FINERACT-2311: Add buydown fees to loan

fineract-loan/src/main/java/org/apache/fineract/accounting/productaccountmapping/service/LoanProductToGLAccountMappingHelper.java

@@ -173,6 +173,9 @@ public class LoanProductToGLAccountMappingHelper extends ProductToGLAccountMappi
         final Long incomeFromRecoveryAccountId = this.fromApiJsonHelper
                 .extractLongNamed(LoanProductAccountingParams.INCOME_FROM_RECOVERY.getValue(), element);
 
+        final Long incomeFromBuyDownFeesAccountId = this.fromApiJsonHelper
+                .extractLongNamed(LoanProductAccountingParams.INCOME_FROM_BUY_DOWN.getValue(), element);
+
         final Long writeOffAccountId = this.fromApiJsonHelper.extractLongNamed(LoanProductAccountingParams.LOSSES_WRITTEN_OFF.getValue(),
                 element);
         final Long overPaymentAccountId = this.fromApiJsonHelper.extractLongNamed(LoanProductAccountingParams.OVERPAYMENT.getValue(),
@@ -198,12 +201,14 @@ public class LoanProductToGLAccountMappingHelper extends ProductToGLAccountMappi
             case ACCRUAL_PERIODIC:
                 populateChangesForAccrualBasedAccounting(changes, fundAccountId, loanPortfolioAccountId, incomeFromInterestId,
                         incomeFromFeeId, incomeFromPenaltyId, writeOffAccountId, overPaymentAccountId, transfersInSuspenseAccountId,
-                        incomeFromRecoveryAccountId, receivableInterestAccountId, receivableFeeAccountId, receivablePenaltyAccountId);
+                        incomeFromRecoveryAccountId, incomeFromBuyDownFeesAccountId, receivableInterestAccountId, receivableFeeAccountId,
+                        receivablePenaltyAccountId);
             break;
             case ACCRUAL_UPFRONT:
                 populateChangesForAccrualBasedAccounting(changes, fundAccountId, loanPortfolioAccountId, incomeFromInterestId,
                         incomeFromFeeId, incomeFromPenaltyId, writeOffAccountId, overPaymentAccountId, transfersInSuspenseAccountId,
-                        incomeFromRecoveryAccountId, receivableInterestAccountId, receivableFeeAccountId, receivablePenaltyAccountId);
+                        incomeFromRecoveryAccountId, incomeFromBuyDownFeesAccountId, receivableInterestAccountId, receivableFeeAccountId,
+                        receivablePenaltyAccountId);
             break;
         }
 
@@ -213,8 +218,8 @@ public class LoanProductToGLAccountMappingHelper extends ProductToGLAccountMappi
     private void populateChangesForAccrualBasedAccounting(final Map<String, Object> changes, final Long fundAccountId,
             final Long loanPortfolioAccountId, final Long incomeFromInterestId, final Long incomeFromFeeId, final Long incomeFromPenaltyId,
             final Long writeOffAccountId, final Long overPaymentAccountId, final Long transfersInSuspenseAccountId,
-            final Long incomeFromRecoveryAccountId, final Long receivableInterestAccountId, final Long receivableFeeAccountId,
-            final Long receivablePenaltyAccountId) {
+            final Long incomeFromRecoveryAccountId, final Long incomeFromBuyDownFeesAccountId, final Long receivableInterestAccountId,
+            final Long receivableFeeAccountId, final Long receivablePenaltyAccountId) {
 
         changes.put(LoanProductAccountingParams.INTEREST_RECEIVABLE.getValue(), receivableInterestAccountId);
         changes.put(LoanProductAccountingParams.FEES_RECEIVABLE.getValue(), receivableFeeAccountId);

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/api/LoanApiConstants.java

@@ -181,6 +181,8 @@ public interface LoanApiConstants {
     String CAPITALIZED_INCOME_ADJUSTMENT_TRANSACTION_COMMAND = "capitalizedIncomeAdjustment";
     String CONTRACT_TERMINATION_COMMAND = "contractTermination";
     String UNDO_CONTRACT_TERMINATION_COMMAND = "undoContractTermination";
+    String BUY_DOWN_FEE_COMMAND = "buyDownFee";
+    String BUY_DOWN_FEE_ADJUSTMENT_COMMAND = "buyDownFeeAdjustment";
 
     // Data Validator names
     String LOAN_FRAUD_DATAVALIDATOR_PREFIX = "loans.fraud";

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/data/LoanTransactionEnumData.java

@@ -72,6 +72,8 @@ public class LoanTransactionEnumData implements Serializable {
     private final boolean capitalizedIncomeAdjustment;
     private final boolean capitalizedIncomeAmortizationAdjustment;
     private final boolean contractTermination;
+    private final boolean buyDownFee;
+    private final boolean buyDownFeeAdjustment;
 
     public LoanTransactionEnumData(final Long id, final String code, final String value) {
         this.id = id;
@@ -114,6 +116,8 @@ public class LoanTransactionEnumData implements Serializable {
         this.capitalizedIncomeAmortizationAdjustment = Long
                 .valueOf(LoanTransactionType.CAPITALIZED_INCOME_AMORTIZATION_ADJUSTMENT.getValue()).equals(this.id);
         this.contractTermination = Long.valueOf(LoanTransactionType.CONTRACT_TERMINATION.getValue()).equals(this.id);
+        this.buyDownFee = Long.valueOf(LoanTransactionType.BUY_DOWN_FEE.getValue()).equals(this.id);
+        this.buyDownFeeAdjustment = Long.valueOf(LoanTransactionType.BUY_DOWN_FEE_ADJUSTMENT.getValue()).equals(this.id);
     }
 
     public boolean isRepaymentType() {

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

@@ -961,4 +961,13 @@ public class LoanTransaction extends AbstractAuditableWithUTCDateTimeCustom<Long
         this.dateOf = transactionDate;
     }
 
+    public static LoanTransaction buyDownFee(final Loan loan, final Money amount, final PaymentDetail paymentDetail,
+            final LocalDate transactionDate, final ExternalId externalId) {
+        return new LoanTransaction(loan, loan.getOffice(), LoanTransactionType.BUY_DOWN_FEE, paymentDetail, amount.getAmount(),
+                transactionDate, externalId);
+    }
+
+    public boolean isBuyDownFee() {
+        return LoanTransactionType.BUY_DOWN_FEE.equals(this.typeOf);
+    }
 }

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

@@ -73,6 +73,9 @@ public enum LoanTransactionType {
     CAPITALIZED_INCOME_AMORTIZATION_ADJUSTMENT(39, "loanTransactionType.capitalizedIncomeAmortizationAdjustment"), //
     // Kind of Final Transactions
     CONTRACT_TERMINATION(38, "loanTransactionType.contractTermination"), //
+
+    BUY_DOWN_FEE(40, "loanTransactionType.buyDownFee"), //
+    BUY_DOWN_FEE_ADJUSTMENT(41, "loanTransactionType.buyDownFeeAdjustment"), //
     ;
 
     private final Integer value;
@@ -128,6 +131,8 @@ public enum LoanTransactionType {
             case 37 -> LoanTransactionType.CAPITALIZED_INCOME_ADJUSTMENT;
             case 38 -> LoanTransactionType.CONTRACT_TERMINATION;
             case 39 -> LoanTransactionType.CAPITALIZED_INCOME_AMORTIZATION_ADJUSTMENT;
+            case 40 -> LoanTransactionType.BUY_DOWN_FEE;
+            case 41 -> LoanTransactionType.BUY_DOWN_FEE_ADJUSTMENT;
             default -> LoanTransactionType.INVALID;
         };
     }
@@ -256,4 +261,12 @@ public enum LoanTransactionType {
     public boolean isContractTermination() {
         return this == LoanTransactionType.CONTRACT_TERMINATION;
     }
+
+    public boolean isBuyDownFee() {
+        return this == LoanTransactionType.BUY_DOWN_FEE;
+    }
+
+    public boolean isBuyDownFeeAdjustment() {
+        return this == LoanTransactionType.BUY_DOWN_FEE_ADJUSTMENT;
+    }
 }

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/exception/LoanTransactionProcessingException.java

@@ -0,0 +1,36 @@
+/**
+ * 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.exception;
+
+import org.apache.fineract.infrastructure.core.exception.AbstractPlatformDomainRuleException;
+
+/**
+ * {@link AbstractPlatformDomainRuleException} thrown when loan transaction processing violates a domain rule.
+ */
+public class LoanTransactionProcessingException extends AbstractPlatformDomainRuleException {
+
+    public LoanTransactionProcessingException(final String defaultUserMessage, final Object... defaultUserMessageArgs) {
+        super("error.msg.loan.transaction.processing", defaultUserMessage, defaultUserMessageArgs);
+    }
+
+    public LoanTransactionProcessingException(final String action, final String defaultUserMessage,
+            final Object... defaultUserMessageArgs) {
+        super("error.msg.loan.transaction." + action, defaultUserMessage, defaultUserMessageArgs);
+    }
+}

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanproduct/service/LoanEnumerations.java

@@ -338,6 +338,10 @@ public final class LoanEnumerations {
             case CAPITALIZED_INCOME_AMORTIZATION_ADJUSTMENT -> new LoanTransactionEnumData(
                     LoanTransactionType.CAPITALIZED_INCOME_AMORTIZATION_ADJUSTMENT.getValue().longValue(),
                     LoanTransactionType.CAPITALIZED_INCOME_AMORTIZATION_ADJUSTMENT.getCode(), "Capitalized Income Amortization Adjustment");
+            case BUY_DOWN_FEE -> new LoanTransactionEnumData(LoanTransactionType.BUY_DOWN_FEE.getValue().longValue(),
+                    LoanTransactionType.BUY_DOWN_FEE.getCode(), "Buy Down Fee");
+            case BUY_DOWN_FEE_ADJUSTMENT -> new LoanTransactionEnumData(LoanTransactionType.BUY_DOWN_FEE_ADJUSTMENT.getValue().longValue(),
+                    LoanTransactionType.BUY_DOWN_FEE_ADJUSTMENT.getCode(), "Buy Down Fee Adjustment");
         };
     }