FINERACT-2326: add installment amount in multiples of handling to flat interest emi calculation

fineract-e2e-tests-core/src/test/java/org/apache/fineract/test/initializer/global/LoanProductGlobalInitializerStep.java

@@ -3168,6 +3168,7 @@ public class LoanProductGlobalInitializerStep implements FineractGlobalInitializ
                 .daysInMonthType(DaysInMonthType.DAYS30.value)//
                 .enableDownPayment(false)//
                 .enableAutoRepaymentForDownPayment(null)//
+                .installmentAmountInMultiplesOf(null)//
                 .disbursedAmountPercentageForDownPayment(null)//
                 .multiDisburseLoan(true)//
                 .disallowExpectedDisbursements(true)//
@@ -3197,6 +3198,7 @@ public class LoanProductGlobalInitializerStep implements FineractGlobalInitializ
                 .recalculationRestFrequencyType(RecalculationRestFrequencyType.SAME_AS_REPAYMENT.value)//
                 .enableDownPayment(false)//
                 .enableAutoRepaymentForDownPayment(null)//
+                .installmentAmountInMultiplesOf(null)//
                 .disbursedAmountPercentageForDownPayment(null)//
                 .multiDisburseLoan(true)//
                 .disallowExpectedDisbursements(true)//
@@ -3230,6 +3232,7 @@ public class LoanProductGlobalInitializerStep implements FineractGlobalInitializ
                 .recalculationRestFrequencyType(RecalculationRestFrequencyType.SAME_AS_REPAYMENT.value)//
                 .enableDownPayment(false)//
                 .enableAutoRepaymentForDownPayment(null)//
+                .installmentAmountInMultiplesOf(null)//
                 .disbursedAmountPercentageForDownPayment(null)//
                 .multiDisburseLoan(true)//
                 .disallowExpectedDisbursements(true)//
@@ -3259,6 +3262,7 @@ public class LoanProductGlobalInitializerStep implements FineractGlobalInitializ
                 .loanScheduleProcessingType("HORIZONTAL")//
                 .enableDownPayment(false)//
                 .enableAutoRepaymentForDownPayment(null)//
+                .installmentAmountInMultiplesOf(null)//
                 .disbursedAmountPercentageForDownPayment(null)//
                 .multiDisburseLoan(true)//
                 .disallowExpectedDisbursements(true)//

fineract-e2e-tests-runner/src/test/resources/features/LoanRepayment.feature

@@ -3204,8 +3204,6 @@ Feature: LoanRepayment
       | Principal due | Interest | Fees | Penalties | Due    | Paid | In advance | Late | Outstanding |
       | 1000.0        | 0        | 0    | 0         | 1000.0 | 0.0  | 0          | 0    | 1000        |
 
-  # TODO fix progressive interest mode FLAT does not respect in multiples of
-  @Skip
   @TestRailId:C3129 @AdvancedPaymentAllocation
   Scenario: Verify installment due date logic for monthly installments - last day of the month
     When Admin sets the business date to "31 January 2024"
@@ -3249,8 +3247,6 @@ Feature: LoanRepayment
       | Principal due | Interest | Fees | Penalties | Due    | Paid  | In advance | Late | Outstanding |
       | 1000.0        | 0.0      | 0.0  | 0.0       | 1000.0 | 250.0 | 0.0        | 0.0  | 750.0       |
 
-  # TODO fix progressive interest mode FLAT does not respect in multiples of
-  @Skip
   @TestRailId:C3130 @AdvancedPaymentAllocation
   Scenario: Verify installment due date logic for monthly installments - last day of the month, expected and real disbursement dates are different
     When Admin sets the business date to "30 January 2024"
@@ -3295,8 +3291,6 @@ Feature: LoanRepayment
       | Principal due | Interest | Fees | Penalties | Due    | Paid  | In advance | Late | Outstanding |
       | 1000.0        | 0.0      | 0.0  | 0.0       | 1000.0 | 250.0 | 0.0        | 0.0  | 750.0       |
 
-  # TODO fix progressive interest mode FLAT does not respect in multiples of
-  @Skip
   @TestRailId:C3131 @AdvancedPaymentAllocation
   Scenario: Verify installment due date logic for monthly installments - last day of the month, repayment start calculated from Submitted on date - submit, approve, disburse on same date
     When Admin sets the business date to "31 January 2024"
@@ -3340,8 +3334,6 @@ Feature: LoanRepayment
       | Principal due | Interest | Fees | Penalties | Due    | Paid  | In advance | Late | Outstanding |
       | 1000.0        | 0.0      | 0.0  | 0.0       | 1000.0 | 250.0 | 0.0        | 0.0  | 750.0       |
 
-  # TODO fix progressive interest mode FLAT does not respect in multiples of
-  @Skip
   @TestRailId:C3132 @AdvancedPaymentAllocation
   Scenario: Verify installment due date logic for monthly installments - last day of the month, repayment start calculated from Submitted on date - submit and approve on same date, disburse on next day
     When Admin sets the business date to "31 January 2024"
@@ -3386,8 +3378,6 @@ Feature: LoanRepayment
       | Principal due | Interest | Fees | Penalties | Due    | Paid  | In advance | Late | Outstanding |
       | 1000.0        | 0.0      | 0.0  | 0.0       | 1000.0 | 250.0 | 0.0        | 0.0  | 750.0       |
 
-  # TODO fix progressive interest mode FLAT does not respect in multiples of
-  @Skip
   @TestRailId:C3133 @AdvancedPaymentAllocation
   Scenario: Verify installment due date logic for monthly installments - last day of the month, repayment start calculated from Submitted on date - submit and approve on same date, expected disbursement date on next day
     When Admin sets the business date to "31 January 2024"

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

@@ -926,10 +926,11 @@ public final class ProgressiveEMICalculator implements EMICalculator {
                 .plus(sumOfInterest).minus(alreadyRepaidPrincipals);
 
         Money periodEmi = total.dividedBy(repaymentPeriods.size(), mc);
-        Money remainder = total.minus(periodEmi.multipliedBy(repaymentPeriods.size(), mc));
+        Money periodEmiInMultiplesOf = applyInstallmentAmountInMultiplesOf(scheduleModel, periodEmi);
+        Money remainder = total.minus(periodEmiInMultiplesOf.multipliedBy(repaymentPeriods.size(), mc));
 
         repaymentPeriods.forEach(rp -> {
-            Money emi = rp.equals(last) ? periodEmi.add(remainder) : periodEmi;
+            Money emi = rp.equals(last) ? periodEmiInMultiplesOf.add(remainder) : periodEmiInMultiplesOf;
             rp.setEmi(emi);
             rp.setOriginalEmi(emi);
             rp.getInterestPeriods().forEach(InterestPeriod::updateOutstandingLoanBalance);