[Quiz][Refactor] 퀴즈 생성 중 타유저가 생성요청 보내더라도 타유저에게 퀴즈 생성 완료 알림을 보낸다

src/main/java/book/book/quiz/domain/QuizSubscriber.java

@@ -0,0 +1,36 @@
+package book.book.quiz.domain;
+
+import book.book.common.BaseTimeEntity;
+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;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Table(name = "quiz_subscriber", uniqueConstraints = {
+        @UniqueConstraint(name = "uk_quiz_subscriber_book_member", columnNames = {"book_id", "member_id"})
+})
+public class QuizSubscriber extends BaseTimeEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    private Long bookId;
+
+    private Long memberId;
+
+    @Builder
+    public QuizSubscriber(Long bookId, Long memberId) {
+        this.bookId = bookId;
+        this.memberId = memberId;
+    }
+}

src/main/java/book/book/quiz/repository/QuizSubscriberRepository.java

@@ -0,0 +1,18 @@
+package book.book.quiz.repository;
+
+import book.book.quiz.domain.QuizSubscriber;
+import java.util.List;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+
+public interface QuizSubscriberRepository extends JpaRepository<QuizSubscriber, Long> {
+
+    List<QuizSubscriber> findAllByBookId(Long bookId);
+
+    @Modifying
+    @Query("DELETE FROM QuizSubscriber qs WHERE qs.bookId = :bookId")
+    void deleteAllByBookId(Long bookId);
+
+    boolean existsByBookIdAndMemberId(Long bookId, Long memberId);
+}

src/main/java/book/book/quiz/service/QuizGenerationAsyncService.java

@@ -2,20 +2,15 @@
 
 import book.book.book.entity.Book;
 import book.book.book.entity.Chapter;
-import book.book.common.CustomException;
-import book.book.common.ErrorCode;
 import book.book.quiz.domain.QuizStatus;
 import book.book.quiz.dto.external.GeminiQuizResponses;
 import book.book.quiz.dto.external.GeminiRequest;
-import book.book.quiz.event.QuizCreatedEvent;
 import book.book.quiz.external.gemini.GeminiRequestFactory;
 import book.book.quiz.external.gemini.GeminiSdkClient;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.CompletionException;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Service;
 
@@ -32,6 +27,7 @@ public class QuizGenerationAsyncService {
     private final QuizSaveService quizSaveService;
     private final GeminiRequestFactory geminiRequestFactory;
     private final QuizGenerationHandlerService quizGenerationHandlerService;
+
     /**
      * 백그라운드에서 퀴즈 생성
      */
@@ -55,7 +51,7 @@ private CompletableFuture<Void> generateQuizzesInternal(Book book, List<Chapter>
 
         return geminiSdkClient.generateContentAsync(request)
                 .thenAccept(batchResponse -> {
-                    quizGenerationHandlerService.handleSuccess(book, chapters, batchResponse, memberId);
+                    quizGenerationHandlerService.handleSuccess(book, chapters, batchResponse);
                 }).exceptionally(ex -> {
                     quizGenerationHandlerService.handleFailure(book, ex);
                     return null;

src/main/java/book/book/quiz/service/QuizGenerationHandlerService.java

@@ -5,14 +5,17 @@
 import book.book.common.CustomException;
 import book.book.common.ErrorCode;
 import book.book.quiz.domain.QuizStatus;
+import book.book.quiz.domain.QuizSubscriber;
 import book.book.quiz.dto.external.GeminiQuizResponses;
 import book.book.quiz.event.QuizCreatedEvent;
+import book.book.quiz.repository.QuizSubscriberRepository;
 import java.util.List;
 import java.util.concurrent.CompletionException;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
 
 @Slf4j
 @Service
@@ -22,18 +25,26 @@ public class QuizGenerationHandlerService {
     private final QuizSaveService quizSaveService;
     private final ApplicationEventPublisher eventPublisher;
     private final QuizAlertService quizAlertService;
+    private final QuizSubscriberRepository quizSubscriberRepository;
 
-    public void handleSuccess(Book book, List<Chapter> chapters, GeminiQuizResponses batchResponse, Long memberId) {
+    @Transactional
+    public void handleSuccess(Book book, List<Chapter> chapters, GeminiQuizResponses batchResponse) {
         List<Long> chapterIds = chapters.stream().map(Chapter::getId).toList();
 
         quizSaveService.saveQuizzesBatchAndUpdateStatus(
                 book.getId(),
                 chapterIds,
                 batchResponse);
 
-        if (memberId != null) {
-            eventPublisher.publishEvent(new QuizCreatedEvent(book.getId(), memberId));
+        sendEventToAllRequesters(book);
+    }
+
+    private void sendEventToAllRequesters(Book book) {
+        List<QuizSubscriber> subscribers = quizSubscriberRepository.findAllByBookId(book.getId());
+        for (QuizSubscriber subscriber : subscribers) {
+            eventPublisher.publishEvent(new QuizCreatedEvent(book.getId(), subscriber.getMemberId()));
         }
+        quizSubscriberRepository.deleteAllByBookId(book.getId());
     }
 
     public void handleFailure(Book book, Throwable ex) {

src/main/java/book/book/quiz/service/QuizGenerationService.java

@@ -7,16 +7,17 @@
 import book.book.common.CustomException;
 import book.book.common.ErrorCode;
 import book.book.quiz.domain.QuizStatus;
+import book.book.quiz.domain.QuizSubscriber;
 import book.book.quiz.dto.external.GeminiQuizResponses;
 import book.book.quiz.dto.external.GeminiRequest;
 import book.book.quiz.dto.response.QuizGenerationAcceptedResponse;
 import book.book.quiz.external.gemini.GeminiRequestFactory;
 import book.book.quiz.external.gemini.GeminiSdkClient;
+import book.book.quiz.repository.QuizSubscriberRepository;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Service;
-import org.springframework.transaction.annotation.Transactional;
 
 @Slf4j
 @Service
@@ -29,6 +30,7 @@ public class QuizGenerationService {
     private final GeminiSdkClient geminiSdkClient;
     private final GeminiRequestFactory geminiRequestFactory;
     private final QuizGenerationHandlerService handlerService;
+    private final QuizSubscriberRepository quizSubscriberRepository;
     private final QuizGenerationAsyncService quizGenerationAsyncService;
 
     /**
@@ -45,7 +47,15 @@ public QuizGenerationAcceptedResponse generateQuizIfAbsent(Long bookId, Long mem
             return QuizGenerationAcceptedResponse.alreadyExists(bookId, chapters.size());
         }
 
-        if (book.getQuizStatus() == QuizStatus.PROCESSING) {
+        // 구독자 추가 (중복 방지)
+        if (!quizSubscriberRepository.existsByBookIdAndMemberId(bookId, memberId)) {
+            quizSubscriberRepository.save(QuizSubscriber.builder()
+                    .bookId(bookId)
+                    .memberId(memberId)
+                    .build());
+        }
+
+        if (book.getQuizStatus() == QuizStatus.PROCESSING || book.getQuizStatus() == QuizStatus.PENDING) {
             // 이미 생성 중이면 중복 요청으로 간주하고 현재 상태 반환 (또는 예외 처리)
             // 여기서는 멱등성을 위해 성공 응답처럼 처리하되, 실제 생성은 스킵
             return QuizGenerationAcceptedResponse.processing(bookId, chapters.size());
@@ -63,7 +73,6 @@ public QuizGenerationAcceptedResponse generateQuizAsync(Long bookId, Long member
         return QuizGenerationAcceptedResponse.of(bookId, chapters.size());
     }
 
-
     private List<Chapter> validateAndGetChapters(Long bookId) {
         List<Chapter> chapters = chapterRepository.findByBookIdOrderByChapterNumber(bookId);
         if (chapters.isEmpty()) {
@@ -76,7 +85,7 @@ private List<Chapter> validateAndGetChapters(Long bookId) {
      * 동기적으로 퀴즈 생성 (스케줄러용)
      */
     public void generateQuizzes(Book book, List<Chapter> chapters) {
-            generateQuizzesSyncInternal(book, chapters, null);
+        generateQuizzesSyncInternal(book, chapters, null);
     }
 
     /**
@@ -94,7 +103,7 @@ private void generateQuizzesSyncInternal(Book book, List<Chapter> chapters, Long
 
             GeminiQuizResponses batchResponse = geminiSdkClient.generateContent(request);
 
-            handlerService.handleSuccess(book, chapters, batchResponse, memberId);
+            handlerService.handleSuccess(book, chapters, batchResponse);
 
         } catch (Exception ex) {
             handlerService.handleFailure(book, ex);

src/test/java/book/book/config/IntegrationTest.java

@@ -12,6 +12,7 @@
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.TestExecutionListeners;
 import org.springframework.test.context.TestExecutionListeners.MergeMode;
+import org.springframework.test.context.event.RecordApplicationEvents;
 
 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)
@@ -26,5 +27,6 @@
 )
 @ExtendWith(CleanDatabaseBeforeEach.class)
 @ExtendWith(GlobalTimeZoneExtension.class)
+@RecordApplicationEvents
 public @interface IntegrationTest {
 }