PMT-26 get all Employees from a specific Project

src/main/java/de/hmmh/pmt/ApiController.java

@@ -20,8 +20,8 @@ import org.springframework.web.client.HttpClientErrorException;
 import org.springframework.web.client.RestClientException;
 
 import java.time.ZoneOffset;
-import java.util.List;
-import java.util.Optional;
+import java.util.*;
+import java.util.stream.Collectors;
 
 @Controller
 @RequestMapping("${openapi.projectManagement.base-path:/api/v1}")
@@ -143,4 +143,30 @@ public class ApiController implements DefaultApi {
 
         return new ResponseEntity<>(HttpStatus.NO_CONTENT);
     }
+
+    @Override
+    public ResponseEntity<List<EmployeeResponseDTO>> getAListOfAllEmployeesFromASpecificProject(Long id) {
+        if (!projectRepository.existsById(id)) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+
+        List<Allocation> allocationsByProject = allocationRepository.findAllByProjectId(id);
+        if (allocationsByProject.isEmpty()) {
+            return new ResponseEntity<>(Collections.emptyList(), HttpStatus.OK);
+        }
+
+        Set<Long> employeeIds = allocationsByProject.stream()
+                .map(Allocation::getEmployeeId)
+                .collect(Collectors.toSet());
+
+        List<EmployeeResponseDTO> employees = apiClientFactory.getEmployeeApi().findAll1().stream()
+                .filter(employeeResponseDTO -> employeeIds.contains(employeeResponseDTO.getId()))
+                .toList();
+
+        // Was wenn, die Liste der Allocation und die Liste der EmployeeResponseDTO nicht die gleiche Anzahl haben.
+        // Das EmployeeResponseDTO wird vom EmployeeService gestellt, sollte man die Daten auf eigenes DTO mappen.
+
+        return new ResponseEntity<>(employees, HttpStatus.OK);
+
+    }
 }

src/main/java/de/hmmh/pmt/db/AllocationRepository.java

@@ -7,4 +7,5 @@ import java.util.List;
 public interface AllocationRepository extends JpaRepository<Allocation, AllocationId> {
 
     List<Allocation> findAllByEmployeeId(Long employeeId);
+    List<Allocation> findAllByProjectId(Long projectId);
 }