Feature/issue label

src/main/java/com/issueDive/controller/LabelController.java

@@ -4,7 +4,9 @@
 import com.issueDive.dto.CreateLabelRequest;
 import com.issueDive.dto.LabelResponse;
 import com.issueDive.dto.UpdateLabelRequest;
+import com.issueDive.dto.IssueLabelsResponse;
 import com.issueDive.service.LabelService;
+import com.issueDive.service.IssueLabelService;
 import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.HttpStatus;
@@ -18,6 +20,7 @@
 @RequiredArgsConstructor
 public class LabelController {
     private final LabelService labelService;
+    private final IssueLabelService issueLabelService;
 
     //라벨 생성
     @PostMapping("/labels")
@@ -40,27 +43,43 @@ public ResponseEntity<ApiResponse<List<LabelResponse>>> getLabels(){
     }
 
     //단일 라벨 조회
-    @GetMapping("/labels/{id}")
-    public ResponseEntity<ApiResponse<LabelResponse>> getLabelById(@PathVariable Long id){
-        LabelResponse data = labelService.getLabel(id);
+    @GetMapping("/labels/{labelId}")
+    public ResponseEntity<ApiResponse<LabelResponse>> getLabelById(@PathVariable Long labelId){
+        LabelResponse data = labelService.getLabel(labelId);
 
         return ResponseEntity.ok(ApiResponse.ok(data));
     }
 
     //라벨 수정
-    @PatchMapping("/labels/{id}")
+    @PatchMapping("/labels/{labelId}")
     public ResponseEntity<ApiResponse<LabelResponse>> updateLabel(
-            @PathVariable Long id,
+            @PathVariable Long labelId,
             @Valid @RequestBody UpdateLabelRequest request){
-        LabelResponse data = labelService.updateLabel(id, request);
+        LabelResponse data = labelService.updateLabel(labelId, request);
 
         return ResponseEntity.ok(ApiResponse.ok(data));
     }
 
     //라벨 삭제
-    @DeleteMapping("/labels/{id}")
-    public ResponseEntity<ApiResponse<Map<String, String>>> deleteLabel(@PathVariable Long id){
-        labelService.deleteLabel(id);
-        return ResponseEntity.ok(ApiResponse.ok(Map.of("message", "Label " + id + " deleted successfully")));
+    @DeleteMapping("/labels/{labelId}")
+    public ResponseEntity<ApiResponse<Map<String, String>>> deleteLabel(@PathVariable Long labelId){
+        labelService.deleteLabel(labelId);
+        return ResponseEntity.ok(ApiResponse.ok(Map.of("message", "Label " + labelId + " deleted successfully")));
+    }
+
+    @PostMapping("/issues/{issueId}/labels")
+    public ResponseEntity<ApiResponse<IssueLabelsResponse>> addLabels(
+            @PathVariable Long issueId,
+            @RequestBody List<Long> labelIds) {
+        IssueLabelsResponse data = issueLabelService.addLabelsToIssue(issueId, labelIds);
+        return ResponseEntity.ok(ApiResponse.ok(data));
+    }
+
+    @DeleteMapping("/issues/{issueId}/labels/{labelId}")
+    public ResponseEntity<ApiResponse<LabelResponse>> deleteLabelFromIssue(
+            @PathVariable Long issueId,
+            @PathVariable Long labelId) {
+        LabelResponse data = issueLabelService.deleteLabelFromIssue(issueId, labelId);
+        return ResponseEntity.ok(ApiResponse.ok(data));
     }
 }

src/main/java/com/issueDive/dto/IssueLabelsResponse.java

@@ -0,0 +1,39 @@
+package com.issueDive.dto;
+
+
+import com.issueDive.entity.Label;
+import lombok.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Getter
+@AllArgsConstructor
+@Builder
+public class IssueLabelsResponse {
+    private Long id;
+    private List<LabelSummary> labels;
+
+    @Getter
+    @AllArgsConstructor
+    @Builder
+    public static class LabelSummary {
+        private Long id;
+        private String name;
+    }
+
+    public static IssueLabelsResponse of(Long issueId, List<Label> labels) {
+        List<LabelSummary> summaries = new ArrayList<>();
+        for (Label label : labels) {
+            summaries.add(LabelSummary.builder()
+                    .id(label.getId())
+                    .name(label.getName())
+                    .build());
+        }
+
+        return IssueLabelsResponse.builder()
+                .id(issueId)
+                .labels(summaries)
+                .build();
+    }
+}

src/main/java/com/issueDive/entity/IssueLabel.java

@@ -0,0 +1,41 @@
+package com.issueDive.entity;
+
+import jakarta.persistence.*;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@NoArgsConstructor
+@AllArgsConstructor
+@Builder
+@Table(name = "issue_label")
+public class IssueLabel {
+
+    @EmbeddedId
+    private IssueLabelId id;
+
+    @MapsId("issueId")
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "issue_id", nullable = false)
+    private Issue issue;
+
+    @MapsId("labelId")
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "label_id", nullable = false)
+    private Label label;
+
+    @Column(name = "added_at", nullable = false, updatable = false)
+    private LocalDateTime addedAt;
+
+    @PrePersist
+    public void prePersist() {
+        if (addedAt == null) {
+            addedAt = LocalDateTime.now();
+        }
+    }
+}

src/main/java/com/issueDive/entity/IssueLabelId.java

@@ -0,0 +1,31 @@
+package com.issueDive.entity;
+
+import jakarta.persistence.Embeddable;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+@Embeddable
+@Getter
+@NoArgsConstructor
+@AllArgsConstructor
+public class IssueLabelId implements Serializable {
+    private Long issueId;
+    private Long labelId;
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof IssueLabelId that)) return false;
+        return Objects.equals(issueId, that.issueId) &&
+                Objects.equals(labelId, that.labelId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(issueId, labelId);
+    }
+}

src/main/java/com/issueDive/entity/Label.java

@@ -3,6 +3,7 @@
 import jakarta.persistence.*;
 import jakarta.validation.constraints.NotBlank;
 import lombok.*;
+
 import java.time.LocalDateTime;
 
 @Entity
@@ -13,7 +14,7 @@
 @Builder
 @Table(name = "label")
 public class Label {
-  
+
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;

src/main/java/com/issueDive/exception/GlobalExceptionHandler.java

@@ -47,10 +47,15 @@ public ResponseEntity<ErrorResponse> handleBaseException(BaseException ex) {
                 .body(ErrorResponse.of(ex.getErrorCode(), ex.getMessage()));
     }
 
+    @ExceptionHandler(IssueLabelNotFoundException.class)
+    public ResponseEntity<ErrorResponse> handleIssueLabelNotFound(IssueLabelNotFoundException e) {
+        return ResponseEntity.status(HttpStatus.NOT_FOUND)
+                .body(ErrorResponse.of(ErrorCode.IssueLabelNotFound, e.getMessage()));
+    }
+
     @ExceptionHandler(MethodArgumentNotValidException.class)
     public ResponseEntity<ErrorResponse> handleValidationException(MethodArgumentNotValidException ex) {
         return ResponseEntity.badRequest()
                 .body(ErrorResponse.of(ErrorCode.ValidationError, "입력 값이 올바르지 않습니다."));
     }
-
 }

src/main/java/com/issueDive/exception/IssueLabelNotFoundException.java

@@ -0,0 +1,10 @@
+package com.issueDive.exception;
+
+public class IssueLabelNotFoundException extends NotFoundException {
+    public IssueLabelNotFoundException(String message) {
+        super(message);
+    }
+    public IssueLabelNotFoundException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

src/main/java/com/issueDive/repository/IssueLabelRepository.java

@@ -0,0 +1,17 @@
+package com.issueDive.repository;
+
+import com.issueDive.entity.Issue;
+import com.issueDive.entity.IssueLabel;
+import com.issueDive.entity.IssueLabelId;
+import com.issueDive.entity.Label;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.List;
+
+public interface IssueLabelRepository extends JpaRepository<IssueLabel, IssueLabelId> {
+    boolean existsByIssueAndLabel(Issue issue, Label label);
+    void deleteByIssueAndLabel(Issue issue, Label label);
+    List<IssueLabel> findAllByIssue(Issue issue);
+    void deleteByLabelId(Long labelId);
+    long countByLabel(Label label);
+}

src/main/java/com/issueDive/service/IssueLabelService.java

@@ -0,0 +1,102 @@
+package com.issueDive.service;
+
+import com.issueDive.dto.IssueLabelsResponse;
+import com.issueDive.dto.LabelResponse;
+import com.issueDive.entity.Issue;
+import com.issueDive.entity.IssueLabel;
+import com.issueDive.entity.IssueLabelId;
+import com.issueDive.entity.Label;
+import com.issueDive.exception.IssueLabelNotFoundException;
+import com.issueDive.exception.LabelNotFoundException;
+import com.issueDive.exception.NotFoundException;
+import com.issueDive.repository.IssueLabelRepository;
+import com.issueDive.repository.IssueRepository;
+import com.issueDive.repository.LabelRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+@Service
+@RequiredArgsConstructor
+public class IssueLabelService {
+
+    private final IssueRepository issueRepository;
+    private final LabelRepository labelRepository;
+    private final IssueLabelRepository issueLabelRepository;
+
+    @Transactional
+    public IssueLabelsResponse addLabelsToIssue(Long issueId, List<Long> labelIds){
+        Issue issue = issueRepository.findById(issueId)
+                .orElseThrow(() -> new NotFoundException("Issue not found"));
+
+        List<Label> labels = labelRepository.findAllById(labelIds);
+
+
+        Set<Long> foundIds = new HashSet<>();
+        for (Label label : labels) {
+            foundIds.add(label.getId());
+        }
+
+        Long missingId = null;
+        for (Long id : labelIds) {
+            if (!foundIds.contains(id)) {
+                missingId = id;
+                break;
+            }
+        }
+        if (missingId != null) {
+            throw new LabelNotFoundException("Label not found: id=" + missingId);
+        }
+
+
+        for (Label label : labels) {
+            boolean alreadyExists = issueLabelRepository.existsByIssueAndLabel(issue, label);
+            if (!alreadyExists) {
+                IssueLabel issueLabel = IssueLabel.builder()
+                        .id(new IssueLabelId(issue.getId(), label.getId()))
+                        .issue(issue)
+                        .label(label)
+                        .build();
+                issueLabelRepository.save(issueLabel);
+            }
+        }
+
+        List<Label> currentLabels = getLabelsOfIssue(issue);
+
+        return IssueLabelsResponse.of(issueId, currentLabels);
+    }
+
+    @Transactional(readOnly = true)
+    public List<Label> getLabelsOfIssue(Issue issue){
+        List<IssueLabel> mappings = issueLabelRepository.findAllByIssue(issue);
+        List<Label> currentLabels = new ArrayList<>();
+        for (IssueLabel issueLabel : mappings) {
+            currentLabels.add(issueLabel.getLabel());
+        }
+        return currentLabels;
+    }
+
+    @Transactional
+    public LabelResponse deleteLabelFromIssue(Long issueId, Long labelId){
+        Issue issue = issueRepository.findById(issueId)
+                .orElseThrow(() -> new NotFoundException("Issue not found"));
+        Label label = labelRepository.findById(labelId)
+                .orElseThrow(() -> new NotFoundException("Label not found"));
+
+        boolean exists = issueLabelRepository.existsByIssueAndLabel(issue, label);
+
+        if (!exists){
+            throw new IssueLabelNotFoundException("Label " + labelId + "is not attached to Issue " + issueId);
+        }
+
+        issueLabelRepository.deleteByIssueAndLabel(issue, label);
+
+        return LabelResponse.from(label);
+    }
+
+}

src/main/java/com/issueDive/service/IssueService.java

@@ -5,10 +5,6 @@
 import com.issueDive.dto.IssueResponse;
 import com.issueDive.dto.UpdateIssueRequest;
 import com.issueDive.entity.*;
-import com.issueDive.entity.Issue;
-import com.issueDive.entity.IssueStatus;
-import com.issueDive.entity.Label;
-import com.issueDive.entity.User;
 import com.issueDive.exception.ErrorCode;
 import com.issueDive.exception.NotFoundException;
 import com.issueDive.exception.ValidationException;

src/main/java/com/issueDive/service/LabelService.java

@@ -8,6 +8,7 @@
 import com.issueDive.exception.LabelNotFoundException;
 import com.issueDive.exception.ValidationException;
 import com.issueDive.repository.LabelRepository;
+import com.issueDive.repository.IssueLabelRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -19,7 +20,7 @@
 public class LabelService {
 
     private final LabelRepository labelRepository;
-
+    private final IssueLabelRepository issueLabelRepository;
     //라벨 생성
     @Transactional
     public LabelResponse createLabel(CreateLabelRequest request) {
@@ -90,6 +91,8 @@ public void deleteLabel(Long id) {
         if (!labelRepository.existsById(id)) {
             throw new LabelNotFoundException("Label not found: id=" + id);
         }
+
+        issueLabelRepository.deleteByLabelId(id);
         labelRepository.deleteById(id);
     }
 }