feat 채팅 첨부파일 보내기 기능 추가

src/main/java/com/cotato/itda/domain/chat/controller/dto/ChatAttachmentRequest.java

@@ -0,0 +1,14 @@
+package com.cotato.itda.domain.chat.controller.dto;
+
+import com.cotato.itda.domain.chat.enums.AttachmentType;
+
+import jakarta.validation.constraints.NotNull;
+
+public record ChatAttachmentRequest (
+	@NotNull AttachmentType attachmentType,
+	@NotNull String objectKey,
+	String mimeType,
+	Long sizeBytes,
+	Integer durationMs
+){
+}

src/main/java/com/cotato/itda/domain/chat/exception/code/ChatErrorCode.java

@@ -11,6 +11,26 @@
 @RequiredArgsConstructor
 public enum ChatErrorCode implements ErrorCode {
 
+	INVALID_MESSAGE_CONTENT(
+		HttpStatus.BAD_REQUEST,
+		"메시지 내용이 유효하지 않습니다.",
+		"CHAT_ERROR_400_INVALID_MESSAGE_CONTENT"
+	),
+	INVALID_ATTACHMENT_FOR_TEXT(
+		HttpStatus.BAD_REQUEST,
+		"텍스트 메시지에는 첨부파일이 포함될 수 없습니다.",
+		"CHAT_ERROR_400_INVALID_ATTACHMENT_FOR_TEXT"
+	),
+	INVALID_ATTACHMENT_REQUIRED(
+		HttpStatus.BAD_REQUEST,
+		"첨부파일 메시지에는 첨부파일이 반드시 포함되어야 합니다.",
+		"CHAT_ERROR_400_INVALID_ATTACHMENT_REQUIRED"
+	),
+	INVALID_ATTACHMENT_OBJECT_KEY(
+		HttpStatus.BAD_REQUEST,
+		"첨부파일의 objectKey가 유효하지 않습니다.",
+		"CHAT_ERROR_400_INVALID_ATTACHMENT_OBJECT_KEY"
+	),
 	// 현재 상태가 ACTIVE가 아닙니다
 	CHAT_ROOM_MEMBER_STATUS_INVALID(
 		HttpStatus.BAD_REQUEST,

src/main/java/com/cotato/itda/domain/chat/repository/ChatMessasgeAttachmentRepository.java → src/main/java/com/cotato/itda/domain/chat/repository/ChatMessageAttachmentRepository.java

@@ -4,5 +4,5 @@
 
 import com.cotato.itda.domain.chat.entity.ChatMessageAttachment;
 
-public interface ChatMessasgeAttachmentRepository extends JpaRepository<ChatMessageAttachment,Long> {
+public interface ChatMessageAttachmentRepository extends JpaRepository<ChatMessageAttachment,Long> {
 }

src/main/java/com/cotato/itda/domain/chat/service/ChatMessageService.java

@@ -8,15 +8,19 @@
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
+import com.cotato.itda.domain.chat.controller.dto.ChatAttachmentRequest;
 import com.cotato.itda.domain.chat.controller.dto.ChatMessageItemDto;
 import com.cotato.itda.domain.chat.controller.dto.ChatMessageSliceResponse;
 import com.cotato.itda.domain.chat.entity.ChatMessage;
+import com.cotato.itda.domain.chat.entity.ChatMessageAttachment;
 import com.cotato.itda.domain.chat.entity.ChatRoom;
 import com.cotato.itda.domain.chat.entity.ChatRoomMember;
+import com.cotato.itda.domain.chat.enums.AttachmentStatus;
 import com.cotato.itda.domain.chat.enums.LastMessageType;
 import com.cotato.itda.domain.chat.enums.MemberRoomStatus;
 import com.cotato.itda.domain.chat.enums.MessageType;
 import com.cotato.itda.domain.chat.exception.code.ChatErrorCode;
+import com.cotato.itda.domain.chat.repository.ChatMessageAttachmentRepository;
 import com.cotato.itda.domain.chat.repository.ChatRoomMemberRepository;
 import com.cotato.itda.domain.chat.repository.ChatRoomQueryRepository;
 import com.cotato.itda.domain.chat.repository.ChatRoomRepository;
@@ -44,7 +48,7 @@ public class ChatMessageService {
 	private final ChatRoomMemberRepository chatRoomMemberRepository;
 	private final ChatMessageRepository chatMessageRepository;
 	private final ChatRoomQueryRepository chatRoomQueryRepository;
-
+	private final ChatMessageAttachmentRepository chatMessageAttachmentRepository;
 	private final MemberRepository memberRepository;
 
 	private final SimpMessagingTemplate messagingTemplate;
@@ -68,6 +72,7 @@ public void sendMessage(Long senderMemberId, ChatSendMessageRequest req) {
 			throw new BusinessException(ChatErrorCode.INVALID_REQUEST_BOTH_ROOMID_OPPONENTID_NULL);
 		}
 
+		validateSendRequest(req);
 		// ===== [1] 발신자 조회 =====
 		log.info("[발신자 조회] senderMemberId={} 조회 시작", senderMemberId);
 		Member sender = memberRepository.findById(senderMemberId)
@@ -172,6 +177,23 @@ public void sendMessage(Long senderMemberId, ChatSendMessageRequest req) {
 			roomId, message.getId(), message.getMessageSeq(), senderMemberId, req.messageType()
 		);
 
+		ChatMessageAttachment savedAttachment = null;
+		if (req.messageType() == MessageType.ATTACHMENT) {
+
+			ChatAttachmentRequest a = req.attachment();
+
+			ChatMessageAttachment attachment = ChatMessageAttachment.builder()
+				.message(message)
+				.attachmentType(a.attachmentType())
+				.objectKey(a.objectKey())
+				.mimeType(a.mimeType())
+				.sizeBytes(a.sizeBytes())
+				.durationMs(a.durationMs())
+				.status(AttachmentStatus.READY) // 초기 상태는 READY
+				.build();
+
+			savedAttachment = chatMessageAttachmentRepository.save(attachment);
+		}
 		// ===== [5] 내 메시지 자동 읽음 처리 =====
 		myMembership.markRead(nextSeq, message.getId());
 		log.info("[읽음 처리] senderMemberId={} 가 보낸 메시지 자동 읽음 처리. roomId={}, readSeq={}, readMessageId={}",
@@ -210,6 +232,19 @@ public void sendMessage(Long senderMemberId, ChatSendMessageRequest req) {
 		log.info("[상대 조회] roomId={}, senderMemberId={}, opponentId={}",
 			roomId, senderMemberId, opponentId
 		);
+		ChatMessageItemDto.AttachmentMeta meta = null;
+
+		if (savedAttachment != null) {
+			meta = ChatMessageItemDto.AttachmentMeta.builder()
+				.attachmentType(savedAttachment.getAttachmentType())
+				.objectKey(savedAttachment.getObjectKey())
+				.mimeType(savedAttachment.getMimeType())
+				.sizeBytes(savedAttachment.getSizeBytes())
+				.status(savedAttachment.getStatus())
+				.durationMs(savedAttachment.getDurationMs())
+				.build();
+		}
+
 
 		// ===== [8] 방 토픽 발행 =====
 		ChatRoomMessageDto roomMessageDto = ChatRoomMessageDto.builder()
@@ -220,7 +255,7 @@ public void sendMessage(Long senderMemberId, ChatSendMessageRequest req) {
 			.messageType(req.messageType())
 			.content(req.content())
 			.createdAt(now)
-			.attachment(null)
+			.attachment(meta)
 			.build();
 
 		String roomTopicDest = "/topic/chat/rooms/" + roomId;
@@ -379,4 +414,30 @@ public ChatMessageSliceResponse getRoomMessages(Long memberId, Long roomId, Inte
 			.nextCursorSeq(nextCursor)
 			.build();
 	}
+
+	private void validateSendRequest(ChatSendMessageRequest req) {
+		if (req.messageType() == MessageType.TEXT) {
+			if (req.content() == null || req.content().isBlank()) {
+				throw new BusinessException(ChatErrorCode.INVALID_MESSAGE_CONTENT);
+			}
+			if (req.attachment() != null) {
+				throw new BusinessException(ChatErrorCode.INVALID_ATTACHMENT_FOR_TEXT);
+			}
+			return;
+		}
+
+		// ATTACHMENT
+		if (req.attachment() == null) {
+			throw new BusinessException(ChatErrorCode.INVALID_ATTACHMENT_REQUIRED);
+		}
+		if (req.attachment().objectKey() == null || req.attachment().objectKey().isBlank()) {
+			throw new BusinessException(ChatErrorCode.INVALID_ATTACHMENT_OBJECT_KEY);
+		}
+
+		// 보안/검증: objectKey 접두어 제한 추천
+		// 예: attachments/ 로 시작하는 것만 허용
+		if (!req.attachment().objectKey().startsWith("attachments/")) {
+			throw new BusinessException(ChatErrorCode.INVALID_ATTACHMENT_OBJECT_KEY);
+		}
+	}
 }

src/main/java/com/cotato/itda/domain/websocket/dto/ChatRoomMessageDto.java

@@ -2,6 +2,7 @@
 
 import java.time.LocalDateTime;
 
+import com.cotato.itda.domain.chat.controller.dto.ChatMessageItemDto;
 import com.cotato.itda.domain.chat.enums.AttachmentStatus;
 import com.cotato.itda.domain.chat.enums.AttachmentType;
 import com.cotato.itda.domain.chat.enums.MessageType;
@@ -20,7 +21,7 @@ public record ChatRoomMessageDto(
 	MessageType messageType,
 	String content,
 	LocalDateTime createdAt,
-	Attachment attachment
+	ChatMessageItemDto.AttachmentMeta attachment
 ) {
 	@Builder
 	public record Attachment(

src/main/java/com/cotato/itda/domain/websocket/dto/ChatSendMessageRequest.java

@@ -1,19 +1,27 @@
 package com.cotato.itda.domain.websocket.dto;
 
+import com.cotato.itda.domain.chat.controller.dto.ChatAttachmentRequest;
 import com.cotato.itda.domain.chat.enums.MessageType;
 
 import jakarta.validation.constraints.NotNull;
-import lombok.ToString;
 
 /**
  * 임시 화면(roomId 없음)에서도 보내야 하므로 roomId는 nullable
  * - clientMessageId: 클라이언트에서 생성한 메시지 ID (중복 방지 및 추적용)
+ * TEXT
+ * - content 필수
+ * - attachment null
+ * ATTACHMENT (S3 업로드 완료 후)
+ * - content null
+ * - attachment 필수
+ * - attachment.objectKey 필수
  */
 public record ChatSendMessageRequest(
 	@NotNull String clientMessageId,
 	Long roomId,
 	Long opponentMemberId, // roomId가 없을 때 필수
 	@NotNull MessageType messageType,
-	String content
+	String content,
+	ChatAttachmentRequest attachment
 	){
 }