FINERACT-2327: Allow to create Interest Refund transaction manually

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

@@ -97,4 +97,7 @@ public interface LoanAccountDomainService {
     LoanTransaction applyInterestRefund(Loan loan, LoanRefundRequestData loanRefundRequest);
 
     void updateAndSaveLoanCollateralTransactionsForIndividualAccounts(Loan loan, LoanTransaction transaction);
+
+    LoanTransaction createManualInterestRefundWithAmount(Loan loan, LoanTransaction targetTransaction, BigDecimal amount,
+            PaymentDetail paymentDetail, ExternalId txnExternalId);
 }

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

@@ -195,6 +195,11 @@ public class LoanTransaction extends AbstractAuditableWithUTCDateTimeCustom<Long
         return new LoanTransaction(loan, loan.getOffice(), LoanTransactionType.INTEREST_REFUND, null, amount, date, externalId);
     }
 
+    public static LoanTransaction interestRefund(final Loan loan, final BigDecimal amount, final LocalDate date,
+            final PaymentDetail paymentDetail, final ExternalId externalId) {
+        return new LoanTransaction(loan, loan.getOffice(), LoanTransactionType.INTEREST_REFUND, paymentDetail, amount, date, externalId);
+    }
+
     public static LoanTransaction chargeAdjustment(final Loan loan, final BigDecimal amount, final LocalDate transactionDate,
             final ExternalId externalId, PaymentDetail paymentDetail) {
         return new LoanTransaction(loan, loan.getOffice(), LoanTransactionType.CHARGE_ADJUSTMENT, paymentDetail, amount, transactionDate,

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/handler/ManualInterestRefundCommandHandler.java

@@ -0,0 +1,42 @@
+/**
+ * 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.handler;
+
+import lombok.RequiredArgsConstructor;
+import org.apache.fineract.commands.annotation.CommandType;
+import org.apache.fineract.commands.handler.NewCommandSourceHandler;
+import org.apache.fineract.infrastructure.core.api.JsonCommand;
+import org.apache.fineract.infrastructure.core.data.CommandProcessingResult;
+import org.apache.fineract.portfolio.loanaccount.service.LoanWritePlatformService;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+@CommandType(entity = "LOAN_TRANSACTION", action = "MANUAL_INTEREST_REFUND")
+public class ManualInterestRefundCommandHandler implements NewCommandSourceHandler {
+
+    private final LoanWritePlatformService loanWritePlatformService;
+
+    @Transactional
+    @Override
+    public CommandProcessingResult processCommand(final JsonCommand command) {
+        return loanWritePlatformService.makeManualInterestRefund(command.getLoanId(), command.entityId(), command);
+    }
+}

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/serialization/LoanTransactionValidator.java

@@ -94,4 +94,6 @@ public interface LoanTransactionValidator {
     void validateExternalId(DataValidatorBuilder baseDataValidator, JsonElement element);
 
     void validateReversalExternalId(DataValidatorBuilder baseDataValidator, JsonElement element);
+
+    void validateManualInterestRefundTransaction(String json);
 }

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/service/LoanReadPlatformService.java

@@ -155,4 +155,6 @@ public interface LoanReadPlatformService {
     List<Long> retrieveLoanIdsByExternalIds(List<ExternalId> externalIds);
 
     boolean existsByLoanId(Long loanId);
+
+    LoanTransactionData retrieveManualInterestRefundTemplate(Long loanId, Long targetTransactionId);
 }

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/service/LoanWritePlatformService.java

@@ -125,4 +125,6 @@ public interface LoanWritePlatformService {
     CommandProcessingResult undoChargeOff(JsonCommand command);
 
     CommandProcessingResult makeRefund(Long loanId, LoanTransactionType loanTransactionType, JsonCommand command);
+
+    CommandProcessingResult makeManualInterestRefund(Long loanId, Long transactionId, JsonCommand command);
 }