FINERACT-2221: Fix - Interest not counted towards totalUnpaidPayableNotDueInterest after partial repayment

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

@@ -182,6 +182,16 @@ public class ProgressiveLoanScheduleGenerator implements LoanScheduleGenerator {
                 .principal(outstandingAmounts.getOutstandingPrincipal()) //
                 .interest(outstandingAmounts.getOutstandingInterest());//
 
+        // We need to deduct any paid amount if there is no interest recalculation
+        if (!loan.isInterestRecalculationEnabled()) {
+            BigDecimal paidInterest = installments.stream().map(LoanRepaymentScheduleInstallment::getInterestPaid).reduce(BigDecimal.ZERO,
+                    BigDecimal::add);
+            BigDecimal paidPrincipal = installments.stream().map(LoanRepaymentScheduleInstallment::getPrincipal).reduce(BigDecimal.ZERO,
+                    BigDecimal::add);
+            result.principal().minus(paidPrincipal);
+            result.interest().minus(paidInterest);
+        }
+
         installments.forEach(installment -> {
             if (installment.isAdditional()) {
                 result.plusPrincipal(installment.getPrincipalOutstanding(currency))

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

@@ -298,7 +298,7 @@ public class ProgressiveLoanInterestScheduleModel {
      * @return
      */
     public Money getTotalDueInterest() {
-        return repaymentPeriods().stream().map(RepaymentPeriod::getCalculatedDueInterest).reduce(zero(), Money::plus);
+        return repaymentPeriods().stream().map(RepaymentPeriod::getDueInterest).reduce(zero(), Money::plus);
     }
 
     /**

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

@@ -1302,10 +1302,9 @@ class ProgressiveEMICalculatorTest {
         final LocalDate dueDate = LocalDate.of(2024, 2, 1);
         final LocalDate startDay = LocalDate.of(2024, 1, 1);
 
-        // TODO: work on interest calculation
-        // emiCalculator.payInterest(interestModel, dueDate, startDay.plusDays(3), toMoney(0.56));
-        // emiCalculator.chargebackInterest(interestModel, startDay.plusDays(3), toMoney(0.0));
-        // emiCalculator.addBalanceCorrection(interestModel, startDay.plusDays(3), toMoney(0.0));
+        emiCalculator.payInterest(interestModel, dueDate, startDay.plusDays(3), toMoney(0.56));
+        emiCalculator.chargebackInterest(interestModel, startDay.plusDays(3), toMoney(0.0));
+        emiCalculator.addBalanceCorrection(interestModel, startDay.plusDays(3), toMoney(0.0));
 
         checkDailyInterest(interestModel, dueDate, startDay, 1, 0.19, 0.19);
         checkDailyInterest(interestModel, dueDate, startDay, 2, 0.19, 0.38);