안 읽은 메시지 카운팅 기능 구현

backend/ddang/src/main/java/com/ddang/ddang/chat/application/ChatRoomService.java

@@ -9,6 +9,7 @@
 import com.ddang.ddang.chat.application.dto.CreateChatRoomDto;
 import com.ddang.ddang.chat.application.dto.ReadChatRoomWithLastMessageDto;
 import com.ddang.ddang.chat.application.dto.ReadParticipatingChatRoomDto;
+import com.ddang.ddang.chat.application.event.CreateReadMessageLogEvent;
 import com.ddang.ddang.chat.application.exception.ChatRoomNotFoundException;
 import com.ddang.ddang.chat.application.exception.InvalidAuctionToChatException;
 import com.ddang.ddang.chat.application.exception.InvalidUserToChat;
@@ -22,6 +23,7 @@
 import com.ddang.ddang.user.domain.User;
 import com.ddang.ddang.user.domain.repository.UserRepository;
 import lombok.RequiredArgsConstructor;
+import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -35,6 +37,7 @@ public class ChatRoomService {
 
     private static final Long DEFAULT_CHAT_ROOM_ID = null;
 
+    private final ApplicationEventPublisher messageLogEventPublisher;
     private final ChatRoomRepository chatRoomRepository;
     private final ChatRoomAndImageRepository chatRoomAndImageRepository;
     private final ChatRoomAndMessageAndImageRepository chatRoomAndMessageAndImageRepository;
@@ -51,9 +54,15 @@ public Long create(final Long userId, final CreateChatRoomDto chatRoomDto) {
                                                      );
 
         return chatRoomRepository.findChatRoomIdByAuctionId(findAuction.getId())
-                                 .orElseGet(() ->
-                                         persistChatRoom(findUser, findAuction).getId()
-                                 );
+                                 .orElseGet(() -> createChatRoom(findUser, findAuction));
+    }
+
+    private Long createChatRoom(final User findUser, final Auction findAuction) {
+        final ChatRoom persistChatRoom = persistChatRoom(findUser, findAuction);
+
+        messageLogEventPublisher.publishEvent(new CreateReadMessageLogEvent(persistChatRoom));
+
+        return persistChatRoom.getId();
     }
 
     private ChatRoom persistChatRoom(final User user, final Auction auction) {

backend/ddang/src/main/java/com/ddang/ddang/chat/application/LastReadMessageLogEventListener.java

@@ -0,0 +1,39 @@
+package com.ddang.ddang.chat.application;
+
+import com.ddang.ddang.chat.application.event.CreateReadMessageLogEvent;
+import com.ddang.ddang.chat.application.event.UpdateReadMessageLogEvent;
+import com.ddang.ddang.chat.application.exception.ReadMessageLogNotFoundException;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Propagation;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.transaction.event.TransactionalEventListener;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class LastReadMessageLogEventListener {
+
+    private final LastReadMessageLogService lastReadMessageLogService;
+
+    @TransactionalEventListener
+    @Transactional(propagation = Propagation.REQUIRES_NEW)
+    public void create(final CreateReadMessageLogEvent createReadMessageLogEvent) {
+        try {
+            lastReadMessageLogService.create(createReadMessageLogEvent);
+        } catch (final IllegalArgumentException ex) {
+            log.error("exception type : {}, ", ex.getClass().getSimpleName(), ex);
+        }
+    }
+
+    @TransactionalEventListener
+    @Transactional(propagation = Propagation.REQUIRES_NEW)
+    public void update(final UpdateReadMessageLogEvent updateReadMessageLogEvent) {
+        try {
+            lastReadMessageLogService.update(updateReadMessageLogEvent);
+        } catch (final ReadMessageLogNotFoundException ex) {
+            log.error("exception type : {}, ", ex.getClass().getSimpleName(), ex);
+        }
+    }
+}

backend/ddang/src/main/java/com/ddang/ddang/chat/application/LastReadMessageLogService.java

@@ -0,0 +1,46 @@
+package com.ddang.ddang.chat.application;
+
+import com.ddang.ddang.chat.application.event.CreateReadMessageLogEvent;
+import com.ddang.ddang.chat.application.event.UpdateReadMessageLogEvent;
+import com.ddang.ddang.chat.application.exception.ReadMessageLogNotFoundException;
+import com.ddang.ddang.chat.domain.ChatRoom;
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
+import com.ddang.ddang.user.domain.User;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+@Service
+@Transactional(readOnly = true)
+@RequiredArgsConstructor
+public class LastReadMessageLogService {
+
+    private final ReadMessageLogRepository readMessageLogRepository;
+
+    @Transactional
+    public void create(final CreateReadMessageLogEvent createReadMessageLogEvent) {
+        final ChatRoom chatRoom = createReadMessageLogEvent.chatRoom();
+        final User buyer = chatRoom.getBuyer();
+        final User seller = chatRoom.getAuction().getSeller();
+        final ReadMessageLog buyerReadMessageLog = new ReadMessageLog(chatRoom, buyer);
+        final ReadMessageLog sellerReadMessageLog = new ReadMessageLog(chatRoom, seller);
+
+        readMessageLogRepository.saveAll(List.of(buyerReadMessageLog, sellerReadMessageLog));
+    }
+
+    @Transactional
+    public void update(final UpdateReadMessageLogEvent updateReadMessageLogEvent) {
+        final User reader = updateReadMessageLogEvent.reader();
+        final ChatRoom chatRoom = updateReadMessageLogEvent.chatRoom();
+        final ReadMessageLog messageLog = readMessageLogRepository.findBy(reader.getId(), chatRoom.getId())
+                                                                  .orElseThrow(() ->
+                                                                          new ReadMessageLogNotFoundException(
+                                                                                  "메시지 조회 로그가 존재하지 않습니다."
+                                                                          ));
+
+        messageLog.updateLastReadMessage(updateReadMessageLogEvent.lastReadMessage().getId());
+    }
+}

backend/ddang/src/main/java/com/ddang/ddang/chat/application/MessageService.java

@@ -3,6 +3,7 @@
 import com.ddang.ddang.chat.application.dto.CreateMessageDto;
 import com.ddang.ddang.chat.application.dto.ReadMessageDto;
 import com.ddang.ddang.chat.application.event.MessageNotificationEvent;
+import com.ddang.ddang.chat.application.event.UpdateReadMessageLogEvent;
 import com.ddang.ddang.chat.application.exception.ChatRoomNotFoundException;
 import com.ddang.ddang.chat.application.exception.MessageNotFoundException;
 import com.ddang.ddang.chat.application.exception.UnableToChatException;
@@ -15,7 +16,6 @@
 import com.ddang.ddang.user.domain.User;
 import com.ddang.ddang.user.domain.repository.UserRepository;
 import lombok.RequiredArgsConstructor;
-import lombok.extern.slf4j.Slf4j;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -25,10 +25,10 @@
 @Service
 @Transactional(readOnly = true)
 @RequiredArgsConstructor
-@Slf4j
 public class MessageService {
 
-    private final ApplicationEventPublisher messageEventPublisher;
+    private final ApplicationEventPublisher messageLogEventPublisher;
+    private final ApplicationEventPublisher messageNotificationEventPublisher;
     private final MessageRepository messageRepository;
     private final ChatRoomRepository chatRoomRepository;
     private final UserRepository userRepository;
@@ -53,16 +53,14 @@ public Long create(final CreateMessageDto dto, final String profileImageAbsolute
 
         final Message persistMessage = messageRepository.save(message);
 
-        messageEventPublisher.publishEvent(new MessageNotificationEvent(persistMessage, profileImageAbsoluteUrl));
+        messageNotificationEventPublisher.publishEvent(new MessageNotificationEvent(persistMessage, profileImageAbsoluteUrl));
 
         return persistMessage.getId();
     }
 
     public List<ReadMessageDto> readAllByLastMessageId(final ReadMessageRequest request) {
-        if (!userRepository.existsById(request.messageReaderId())) {
-            throw new UserNotFoundException("지정한 아이디에 대한 사용자를 찾을 수 없습니다.");
-        }
-
+        final User reader = userRepository.findById(request.messageReaderId())
+                                          .orElseThrow(() -> new UserNotFoundException("지정한 아이디에 대한 사용자를 찾을 수 없습니다."));
         final ChatRoom chatRoom = chatRoomRepository.findById(request.chatRoomId())
                                                     .orElseThrow(() -> new ChatRoomNotFoundException(
                                                             "지정한 아이디에 대한 채팅방을 찾을 수 없습니다."));
@@ -77,6 +75,12 @@ public List<ReadMessageDto> readAllByLastMessageId(final ReadMessageRequest requ
                 request.lastMessageId()
         );
 
+        if (!readMessages.isEmpty()) {
+            final Message lastReadMessage = readMessages.get(readMessages.size() - 1);
+
+            messageLogEventPublisher.publishEvent(new UpdateReadMessageLogEvent(reader, chatRoom, lastReadMessage));
+        }
+
         return readMessages.stream()
                            .map(message -> ReadMessageDto.from(message, chatRoom))
                            .toList();

backend/ddang/src/main/java/com/ddang/ddang/chat/application/dto/ReadChatRoomWithLastMessageDto.java

@@ -11,6 +11,7 @@ public record ReadChatRoomWithLastMessageDto(
         ReadAuctionInChatRoomDto auctionDto,
         ReadUserInChatRoomDto partnerDto,
         ReadLastMessageDto lastMessageDto,
+        Long unreadMessageCount,
         boolean isChatAvailable
 ) {
 
@@ -22,12 +23,14 @@ public static ReadChatRoomWithLastMessageDto of(
         final User partner = chatRoom.calculateChatPartnerOf(findUser);
         final Message lastMessage = chatRoomAndMessageAndImageDto.message();
         final AuctionImage thumbnailImage = chatRoomAndMessageAndImageDto.thumbnailImage();
+        final Long unreadMessages = chatRoomAndMessageAndImageDto.unreadMessageCount();
 
         return new ReadChatRoomWithLastMessageDto(
                 chatRoom.getId(),
                 ReadAuctionInChatRoomDto.of(chatRoom.getAuction(), thumbnailImage),
                 ReadUserInChatRoomDto.from(partner),
                 ReadLastMessageDto.from(lastMessage),
+                unreadMessages,
                 chatRoom.isChatAvailablePartner(partner)
         );
     }

backend/ddang/src/main/java/com/ddang/ddang/chat/application/event/CreateReadMessageLogEvent.java

@@ -0,0 +1,6 @@
+package com.ddang.ddang.chat.application.event;
+
+import com.ddang.ddang.chat.domain.ChatRoom;
+
+public record CreateReadMessageLogEvent(ChatRoom chatRoom) {
+}

backend/ddang/src/main/java/com/ddang/ddang/chat/application/event/UpdateReadMessageLogEvent.java

@@ -0,0 +1,8 @@
+package com.ddang.ddang.chat.application.event;
+
+import com.ddang.ddang.chat.domain.ChatRoom;
+import com.ddang.ddang.chat.domain.Message;
+import com.ddang.ddang.user.domain.User;
+
+public record UpdateReadMessageLogEvent(User reader, ChatRoom chatRoom, Message lastReadMessage) {
+}

backend/ddang/src/main/java/com/ddang/ddang/chat/application/exception/ReadMessageLogNotFoundException.java

@@ -0,0 +1,8 @@
+package com.ddang.ddang.chat.application.exception;
+
+public class ReadMessageLogNotFoundException extends IllegalArgumentException {
+
+    public ReadMessageLogNotFoundException(final String message) {
+        super(message);
+    }
+}

backend/ddang/src/main/java/com/ddang/ddang/chat/domain/ReadMessageLog.java

@@ -0,0 +1,49 @@
+package com.ddang.ddang.chat.domain;
+
+import com.ddang.ddang.user.domain.User;
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.ForeignKey;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToOne;
+import lombok.AccessLevel;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.ToString;
+
+@Entity
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Getter
+@EqualsAndHashCode(of = "id", callSuper = false)
+@ToString(of = {"id", "lastReadMessageId"})
+public class ReadMessageLog {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY, cascade = {CascadeType.REMOVE})
+    @JoinColumn(name = "chat_room_id", nullable = false, foreignKey = @ForeignKey(name = "fk_read_message_log_chat_room"))
+    private ChatRoom chatRoom;
+
+    @OneToOne(fetch = FetchType.LAZY, cascade = {CascadeType.REMOVE})
+    @JoinColumn(name = "reader_id", nullable = false, foreignKey = @ForeignKey(name = "fk_read_message_log_reader"))
+    private User reader;
+
+    private Long lastReadMessageId = 0L;
+
+    public ReadMessageLog(final ChatRoom chatRoom, final User reader) {
+        this.chatRoom = chatRoom;
+        this.reader = reader;
+    }
+
+    public void updateLastReadMessage(final Long lastReadMessageId) {
+        this.lastReadMessageId = lastReadMessageId;
+    }
+}

backend/ddang/src/main/java/com/ddang/ddang/chat/domain/dto/ChatRoomAndMessageAndImageDto.java

@@ -4,5 +4,10 @@
 import com.ddang.ddang.chat.domain.Message;
 import com.ddang.ddang.image.domain.AuctionImage;
 
-public record ChatRoomAndMessageAndImageDto(ChatRoom chatRoom, Message message, AuctionImage thumbnailImage) {
+public record ChatRoomAndMessageAndImageDto(
+        ChatRoom chatRoom,
+        Message message,
+        AuctionImage thumbnailImage,
+        Long unreadMessageCount
+) {
 }

backend/ddang/src/main/java/com/ddang/ddang/chat/domain/repository/ReadMessageLogRepository.java

@@ -0,0 +1,13 @@
+package com.ddang.ddang.chat.domain.repository;
+
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface ReadMessageLogRepository {
+
+    Optional<ReadMessageLog> findBy(final Long readerId, final Long chatRoomId);
+
+    List<ReadMessageLog> saveAll(List<ReadMessageLog> readMessageLogs);
+}

backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/JpaReadMessageLogRepository.java

@@ -0,0 +1,17 @@
+package com.ddang.ddang.chat.infrastructure.persistence;
+
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+
+import java.util.Optional;
+
+public interface JpaReadMessageLogRepository extends JpaRepository<ReadMessageLog, Long> {
+
+    @Query("""
+        SELECT rml
+        FROM ReadMessageLog rml 
+        WHERE rml.chatRoom.id = :chatRoomId AND rml.reader.id = :readerId
+    """)
+    Optional<ReadMessageLog> findLastReadMessageByUserIdAndChatRoomId(final Long readerId, final Long chatRoomId);
+}

backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/QuerydslChatRoomAndMessageAndImageRepository.java

@@ -5,6 +5,7 @@
 import com.ddang.ddang.chat.infrastructure.persistence.dto.QChatRoomAndMessageAndImageQueryProjectionDto;
 import com.querydsl.core.types.dsl.BooleanExpression;
 import com.querydsl.jpa.JPAExpressions;
+import com.querydsl.jpa.JPQLQuery;
 import com.querydsl.jpa.impl.JPAQueryFactory;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Repository;
@@ -15,6 +16,7 @@
 import static com.ddang.ddang.auction.domain.QAuction.auction;
 import static com.ddang.ddang.chat.domain.QChatRoom.chatRoom;
 import static com.ddang.ddang.chat.domain.QMessage.message;
+import static com.ddang.ddang.chat.domain.QReadMessageLog.readMessageLog;
 import static com.ddang.ddang.image.domain.QAuctionImage.auctionImage;
 import static java.util.Comparator.comparing;
 
@@ -26,8 +28,12 @@ public class QuerydslChatRoomAndMessageAndImageRepository {
 
     public List<ChatRoomAndMessageAndImageDto> findAllChatRoomInfoByUserIdOrderByLastMessage(final Long userId) {
         final List<ChatRoomAndMessageAndImageQueryProjectionDto> unsortedDtos =
-                queryFactory.select(new QChatRoomAndMessageAndImageQueryProjectionDto(chatRoom, message, auctionImage))
-                            .from(chatRoom)
+                queryFactory.select(new QChatRoomAndMessageAndImageQueryProjectionDto(
+                                    chatRoom,
+                                    message,
+                                    auctionImage,
+                                    countUnreadMessages(userId)
+                            )).from(chatRoom)
                             .leftJoin(chatRoom.buyer).fetchJoin()
                             .leftJoin(chatRoom.auction, auction).fetchJoin()
                             .leftJoin(auction.seller).fetchJoin()
@@ -52,6 +58,21 @@ public List<ChatRoomAndMessageAndImageDto> findAllChatRoomInfoByUserIdOrderByLas
         return sortByLastMessageIdDesc(unsortedDtos);
     }
 
+    private static JPQLQuery<Long> countUnreadMessages(final Long userId) {
+        return JPAExpressions.select(message.count())
+                             .from(message)
+                             .where(
+                                     message.chatRoom.id.eq(chatRoom.id),
+                                     message.writer.id.ne(userId),
+                                     message.id.gt(
+                                             JPAExpressions
+                                                     .select(readMessageLog.lastReadMessageId)
+                                                     .from(readMessageLog)
+                                                     .where(readMessageLog.reader.id.eq(userId))
+                                     )
+                             );
+    }
+
     private List<ChatRoomAndMessageAndImageDto> sortByLastMessageIdDesc(
             final List<ChatRoomAndMessageAndImageQueryProjectionDto> unsortedDtos
     ) {