feat: view like

src/timeline-service/src/main/java/org/palette/easeltimelineservice/service/PaintLikeService.java

@@ -0,0 +1,33 @@
+package org.palette.easeltimelineservice.service;
+
+import lombok.RequiredArgsConstructor;
+import org.palette.easeltimelineservice.util.RedisKeyUtil;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.stereotype.Service;
+
+import java.util.Optional;
+
+import static org.palette.easeltimelineservice.service.RedisKeyConstants.LIKED_PAINT_PREFIX;
+
+
+@Service
+@RequiredArgsConstructor
+public class PaintLikeService {
+
+    private final RedisTemplate<String, String> redisTemplate;
+
+    public boolean isLiked(Long userId, Long paintId) {
+        String key = RedisKeyUtil.constructKey(LIKED_PAINT_PREFIX.getKey(), paintId);
+        return Optional.ofNullable(redisTemplate.opsForSet().isMember(key, userId.toString())).orElse(false);
+    }
+
+    public void like(Long userId, Long paintId) {
+        String key = RedisKeyUtil.constructKey(LIKED_PAINT_PREFIX.getKey(), paintId);
+        redisTemplate.opsForSet().add(key, userId.toString());
+    }
+
+    public void unlike(Long userId, Long paintId) {
+        String key = RedisKeyUtil.constructKey(LIKED_PAINT_PREFIX.getKey(), paintId);
+        redisTemplate.opsForSet().remove(key, userId.toString());
+    }
+}

src/timeline-service/src/main/java/org/palette/easeltimelineservice/service/PaintMetricsService.java

@@ -49,12 +49,8 @@ public void incrementViewCount(final Long aLong) {
     }
 
     private void changeMetricCount(final Long pid, final String metric, final int delta) {
-        redistemplate.opsForHash()
-                .increment(
-                        RedisKeyUtil.constructKey(RedisKeyConstants.METRICS_PREFIX.getKey(), pid),
-                        metric,
-                        delta
-                );
+        String key = RedisKeyUtil.constructKey(RedisKeyConstants.METRICS_PREFIX.getKey(), metric, pid);
+        redistemplate.opsForValue().increment(key, delta);
     }
 
     public PaintMetrics getPaintMetrics(final Long pid) {

src/timeline-service/src/main/java/org/palette/easeltimelineservice/service/PaintResponse.java

@@ -65,7 +65,7 @@ public static PaintResponse of(Paint paint, PaintMetrics metrics) {
                 metrics.replyCount(),
                 metrics.repaintCount(),
                 metrics.likeCount(),
-                false,
+                isLiked,
                 false,
                 false,
                 metrics.viewCount(),

src/timeline-service/src/main/java/org/palette/easeltimelineservice/service/RedisKeyConstants.java

@@ -8,7 +8,8 @@
 public enum RedisKeyConstants {
     FOLLOWER_PAINT_TIMELINE_PREFIX("follow_timeline"),
     PAINT_PREFIX("paint"),
-    METRICS_PREFIX("metrics");
+    METRICS_PREFIX("metrics"),
+    LIKED_PAINT_PREFIX("liked_paint");
 
     private final String key;
 }

src/timeline-service/src/main/java/org/palette/easeltimelineservice/usecase/TimelineUsecase.java

@@ -22,6 +22,7 @@ public class TimelineUsecase {
     private final FollowerPaintMapService followerPaintMapService;
     private final PaintCacheService paintCacheService;
     private final PaintMetricsService paintMetricsService;
+    private final PaintLikeService paintLikeService;
 
     public void handlePaintCreatedEvent(PaintCreatedEvent paintCreatedEvent) {
         final GFollowerIdsResponse followerIds = gRPCSocialClient.getFollowerIds(paintCreatedEvent.authorId());
@@ -37,16 +38,20 @@ public List<PaintResponse> getFollowingTimeline(final Long userId) {
         final List<Paint> paints = paintCacheService.getPaints(paintIds);
         return paints.stream().map(paint -> {
                     PaintMetrics metrics = paintMetricsService.getPaintMetrics(paint.getId());
-                    return PaintResponse.of(paint, metrics);
+                    final boolean liked = paintLikeService.isLiked(userId, paint.getId());
+                    return PaintResponse.of(paint, metrics, liked);
                 }
         ).toList();
     }
 
+
     public void handleLikedPaintEvent(final LikedPaintEvent likedPaintEvent) {
+        paintLikeService.like(likedPaintEvent.likingUserId(), likedPaintEvent.paintId());
         paintMetricsService.incrementLikeCount(likedPaintEvent.paintId());
     }
 
     public void handleUnlikedPaintEvent(final UnlikedPaintEvent unlikedPaintEvent) {
+        paintLikeService.unlike(unlikedPaintEvent.unlikingUserId(), unlikedPaintEvent.paintId());
         paintMetricsService.decrementLikeCount(unlikedPaintEvent.paintId());
     }
 
@@ -61,7 +66,8 @@ public List<PaintResponse> getForYouTimeline(final Long userId) {
 
         return filteredPaints.stream().map(paint -> {
                     PaintMetrics metrics = paintMetricsService.getPaintMetrics(paint.getId());
-                    return PaintResponse.of(paint, metrics);
+                    final boolean liked = paintLikeService.isLiked(userId, paint.getId());
+                    return PaintResponse.of(paint, metrics, liked);
                 }
         ).toList();
     }

src/timeline-service/src/main/java/org/palette/easeltimelineservice/util/RedisKeyUtil.java

@@ -11,6 +11,10 @@ public static String constructKey(String prefix, Long id) {
         return prefix + ":" + id;
     }
 
+    public static String constructKey(String prefix, String metric, Long id) {
+        return prefix + ":" + metric + ":" + id;
+    }
+
     public static List<String> constructKeys(final String prefix, final List<Long> ids) {
         return ids.stream()
                 .map(paintId -> constructKey(prefix, paintId))