate(final ProgressiveLoanInterestScheduleModel scheduleModel, final EmiChangeOperation operation) {
+        final LocalDate interestRateChangeEffectiveDate = operation.getSubmittedOnDate().minusDays(1);
+        scheduleModel.addInterestRate(interestRateChangeEffectiveDate, operation.getInterestRate());
        scheduleModel
                .changeOutstandingBalanceAndUpdateInterestPeriods(interestRateChangeEffectiveDate, scheduleModel.zero(),
                        scheduleModel.zero())
                .ifPresent(repaymentPeriod -> calculateEMIValueAndRateFactors(
-                        getEffectiveRepaymentDueDate(scheduleModel, repaymentPeriod, interestRateChangeEffectiveDate), scheduleModel));
+                        getEffectiveRepaymentDueDate(scheduleModel, repaymentPeriod, interestRateChangeEffectiveDate), scheduleModel,
+                        operation));
    }

    @Override
@@ -283,15 +295,24 @@ public final class ProgressiveEMICalculator implements EMICalculator {
    /**
     * Calculate Equal Monthly Installment value and Rate Factor -1 values for calculate Interest
     */
-    void calculateEMIValueAndRateFactors(final LocalDate calculateFromRepaymentPeriodDueDate,
-            final ProgressiveLoanInterestScheduleModel scheduleModel) {
+    private void calculateEMIValueAndRateFactors(final LocalDate calculateFromRepaymentPeriodDueDate,
+            final ProgressiveLoanInterestScheduleModel scheduleModel, final EmiChangeOperation operation) {
        final List<RepaymentPeriod> relatedRepaymentPeriods = scheduleModel.getRelatedRepaymentPeriods(calculateFromRepaymentPeriodDueDate);
+        final boolean onlyOnActualModelShouldApply = scheduleModel.isEmpty()
+                || operation.getAction() == EmiChangeOperation.Action.INTEREST_RATE_CHANGE;
+
        calculateRateFactorForPeriods(relatedRepaymentPeriods, scheduleModel);
        calculateOutstandingBalance(scheduleModel);
-        calculateEMIOnPeriods(relatedRepaymentPeriods, scheduleModel);
+        if (onlyOnActualModelShouldApply) {
+            calculateEMIOnActualModel(relatedRepaymentPeriods, scheduleModel);
+        } else {
+            calculateEMIOnNewEmptyModelAndMerge(relatedRepaymentPeriods, scheduleModel, operation);
+        }
        calculateOutstandingBalance(scheduleModel);
        calculateLastUnpaidRepaymentPeriodEMI(scheduleModel);
-        checkAndAdjustEmiIfNeededOnRelatedRepaymentPeriods(scheduleModel, relatedRepaymentPeriods);
+        if (onlyOnActualModelShouldApply) {
+            checkAndAdjustEmiIfNeededOnRelatedRepaymentPeriods(scheduleModel, relatedRepaymentPeriods);
+        }
    }

    private void calculateLastUnpaidRepaymentPeriodEMI(ProgressiveLoanInterestScheduleModel scheduleModel) {
@@ -378,19 +399,19 @@ public final class ProgressiveEMICalculator implements EMICalculator {
     *
     * @return Rate Interest Rate in fraction format
     */
-    BigDecimal calcNominalInterestRatePercentage(final BigDecimal interestRate, MathContext mc) {
+    private BigDecimal calcNominalInterestRatePercentage(final BigDecimal interestRate, MathContext mc) {
        return MathUtil.nullToZero(interestRate).divide(DIVISOR_100, mc);
    }

    /**
     * * Calculate rate factors from ONLY repayment periods
     */
-    void calculateRateFactorForPeriods(final List<RepaymentPeriod> repaymentPeriods,
+    private void calculateRateFactorForPeriods(final List<RepaymentPeriod> repaymentPeriods,
            final ProgressiveLoanInterestScheduleModel scheduleModel) {
        repaymentPeriods.forEach(repaymentPeriod -> calculateRateFactorForRepaymentPeriod(repaymentPeriod, scheduleModel));
    }

-    void calculateRateFactorForRepaymentPeriod(final RepaymentPeriod repaymentPeriod,
+    private void calculateRateFactorForRepaymentPeriod(final RepaymentPeriod repaymentPeriod,
            final ProgressiveLoanInterestScheduleModel scheduleModel) {
        repaymentPeriod.getInterestPeriods().forEach(interestPeriod -> {
            interestPeriod.setRateFactor(calculateRateFactorPerPeriod(scheduleModel, repaymentPeriod, interestPeriod.getFromDate(),
@@ -403,8 +424,8 @@ public final class ProgressiveEMICalculator implements EMICalculator {
    /**
     * Calculate Rate Factor for an exact Period
     */
-    BigDecimal calculateRateFactorPerPeriod(final ProgressiveLoanInterestScheduleModel scheduleModel, final RepaymentPeriod repaymentPeriod,
-            final LocalDate interestPeriodFromDate, final LocalDate interestPeriodDueDate) {
+    private BigDecimal calculateRateFactorPerPeriod(final ProgressiveLoanInterestScheduleModel scheduleModel,
+            final RepaymentPeriod repaymentPeriod, final LocalDate interestPeriodFromDate, final LocalDate interestPeriodDueDate) {
        final MathContext mc = scheduleModel.mc();
        final LoanProductMinimumRepaymentScheduleRelatedDetail loanProductRelatedDetail = scheduleModel.loanProductRelatedDetail();
        final BigDecimal interestRate = calcNominalInterestRatePercentage(scheduleModel.getInterestRate(interestPeriodFromDate),
@@ -443,7 +464,8 @@ public final class ProgressiveEMICalculator implements EMICalculator {
     * @param interestPeriodDueDate
     * @return
     */
-    BigDecimal calculatePeriodFractions(final LocalDate interestPeriodFromDate, final LocalDate interestPeriodDueDate, MathContext mc) {
+    private BigDecimal calculatePeriodFractions(final LocalDate interestPeriodFromDate, final LocalDate interestPeriodDueDate,
+            MathContext mc) {
        BigDecimal cumulatedRateFactor = BigDecimal.ZERO;
        int actualYear = interestPeriodFromDate.getYear();
        int endYear = interestPeriodDueDate.getYear();
@@ -473,7 +495,7 @@ public final class ProgressiveEMICalculator implements EMICalculator {
     * @param calculatedDaysInPeriod
     * @return
     */
-    BigDecimal calculateRateFactorPerPeriodBasedOnRepaymentFrequency(final BigDecimal interestRate,
+    private BigDecimal calculateRateFactorPerPeriodBasedOnRepaymentFrequency(final BigDecimal interestRate,
            final PeriodFrequencyType repaymentFrequency, final BigDecimal repaymentEvery, final BigDecimal daysInMonth,
            final BigDecimal daysInYear, final BigDecimal actualDaysInPeriod, final BigDecimal calculatedDaysInPeriod,
            final MathContext mc) {
@@ -488,7 +510,7 @@ public final class ProgressiveEMICalculator implements EMICalculator {
        };
    }

-    void calculateEMIOnPeriods(final List<RepaymentPeriod> repaymentPeriods, final ProgressiveLoanInterestScheduleModel scheduleModel) {
+    private void calculateEMIOnActualModel(List<RepaymentPeriod> repaymentPeriods, ProgressiveLoanInterestScheduleModel scheduleModel) {
        if (repaymentPeriods.isEmpty()) {
            return;
        }
@@ -496,7 +518,7 @@ public final class ProgressiveEMICalculator implements EMICalculator {
        final BigDecimal rateFactorN = MathUtil.stripTrailingZeros(calculateRateFactorPlus1N(repaymentPeriods, mc));
        final BigDecimal fnResult = MathUtil.stripTrailingZeros(calculateFnResult(repaymentPeriods, mc));
        final RepaymentPeriod startPeriod = repaymentPeriods.get(0);
-        // TODO: double check
+
        final Money outstandingBalance = startPeriod.getInitialBalanceForEmiRecalculation();

        final Money equalMonthlyInstallment = Money.of(outstandingBalance.getCurrencyData(),
@@ -511,7 +533,22 @@ public final class ProgressiveEMICalculator implements EMICalculator {
        });
    }

-    Money applyInstallmentAmountInMultiplesOf(final ProgressiveLoanInterestScheduleModel scheduleModel,
+    private void calculateEMIOnNewEmptyModelAndMerge(List<RepaymentPeriod> repaymentPeriods,
+            ProgressiveLoanInterestScheduleModel scheduleModel, final EmiChangeOperation operation) {
+        if (repaymentPeriods.isEmpty()) {
+            return;
+        }
+        final ProgressiveLoanInterestScheduleModel scheduleModelCopy = scheduleModel.emptyCopy();
+        addDisbursement(scheduleModelCopy, operation);
+
+        final LocalDate firstDueDate = repaymentPeriods.get(0).getDueDate();
+        scheduleModel.copyPeriodsFrom(firstDueDate, scheduleModelCopy.repaymentPeriods(), (newRepaymentPeriod, actualRepaymentPeriod) -> {
+            actualRepaymentPeriod.setEmi(actualRepaymentPeriod.getEmi().plus(newRepaymentPeriod.getEmi()));
+            actualRepaymentPeriod.setOriginalEmi(actualRepaymentPeriod.getOriginalEmi().plus(newRepaymentPeriod.getOriginalEmi()));
+        });
+    }
+
+    private Money applyInstallmentAmountInMultiplesOf(final ProgressiveLoanInterestScheduleModel scheduleModel,
            final Money equalMonthlyInstallment) {
        return scheduleModel.installmentAmountInMultiplesOf() != null
                ? Money.roundToMultiplesOf(equalMonthlyInstallment, scheduleModel.installmentAmountInMultiplesOf())
@@ -534,7 +571,7 @@ public final class ProgressiveEMICalculator implements EMICalculator {
    /**
     * Calculate Rate Factor Product from rate factors
     */
-    BigDecimal calculateRateFactorPlus1N(final List<RepaymentPeriod> periods, MathContext mc) {
+    private BigDecimal calculateRateFactorPlus1N(final List<RepaymentPeriod> periods, MathContext mc) {
        return periods.stream().map(RepaymentPeriod::getRateFactorPlus1).reduce(BigDecimal.ONE,
                (BigDecimal acc, BigDecimal value) -> acc.multiply(value, mc));
    }
@@ -542,7 +579,7 @@ public final class ProgressiveEMICalculator implements EMICalculator {
    /**
     * Summarize Fn values
     */
-    BigDecimal calculateFnResult(final List<RepaymentPeriod> periods, final MathContext mc) {
+    private BigDecimal calculateFnResult(final List<RepaymentPeriod> periods, final MathContext mc) {
        return periods.stream()//
                .skip(1)//
                .map(RepaymentPeriod::getRateFactorPlus1)//
@@ -552,8 +589,8 @@ public final class ProgressiveEMICalculator implements EMICalculator {
    /**
     * Calculate the EMI (Equal Monthly Installment) value
     */
-    BigDecimal calculateEMIValue(final BigDecimal rateFactorPlus1N, final BigDecimal outstandingBalanceForRest, final BigDecimal fnResult,
-            MathContext mc) {
+    private BigDecimal calculateEMIValue(final BigDecimal rateFactorPlus1N, final BigDecimal outstandingBalanceForRest,
+            final BigDecimal fnResult, MathContext mc) {
        return rateFactorPlus1N.multiply(outstandingBalanceForRest, mc).divide(fnResult, mc);
    }

@@ -581,8 +618,8 @@ public final class ProgressiveEMICalculator implements EMICalculator {
     *
     * @return Rate Factor for period
     */
-    BigDecimal rateFactorByRepaymentEveryDay(final BigDecimal interestRate, final BigDecimal repaymentEvery, final BigDecimal daysInYear,
-            final BigDecimal actualDaysInPeriod, final BigDecimal calculatedDaysInPeriod, MathContext mc) {
+    private BigDecimal rateFactorByRepaymentEveryDay(final BigDecimal interestRate, final BigDecimal repaymentEvery,
+            final BigDecimal daysInYear, final BigDecimal actualDaysInPeriod, final BigDecimal calculatedDaysInPeriod, MathContext mc) {
        return rateFactorByRepaymentPeriod(interestRate, BigDecimal.ONE, repaymentEvery, daysInYear, actualDaysInPeriod,
                calculatedDaysInPeriod, mc);
    }
@@ -611,8 +648,8 @@ public final class ProgressiveEMICalculator implements EMICalculator {
     *
     * @return Rate Factor for period
     */
-    BigDecimal rateFactorByRepaymentEveryWeek(final BigDecimal interestRate, final BigDecimal repaymentEvery, final BigDecimal daysInYear,
-            final BigDecimal actualDaysInPeriod, final BigDecimal calculatedDaysInPeriod, MathContext mc) {
+    private BigDecimal rateFactorByRepaymentEveryWeek(final BigDecimal interestRate, final BigDecimal repaymentEvery,
+            final BigDecimal daysInYear, final BigDecimal actualDaysInPeriod, final BigDecimal calculatedDaysInPeriod, MathContext mc) {
        return rateFactorByRepaymentPeriod(interestRate, ONE_WEEK_IN_DAYS, repaymentEvery, daysInYear, actualDaysInPeriod,
                calculatedDaysInPeriod, mc);
    }
@@ -678,7 +715,7 @@ public final class ProgressiveEMICalculator implements EMICalculator {
     *
     * @return Rate Factor for period
     */
-    BigDecimal rateFactorByRepaymentPeriod(final BigDecimal interestRate, final BigDecimal repaymentPeriodMultiplierInDays,
+    private BigDecimal rateFactorByRepaymentPeriod(final BigDecimal interestRate, final BigDecimal repaymentPeriodMultiplierInDays,
            final BigDecimal repaymentEvery, final BigDecimal daysInYear, final BigDecimal actualDaysInPeriod,
            final BigDecimal calculatedDaysInPeriod, final MathContext mc) {
        if (MathUtil.isZero(calculatedDaysInPeriod)) {
@@ -697,7 +734,7 @@ public final class ProgressiveEMICalculator implements EMICalculator {
     * Calculate Rate Factor based on Partial Period
     *
     */
-    BigDecimal rateFactorByRepaymentPartialPeriod(final BigDecimal interestRate, final BigDecimal repaymentEvery,
+    private BigDecimal rateFactorByRepaymentPartialPeriod(final BigDecimal interestRate, final BigDecimal repaymentEvery,
            final BigDecimal cumulatedPeriodRatio, final BigDecimal actualDaysInPeriod, final BigDecimal calculatedDaysInPeriod,
            final MathContext mc) {
        if (MathUtil.isZero(calculatedDaysInPeriod)) {