[feat #116] 채팅방 목록 조회 API (#121)

* [feat] : 채팅 메시지 조회 DTO에 읽음 여부 필드 추가

* [test] : DTO에 읽음 여부 필드 추가 반영

* [feat] : 채팅방 목록 조회용 dto 추가

* [feat] : 채팅방 query repository 추가

* [test] : 채팅방 query repository 테스트

* [feat] : 채팅방 최근 메시지 DTO 추가

* [feat] : mongoDB로 각 채팅방별 최근 메시지 조회

* [test] : mongoDB로 각 채팅방별 최근 메시지 조회 테스트

* [feat] : 채팅방 목록 조회 DTO 추가

* [feat] : 채팅방 목록 조회 비즈니스 로직 추가

* [feat] : 채팅방 목록 조회 API 메서드 작성

* [test] : 채팅방 목록 조회 API 통합 테스트

* [style] : 코드 리포멧팅

* [feat] : 예외 메세지 수정

* [feat] : 채팅 메시지 요청 필드명 수정

src/main/java/com/dnd/gongmuin/chat/controller/ChatRoomController.java

@@ -1,5 +1,7 @@
 package com.dnd.gongmuin.chat.controller;
 
+import java.util.List;
+
 import org.springframework.data.domain.Pageable;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
@@ -14,6 +16,7 @@
 import com.dnd.gongmuin.chat.dto.response.AcceptChatResponse;
 import com.dnd.gongmuin.chat.dto.response.ChatMessageResponse;
 import com.dnd.gongmuin.chat.dto.response.ChatRoomDetailResponse;
+import com.dnd.gongmuin.chat.dto.response.ChatRoomSimpleResponse;
 import com.dnd.gongmuin.chat.dto.response.RejectChatResponse;
 import com.dnd.gongmuin.chat.service.ChatRoomService;
 import com.dnd.gongmuin.common.dto.PageResponse;
@@ -52,6 +55,15 @@ public ResponseEntity<ChatRoomDetailResponse> createChatRoom(
 		return ResponseEntity.ok(response);
 	}
 
+	@Operation(summary = "채팅방 목록 조회 API", description = "회원의 채팅방 목록을 조회한다.")
+	@GetMapping("/api/chat-rooms")
+	public ResponseEntity<List<ChatRoomSimpleResponse>> getChatRoomsByMember(
+		@AuthenticationPrincipal Member member
+	) {
+		List<ChatRoomSimpleResponse> response = chatRoomService.getChatRoomsByMember(member);
+		return ResponseEntity.ok(response);
+	}
+
 	@Operation(summary = "채팅방 조회 API", description = "채팅방 아이디로 채팅방을 조회한다.")
 	@GetMapping("/api/chat-rooms/{chatRoomId}")
 	public ResponseEntity<ChatRoomDetailResponse> createChatRoom(

src/main/java/com/dnd/gongmuin/chat/dto/ChatMessageMapper.java

@@ -18,6 +18,7 @@ public static ChatMessageResponse toChatMessageResponse(
 			chatMessage.getMemberId(),
 			chatMessage.getContent(),
 			chatMessage.getType().getLabel(),
+			chatMessage.getIsRead(),
 			chatMessage.getCreatedAt().toString()
 		);
 	}

src/main/java/com/dnd/gongmuin/chat/dto/request/ChatMessageRequest.java

@@ -10,6 +10,6 @@ public record ChatMessageRequest(
 	String type,
 
 	@NotNull(message = "회원 아이디를 입력해주세요.")
-	Long memberId
+	Long senderId
 ) {
 }

src/main/java/com/dnd/gongmuin/chat/dto/request/CreateChatRoomRequest.java

@@ -6,7 +6,7 @@ public record CreateChatRoomRequest(
 	@NotNull(message = "질문 게시글 아이디는 필수 입력 항목입니다.")
 	Long questionPostId,
 
-	@NotNull(message = "답변 아이디는 필수 입력 항목입니다.")
+	@NotNull(message = "답변자 아이디는 필수 입력 항목입니다.")
 	Long answererId
 ) {
 }

src/main/java/com/dnd/gongmuin/chat/dto/response/ChatMessageResponse.java

@@ -4,6 +4,7 @@ public record ChatMessageResponse(
 	Long senderId,
 	String content,
 	String type,
+	boolean isRead,
 	String createdAt
 ) {
 }

src/main/java/com/dnd/gongmuin/chat/dto/response/ChatRoomInfo.java

@@ -0,0 +1,29 @@
+package com.dnd.gongmuin.chat.dto.response;
+
+import com.dnd.gongmuin.member.domain.JobGroup;
+import com.querydsl.core.annotations.QueryProjection;
+
+public record ChatRoomInfo(
+	Long chatRoomId,
+	Long partnerId,
+	String partnerNickname,
+	String partnerJobGroup,
+	int partnerProfileImageNo
+) {
+	@QueryProjection
+	public ChatRoomInfo(
+		Long chatRoomId,
+		Long partnerId,
+		String partnerNickname,
+		JobGroup partnerJobGroup,
+		int partnerProfileImageNo
+	) {
+		this(
+			chatRoomId,
+			partnerId,
+			partnerNickname,
+			partnerJobGroup.getLabel(),
+			partnerProfileImageNo
+		);
+	}
+}

src/main/java/com/dnd/gongmuin/chat/dto/response/ChatRoomSimpleResponse.java

@@ -0,0 +1,12 @@
+package com.dnd.gongmuin.chat.dto.response;
+
+import com.dnd.gongmuin.question_post.dto.response.MemberInfo;
+
+public record ChatRoomSimpleResponse(
+	Long chatRoomId,
+	MemberInfo chatPartner,
+	String latestMessage,
+	String messageType,
+	String messageCreatedAt
+) {
+}

src/main/java/com/dnd/gongmuin/chat/dto/response/LatestChatMessage.java

@@ -0,0 +1,11 @@
+package com.dnd.gongmuin.chat.dto.response;
+
+import java.time.LocalDateTime;
+
+public record LatestChatMessage(
+	Long chatRoomId,
+	String content,
+	String type,
+	LocalDateTime createdAt
+) {
+}

src/main/java/com/dnd/gongmuin/chat/repository/ChatMessageQueryRepository.java

@@ -0,0 +1,40 @@
+package com.dnd.gongmuin.chat.repository;
+
+import java.util.List;
+
+import org.springframework.data.domain.Sort;
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.data.mongodb.core.aggregation.Aggregation;
+import org.springframework.data.mongodb.core.aggregation.AggregationOperation;
+import org.springframework.data.mongodb.core.aggregation.AggregationResults;
+import org.springframework.data.mongodb.core.query.Criteria;
+import org.springframework.stereotype.Component;
+
+import com.dnd.gongmuin.chat.dto.response.LatestChatMessage;
+
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Component
+public class ChatMessageQueryRepository {
+
+	private final MongoTemplate mongoTemplate;
+
+	public List<LatestChatMessage> findLatestChatByChatRoomIds(List<Long> chatRoomIds) {
+		AggregationOperation sort = Aggregation.sort(Sort.Direction.DESC, "createdAt");
+		AggregationOperation match = Aggregation.match(Criteria.where("chatRoomId").in(chatRoomIds));
+		AggregationOperation group = Aggregation.group("chatRoomId")
+			.first("createdAt").as("createdAt")
+			.first("content").as("content")
+			.first("type").as("type");
+		AggregationOperation project = Aggregation.project()
+			.and("_id").as("chatRoomId")
+			.and("createdAt").as("createdAt")
+			.and("content").as("content")
+			.and("type").as("type");
+		Aggregation aggregation = Aggregation.newAggregation(sort, match, group, project);
+		AggregationResults<LatestChatMessage> results = mongoTemplate.aggregate(aggregation, "chat_messages",
+			LatestChatMessage.class);
+		return results.getMappedResults();
+	}
+}

src/main/java/com/dnd/gongmuin/chat/repository/ChatRoomQueryRepository.java

@@ -0,0 +1,10 @@
+package com.dnd.gongmuin.chat.repository;
+
+import java.util.List;
+
+import com.dnd.gongmuin.chat.dto.response.ChatRoomInfo;
+import com.dnd.gongmuin.member.domain.Member;
+
+public interface ChatRoomQueryRepository {
+	List<ChatRoomInfo> getChatRoomsByMember(Member member);
+}

src/main/java/com/dnd/gongmuin/chat/repository/ChatRoomQueryRepositoryImpl.java

@@ -0,0 +1,45 @@
+package com.dnd.gongmuin.chat.repository;
+
+import static com.dnd.gongmuin.chat.domain.QChatRoom.*;
+
+import java.util.List;
+
+import com.dnd.gongmuin.chat.dto.response.ChatRoomInfo;
+import com.dnd.gongmuin.chat.dto.response.QChatRoomInfo;
+import com.dnd.gongmuin.member.domain.Member;
+import com.querydsl.core.types.dsl.CaseBuilder;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+public class ChatRoomQueryRepositoryImpl implements ChatRoomQueryRepository {
+	private final JPAQueryFactory queryFactory;
+
+	public List<ChatRoomInfo> getChatRoomsByMember(Member member) {
+		return queryFactory
+			.select(new QChatRoomInfo(
+				chatRoom.id,
+				new CaseBuilder()
+					.when(chatRoom.inquirer.id.eq(member.getId()))
+					.then(chatRoom.answerer.id)
+					.otherwise(chatRoom.inquirer.id),
+				new CaseBuilder()
+					.when(chatRoom.inquirer.id.eq(member.getId()))
+					.then(chatRoom.answerer.nickname)
+					.otherwise(chatRoom.inquirer.nickname),
+				new CaseBuilder()
+					.when(chatRoom.inquirer.id.eq(member.getId()))
+					.then(chatRoom.answerer.jobGroup)
+					.otherwise(chatRoom.inquirer.jobGroup),
+				new CaseBuilder()
+					.when(chatRoom.inquirer.id.eq(member.getId()))
+					.then(chatRoom.answerer.profileImageNo)
+					.otherwise(chatRoom.inquirer.profileImageNo)
+			))
+			.from(chatRoom)
+			.where(chatRoom.inquirer.id.eq(member.getId())
+				.or(chatRoom.answerer.id.eq(member.getId())))
+			.fetch();
+	}
+}

src/main/java/com/dnd/gongmuin/chat/repository/ChatRoomRepository.java

@@ -4,5 +4,5 @@
 
 import com.dnd.gongmuin.chat.domain.ChatRoom;
 
-public interface ChatRoomRepository extends JpaRepository<ChatRoom, Long> {
+public interface ChatRoomRepository extends JpaRepository<ChatRoom, Long>, ChatRoomQueryRepository {
 }

src/main/java/com/dnd/gongmuin/chat/service/ChatMessageService.java

@@ -24,10 +24,10 @@ public ChatMessageResponse saveChatMessage(
 		ChatMessageRequest request,
 		Long chatRoomId
 	) {
-		Long memberId = request.memberId();
+		Long senderId = request.senderId();
 		ChatMessage chatMessage = chatMessageRepository.save(
-			ChatMessageMapper.toChatMessage(request, chatRoomId, memberId));
-		log.info("chatRoomId = {}, memberId= {}, chatMessageId= {}", chatRoomId, memberId, chatMessage.getId());
+			ChatMessageMapper.toChatMessage(request, chatRoomId, senderId));
+		log.info("chatRoomId = {}, senderId= {}, chatMessageId= {}", chatRoomId, senderId, chatMessage.getId());
 		return ChatMessageMapper.toChatMessageResponse(chatMessage);
 	}
 }

src/main/java/com/dnd/gongmuin/chat/service/ChatRoomService.java

@@ -1,6 +1,10 @@
 package com.dnd.gongmuin.chat.service;
 
+import java.util.Comparator;
+import java.util.List;
+import java.util.Map;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Slice;
@@ -14,8 +18,12 @@
 import com.dnd.gongmuin.chat.dto.response.AcceptChatResponse;
 import com.dnd.gongmuin.chat.dto.response.ChatMessageResponse;
 import com.dnd.gongmuin.chat.dto.response.ChatRoomDetailResponse;
+import com.dnd.gongmuin.chat.dto.response.ChatRoomInfo;
+import com.dnd.gongmuin.chat.dto.response.ChatRoomSimpleResponse;
+import com.dnd.gongmuin.chat.dto.response.LatestChatMessage;
 import com.dnd.gongmuin.chat.dto.response.RejectChatResponse;
 import com.dnd.gongmuin.chat.exception.ChatErrorCode;
+import com.dnd.gongmuin.chat.repository.ChatMessageQueryRepository;
 import com.dnd.gongmuin.chat.repository.ChatMessageRepository;
 import com.dnd.gongmuin.chat.repository.ChatRoomRepository;
 import com.dnd.gongmuin.common.dto.PageMapper;
@@ -26,6 +34,7 @@
 import com.dnd.gongmuin.member.exception.MemberErrorCode;
 import com.dnd.gongmuin.member.repository.MemberRepository;
 import com.dnd.gongmuin.question_post.domain.QuestionPost;
+import com.dnd.gongmuin.question_post.dto.response.MemberInfo;
 import com.dnd.gongmuin.question_post.exception.QuestionPostErrorCode;
 import com.dnd.gongmuin.question_post.repository.QuestionPostRepository;
 
@@ -36,6 +45,7 @@
 public class ChatRoomService {
 
 	private final ChatMessageRepository chatMessageRepository;
+	private final ChatMessageQueryRepository chatMessageQueryRepository;
 	private final ChatRoomRepository chatRoomRepository;
 	private final MemberRepository memberRepository;
 	private final QuestionPostRepository questionPostRepository;
@@ -66,6 +76,37 @@ public ChatRoomDetailResponse createChatRoom(CreateChatRoomRequest request, Memb
 		);
 	}
 
+	@Transactional(readOnly = true)
+	public List<ChatRoomSimpleResponse> getChatRoomsByMember(Member member) {
+		// 회원 채팅방 정보 가져오기
+		List<ChatRoomInfo> chatRoomInfos = chatRoomRepository.getChatRoomsByMember(member);
+		// chatRoomId 리스트 추출
+		List<Long> chatRoomIds = chatRoomInfos.stream()
+			.map(ChatRoomInfo::chatRoomId)
+			.toList();
+		// 각 채팅방 최근 메시지 정보
+		List<LatestChatMessage> latestChatMessages = chatMessageQueryRepository.findLatestChatByChatRoomIds(
+			chatRoomIds);
+		// <chatRoomId, LatestMessage> -> 순서 보장 x
+		Map<Long, LatestChatMessage> messageMap = latestChatMessages.stream()
+			.collect(Collectors.toMap(LatestChatMessage::chatRoomId, message -> message));
+		// 최신순 정렬
+		return chatRoomInfos.stream()
+			.sorted(
+				Comparator.comparing((ChatRoomInfo info) -> messageMap.get(info.chatRoomId()).createdAt()).reversed())
+			.map(chatRoomInfo -> {
+				LatestChatMessage latestMessage = messageMap.get(chatRoomInfo.chatRoomId());
+				return new ChatRoomSimpleResponse(
+					chatRoomInfo.chatRoomId(),
+					new MemberInfo(chatRoomInfo.partnerId(), chatRoomInfo.partnerNickname(),
+						chatRoomInfo.partnerJobGroup(), chatRoomInfo.partnerProfileImageNo()),
+					latestMessage.content(),
+					latestMessage.type(),
+					latestMessage.createdAt().toString()
+				);
+			}).toList();
+	}
+
 	@Transactional(readOnly = true)
 	public ChatRoomDetailResponse getChatRoomById(Long chatRoomId, Member member) {
 		ChatRoom chatRoom = getChatRoomById(chatRoomId);

src/main/java/com/dnd/gongmuin/member/domain/Member.java

@@ -62,16 +62,6 @@ private Member(String nickname, String socialName, JobGroup jobGroup, JobCategor
 		this.role = role;
 	}
 
-	@Override
-	public String toString() {
-		return "MEMBER INFO{" +
-			"id=" + id +
-			", role='" + role + '\'' +
-			", jobGroup=" + jobGroup +
-			", socialEmail='" + socialEmail + '\'' +
-			'}';
-	}
-
 	public static Member of(String socialName, String socialEmail, int credit) {
 		return Member.builder()
 			.socialName(socialName)
@@ -103,6 +93,16 @@ public static Member of(String nickname, String socialName, JobGroup jobGroup, J
 			.build();
 	}
 
+	@Override
+	public String toString() {
+		return "MEMBER INFO{" +
+			"id=" + id +
+			", role='" + role + '\'' +
+			", jobGroup=" + jobGroup +
+			", socialEmail='" + socialEmail + '\'' +
+			'}';
+	}
+
 	public void updateSocialEmail(String socialEmail) {
 		this.socialEmail = socialEmail;
 	}