refactor: 채팅방 생성 재사용 책임 분리

src/main/java/gg/agit/konect/domain/chat/service/ChatRoomCreationService.java

@@ -0,0 +1,121 @@
+package gg.agit.konect.domain.chat.service;
+
+import static gg.agit.konect.domain.chat.service.ChatRoomMembershipService.SYSTEM_ADMIN_ID;
+import static gg.agit.konect.global.code.ApiResponseCode.CANNOT_CREATE_CHAT_ROOM_WITH_SELF;
+import static gg.agit.konect.global.code.ApiResponseCode.NOT_FOUND_USER;
+
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import gg.agit.konect.domain.chat.dto.ChatRoomCreateRequest;
+import gg.agit.konect.domain.chat.dto.ChatRoomResponse;
+import gg.agit.konect.domain.chat.enums.ChatType;
+import gg.agit.konect.domain.chat.model.ChatRoom;
+import gg.agit.konect.domain.chat.model.ChatRoomMember;
+import gg.agit.konect.domain.chat.repository.ChatRoomMemberRepository;
+import gg.agit.konect.domain.chat.repository.ChatRoomRepository;
+import gg.agit.konect.domain.user.enums.UserRole;
+import gg.agit.konect.domain.user.model.User;
+import gg.agit.konect.domain.user.repository.UserRepository;
+import gg.agit.konect.global.exception.CustomException;
+import lombok.RequiredArgsConstructor;
+
+@Service
+@RequiredArgsConstructor
+@Transactional
+public class ChatRoomCreationService {
+
+    private final ChatRoomRepository chatRoomRepository;
+    private final ChatRoomMemberRepository chatRoomMemberRepository;
+    private final UserRepository userRepository;
+    private final ChatRoomMembershipService chatRoomMembershipService;
+
+    public ChatRoomResponse createOrGetChatRoom(Integer currentUserId, ChatRoomCreateRequest request) {
+        User currentUser = userRepository.getById(currentUserId);
+        User targetUser = userRepository.getById(request.userId());
+
+        if (currentUser.getId().equals(targetUser.getId())) {
+            throw CustomException.of(CANNOT_CREATE_CHAT_ROOM_WITH_SELF);
+        }
+
+        if (currentUser.isAdmin() && !targetUser.isAdmin()) {
+            return getOrCreateSystemAdminChatRoomForUser(targetUser, currentUser);
+        }
+
+        ChatRoom chatRoom = chatRoomRepository.findByTwoUsers(
+                currentUser.getId(),
+                targetUser.getId(),
+                ChatType.DIRECT
+            )
+            .orElseGet(() -> chatRoomRepository.save(ChatRoom.directOf()));
+
+        LocalDateTime joinedAt = Objects.requireNonNull(chatRoom.getCreatedAt(), "chatRoom.createdAt must not be null");
+        chatRoomMembershipService.ensureDirectRoomRequester(chatRoom, currentUser, joinedAt);
+        chatRoomMembershipService.ensureMember(chatRoom, targetUser, joinedAt);
+
+        return ChatRoomResponse.from(chatRoom);
+    }
+
+    public ChatRoomResponse createOrGetAdminChatRoom(Integer currentUserId) {
+        User adminUser = userRepository.findFirstByRoleAndDeletedAtIsNullOrderByIdAsc(UserRole.ADMIN)
+            .orElseThrow(() -> CustomException.of(NOT_FOUND_USER));
+
+        return createOrGetChatRoom(currentUserId, new ChatRoomCreateRequest(adminUser.getId()));
+    }
+
+    public ChatRoomResponse createGroupChatRoom(Integer currentUserId, ChatRoomCreateRequest.Group request) {
+        User creator = userRepository.getById(currentUserId);
+
+        List<Integer> distinctUserIds = request.userIds().stream()
+            .distinct()
+            .filter(id -> !id.equals(currentUserId))
+            .toList();
+
+        if (distinctUserIds.isEmpty()) {
+            throw CustomException.of(CANNOT_CREATE_CHAT_ROOM_WITH_SELF);
+        }
+
+        List<User> invitees = userRepository.findAllByIdIn(distinctUserIds);
+        if (invitees.size() != distinctUserIds.size()) {
+            throw CustomException.of(NOT_FOUND_USER);
+        }
+
+        ChatRoom chatRoom = chatRoomRepository.save(ChatRoom.groupOf());
+        LocalDateTime joinedAt = Objects.requireNonNull(
+            chatRoom.getCreatedAt(), "chatRoom.createdAt must not be null"
+        );
+
+        List<ChatRoomMember> members = new ArrayList<>();
+        members.add(ChatRoomMember.ofOwner(chatRoom, creator, joinedAt));
+        invitees.forEach(user -> members.add(ChatRoomMember.of(chatRoom, user, joinedAt)));
+        chatRoomMemberRepository.saveAll(members);
+
+        return ChatRoomResponse.from(chatRoom);
+    }
+
+    private ChatRoomResponse getOrCreateSystemAdminChatRoomForUser(User targetUser, User adminUser) {
+        ChatRoom chatRoom = chatRoomRepository.findByTwoUsers(SYSTEM_ADMIN_ID, targetUser.getId(), ChatType.DIRECT)
+            .orElseGet(() -> {
+                ChatRoom newRoom = chatRoomRepository.save(ChatRoom.directOf());
+                User systemAdmin = userRepository.getById(SYSTEM_ADMIN_ID);
+                LocalDateTime joinedAt = Objects.requireNonNull(
+                    newRoom.getCreatedAt(), "chatRoom.createdAt must not be null"
+                );
+                chatRoomMembershipService.ensureMember(newRoom, systemAdmin, joinedAt);
+                chatRoomMembershipService.ensureMember(newRoom, targetUser, joinedAt);
+                return newRoom;
+            });
+
+        LocalDateTime joinedAt = Objects.requireNonNull(
+            chatRoom.getCreatedAt(), "chatRoom.createdAt must not be null"
+        );
+        chatRoomMembershipService.ensureDirectRoomRequester(chatRoom, adminUser, joinedAt);
+
+        return ChatRoomResponse.from(chatRoom);
+    }
+}

src/main/java/gg/agit/konect/domain/chat/service/ChatRoomMembershipService.java

@@ -148,7 +148,8 @@ private ChatRoom findOrCreateClubRoom(Club club) {
             });
     }
 
-    private void ensureMember(ChatRoom room, User user, LocalDateTime baseline) {
+    @Transactional
+    public void ensureMember(ChatRoom room, User user, LocalDateTime baseline) {
         chatRoomMemberRepository.findByChatRoomIdAndUserId(room.getId(), user.getId())
             .ifPresentOrElse(member -> {
                 LocalDateTime lastReadAt = member.getLastReadAt();
@@ -158,6 +159,26 @@ private void ensureMember(ChatRoom room, User user, LocalDateTime baseline) {
             }, () -> saveRoomMemberIgnoringDuplicate(room, user, baseline));
     }
 
+    @Transactional
+    public void ensureDirectRoomRequester(ChatRoom room, User user, LocalDateTime joinedAt) {
+        if (shouldSkipSystemAdminMembership(room, user)) {
+            return;
+        }
+
+        chatRoomMemberRepository.findByChatRoomIdAndUserId(room.getId(), user.getId())
+            .ifPresentOrElse(member -> {
+                if (member.hasLeft()) {
+                    member.reopenDirectRoom(LocalDateTime.now());
+                    return;
+                }
+
+                LocalDateTime lastReadAt = member.getLastReadAt();
+                if (lastReadAt == null || lastReadAt.isBefore(joinedAt)) {
+                    member.updateLastReadAt(joinedAt);
+                }
+            }, () -> saveRoomMemberIgnoringDuplicate(room, user, joinedAt));
+    }
+
     private void saveRoomMemberIgnoringDuplicate(ChatRoom room, User user, LocalDateTime baseline) {
         try {
             chatRoomMemberRepository.save(ChatRoomMember.of(room, user, baseline));
@@ -184,6 +205,12 @@ private void ensureDirectRoomMemberExists(ChatRoom room, User user, LocalDateTim
         throw CustomException.of(FORBIDDEN_CHAT_ROOM_ACCESS);
     }
 
+    private boolean shouldSkipSystemAdminMembership(ChatRoom room, User user) {
+        // 문의방은 SYSTEM_ADMIN + 일반 사용자 2인 구조를 전제로 재사용(findByTwoUsers)되므로,
+        // 생성/재오픈 경로에서도 일반 ADMIN을 멤버로 추가하면 안 된다.
+        return user.isAdmin() && chatRoomSystemAdminService.isSystemAdminRoom(room.getId());
+    }
+
     private boolean isDuplicateKeyException(DataIntegrityViolationException e) {
         if (e instanceof DuplicateKeyException) {
             return true;

src/main/java/gg/agit/konect/domain/chat/service/ChatService.java

@@ -9,7 +9,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Set;
 import java.util.stream.Collectors;
 
@@ -76,95 +75,24 @@ public class ChatService {
     private final ChatSearchService chatSearchService;
     private final ChatInviteService chatInviteService;
     private final ChatMessagePageResolver chatMessagePageResolver;
+    private final ChatRoomCreationService chatRoomCreationService;
     private final ChatRoomSystemAdminService chatRoomSystemAdminService;
     private final ChatDirectRoomAccessService chatDirectRoomAccessService;
     private final ChatMessageSendService chatMessageSendService;
 
     @Transactional
     public ChatRoomResponse createOrGetChatRoom(Integer currentUserId, ChatRoomCreateRequest request) {
-        User currentUser = userRepository.getById(currentUserId);
-        User targetUser = userRepository.getById(request.userId());
-
-        if (currentUser.getId().equals(targetUser.getId())) {
-            throw CustomException.of(CANNOT_CREATE_CHAT_ROOM_WITH_SELF);
-        }
-
-        if (currentUser.isAdmin() && !targetUser.isAdmin()) {
-            return getOrCreateSystemAdminChatRoomForUser(targetUser, currentUser);
-        }
-
-        ChatRoom chatRoom = chatRoomRepository.findByTwoUsers(
-                currentUser.getId(),
-                targetUser.getId(),
-                ChatType.DIRECT
-            )
-            .orElseGet(() -> chatRoomRepository.save(ChatRoom.directOf()));
-
-        LocalDateTime joinedAt = Objects.requireNonNull(chatRoom.getCreatedAt(), "chatRoom.createdAt must not be null");
-        ensureDirectRoomRequester(chatRoom, currentUser, joinedAt);
-        ensureRoomMember(chatRoom, targetUser, joinedAt);
-
-        return ChatRoomResponse.from(chatRoom);
-    }
-
-    private ChatRoomResponse getOrCreateSystemAdminChatRoomForUser(User targetUser, User adminUser) {
-        ChatRoom chatRoom = chatRoomRepository.findByTwoUsers(SYSTEM_ADMIN_ID, targetUser.getId(), ChatType.DIRECT)
-            .orElseGet(() -> {
-                ChatRoom newRoom = chatRoomRepository.save(ChatRoom.directOf());
-                User systemAdmin = userRepository.getById(SYSTEM_ADMIN_ID);
-                LocalDateTime joinedAt = Objects.requireNonNull(
-                    newRoom.getCreatedAt(), "chatRoom.createdAt must not be null"
-                );
-                ensureRoomMember(newRoom, systemAdmin, joinedAt);
-                ensureRoomMember(newRoom, targetUser, joinedAt);
-                return newRoom;
-            });
-
-        LocalDateTime joinedAt = Objects.requireNonNull(
-            chatRoom.getCreatedAt(), "chatRoom.createdAt must not be null"
-        );
-        ensureDirectRoomRequester(chatRoom, adminUser, joinedAt);
-
-        return ChatRoomResponse.from(chatRoom);
+        return chatRoomCreationService.createOrGetChatRoom(currentUserId, request);
     }
 
     @Transactional
     public ChatRoomResponse createOrGetAdminChatRoom(Integer currentUserId) {
-        User adminUser = userRepository.findFirstByRoleAndDeletedAtIsNullOrderByIdAsc(UserRole.ADMIN)
-            .orElseThrow(() -> CustomException.of(NOT_FOUND_USER));
-
-        return createOrGetChatRoom(currentUserId, new ChatRoomCreateRequest(adminUser.getId()));
+        return chatRoomCreationService.createOrGetAdminChatRoom(currentUserId);
     }
 
     @Transactional
     public ChatRoomResponse createGroupChatRoom(Integer currentUserId, ChatRoomCreateRequest.Group request) {
-        User creator = userRepository.getById(currentUserId);
-
-        List<Integer> distinctUserIds = request.userIds().stream()
-            .distinct()
-            .filter(id -> !id.equals(currentUserId))
-            .toList();
-
-        if (distinctUserIds.isEmpty()) {
-            throw CustomException.of(CANNOT_CREATE_CHAT_ROOM_WITH_SELF);
-        }
-
-        List<User> invitees = userRepository.findAllByIdIn(distinctUserIds);
-        if (invitees.size() != distinctUserIds.size()) {
-            throw CustomException.of(NOT_FOUND_USER);
-        }
-
-        ChatRoom chatRoom = chatRoomRepository.save(ChatRoom.groupOf());
-        LocalDateTime joinedAt = Objects.requireNonNull(
-            chatRoom.getCreatedAt(), "chatRoom.createdAt must not be null"
-        );
-
-        List<ChatRoomMember> members = new ArrayList<>();
-        members.add(ChatRoomMember.ofOwner(chatRoom, creator, joinedAt));
-        invitees.forEach(user -> members.add(ChatRoomMember.of(chatRoom, user, joinedAt)));
-        chatRoomMemberRepository.saveAll(members);
-
-        return ChatRoomResponse.from(chatRoom);
+        return chatRoomCreationService.createGroupChatRoom(currentUserId, request);
     }
 
     @Transactional
@@ -743,31 +671,6 @@ private void ensureRoomMember(ChatRoom room, User user, LocalDateTime joinedAt)
             }, () -> chatRoomMemberRepository.save(ChatRoomMember.of(room, user, joinedAt)));
     }
 
-    private void ensureDirectRoomRequester(ChatRoom room, User user, LocalDateTime joinedAt) {
-        if (shouldSkipSystemAdminMembership(room, user)) {
-            return;
-        }
-
-        chatRoomMemberRepository.findByChatRoomIdAndUserId(room.getId(), user.getId())
-            .ifPresentOrElse(member -> {
-                if (member.hasLeft()) {
-                    member.reopenDirectRoom(LocalDateTime.now());
-                    return;
-                }
-
-                LocalDateTime lastReadAt = member.getLastReadAt();
-                if (lastReadAt == null || lastReadAt.isBefore(joinedAt)) {
-                    member.updateLastReadAt(joinedAt);
-                }
-            }, () -> chatRoomMemberRepository.save(ChatRoomMember.of(room, user, joinedAt)));
-    }
-
-    private boolean shouldSkipSystemAdminMembership(ChatRoom room, User user) {
-        // 문의방은 SYSTEM_ADMIN + 일반 사용자 2인 구조를 전제로 재사용(findByTwoUsers)되므로,
-        // 생성/재오픈 경로에서도 일반 ADMIN을 멤버로 추가하면 안 된다.
-        return user.isAdmin() && chatRoomSystemAdminService.isSystemAdminRoom(room.getId());
-    }
-
     private String normalizeCustomRoomName(String roomName) {
         if (!StringUtils.hasText(roomName)) {
             return null;

src/test/java/gg/agit/konect/unit/domain/chat/service/ChatServiceTest.java

@@ -56,6 +56,7 @@
 import gg.agit.konect.domain.chat.service.ChatMessageSendService;
 import gg.agit.konect.domain.chat.service.ChatMessagePageResolver;
 import gg.agit.konect.domain.chat.service.ChatPresenceService;
+import gg.agit.konect.domain.chat.service.ChatRoomCreationService;
 import gg.agit.konect.domain.chat.service.ChatRoomMembershipService;
 import gg.agit.konect.domain.chat.service.ChatRoomSummaryService;
 import gg.agit.konect.domain.chat.service.ChatSearchService;
@@ -138,6 +139,19 @@ void setUp() {
             clubMemberRepository,
             chatRoomSystemAdminService
         );
+        ChatRoomMembershipService chatRoomMembershipForCreation = new ChatRoomMembershipService(
+            chatRoomRepository,
+            chatRoomMemberRepository,
+            clubMemberRepository,
+            userRepository,
+            chatRoomSystemAdminService
+        );
+        ChatRoomCreationService chatRoomCreationService = new ChatRoomCreationService(
+            chatRoomRepository,
+            chatRoomMemberRepository,
+            userRepository,
+            chatRoomMembershipForCreation
+        );
         ChatMessageSendService chatMessageSendService = new ChatMessageSendService(
             chatRoomRepository,
             chatMessageRepository,
@@ -163,6 +177,7 @@ void setUp() {
             chatSearchService,
             chatInviteService,
             chatMessagePageResolver,
+            chatRoomCreationService,
             chatRoomSystemAdminService,
             chatDirectRoomAccessService,
             chatMessageSendService