[Feat] 기록 삭제 시 랭킹 집계 테이블에 반영되는 기능 추가

src/main/java/org/example/studylog/event/RecordDeletedEvent.java

@@ -0,0 +1,12 @@
+package org.example.studylog.event;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public class RecordDeletedEvent {
+    private final Long userId;
+    private final int year;
+    private final int month;
+}

src/main/java/org/example/studylog/event/listener/RecordEventListener.java

@@ -1,9 +1,9 @@
 package org.example.studylog.event.listener;
 
-import jakarta.transaction.Transactional;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.example.studylog.event.RecordCreatedEvent;
+import org.example.studylog.event.RecordDeletedEvent;
 import org.example.studylog.repository.custom.RankingRepositoryImpl;
 import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Component;
@@ -20,8 +20,15 @@ public class RecordEventListener {
 
     @Async
     @TransactionalEventListener(phase = AFTER_COMMIT)
-    public void handleRecordCreated(RecordCreatedEvent event){
-        log.info("랭킹 집계 이벤트 발행: USER={}, YEAR={}, MONTH={}", event.getUserId(), event.getYear(), event.getMonth());
+    public void handleRecordCreated(RecordCreatedEvent event) {
+        log.info("랭킹 집계 증가 이벤트 발행: USER={}, YEAR={}, MONTH={}", event.getUserId(), event.getYear(), event.getMonth());
         rankingRepository.incrementOrInsert(event.getUserId(), event.getYear(), event.getMonth());
     }
+
+    @Async
+    @TransactionalEventListener(phase = AFTER_COMMIT)
+    public void handleRecordDeleted(RecordDeletedEvent event){
+        log.info("랭킹 집계 감소 이벤트 발행: USER={}, YEAR={}, MONTH={}", event.getUserId(), event.getYear(), event.getMonth());
+        rankingRepository.decrement(event.getUserId(), event.getYear(), event.getMonth());
+    }
 }

src/main/java/org/example/studylog/repository/custom/RankingRepositoryCustom.java

@@ -7,4 +7,5 @@
 public interface RankingRepositoryCustom {
     List<RankingResponseDTO> findFriendRankings(int year, int month, List<Long> userIds);
     void incrementOrInsert(Long userId, int year, int month);
+    void decrement(Long userId, int year, int month);
 }

src/main/java/org/example/studylog/repository/custom/RankingRepositoryImpl.java

@@ -5,6 +5,7 @@
 import com.querydsl.jpa.impl.JPAQueryFactory;
 import jakarta.transaction.Transactional;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import org.example.studylog.dto.RankingResponseDTO;
 import org.example.studylog.entity.QUserMonthlyStat;
 import org.example.studylog.entity.UserMonthlyStat;
@@ -13,6 +14,7 @@
 import org.springframework.stereotype.Repository;
 import java.util.List;
 
+@Slf4j
 @Repository
 @RequiredArgsConstructor
 public class RankingRepositoryImpl implements RankingRepositoryCustom{
@@ -85,4 +87,27 @@ public void incrementOrInsert(Long userId, int year, int month) {
                     .execute();
         }
     }
+
+    @Override
+    @Transactional
+    public void decrement(Long userId, int year, int month) {
+        QUserMonthlyStat stat = QUserMonthlyStat.userMonthlyStat;
+        // 존재하는 경우에만 recordCount - 1
+        long updated = queryFactory
+                .update(stat)
+                .set(stat.recordCount, stat.recordCount.subtract(1))
+                .where(
+                        stat.user.id.eq(userId),
+                        stat.year.eq(year),
+                        stat.month.eq(month),
+                        stat.recordCount.gt(0) // 음수 방지
+                )
+                .execute();
+
+        // 혹시라도 업데이트된 행이 없다면 (예: 존재하지 않거나 이미 0인 경우)
+        if (updated == 0) {
+            log.warn("user_monthly_stat에 행이 없거나 recordCount가 이미 0: userId={}, year={}, month={}",
+                    userId, year, month);
+        }
+    }
 }

src/main/java/org/example/studylog/service/StudyRecordService.java

@@ -11,6 +11,7 @@
 import org.example.studylog.entity.Streak;
 import org.example.studylog.entity.user.User;
 import org.example.studylog.event.RecordCreatedEvent;
+import org.example.studylog.event.RecordDeletedEvent;
 import org.example.studylog.event.RecordEvent;
 import org.example.studylog.repository.CategoryRepository;
 import org.example.studylog.repository.StudyRecordRepository;
@@ -83,6 +84,11 @@ public void deleteStudyRecord(User user, Long recordId) {
         user.decrementRecordCount();
         log.info("기록 삭제 이벤트 발행: USER={}, ID={}", user.getOauthId(), recordId);
         eventPublisher.publishEvent(new RecordEvent(user));
+        LocalDate createDate = studyRecord.getCreateDate().toLocalDate();
+        int year = createDate.getYear();
+        int month = createDate.getMonthValue();
+        log.info("기록 삭제 내역을 랭킹 집계 테이블에 반영: USER={}, YEAR={}, MONTH={}", user.getId(), year, month);
+        eventPublisher.publishEvent(new RecordDeletedEvent(user.getId(), year, month));
 
         log.info("기록 삭제 완료: ID={}", recordId);
     }