FINERACT-2418: fetch loan originators by loan

fineract-loan-origination/dependencies.gradle

@@ -25,6 +25,7 @@ dependencies {
     // implementation dependencies are directly used (compiled against) in src/main (and src/test)
     //
     implementation(project(path: ':fineract-core'))
+    implementation(project(path: ':fineract-loan'))
 
     implementation(
             'org.springframework.boot:spring-boot-starter-web',

fineract-loan-origination/src/main/java/org/apache/fineract/portfolio/loanorigination/api/LoanOriginatorsApiResource.java

@@ -0,0 +1,93 @@
+/**
+ * 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.loanorigination.api;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.ws.rs.Consumes;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.MediaType;
+import lombok.RequiredArgsConstructor;
+import org.apache.fineract.infrastructure.core.domain.ExternalId;
+import org.apache.fineract.infrastructure.core.service.ExternalIdFactory;
+import org.apache.fineract.infrastructure.security.service.PlatformSecurityContext;
+import org.apache.fineract.portfolio.loanaccount.exception.LoanNotFoundException;
+import org.apache.fineract.portfolio.loanaccount.service.LoanReadPlatformService;
+import org.apache.fineract.portfolio.loanorigination.data.LoanOriginatorsResponse;
+import org.apache.fineract.portfolio.loanorigination.service.LoanOriginatorReadPlatformService;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.stereotype.Component;
+
+@Path("/v1/loans")
+@Component
+@ConditionalOnProperty(value = "fineract.module.loan-origination.enabled", havingValue = "true")
+@Tag(name = "Loan Originators", description = "Fetch loan originator details for a specific loan")
+@RequiredArgsConstructor
+public class LoanOriginatorsApiResource {
+
+    private static final String LOAN_RESOURCE_NAME = "LOAN";
+
+    private final PlatformSecurityContext context;
+    private final LoanReadPlatformService loanReadPlatformService;
+    private final LoanOriginatorReadPlatformService loanOriginatorReadPlatformService;
+
+    @GET
+    @Path("{loanId}/originators")
+    @Consumes({ MediaType.APPLICATION_JSON })
+    @Produces({ MediaType.APPLICATION_JSON })
+    @Operation(summary = "Retrieve originators for a loan by loan ID", description = "Retrieves all originators attached to a specific loan. Requires READ_LOAN permission.")
+    @ApiResponse(responseCode = "200", description = "OK - Returns wrapped list of originators (may be empty)")
+    @ApiResponse(responseCode = "403", description = "Insufficient permissions")
+    @ApiResponse(responseCode = "404", description = "Loan not found")
+    public LoanOriginatorsResponse retrieveOriginatorsByLoanId(@PathParam("loanId") @Parameter(description = "loanId") final Long loanId) {
+        this.context.authenticatedUser().validateHasReadPermission(LOAN_RESOURCE_NAME);
+
+        if (!this.loanReadPlatformService.existsByLoanId(loanId)) {
+            throw new LoanNotFoundException(loanId);
+        }
+
+        return LoanOriginatorsResponse.of(this.loanOriginatorReadPlatformService.retrieveByLoanId(loanId));
+    }
+
+    @GET
+    @Path("external-id/{loanExternalId}/originators")
+    @Consumes({ MediaType.APPLICATION_JSON })
+    @Produces({ MediaType.APPLICATION_JSON })
+    @Operation(summary = "Retrieve originators for a loan by loan external ID", description = "Retrieves all originators attached to a specific loan using loan external ID. Requires READ_LOAN permission.")
+    @ApiResponse(responseCode = "200", description = "OK - Returns wrapped list of originators (may be empty)")
+    @ApiResponse(responseCode = "403", description = "Insufficient permissions")
+    @ApiResponse(responseCode = "404", description = "Loan not found")
+    public LoanOriginatorsResponse retrieveOriginatorsByLoanExternalId(
+            @PathParam("loanExternalId") @Parameter(description = "loanExternalId") final String loanExternalId) {
+        this.context.authenticatedUser().validateHasReadPermission(LOAN_RESOURCE_NAME);
+
+        final ExternalId externalId = ExternalIdFactory.produce(loanExternalId);
+        final Long loanId = this.loanReadPlatformService.retrieveLoanIdByExternalId(externalId);
+        if (loanId == null) {
+            throw new LoanNotFoundException(externalId);
+        }
+
+        return LoanOriginatorsResponse.of(this.loanOriginatorReadPlatformService.retrieveByLoanId(loanId));
+    }
+}

fineract-loan-origination/src/main/java/org/apache/fineract/portfolio/loanorigination/data/LoanOriginatorsResponse.java

@@ -0,0 +1,41 @@
+/**
+ * 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.loanorigination.data;
+
+import java.io.Serial;
+import java.io.Serializable;
+import java.util.List;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class LoanOriginatorsResponse implements Serializable {
+
+    @Serial
+    private static final long serialVersionUID = 1L;
+
+    private List<LoanOriginatorData> originators;
+
+    public static LoanOriginatorsResponse of(List<LoanOriginatorData> originators) {
+        return new LoanOriginatorsResponse(originators);
+    }
+}

fineract-loan-origination/src/main/java/org/apache/fineract/portfolio/loanorigination/domain/LoanOriginatorMappingRepository.java

@@ -39,4 +39,13 @@ public interface LoanOriginatorMappingRepository
     boolean existsByLoanIdAndOriginatorId(Long loanId, Long originatorId);
 
     void deleteByLoanIdAndOriginatorId(Long loanId, Long originatorId);
+
+    @org.springframework.data.jpa.repository.Query("""
+            SELECT m FROM LoanOriginatorMapping m
+            JOIN FETCH m.originator o
+            LEFT JOIN FETCH o.originatorType
+            LEFT JOIN FETCH o.channelType
+            WHERE m.loanId = :loanId
+            """)
+    List<LoanOriginatorMapping> findByLoanIdWithOriginator(@org.springframework.data.repository.query.Param("loanId") Long loanId);
 }

fineract-loan-origination/src/main/java/org/apache/fineract/portfolio/loanorigination/service/LoanOriginatorReadPlatformService.java

@@ -30,4 +30,6 @@ public interface LoanOriginatorReadPlatformService {
     LoanOriginatorData retrieveByExternalId(String externalId);
 
     Long resolveIdByExternalId(String externalId);
+
+    List<LoanOriginatorData> retrieveByLoanId(Long loanId);
 }

fineract-loan-origination/src/main/java/org/apache/fineract/portfolio/loanorigination/service/LoanOriginatorReadPlatformServiceImpl.java

@@ -18,11 +18,14 @@
  */
 package org.apache.fineract.portfolio.loanorigination.service;
 
+import java.util.Collections;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.apache.fineract.infrastructure.core.domain.ExternalId;
 import org.apache.fineract.portfolio.loanorigination.data.LoanOriginatorData;
 import org.apache.fineract.portfolio.loanorigination.domain.LoanOriginator;
+import org.apache.fineract.portfolio.loanorigination.domain.LoanOriginatorMapping;
+import org.apache.fineract.portfolio.loanorigination.domain.LoanOriginatorMappingRepository;
 import org.apache.fineract.portfolio.loanorigination.domain.LoanOriginatorRepository;
 import org.apache.fineract.portfolio.loanorigination.exception.LoanOriginatorNotFoundException;
 import org.apache.fineract.portfolio.loanorigination.mapper.LoanOriginatorMapper;
@@ -37,6 +40,7 @@ import org.springframework.transaction.annotation.Transactional;
 public class LoanOriginatorReadPlatformServiceImpl implements LoanOriginatorReadPlatformService {
 
     private final LoanOriginatorRepository loanOriginatorRepository;
+    private final LoanOriginatorMappingRepository loanOriginatorMappingRepository;
     private final LoanOriginatorMapper loanOriginatorMapper;
 
     @Override
@@ -65,4 +69,13 @@ public class LoanOriginatorReadPlatformServiceImpl implements LoanOriginatorRead
                 .orElseThrow(() -> new LoanOriginatorNotFoundException(externalId));
         return originator.getId();
     }
+
+    @Override
+    public List<LoanOriginatorData> retrieveByLoanId(final Long loanId) {
+        final List<LoanOriginatorMapping> mappings = this.loanOriginatorMappingRepository.findByLoanIdWithOriginator(loanId);
+        if (mappings.isEmpty()) {
+            return Collections.emptyList();
+        }
+        return mappings.stream().map(LoanOriginatorMapping::getOriginator).map(this.loanOriginatorMapper::toData).toList();
+    }
 }