feat: 총동연 피드 랭킹 스냅샷 조회 API 추가 및 가중치 계산 중복 제거

src/main/java/ddingdong/ddingdongBE/domain/feed/api/AdminFeedApi.java

@@ -31,4 +31,15 @@ List<AdminClubFeedRankingResponse> getClubFeedRanking(
             @RequestParam("year") @Min(value = 2000, message = "year는 2000 이상이어야 합니다.") @Max(value = 2100, message = "year는 2100 이하여야 합니다.") int year,
             @RequestParam("month") @Min(value = 1, message = "month는 1 이상이어야 합니다.") @Max(value = 12, message = "month는 12 이하여야 합니다.") int month
     );
+
+    @Operation(summary = "총동연 피드 랭킹 스냅샷 조회 API")
+    @ApiResponse(responseCode = "200", description = "동아리별 피드 랭킹 스냅샷 조회 성공",
+            content = @Content(array = @ArraySchema(schema = @Schema(implementation = AdminClubFeedRankingResponse.class))))
+    @ResponseStatus(HttpStatus.OK)
+    @SecurityRequirement(name = "AccessToken")
+    @GetMapping("/ranking/snapshot")
+    List<AdminClubFeedRankingResponse> getClubFeedRankingSnapshot(
+            @RequestParam("year") @Min(value = 2000, message = "year는 2000 이상이어야 합니다.") @Max(value = 2100, message = "year는 2100 이하여야 합니다.") int year,
+            @RequestParam("month") @Min(value = 1, message = "month는 1 이상이어야 합니다.") @Max(value = 12, message = "month는 12 이하여야 합니다.") int month
+    );
 }

src/main/java/ddingdong/ddingdongBE/domain/feed/controller/AdminFeedController.java

@@ -21,4 +21,11 @@ public List<AdminClubFeedRankingResponse> getClubFeedRanking(int year, int month
                 feedRankingService.getClubFeedRanking(year, month)
         );
     }
+
+    @Override
+    public List<AdminClubFeedRankingResponse> getClubFeedRankingSnapshot(int year, int month) {
+        return AdminClubFeedRankingResponse.from(
+                feedRankingService.getClubFeedRankingSnapshot(year, month)
+        );
+    }
 }

src/main/java/ddingdong/ddingdongBE/domain/feed/repository/FeedMonthlyRankingRepository.java

@@ -10,4 +10,7 @@ public interface FeedMonthlyRankingRepository extends JpaRepository<FeedMonthlyR
 
     List<FeedMonthlyRanking> findAllByTargetYearAndTargetMonthAndRanking(
             int targetYear, int targetMonth, int ranking);
+
+    List<FeedMonthlyRanking> findAllByTargetYearAndTargetMonthOrderByRankingAsc(
+            int targetYear, int targetMonth);
 }

src/main/java/ddingdong/ddingdongBE/domain/feed/service/FeedRankingService.java

@@ -9,4 +9,6 @@ public interface FeedRankingService {
     List<ClubFeedRankingQuery> getClubFeedRanking(int year, int month);
 
     ClubMonthlyStatusQuery getClubMonthlyStatus(Long userId, int year, int month);
+
+    List<ClubFeedRankingQuery> getClubFeedRankingSnapshot(int year, int month);
 }

src/main/java/ddingdong/ddingdongBE/domain/feed/service/GeneralFeedRankingService.java

@@ -2,6 +2,8 @@
 
 import ddingdong.ddingdongBE.domain.club.entity.Club;
 import ddingdong.ddingdongBE.domain.club.service.ClubService;
+import ddingdong.ddingdongBE.domain.feed.entity.FeedMonthlyRanking;
+import ddingdong.ddingdongBE.domain.feed.repository.FeedMonthlyRankingRepository;
 import ddingdong.ddingdongBE.domain.feed.repository.FeedRepository;
 import ddingdong.ddingdongBE.domain.feed.repository.dto.MonthlyFeedRankingDto;
 import ddingdong.ddingdongBE.domain.feed.service.dto.query.ClubFeedRankingQuery;
@@ -24,6 +26,7 @@ public class GeneralFeedRankingService implements FeedRankingService {
     private static final int COMMENT_WEIGHT = 5;
 
     private final FeedRepository feedRepository;
+    private final FeedMonthlyRankingRepository feedMonthlyRankingRepository;
     private final ClubService clubService;
 
     @Override
@@ -82,16 +85,39 @@ private int getLastMonthRank(Long clubId, int year, int month) {
                 .orElse(0);
     }
 
-    private ClubFeedRankingQuery toClubFeedRankingQuery(int rank, MonthlyFeedRankingDto rawRanking) {
-        long feedScore = rawRanking.getFeedCount() * FEED_WEIGHT;
-        long viewScore = rawRanking.getViewCount() * VIEW_WEIGHT;
-        long likeScore = rawRanking.getLikeCount() * LIKE_WEIGHT;
-        long commentScore = rawRanking.getCommentCount() * COMMENT_WEIGHT;
+    @Override
+    public List<ClubFeedRankingQuery> getClubFeedRankingSnapshot(int year, int month) {
+        List<FeedMonthlyRanking> snapshots = feedMonthlyRankingRepository
+                .findAllByTargetYearAndTargetMonthOrderByRankingAsc(year, month);
+
+        return snapshots.stream()
+                .map(this::toClubFeedRankingQueryFromSnapshot)
+                .toList();
+    }
+
+    private ClubFeedRankingQuery toClubFeedRankingQuery(int rank, Long clubId, String clubName,
+            long feedCount, long viewCount, long likeCount, long commentCount) {
+        long feedScore = feedCount * FEED_WEIGHT;
+        long viewScore = viewCount * VIEW_WEIGHT;
+        long likeScore = likeCount * LIKE_WEIGHT;
+        long commentScore = commentCount * COMMENT_WEIGHT;
         long totalScore = feedScore + viewScore + likeScore + commentScore;
-        return ClubFeedRankingQuery.of(rank, rawRanking.getClubId(), rawRanking.getClubName(),
+        return ClubFeedRankingQuery.of(rank, clubId, clubName,
                 feedScore, viewScore, likeScore, commentScore, totalScore);
     }
 
+    private ClubFeedRankingQuery toClubFeedRankingQueryFromSnapshot(FeedMonthlyRanking snapshot) {
+        return toClubFeedRankingQuery(snapshot.getRanking(), snapshot.getClubId(), snapshot.getClubName(),
+                snapshot.getFeedCount(), snapshot.getViewCount(),
+                snapshot.getLikeCount(), snapshot.getCommentCount());
+    }
+
+    private ClubFeedRankingQuery toClubFeedRankingQuery(int rank, MonthlyFeedRankingDto rawRanking) {
+        return toClubFeedRankingQuery(rank, rawRanking.getClubId(), rawRanking.getClubName(),
+                rawRanking.getFeedCount(), rawRanking.getViewCount(),
+                rawRanking.getLikeCount(), rawRanking.getCommentCount());
+    }
+
     private long calculateScore(MonthlyFeedRankingDto rawRanking) {
         return rawRanking.getFeedCount() * FEED_WEIGHT
                 + rawRanking.getViewCount() * VIEW_WEIGHT

src/test/java/ddingdong/ddingdongBE/domain/feed/service/GeneralFeedRankingServiceTest.java

@@ -5,12 +5,15 @@
 
 import ddingdong.ddingdongBE.common.fixture.ClubFixture;
 import ddingdong.ddingdongBE.common.fixture.FeedFixture;
+import ddingdong.ddingdongBE.common.fixture.FeedMonthlyRankingFixture;
 import ddingdong.ddingdongBE.common.fixture.UserFixture;
 import ddingdong.ddingdongBE.common.support.TestContainerSupport;
 import ddingdong.ddingdongBE.domain.club.entity.Club;
 import ddingdong.ddingdongBE.domain.club.repository.ClubRepository;
 import ddingdong.ddingdongBE.domain.feed.entity.Feed;
+import ddingdong.ddingdongBE.domain.feed.entity.FeedMonthlyRanking;
 import ddingdong.ddingdongBE.domain.feed.repository.FeedCommentRepository;
+import ddingdong.ddingdongBE.domain.feed.repository.FeedMonthlyRankingRepository;
 import ddingdong.ddingdongBE.domain.feed.repository.FeedRepository;
 import ddingdong.ddingdongBE.domain.feed.service.dto.query.ClubFeedRankingQuery;
 import ddingdong.ddingdongBE.domain.feed.service.dto.query.ClubMonthlyStatusQuery;
@@ -41,6 +44,9 @@ class GeneralFeedRankingServiceTest extends TestContainerSupport {
     @Autowired
     private FeedCommentRepository feedCommentRepository;
 
+    @Autowired
+    private FeedMonthlyRankingRepository feedMonthlyRankingRepository;
+
     @Autowired
     private UserRepository userRepository;
 
@@ -384,4 +390,64 @@ void getClubMonthlyStatus_januaryLooksAtDecember() {
             softly.assertThat(result.lastMonthRank()).isEqualTo(1);
         });
     }
+
+    @DisplayName("피드 랭킹 스냅샷 조회 - 성공: 스냅샷이 있으면 ranking 순서대로 조회된다")
+    @Test
+    void getClubFeedRankingSnapshot_sortedByRanking() {
+        // given
+        FeedMonthlyRanking rank1 = FeedMonthlyRankingFixture.create(
+                1L, "동아리A", 10, 100, 50, 20, 2026, 2, 1);
+        FeedMonthlyRanking rank2 = FeedMonthlyRankingFixture.create(
+                2L, "동아리B", 5, 50, 25, 10, 2026, 2, 2);
+        FeedMonthlyRanking rank3 = FeedMonthlyRankingFixture.create(
+                3L, "동아리C", 3, 30, 15, 5, 2026, 2, 3);
+        feedMonthlyRankingRepository.saveAll(List.of(rank1, rank2, rank3));
+
+        // when
+        List<ClubFeedRankingQuery> result = feedRankingService.getClubFeedRankingSnapshot(2026, 2);
+
+        // then
+        assertThat(result).hasSize(3);
+        assertSoftly(softly -> {
+            softly.assertThat(result.get(0).rank()).isEqualTo(1);
+            softly.assertThat(result.get(0).clubName()).isEqualTo("동아리A");
+            softly.assertThat(result.get(1).rank()).isEqualTo(2);
+            softly.assertThat(result.get(1).clubName()).isEqualTo("동아리B");
+            softly.assertThat(result.get(2).rank()).isEqualTo(3);
+            softly.assertThat(result.get(2).clubName()).isEqualTo("동아리C");
+        });
+    }
+
+    @DisplayName("피드 랭킹 스냅샷 조회 - 성공: 스냅샷이 없으면 빈 리스트가 반환된다")
+    @Test
+    void getClubFeedRankingSnapshot_emptyWhenNoSnapshot() {
+        // when
+        List<ClubFeedRankingQuery> result = feedRankingService.getClubFeedRankingSnapshot(2026, 2);
+
+        // then
+        assertThat(result).isEmpty();
+    }
+
+    @DisplayName("피드 랭킹 스냅샷 조회 - 성공: 가중치 점수가 정확히 계산된다")
+    @Test
+    void getClubFeedRankingSnapshot_calculatesWeightedScores() {
+        // given — feedCount=10, viewCount=100, likeCount=50, commentCount=20
+        FeedMonthlyRanking snapshot = FeedMonthlyRankingFixture.create(
+                1L, "동아리A", 10, 100, 50, 20, 2026, 2, 1);
+        feedMonthlyRankingRepository.save(snapshot);
+
+        // when
+        List<ClubFeedRankingQuery> result = feedRankingService.getClubFeedRankingSnapshot(2026, 2);
+
+        // then
+        // feedScore=10*10=100, viewScore=100*1=100, likeScore=50*3=150, commentScore=20*5=100, total=450
+        assertThat(result).hasSize(1);
+        assertSoftly(softly -> {
+            softly.assertThat(result.get(0).feedScore()).isEqualTo(100L);
+            softly.assertThat(result.get(0).viewScore()).isEqualTo(100L);
+            softly.assertThat(result.get(0).likeScore()).isEqualTo(150L);
+            softly.assertThat(result.get(0).commentScore()).isEqualTo(100L);
+            softly.assertThat(result.get(0).totalScore()).isEqualTo(450L);
+        });
+    }
 }