Recalculate avg post rating on every rate

backend/src/main/java/hr/algebra/socialnetwork/controller/PostController.java

@@ -71,10 +71,9 @@ public ResponseEntity<List<PostDTO>> getPostsByUserId(@PathVariable Long userId)
   }
 
   @PostMapping("/{id}/rate")
-  public ResponseEntity<Void> ratePost(
+  public ResponseEntity<Double> ratePost(
       @PathVariable Long id, Principal principal, @RequestParam int stars) {
-    postService.ratePost(id, principal.getName(), stars);
-    return ResponseEntity.ok().build();
+    return ResponseEntity.ok(postService.ratePost(id, principal.getName(), stars));
   }
 
   @PostMapping("/{id}/comments")

backend/src/main/java/hr/algebra/socialnetwork/repository/RatingRepository.java

@@ -1,8 +1,18 @@
 package hr.algebra.socialnetwork.repository;
 
+import hr.algebra.socialnetwork.model.Post;
 import hr.algebra.socialnetwork.model.Rating;
+import hr.algebra.socialnetwork.model.User;
+import java.util.Optional;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
 @Repository
-public interface RatingRepository extends CrudRepository<Rating, Long> {}
+public interface RatingRepository extends CrudRepository<Rating, Long> {
+  Optional<Rating> findByPostAndUser(Post post, User user);
+
+  @Query("SELECT AVG(r.stars) FROM Rating r WHERE r.post.id = :postId")
+  Double calculateAverageStarsForPost(@Param("postId") Long postId);
+}

backend/src/main/java/hr/algebra/socialnetwork/service/PostService.java

@@ -62,14 +62,26 @@ public List<PostDTO> getPostsByUserId(Long userId) {
     return postRepository.findAllByUserId(userId).stream().map(postDTOMapper).toList();
   }
 
-  public void ratePost(Long postId, String email, int stars) {
+  public double ratePost(Long postId, String email, int stars) {
     validateStars(stars);
 
     Post post = findPostById(postId);
     User user = findUserByEmail(email);
-    Rating rating = buildRating(post, user, stars);
+
+    Rating rating =
+        ratingRepository
+            .findByPostAndUser(post, user)
+            .map(
+                existing -> {
+                  existing.setStars(stars);
+                  existing.setUpdatedAt(LocalDateTime.now());
+                  return existing;
+                })
+            .orElseGet(() -> buildRating(post, user, stars));
 
     ratingRepository.save(rating);
+
+    return post.getAverageRating();
   }
 
   public void commentOnPost(Long postId, String email, String content) {

frontend/src/components/posts/PostItem.jsx

@@ -19,19 +19,24 @@ import {
 import CommentItem from "./CommentItem";
 
 const PostItem = ({ post }) => {
-  const [rating, setRating] = useState(0);
+  const [averageRating, setAverageRating] = useState(post.averageRating || 0);
   const [comment, setComment] = useState("");
   const [comments, setComments] = useState([]);
   const UID = getUID();
 
-  const handleRating = (value) => {
-    ratePost(post.id, value);
-    setRating(value);
+  const handleRating = async (value) => {
+    try {
+      const response = await ratePost(post.id, value);
+      if (typeof response.data === "number") {
+        setAverageRating(response.data);
+      }
+    } catch (e) {
+      console.error("Rating error:", e);
+    }
   };
 
   const handleAddComment = async () => {
     if (!comment.trim()) return;
-
     try {
       await commentOnPost(post.id, comment);
       setComment("");
@@ -42,33 +47,29 @@ const PostItem = ({ post }) => {
         setComments(updatedComments);
       }
     } catch (e) {
-      console.log("Comment error:", e);
+      console.error("Comment error:", e);
     }
   };
 
   const handleDeletePost = async () => {
-    console.log("Post: " + post.id);
     try {
       await deletePostById(post.id);
     } catch (e) {
-      console.log("Failed to delete post. " + e);
+      console.error("Failed to delete post:", e);
     }
   };
 
   useEffect(() => {
-    setRating(post.averageRating);
-
     const fetchComments = async () => {
       try {
         const response = await getCommentsForPost(post.id);
-        const comments = response.data;
+        const fetchedComments = response.data;
 
         if (
-          Array.isArray(comments) &&
-          comments.length > 0 &&
-          comments.some((c) => Object.keys(c).length > 0)
+          Array.isArray(fetchedComments) &&
+          fetchedComments.some((c) => Object.keys(c).length > 0)
         ) {
-          setComments(comments);
+          setComments(fetchedComments);
         }
       } catch (e) {
         console.error("Error fetching comments:", e);
@@ -92,7 +93,7 @@ const PostItem = ({ post }) => {
         <Avatar.Root
           size={"lg"}
           mb={4}
-          pos={"relative"}
+          pos="relative"
           _after={{
             content: '""',
             w: 5,
@@ -122,6 +123,11 @@ const PostItem = ({ post }) => {
       <Text fontSize="lg" fontWeight="semibold" mb={1} color="black">
         {post?.title || "Greska u post titleu"}
       </Text>
+
+      <Text fontSize="sm" color="gray.600" mb={2}>
+        Average Rating: {averageRating?.toFixed(1)} / 5
+      </Text>
+
       <Text fontSize="md" color="gray.700" mb={4}>
         {post?.content || "Greska u post contentu"}
       </Text>
@@ -149,7 +155,7 @@ const PostItem = ({ post }) => {
         </Text>
         <HStack spacing={1}>
           {[1, 2, 3, 4, 5].map((val) =>
-            val <= rating ? (
+            val <= Math.round(averageRating) ? (
               <FaStar
                 key={val}
                 color="gold"

frontend/src/services/postsService.js

@@ -77,7 +77,7 @@ export const ratePost = async (id, stars) => {
   try {
     return await axios.post(
       `${API_BASE}/api/v1/posts/${id}/rate?stars=${stars}`,
-      {}, // empty body, TODO check if recalculated average should be send
+      {},
       getAuthConfig(),
     );
   } catch (e) {