[REFACTOR] 별점 EMA 도입

src/main/java/org/sopt/poti/domain/groupbuy/entity/GroupBuyPost.java

@@ -72,6 +72,15 @@ public class GroupBuyPost extends BaseTimeEntity {
   @Column(name = "current_quantity", nullable = false)
   private int currentQuantity;  // 현재 인원
 
+  @Column(name = "rating_avg", nullable = true)
+  private double ratingAvg = 0.0; //공구 글 당 평점
+
+  @Column(name = "rating_sum", nullable = true)
+  private long ratingSum = 0L;
+
+  @Column(name = "rating_count", nullable = true)
+  private int ratingCount = 0;
+
   @Enumerated(EnumType.STRING)
   @Column(nullable = false, length = 30)
   private GroupBuyPostStatus status;
@@ -198,4 +207,20 @@ public void completePostDelivery() {
     this.status = GroupBuyPostStatus.DELIVERED;
   }
 
+  public void addRating(int score) {
+    validateScore(score);
+
+    this.ratingSum += score;
+    this.ratingCount += 1;
+
+    double avg = (double) this.ratingSum / this.ratingCount;
+    this.ratingAvg = Math.round(avg * 10) / 10.0;
+  }
+
+  private void validateScore(int score) {
+    if (score < 1 || score > 5) {
+      throw new BusinessException(ErrorStatus.INVALID_RATING_SCORE);
+    }
+  }
+
 }

src/main/java/org/sopt/poti/domain/groupbuy/repository/GroupBuyRepository.java

@@ -1,10 +1,12 @@
 package org.sopt.poti.domain.groupbuy.repository;
 
+import jakarta.persistence.LockModeType;
 import java.util.List;
 import java.util.Optional;
 import org.sopt.poti.domain.groupbuy.entity.GroupBuyPost;
 import org.sopt.poti.domain.groupbuy.entity.GroupBuyPostStatus;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
@@ -28,4 +30,8 @@ List<GroupBuyPost> findByLeader_IdAndStatusInOrderByCreatedAtDesc(Long leaderId,
       List<GroupBuyPostStatus> statuses);
 
   boolean existsByOrderNumber(String orderNumber);
+
+  @Lock(LockModeType.PESSIMISTIC_WRITE)
+  @Query("select p from GroupBuyPost p where p.id = :postId")
+  java.util.Optional<GroupBuyPost> findByIdWithLock(@Param("postId") Long postId);
 }

src/main/java/org/sopt/poti/domain/groupbuy/service/GroupBuyService.java

@@ -497,4 +497,22 @@ public GroupBuySaleDetailResponse getGroupBuyPostDetailForSale(Long userId, Long
   public List<String> searchTitlesNgram(Long artistId, String keyword) {
     return groupBuyRepository.findTitlesByNgram(artistId, keyword, 50);
   }
+
+  @Transactional
+  public void addPostRating(Long postId, int score) {
+    GroupBuyPost post = groupBuyRepository.findByIdWithLock(postId)
+        .orElseThrow(() -> new BusinessException(ErrorStatus.POST_NOT_FOUND));
+
+    post.addRating(score);
+  }
+
+  @Transactional
+  public GroupBuyPost getPostWithLock(Long postId) {
+    return groupBuyRepository.findByIdWithLock(postId)
+        .orElseThrow(() -> new BusinessException(ErrorStatus.POST_NOT_FOUND));
+  }
+
+  public int countPostsByLeader(Long leaderId) {
+    return groupBuyRepository.countByLeader_Id(leaderId);
+  }
 }

src/main/java/org/sopt/poti/domain/review/application/ReviewApplicationService.java

@@ -0,0 +1,54 @@
+package org.sopt.poti.domain.review.application;
+
+import lombok.RequiredArgsConstructor;
+import org.sopt.poti.domain.groupbuy.entity.GroupBuyPost;
+import org.sopt.poti.domain.groupbuy.service.GroupBuyService;
+import org.sopt.poti.domain.order.entity.Order;
+import org.sopt.poti.domain.order.service.OrderService;
+import org.sopt.poti.domain.review.dto.request.ReviewRequest;
+import org.sopt.poti.domain.review.service.ReviewService;
+import org.sopt.poti.domain.user.service.UserService;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+@Transactional
+public class ReviewApplicationService {
+
+  private final OrderService orderService;
+  private final ReviewService reviewService;
+  private final UserService userService;
+  private final GroupBuyService groupBuyService;
+
+  @Transactional
+  public Long createReview(Long writerUserId, ReviewRequest request) {
+    Long orderId = request.transactionId();
+    int score = request.star();
+
+    Order order = orderService.getOrderById(orderId);
+
+    orderService.validateDelivered(order);
+    orderService.validateOrderOwner(order, writerUserId);
+
+    Long reviewId = reviewService.createReviewEntity(writerUserId, order, score);
+
+    Long sellerId = order.getGroupBuyPost().getLeader().getId();
+    Long postId = order.getGroupBuyPost().getId();
+
+    // 1 팟 내부 단순평균 업데이트
+    groupBuyService.addPostRating(postId, score);
+
+    // 2 최신 팟 상태 조회 및 데이터 수집
+    GroupBuyPost post = groupBuyService.getPostWithLock(postId);
+    int reviewCount = post.getRatingCount();
+    double postAvg = post.getRatingAvg();
+
+    int postCount = groupBuyService.countPostsByLeader(sellerId);
+
+    // 3 판매자 평점 반영
+    userService.applyPostContribution(sellerId, postId, postAvg, reviewCount, postCount);
+
+    return reviewId;
+  }
+}

src/main/java/org/sopt/poti/domain/review/controller/ReviewController.java

@@ -4,33 +4,37 @@
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
+import org.sopt.poti.domain.review.application.ReviewApplicationService;
 import org.sopt.poti.domain.review.dto.request.ReviewRequest;
 import org.sopt.poti.domain.review.dto.response.ReviewResponse;
-import org.sopt.poti.domain.review.service.ReviewService;
 import org.sopt.poti.global.common.ApiResponse;
 import org.sopt.poti.global.common.SuccessStatus;
 import org.sopt.poti.global.security.UserPrincipal;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
-import org.springframework.web.bind.annotation.*;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
 
 @RestController
 @RequiredArgsConstructor
 @Tag(name = "Reviews", description = "리뷰 관련 API")
 @RequestMapping("/api/v1/reviews")
 public class ReviewController {
 
-    private final ReviewService reviewService;
+  private final ReviewApplicationService reviewApplicationService;
 
-    @PostMapping
-    @Operation(summary = "리뷰 작성(별점 작성)", description = "로그인 한 유저가 거래가 완료된 주문에 대해 별점을 줍니다.")
-    public ResponseEntity<ApiResponse<ReviewResponse>> createReview(
-            @AuthenticationPrincipal UserPrincipal userPrincipal,
-            @Valid @RequestBody ReviewRequest request
-    ) {
-        Long reviewId = reviewService.createReview(userPrincipal.getUserId(), request);
-        return ResponseEntity
-                .status(SuccessStatus.CREATED.getHttpStatus())
-                .body(ApiResponse.created(SuccessStatus.CREATED, new ReviewResponse(reviewId)));
-    }
+  @PostMapping
+  @Operation(summary = "리뷰 작성(별점 작성)", description = "로그인 한 유저가 거래가 완료된 주문에 대해 별점을 줍니다.")
+  public ResponseEntity<ApiResponse<ReviewResponse>> createReview(
+      @AuthenticationPrincipal UserPrincipal userPrincipal,
+      @Valid @RequestBody ReviewRequest request
+  ) {
+    Long reviewId = reviewApplicationService.createReview(userPrincipal.getUserId(), request);
+
+    return ResponseEntity
+        .status(SuccessStatus.CREATED.getHttpStatus())
+        .body(ApiResponse.created(SuccessStatus.CREATED, new ReviewResponse(reviewId)));
+  }
 }

src/main/java/org/sopt/poti/domain/review/repository/ReviewRepository.java

@@ -2,15 +2,10 @@
 
 import org.sopt.poti.domain.review.entity.Review;
 import org.springframework.data.jpa.repository.JpaRepository;
-import org.springframework.data.jpa.repository.Query;
-import org.springframework.data.repository.query.Param;
 
 public interface ReviewRepository extends JpaRepository<Review, Long> {
 
   boolean existsByOrder_Id(Long orderId);
 
-  @Query("select coalesce(avg(r.score), 0) from Review r where r.seller.id = :sellerId")
-  double avgScoreBySellerId(@Param("sellerId") Long sellerId);
-
   long countBySeller_Id(Long sellerId);
 }

src/main/java/org/sopt/poti/domain/review/service/ReviewService.java

@@ -2,14 +2,13 @@
 
 import lombok.RequiredArgsConstructor;
 import org.sopt.poti.domain.order.entity.Order;
-import org.sopt.poti.domain.order.service.OrderService;
-import org.sopt.poti.domain.review.dto.request.ReviewRequest;
 import org.sopt.poti.domain.review.entity.Review;
 import org.sopt.poti.domain.review.repository.ReviewRepository;
 import org.sopt.poti.domain.user.entity.User;
 import org.sopt.poti.domain.user.service.UserService;
 import org.sopt.poti.global.error.BusinessException;
 import org.sopt.poti.global.error.ErrorStatus;
+import org.springframework.dao.DataIntegrityViolationException;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -19,33 +18,26 @@
 public class ReviewService {
 
   private final ReviewRepository reviewRepository;
-  private final OrderService orderService;
   private final UserService userService;
 
-  public Long createReview(Long writerUserId, ReviewRequest request) {
-    Long orderId = request.transactionId();
-
-    Order order = orderService.getOrderById(orderId);
-
-    orderService.validateDelivered(order);
-    orderService.validateOrderOwner(order, writerUserId);
+  public Long createReviewEntity(Long writerUserId, Order order, int score) {
+    Long orderId = order.getId();
 
     if (reviewRepository.existsByOrder_Id(orderId)) {
       throw new BusinessException(ErrorStatus.REVIEW_ALREADY_EXISTS);
     }
 
     User writer = userService.getUserById(writerUserId);
-
     User seller = order.getGroupBuyPost().getLeader();
 
-    Review review = Review.create(request.star(), order, writer, seller);
-    Review saved = reviewRepository.save(review);
+    Review review = Review.create(score, order, writer, seller);
 
-    double rawAvg = reviewRepository.avgScoreBySellerId(seller.getId());
-    double roundAvg = Math.round(rawAvg * 10) / 10.0;
-    seller.updateRatingAvg(roundAvg);
-
-    return saved.getId();
+    try {
+      Review saved = reviewRepository.save(review);
+      return saved.getId();
+    } catch (DataIntegrityViolationException e) {
+      throw new BusinessException(ErrorStatus.REVIEW_ALREADY_EXISTS);
+    }
   }
 
   public Integer countReviewsForSeller(Long sellerId) {

src/main/java/org/sopt/poti/domain/user/entity/SellerPostRatingContribution.java

@@ -0,0 +1,64 @@
+package org.sopt.poti.domain.user.entity;
+
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import jakarta.persistence.UniqueConstraint;
+import lombok.AccessLevel;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@Entity
+@Table(
+    name = "seller_post_rating_contributions",
+    uniqueConstraints = @UniqueConstraint(name = "uk_seller_post", columnNames = {"seller_id",
+        "post_id"})
+)
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class SellerPostRatingContribution {
+
+  @Id
+  @GeneratedValue(strategy = GenerationType.IDENTITY)
+  private Long id;
+
+  @Column(name = "seller_id", nullable = false)
+  private Long sellerId;
+
+  @Column(name = "post_id", nullable = false)
+  private Long postId;
+
+  @Column(name = "applied_avg", nullable = false)
+  private double appliedAvg;      // 해당 post가 seller에 반영된 평균값
+
+  @Column(name = "applied_weight", nullable = false)
+  private double appliedWeight;   // 해당 post가 seller에 반영된 가중치
+
+  @Builder
+  private SellerPostRatingContribution(Long sellerId, Long postId, double appliedAvg,
+      double appliedWeight) {
+    this.sellerId = sellerId;
+    this.postId = postId;
+    this.appliedAvg = appliedAvg;
+    this.appliedWeight = appliedWeight;
+  }
+
+  public static SellerPostRatingContribution create(Long sellerId, Long postId) {
+    return SellerPostRatingContribution.builder()
+        .sellerId(sellerId)
+        .postId(postId)
+        .appliedAvg(0.0)
+        .appliedWeight(0.0)
+        .build();
+  }
+
+  public void update(double avg, double weight) {
+    this.appliedAvg = avg;
+    this.appliedWeight = weight;
+  }
+}

src/main/java/org/sopt/poti/domain/user/entity/User.java

@@ -56,6 +56,18 @@ public class User extends BaseSoftDeleteEntity {
   @Column(name = "rating_avg")
   private Double ratingAvg;
 
+  @Column(name = "rating_sum", nullable = false)
+  private long ratingSum = 0L;
+
+  @Column(name = "rating_count", nullable = false)
+  private int ratingCount = 0;
+
+  @Column(name = "rating_weighted_sum", nullable = false)
+  private double ratingWeightedSum = 0.0;
+
+  @Column(name = "rating_weight_total", nullable = false)
+  private double ratingWeightTotal = 0.0;
+
   @Enumerated(EnumType.STRING)
   private UserStatus status;
 
@@ -103,10 +115,6 @@ public void updateFavoriteArtist(Artist artist) {
     this.favoriteArtist = artist;
   }
 
-  public void updateRatingAvg(double avg) {
-    this.ratingAvg = avg;
-  }
-
   public void withdraw() {
     this.status = UserStatus.WITHDRAWN;
     this.deletedAt = LocalDateTime.now();
@@ -115,4 +123,20 @@ public void withdraw() {
     this.profileImageUrl = null;
     this.socialId = "deleted_" + this.id + "_" + UUID.randomUUID(); // 유니크 제약 회피
   }
+
+  public void addRatingWeightedDelta(double deltaWeightedSum, double deltaWeight) {
+    this.ratingWeightedSum += deltaWeightedSum;
+    this.ratingWeightTotal += deltaWeight;
+
+    if (this.ratingWeightTotal <= 0.0) {
+      this.ratingWeightedSum = 0.0;
+      this.ratingWeightTotal = 0.0;
+      this.ratingAvg = 0.0;
+      return;
+    }
+
+    double avg = this.ratingWeightedSum / this.ratingWeightTotal;
+    this.ratingAvg = Math.round(avg * 10) / 10.0;
+  }
+
 }