[Feature] Implment GET endpoint to retrieve all tours that given task is linked to

src/main/java/com/itasocialacademy/oitassist/taskassignment/controller/AssignmentController.java

@@ -6,9 +6,11 @@
 import com.itasocialacademy.oitassist.taskassignment.dto.request.CreateTaskAssignmentRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.UpdateTaskAssignmentRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.response.DetailedTaskAssignmentResponseDTO;
+import com.itasocialacademy.oitassist.taskassignment.dto.response.LinkedToursResponseDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.response.TaskAssignmentResponseDTO;
 import com.itasocialacademy.oitassist.taskassignment.service.interfaces.AssignmentService;
 import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.ArraySchema;
 import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
@@ -23,6 +25,7 @@
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.*;
+import java.util.List;
 
 @RestController
 @RequestMapping("/api/v1")
@@ -112,6 +115,24 @@ public ResponseEntity<PageResponse<TaskAssignmentResponseDTO>> getByTour(@PathVa
         return ResponseEntity.ok(PageResponse.from(assignmentService.getAssignmentsByTourId(pageable, tourId)));
     }
 
+    @Operation(
+        summary = "Get tours linked to a task",
+        description = "Retrieves a list of tours linked to the specified task body. Requires ADMIN or ORG role.")
+    @ApiResponses(value = {
+        @ApiResponse(responseCode = "200", description = "Linked tours retrieved successfully",
+            content = @Content(mediaType = "application/json",
+                array = @ArraySchema(schema = @Schema(implementation = LinkedToursResponseDTO.class)))),
+        @ApiResponse(responseCode = "403", description = "Access denied (requires ADMIN or ORG role)",
+            content = @Content(mediaType = "application/json", schema = @Schema(implementation = ErrorResponse.class))),
+        @ApiResponse(responseCode = "404", description = "Task body or linked tour not found",
+            content = @Content(mediaType = "application/json", schema = @Schema(implementation = ErrorResponse.class)))
+    })
+    @GetMapping("/tasks/{taskId}/linked-tours")
+    @PreAuthorize("hasAnyRole('ADMIN', 'ORG')")
+    public ResponseEntity<List<LinkedToursResponseDTO>> getLinkedTours(@PathVariable Long taskId) {
+        return ResponseEntity.ok().body(assignmentService.getLinkedToursByTaskId(taskId));
+    }
+
     @Operation(
         summary = "Update a task assignment",
         description = "Updates an existing task assignment. Only users with ADMIN or ORG role can perform this action.")

src/main/java/com/itasocialacademy/oitassist/taskassignment/dao/repository/TaskAssignmentRepository.java

@@ -4,7 +4,9 @@
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.stereotype.Repository;
+import java.util.List;
 
 @Repository
 public interface TaskAssignmentRepository extends JpaRepository<TaskAssignment, Long> {
@@ -13,4 +15,7 @@ public interface TaskAssignmentRepository extends JpaRepository<TaskAssignment,
     boolean existsByTaskBodyIdAndTourId(Long taskBodyId, Long tourId);
 
     boolean existsByTaskBodyId(Long taskBodyId);
+
+    @Query("SELECT t.tourId FROM TaskAssignment t WHERE t.taskBodyId = :taskBodyId")
+    List<Long> findTourIdsByTaskBodyId(Long taskBodyId);
 }

src/main/java/com/itasocialacademy/oitassist/taskassignment/dto/response/LinkedToursResponseDTO.java

@@ -0,0 +1,29 @@
+package com.itasocialacademy.oitassist.taskassignment.dto.response;
+
+import com.itasocialacademy.oitassist.competition.dao.enums.ExecutionStatus;
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.Builder;
+
+@Builder
+@Schema(description = "DTO representing linked tour details of some given task")
+public record LinkedToursResponseDTO(
+    @Schema(
+        description = "Id of the tour the task is linked to",
+        example = "1") Long tourId,
+
+    @Schema(
+        description = "Title of the tour",
+        example = "Тур 1: Алгоритми та структури даних") String title,
+
+    @Schema(
+        description = "Description of the tour",
+        example = "Розв'язати алгоритмічні задачі") String description,
+
+    @Schema(
+        description = "Physical or virtual location where the tour takes place",
+        example = "Ліцей №1, Львів") String location,
+
+    @Schema(
+        description = "The current state of execution ",
+        example = "IN_PROGRESS") ExecutionStatus executionStatus) {
+}

src/main/java/com/itasocialacademy/oitassist/taskassignment/mapper/TaskAssignmentMapper.java

@@ -1,14 +1,17 @@
 package com.itasocialacademy.oitassist.taskassignment.mapper;
 
+import com.itasocialacademy.oitassist.competition.api.dto.TourDetail;
 import com.itasocialacademy.oitassist.filemanager.api.dto.FileDetailsDTO;
 import com.itasocialacademy.oitassist.taskassignment.api.dto.TaskAssignmentDetailDTO;
 import com.itasocialacademy.oitassist.taskassignment.dao.model.TaskAssignment;
 import com.itasocialacademy.oitassist.taskassignment.dao.model.TaskRequirements;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.CreateTaskAssignmentRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.TaskRequirementsRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.response.DetailedTaskAssignmentResponseDTO;
+import com.itasocialacademy.oitassist.taskassignment.dto.response.LinkedToursResponseDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.response.TaskAssignmentResponseDTO;
 import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
 import org.mapstruct.ReportingPolicy;
 import java.util.List;
 
@@ -24,4 +27,7 @@ public interface TaskAssignmentMapper {
 
     DetailedTaskAssignmentResponseDTO toDetailedResponse(TaskAssignment entity, String taskTitle,
         String taskDescription, List<FileDetailsDTO> files);
+
+    @Mapping(target = "tourId", source = "id")
+    LinkedToursResponseDTO toLinkedToursResponse(TourDetail tourDetail);
 }

src/main/java/com/itasocialacademy/oitassist/taskassignment/service/AssignmentServiceImpl.java

@@ -5,6 +5,8 @@
 import com.itasocialacademy.oitassist.competition.dao.enums.ExecutionStatus;
 import com.itasocialacademy.oitassist.competition.exceptions.CompetitionHierarchyValidationException;
 import com.itasocialacademy.oitassist.competition.exceptions.TourNotFoundException;
+import com.itasocialacademy.oitassist.core.enums.ErrorCode;
+import com.itasocialacademy.oitassist.core.exceptions.AuthorizationException;
 import com.itasocialacademy.oitassist.filemanager.api.FileManagerFacade;
 import com.itasocialacademy.oitassist.filemanager.api.dto.FileDetailsDTO;
 import com.itasocialacademy.oitassist.filemanager.dao.enums.FileRole;
@@ -21,6 +23,7 @@
 import com.itasocialacademy.oitassist.taskassignment.dto.request.CreateTaskAssignmentRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.UpdateTaskAssignmentRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.response.DetailedTaskAssignmentResponseDTO;
+import com.itasocialacademy.oitassist.taskassignment.dto.response.LinkedToursResponseDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.response.TaskAssignmentResponseDTO;
 import com.itasocialacademy.oitassist.taskassignment.exceptions.TaskAlreadyAssignedException;
 import com.itasocialacademy.oitassist.taskassignment.exceptions.TaskAssignmentNotFoundException;
@@ -212,6 +215,46 @@ public boolean existsByTaskBodyId(Long taskBodyId) {
         return taskAssignmentRepository.existsByTaskBodyId(taskBodyId);
     }
 
+    @Override
+    @Transactional(readOnly = true)
+    public List<LinkedToursResponseDTO> getLinkedToursByTaskId(Long taskBodyId) {
+        TaskBodyDetail taskBody = taskBodyFacade.findTaskBodyById(taskBodyId).orElseThrow(
+            () -> new TaskNotFoundException(taskBodyId));
+
+        checkAdminOrOrg();
+
+        List<Long> tourIds = taskAssignmentRepository.findTourIdsByTaskBodyId(taskBody.id());
+
+        log.debug("Get LinkedTours by task body Id {}", taskBodyId);
+
+        if (tourIds.isEmpty()) {
+            return List.of();
+        }
+
+        List<TourDetail> tours = competitionFacade.findToursByIds(tourIds);
+
+        List<Long> returnedIds = tours.stream()
+            .map(TourDetail::id)
+            .toList();
+
+        List<Long> missingIds = tourIds.stream()
+            .filter(id -> !returnedIds.contains(id))
+            .toList();
+
+        if (!missingIds.isEmpty()) {
+            log.warn(
+                "Missing linked tours for task body Id {}: requested {} tour(s) but only found {}. "
+                    + "Missing tour IDs: {}",
+                taskBodyId,
+                tourIds.size(),
+                tours.size(),
+                missingIds);
+        }
+
+        return tours.stream().map(taskAssignmentMapper::toLinkedToursResponse).toList();
+    }
+
+    // helpers
     private List<FileDetailsDTO> resolveTaskFiles(Long taskBodyId) {
         Set<FileRole> allowedFileRoles;
 
@@ -229,4 +272,10 @@ private void validateTourStatus(TourDetail tour, String msg) {
             throw new CompetitionHierarchyValidationException(msg + " Tour has already started");
         }
     }
+
+    private void checkAdminOrOrg() {
+        if (!securityFacade.hasRole("ADMIN") && !securityFacade.hasRole("ORG")) {
+            throw new AuthorizationException("You do not have permission to this operation", ErrorCode.ACCESS_DENIED);
+        }
+    }
 }

src/main/java/com/itasocialacademy/oitassist/taskassignment/service/interfaces/AssignmentService.java

@@ -1,17 +1,20 @@
 package com.itasocialacademy.oitassist.taskassignment.service.interfaces;
 
 import com.itasocialacademy.oitassist.competition.exceptions.TourNotFoundException;
+import com.itasocialacademy.oitassist.task.exceptions.TaskNotFoundException;
 import com.itasocialacademy.oitassist.taskassignment.api.dto.TaskAssignmentDetailDTO;
 import com.itasocialacademy.oitassist.taskassignment.dao.enums.AssignmentVisibility;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.CreateAndAssignTaskRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.CreateTaskAssignmentRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.UpdateTaskAssignmentRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.response.DetailedTaskAssignmentResponseDTO;
+import com.itasocialacademy.oitassist.taskassignment.dto.response.LinkedToursResponseDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.response.TaskAssignmentResponseDTO;
 import com.itasocialacademy.oitassist.taskassignment.exceptions.TaskAlreadyAssignedException;
 import com.itasocialacademy.oitassist.taskassignment.exceptions.TaskAssignmentNotFoundException;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
+import java.util.List;
 import java.util.Optional;
 
 public interface AssignmentService {
@@ -110,4 +113,15 @@ DetailedTaskAssignmentResponseDTO updateTaskAssignment(Long taskAssignmentId,
      *         body id, {@code false} otherwise
      */
     boolean existsByTaskBodyId(Long taskBodyId);
+
+    /**
+     * Retrieves all tours linked to the specified task body.
+     *
+     * @param taskBodyId the ID of the task body
+     * @return a list of {@link LinkedToursResponseDTO} containing details of the
+     *         tours linked to the task
+     * @throws TaskNotFoundException if no task body exists with the given ID
+     * @throws TourNotFoundException if any linked tour cannot be found
+     */
+    List<LinkedToursResponseDTO> getLinkedToursByTaskId(Long taskBodyId);
 }

src/test/java/com/itasocialacademy/oitassist/taskassignment/controller/AssignmentControllerTest.java

@@ -1,16 +1,19 @@
 package com.itasocialacademy.oitassist.taskassignment.controller;
 
 import com.itasocialacademy.oitassist.ControllerUnitTest;
+import com.itasocialacademy.oitassist.competition.dao.enums.ExecutionStatus;
 import com.itasocialacademy.oitassist.competition.exceptions.CompetitionHierarchyValidationException;
 import com.itasocialacademy.oitassist.competition.exceptions.TourNotFoundException;
 import com.itasocialacademy.oitassist.filemanager.api.dto.FileDetailsDTO;
+import com.itasocialacademy.oitassist.task.exceptions.TaskNotFoundException;
 import com.itasocialacademy.oitassist.taskassignment.dao.enums.AssignmentVisibility;
 import com.itasocialacademy.oitassist.taskassignment.dao.model.TaskRequirements;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.CreateAndAssignTaskRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.CreateTaskAssignmentRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.TaskRequirementsRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.request.UpdateTaskAssignmentRequestDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.response.DetailedTaskAssignmentResponseDTO;
+import com.itasocialacademy.oitassist.taskassignment.dto.response.LinkedToursResponseDTO;
 import com.itasocialacademy.oitassist.taskassignment.dto.response.TaskAssignmentResponseDTO;
 import com.itasocialacademy.oitassist.taskassignment.exceptions.TaskAlreadyAssignedException;
 import com.itasocialacademy.oitassist.taskassignment.exceptions.TaskAssignmentNotFoundException;
@@ -274,6 +277,49 @@ void getByTour_tourNotFound_shouldReturn404() throws Exception {
             .andExpect(status().isNotFound());
     }
 
+    // GET /api/v1/tasks/{taskId}/linked-tours — getLinkedTours
+
+    @Test
+    void getLinkedTours_shouldReturnListAnd200() throws Exception {
+        LinkedToursResponseDTO mockTourResponse = LinkedToursResponseDTO.builder()
+            .tourId(10L)
+            .title("Tour 1")
+            .description("Description")
+            .location("Location")
+            .executionStatus(ExecutionStatus.SCHEDULED)
+            .build();
+
+        when(assignmentService.getLinkedToursByTaskId(3L))
+            .thenReturn(List.of(mockTourResponse));
+
+        mockMvc.perform(get("/api/v1/tasks/{taskId}/linked-tours", 3L))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("$").isArray())
+            .andExpect(jsonPath("$[0].tourId").value(10L))
+            .andExpect(jsonPath("$[0].title").value("Tour 1"))
+            .andExpect(jsonPath("$[0].description").value("Description"))
+            .andExpect(jsonPath("$[0].location").value("Location"))
+            .andExpect(jsonPath("$[0].executionStatus").value("SCHEDULED"));
+    }
+
+    @Test
+    void getLinkedTours_taskNotFound_shouldReturn404() throws Exception {
+        when(assignmentService.getLinkedToursByTaskId(99L))
+            .thenThrow(new TaskNotFoundException(99L));
+
+        mockMvc.perform(get("/api/v1/tasks/{taskId}/linked-tours", 99L))
+            .andExpect(status().isNotFound());
+    }
+
+    @Test
+    void getLinkedTours_tourNotFound_shouldReturn404() throws Exception {
+        when(assignmentService.getLinkedToursByTaskId(3L))
+            .thenThrow(new TourNotFoundException(10L));
+
+        mockMvc.perform(get("/api/v1/tasks/{taskId}/linked-tours", 3L))
+            .andExpect(status().isNotFound());
+    }
+
     // PATCH /api/v1/task-assignments/{assignmentId} — update
 
     @Test

src/test/java/com/itasocialacademy/oitassist/taskassignment/service/AssignmentServiceTest.java

@@ -3,6 +3,7 @@
 import java.util.Set;
 import com.itasocialacademy.oitassist.competition.dao.enums.ExecutionStatus;
 import com.itasocialacademy.oitassist.filemanager.dao.enums.FileRole;
+import com.itasocialacademy.oitassist.taskassignment.dto.response.LinkedToursResponseDTO;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -564,4 +565,52 @@ void existsByTaskBodyId_whenNotExists_shouldReturnFalse() {
 
         assertFalse(assignmentService.existsByTaskBodyId(99L));
     }
+
+    // ---- getLinkedToursByTaskId ----
+
+    @Test
+    void getLinkedToursByTaskId_whenTaskExistsAndUserAuthorized_shouldReturnLinkedTours() {
+        LinkedToursResponseDTO mockTourResponse = LinkedToursResponseDTO.builder()
+            .tourId(10L)
+            .title("Tour 1")
+            .description("Description")
+            .location("Location")
+            .executionStatus(ExecutionStatus.SCHEDULED)
+            .build();
+
+        when(taskBodyFacade.findTaskBodyById(3L)).thenReturn(Optional.of(taskBodyDetail));
+        when(securityFacade.hasRole("ADMIN")).thenReturn(true);
+        when(taskAssignmentRepository.findTourIdsByTaskBodyId(3L)).thenReturn(List.of(10L));
+        when(competitionFacade.findToursByIds(List.of(10L))).thenReturn(List.of(tourDetail));
+        when(taskAssignmentMapper.toLinkedToursResponse(tourDetail)).thenReturn(mockTourResponse);
+
+        List<LinkedToursResponseDTO> result = assignmentService.getLinkedToursByTaskId(3L);
+
+        assertNotNull(result);
+        assertEquals(1, result.size());
+        assertEquals(10L, result.getFirst().tourId());
+        assertEquals("Tour 1", result.getFirst().title());
+        assertEquals("Description", result.getFirst().description());
+        assertEquals("Location", result.getFirst().location());
+        assertEquals(ExecutionStatus.SCHEDULED, result.getFirst().executionStatus());
+    }
+
+    @Test
+    void getLinkedToursByTaskId_whenTaskDoesNotExist_shouldThrowTaskNotFoundException() {
+        when(taskBodyFacade.findTaskBodyById(99L)).thenReturn(Optional.empty());
+
+        assertThrows(TaskNotFoundException.class, () -> assignmentService.getLinkedToursByTaskId(99L));
+        verify(taskAssignmentRepository, never()).findTourIdsByTaskBodyId(any());
+    }
+
+    @Test
+    void getLinkedToursByTaskId_whenUserNotAuthorized_shouldThrowAuthorizationException() {
+        when(taskBodyFacade.findTaskBodyById(3L)).thenReturn(Optional.of(taskBodyDetail));
+        when(securityFacade.hasRole("ADMIN")).thenReturn(false);
+        when(securityFacade.hasRole("ORG")).thenReturn(false);
+
+        assertThrows(com.itasocialacademy.oitassist.core.exceptions.AuthorizationException.class,
+            () -> assignmentService.getLinkedToursByTaskId(3L));
+        verify(taskAssignmentRepository, never()).findTourIdsByTaskBodyId(any());
+    }
 }