Feat: 메모 기능 구현 (#183)

src/main/java/com/back/domain/study/memo/controller/MemoController.java

@@ -0,0 +1,60 @@
+package com.back.domain.study.memo.controller;
+
+
+import com.back.domain.study.memo.dto.MemoRequestDto;
+import com.back.domain.study.memo.dto.MemoResponseDto;
+import com.back.domain.study.memo.service.MemoService;
+import com.back.global.common.dto.RsData;
+import com.back.global.security.user.CustomUserDetails;
+import jakarta.validation.Valid;
+import lombok.RequiredArgsConstructor;
+import org.springframework.format.annotation.DateTimeFormat;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.web.bind.annotation.*;
+
+import java.time.LocalDate;
+import java.util.List;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/api/memos")
+public class MemoController {
+    private final MemoService memoService;
+
+    // ==================== 생성 및 수정 ===================
+    // 메모 생성 및 수정
+    @PostMapping
+    public ResponseEntity<RsData<MemoResponseDto>> createOrUpdateMemo(
+            @AuthenticationPrincipal CustomUserDetails user,
+            @Valid @RequestBody MemoRequestDto request
+    ) {
+        Long userId = user.getUserId();
+        MemoResponseDto response = memoService.createOrUpdateMemo(userId, request);
+        return ResponseEntity.ok(RsData.success("메모가 저장되었습니다.", response));
+    }
+
+    // ==================== 조회 ===================
+    // 날짜별 메모 조회
+    @GetMapping
+    public ResponseEntity<RsData<MemoResponseDto>> getMemoByDate(
+            @AuthenticationPrincipal CustomUserDetails user,
+            @RequestParam @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) LocalDate date
+    ) {
+        Long userId = user.getUserId();
+        MemoResponseDto response = memoService.getMemoByDate(userId, date);
+        return ResponseEntity.ok(RsData.success("메모를 조회했습니다.", response));
+    }
+
+    // ==================== 삭제 ===================
+    // 메모 삭제
+    @DeleteMapping("/{memoId}")
+    public ResponseEntity<RsData<MemoResponseDto>> deleteMemo(
+            @AuthenticationPrincipal CustomUserDetails user,
+            @PathVariable Long memoId
+    ) {
+        Long userId = user.getUserId();
+        MemoResponseDto response = memoService.deleteMemo(userId, memoId);
+        return ResponseEntity.ok(RsData.success("메모가 삭제되었습니다.", response));
+    }
+}

src/main/java/com/back/domain/study/memo/dto/MemoRequestDto.java

@@ -0,0 +1,15 @@
+package com.back.domain.study.memo.dto;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDate;
+
+@Getter
+@NoArgsConstructor
+public class MemoRequestDto {
+    private LocalDate date;
+
+    private String description;
+
+}

src/main/java/com/back/domain/study/memo/dto/MemoResponseDto.java

@@ -0,0 +1,24 @@
+package com.back.domain.study.memo.dto;
+
+import com.back.domain.study.memo.entity.Memo;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDate;
+
+@Getter
+@NoArgsConstructor
+public class MemoResponseDto {
+    private Long id;
+    private LocalDate date;
+    private String description;
+
+    // 엔티티 -> DTO 변환
+    public static MemoResponseDto from(Memo memo) {
+        MemoResponseDto dto = new MemoResponseDto();
+        dto.id = memo.getId();
+        dto.date = memo.getDate();
+        dto.description = memo.getDescription();
+        return dto;
+    }
+}

src/main/java/com/back/domain/study/memo/entity/Memo.java

@@ -0,0 +1,38 @@
+package com.back.domain.study.memo.entity;
+
+import com.back.domain.user.entity.User;
+import com.back.global.entity.BaseEntity;
+import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDate;
+
+@Entity
+@Getter
+@NoArgsConstructor
+public class Memo extends BaseEntity {
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id", nullable = false)
+    private User user;
+
+    @Column(nullable = false)
+    private LocalDate date;
+
+    @Column(columnDefinition = "TEXT")
+    private String description;
+
+    // setter 사용 안하고 메서드를 이용
+    // 생성
+    public static Memo create(User user, LocalDate date, String description) {
+        Memo memo = new Memo();
+        memo.user = user;
+        memo.date = date;
+        memo.description = description;
+        return memo;
+    }
+    // 수정
+    public void update(String description) {
+        this.description = description;
+    }
+}

src/main/java/com/back/domain/study/memo/repository/MemoRepository.java

@@ -0,0 +1,15 @@
+package com.back.domain.study.memo.repository;
+
+import com.back.domain.study.memo.entity.Memo;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+import java.time.LocalDate;
+import java.util.Optional;
+
+@Repository
+public interface MemoRepository extends JpaRepository<Memo, Long> {
+    // 사용자의 날짜별 메모 조회
+    Optional<Memo> findByUserIdAndDate(Long userId, LocalDate date);
+
+}

src/main/java/com/back/domain/study/memo/service/MemoService.java

@@ -0,0 +1,81 @@
+package com.back.domain.study.memo.service;
+
+import com.back.domain.study.memo.dto.MemoRequestDto;
+import com.back.domain.study.memo.dto.MemoResponseDto;
+import com.back.domain.study.memo.entity.Memo;
+import com.back.domain.study.memo.repository.MemoRepository;
+import com.back.domain.user.entity.User;
+import com.back.domain.user.repository.UserRepository;
+import com.back.global.exception.CustomException;
+import com.back.global.exception.ErrorCode;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDate;
+import java.util.Optional;
+
+@Service
+@RequiredArgsConstructor
+@Transactional(readOnly = true)
+public class MemoService {
+    private final MemoRepository memoRepository;
+    private final UserRepository userRepository;
+
+    // ==================== 생성 및 수정 ===================
+    // 같은 날짜에 메모가 있으면 수정, 없으면 생성
+    @Transactional
+    public MemoResponseDto createOrUpdateMemo(Long userId, MemoRequestDto request) {
+        // 사용자 조회
+        User user = userRepository.findById(userId)
+                .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
+
+        // 같은 날짜의 메모가 있는지 확인
+        Optional<Memo> existingMemo = memoRepository.findByUserIdAndDate(userId, request.getDate());
+
+        Memo memo;
+        if (existingMemo.isPresent()) {
+            // 기존 메모 수정
+            memo = existingMemo.get();
+            memo.update(request.getDescription());
+        } else {
+            // 새 메모 생성
+            memo = Memo.create(user, request.getDate(), request.getDescription());
+            memo = memoRepository.save(memo);
+        }
+
+        return MemoResponseDto.from(memo);
+    }
+
+    // ==================== 조회 ===================
+    public MemoResponseDto getMemoByDate(Long userId, LocalDate date) {
+        // 사용자 존재 확인
+        if (!userRepository.existsById(userId)) {
+            throw new CustomException(ErrorCode.USER_NOT_FOUND);
+        }
+
+        // 메모를 조회해서 해당 날짜에 없으면 null
+        return memoRepository.findByUserIdAndDate(userId, date)
+                .map(MemoResponseDto::from)
+                .orElse(null);
+    }
+
+    // ==================== 삭제 ===================
+    @Transactional
+    public MemoResponseDto deleteMemo(Long userId, Long memoId) {
+        Memo memo = memoRepository.findById(memoId)
+                .orElseThrow(() -> new CustomException(ErrorCode.MEMO_NOT_FOUND));
+
+        // 권한 확인
+        if (!memo.getUser().getId().equals(userId)) {
+            throw new CustomException(ErrorCode.FORBIDDEN);
+        }
+
+        MemoResponseDto memoDto = MemoResponseDto.from(memo);
+
+        memoRepository.delete(memo);
+        // 삭제된 메모 정보 반환
+        return memoDto;
+    }
+
+}

src/main/java/com/back/global/exception/ErrorCode.java

@@ -56,6 +56,9 @@ public enum ErrorCode {
     // ======================== 학습 기록 관련 ========================
     DURATION_MISMATCH(HttpStatus.BAD_REQUEST, "RECORD_001", "받은 duration과 계산된 duration이 5초 이상 차이납니다."),
 
+    // ======================== 알림 관련 ========================
+    MEMO_NOT_FOUND(HttpStatus.NOT_FOUND, "MEMO_001", "존재하지 않는 메모입니다."),
+
     // ======================== 알림 관련 ========================
     NOTIFICATION_NOT_FOUND(HttpStatus.NOT_FOUND, "NOTIFICATION_001", "존재하지 않는 알림입니다."),
     NOTIFICATION_FORBIDDEN(HttpStatus.FORBIDDEN, "NOTIFICATION_002", "알림에 대한 접근 권한이 없습니다."),