FINERACT-1981: Fix down-payment handling on overpaid loan (Advanced payment allocation loan)

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

@@ -148,9 +148,14 @@ public class LoanTransaction extends AbstractAuditableWithUTCDateTimeCustom {
     }
 
     public static LoanTransaction disbursement(final Office office, final Money amount, final PaymentDetail paymentDetail,
-            final LocalDate disbursementDate, final ExternalId externalId) {
+            final LocalDate disbursementDate, final ExternalId externalId, final Money loanTotalOverpaid) {
-        return new LoanTransaction(null, office, LoanTransactionType.DISBURSEMENT, paymentDetail, amount.getAmount(), disbursementDate,
+        // We need to set the overpayment amount because it could happen the transaction got saved before the proper
-                externalId);
+        // portion calculation and side effect would be reverse-replay
+        Money overPaymentPortion = amount.isGreaterThan(loanTotalOverpaid) ? loanTotalOverpaid : amount;
+        LoanTransaction disbursement = new LoanTransaction(null, office, LoanTransactionType.DISBURSEMENT, paymentDetail,
+                amount.getAmount(), disbursementDate, externalId);
+        disbursement.setOverPayments(overPaymentPortion);
+        return disbursement;
     }
 
     public static LoanTransaction repayment(final Office office, final Money amount, final PaymentDetail paymentDetail,

fineract-provider/src/main/java/org/apache/fineract/portfolio/loanaccount/domain/DefaultLoanLifecycleStateMachine.java

@@ -82,7 +82,9 @@ public class DefaultLoanLifecycleStateMachine implements LoanLifecycleStateMachi
                 }
             break;
             case LOAN_DISBURSED:
-                if (anyOfAllowedWhenComingFrom(from, LoanStatus.APPROVED, LoanStatus.CLOSED_OBLIGATIONS_MET, LoanStatus.OVERPAID)) {
+                if (anyOfAllowedWhenComingFrom(from, LoanStatus.APPROVED, LoanStatus.CLOSED_OBLIGATIONS_MET)) {
+                    newState = activeTransition();
+                } else if (from.isOverpaid() && loan.getTotalOverpaidAsMoney().isZero()) {
                     newState = activeTransition();
                 }
             break;

fineract-provider/src/main/java/org/apache/fineract/portfolio/loanaccount/domain/LoanAccountDomainServiceJpa.java

@@ -535,7 +535,7 @@ public class LoanAccountDomainServiceJpa implements LoanAccountDomainService {
         final List<Long> existingReversedTransactionIds = new ArrayList<>();
         final Money amount = Money.of(loan.getCurrency(), transactionAmount);
         LoanTransaction disbursementTransaction = LoanTransaction.disbursement(loan.getOffice(), amount, paymentDetail, transactionDate,
-                txnExternalId);
+                txnExternalId, loan.getTotalOverpaidAsMoney());
 
         // Subtract Previous loan outstanding balance from netDisbursalAmount
         loan.deductFromNetDisbursalAmount(transactionAmount);

fineract-provider/src/main/java/org/apache/fineract/portfolio/loanaccount/service/LoanWritePlatformServiceJpaRepositoryImpl.java

@@ -436,7 +436,7 @@ public class LoanWritePlatformServiceJpaRepositoryImpl implements LoanWritePlatf
                 existingTransactionIds.addAll(loan.findExistingTransactionIds());
                 existingReversedTransactionIds.addAll(loan.findExistingReversedTransactionIds());
                 disbursementTransaction = LoanTransaction.disbursement(loan.getOffice(), amountToDisburse, paymentDetail,
-                        actualDisbursementDate, txnExternalId);
+                        actualDisbursementDate, txnExternalId, loan.getTotalOverpaidAsMoney());
                 disbursementTransaction.updateLoan(loan);
                 loan.addLoanTransaction(disbursementTransaction);
             }
@@ -752,7 +752,7 @@ public class LoanWritePlatformServiceJpaRepositoryImpl implements LoanWritePlatf
                     existingTransactionIds.addAll(loan.findExistingTransactionIds());
                     existingReversedTransactionIds.addAll(loan.findExistingReversedTransactionIds());
                     LoanTransaction disbursementTransaction = LoanTransaction.disbursement(loan.getOffice(), disburseAmount, paymentDetail,
-                            actualDisbursementDate, txnExternalId);
+                            actualDisbursementDate, txnExternalId, loan.getTotalOverpaidAsMoney());
                     disbursementTransaction.updateLoan(loan);
                     loan.addLoanTransaction(disbursementTransaction);
                     businessEventNotifierService

fineract-provider/src/test/java/org/apache/fineract/portfolio/loanaccount/domain/DefaultLoanLifecycleStateMachineTest.java

@@ -23,12 +23,21 @@ import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoInteractions;
 
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import org.apache.fineract.infrastructure.core.service.ThreadLocalContextUtil;
 import org.apache.fineract.infrastructure.event.business.domain.loan.LoanStatusChangedBusinessEvent;
 import org.apache.fineract.infrastructure.event.business.service.BusinessEventNotifierService;
+import org.apache.fineract.organisation.monetary.domain.MonetaryCurrency;
+import org.apache.fineract.organisation.monetary.domain.Money;
+import org.apache.fineract.organisation.monetary.domain.MoneyHelper;
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
+import org.mockito.MockedStatic;
+import org.mockito.Mockito;
 import org.mockito.junit.jupiter.MockitoExtension;
 
 @ExtendWith(MockitoExtension.class)
@@ -39,11 +48,22 @@ class DefaultLoanLifecycleStateMachineTest {
 
     private DefaultLoanLifecycleStateMachine underTest;
 
+    private MockedStatic<MoneyHelper> moneyHelperStatic;
+
     @BeforeEach
     public void setUp() {
+
+        moneyHelperStatic = Mockito.mockStatic(MoneyHelper.class);
+        moneyHelperStatic.when(() -> MoneyHelper.getRoundingMode()).thenReturn(RoundingMode.UP);
         underTest = new DefaultLoanLifecycleStateMachine(businessEventNotifierService);
     }
 
+    @AfterEach
+    public void deregister() {
+        ThreadLocalContextUtil.reset();
+        moneyHelperStatic.close();
+    }
+
     @Test
     public void testTransitionShouldWorkProperlyForLoanCreation() {
         // given
@@ -113,14 +133,33 @@ class DefaultLoanLifecycleStateMachineTest {
     @Test
     public void testTransitionShouldWorkProperlyForLoanDisbursementWhenLoanIsOverpaid() {
         // given
-        Loan loan = createLoanWithStatus(LoanStatus.OVERPAID);
+        Money overpayment = Money.of(new MonetaryCurrency("USD", 2, null), BigDecimal.ZERO);
+        Loan loan = Mockito.mock(Loan.class);
+        Mockito.when(loan.getPlainStatus()).thenReturn(LoanStatus.OVERPAID.getValue());
+        Mockito.when(loan.getStatus()).thenReturn(LoanStatus.OVERPAID);
+        Mockito.when(loan.getTotalOverpaidAsMoney()).thenReturn(overpayment);
         // when
         underTest.transition(LoanEvent.LOAN_DISBURSED, loan);
         // then
-        assertThat(loan.getStatus()).isEqualTo(LoanStatus.ACTIVE);
+        verify(loan, Mockito.times(1)).setLoanStatus(LoanStatus.ACTIVE.getValue());
         verify(businessEventNotifierService).notifyPostBusinessEvent(any(LoanStatusChangedBusinessEvent.class));
     }
 
+    @Test
+    public void testTransitionShouldWorkProperlyForLoanDisbursementWhenLoanIsOverpaidAndRemainsOverpaid() {
+        // given
+        Money overpayment = Money.of(new MonetaryCurrency("USD", 2, null), BigDecimal.TEN);
+        Loan loan = Mockito.mock(Loan.class);
+        Mockito.when(loan.getPlainStatus()).thenReturn(LoanStatus.OVERPAID.getValue());
+        Mockito.when(loan.getStatus()).thenReturn(LoanStatus.OVERPAID);
+        Mockito.when(loan.getTotalOverpaidAsMoney()).thenReturn(overpayment);
+        // when
+        underTest.transition(LoanEvent.LOAN_DISBURSED, loan);
+        // then
+        verify(loan, Mockito.never()).setLoanStatus(LoanStatus.ACTIVE.getValue());
+        verify(businessEventNotifierService, Mockito.never()).notifyPostBusinessEvent(any(LoanStatusChangedBusinessEvent.class));
+    }
+
     @Test
     public void testTransitionShouldWorkProperlyForLoanApprovalUndo() {
         // given