feat: 채팅방 입장 정책 검증, Lazy 생성 구현

Author: heygeeji

src/main/java/com/back/web7_9_codecrete_be/domain/chats/controller/ChatController.java

@@ -0,0 +1,47 @@
+package com.back.web7_9_codecrete_be.domain.chats.controller;
+
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.back.web7_9_codecrete_be.domain.chats.service.ChatRoomService;
+import com.back.web7_9_codecrete_be.global.rq.Rq;
+import com.back.web7_9_codecrete_be.global.rsData.RsData;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.RequiredArgsConstructor;
+
+@Tag(name = "Chat Room", description = "공연 채팅방 입장 및 퇴장 API")
+@RestController
+@RequestMapping("/api/v1/chat-room")
+@RequiredArgsConstructor
+public class ChatRoomController {
+
+	private final ChatRoomService chatRoomService;
+	private final Rq rq;
+
+	@Operation(
+		summary = "채팅방 입장",
+		description = """
+			공연 채팅방에 입장합니다.
+			- 정책 기간(예매일 3일 전 ~ 예매일 3일 후) 안에서만 입장이 가능합니다.
+			- 채팅방이 존재하지 않으면 최초 1회 Lazy 생성됩니다.
+
+			입장 성공 후 프론트엔드는 WebSocket(STOMP)에 연결하여
+			Redis Stream 기반 과거 채팅과 실시간 채팅을 수신합니다.
+			""" )
+	@ApiResponse( responseCode = "200", description = "채팅방 입장에 성공하였습니다." )
+	@ApiResponse( responseCode = "403", description = "로그인이 필요합니다." )
+	@ApiResponse( responseCode = "403", description = "채팅 가능한 기간이 아닙니다." )
+	@ApiResponse( responseCode = "404", description = "콘서트가 존재하지 않습니다." )
+	@PostMapping("/concert/{concertId}/join")
+	public RsData<Void> joinChatRoom(@PathVariable Long concertId) {
+
+		chatRoomService.joinChatRoom(concertId);
+		return RsData.success(null);
+	}
+
+}

src/main/java/com/back/web7_9_codecrete_be/domain/chats/controller/ChatRoomController.java

@@ -2,35 +2,48 @@
 
 import java.time.LocalDateTime;
 
+import org.springframework.data.annotation.CreatedDate;
+import org.springframework.data.jpa.domain.support.AuditingEntityListener;
+
 import com.back.web7_9_codecrete_be.domain.concerts.entity.Concert;
 
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
+import jakarta.persistence.EntityListeners;
 import jakarta.persistence.FetchType;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
 import jakarta.persistence.JoinColumn;
 import jakarta.persistence.OneToOne;
+import lombok.AccessLevel;
 import lombok.Getter;
+import lombok.NoArgsConstructor;
 
 @Getter
 @Entity
+@EntityListeners(AuditingEntityListener.class)
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
 public class ChatRoom {
 
 	@Id
 	@GeneratedValue(strategy = GenerationType.IDENTITY)
 	@Column(name = "chat_room_id")
-	private long id;
+	private Long id;
 
-	@Column(nullable = false)
+	@CreatedDate
+	@Column(name = "created_date", nullable = false)
 	private LocalDateTime createdDate;
 
-	@Column(nullable = false)
-	private LocalDateTime expiresDate;
-
 	@OneToOne(fetch = FetchType.LAZY)
 	@JoinColumn(name = "concert_id", nullable = false, unique = true)
 	private Concert concert;
 
+	private ChatRoom(Concert concert) {
+		this.concert = concert;
+	}
+
+	public static ChatRoom create(Concert concert) {
+		return new ChatRoom(concert);
+	}
 }

src/main/java/com/back/web7_9_codecrete_be/domain/chats/dto/dummy.txt

@@ -1,8 +1,13 @@
 package com.back.web7_9_codecrete_be.domain.chats.repository;
 
+import java.util.Optional;
+
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import com.back.web7_9_codecrete_be.domain.chats.entity.ChatRoom;
 
 public interface ChatRoomRepository extends JpaRepository<ChatRoom, Long> {
+
+	Optional<ChatRoom> findByConcert_ConcertId(Long concertId);
+
 }

src/main/java/com/back/web7_9_codecrete_be/domain/chats/entity/ChatRoom.java

@@ -0,0 +1,75 @@
+package com.back.web7_9_codecrete_be.domain.chats.service;
+
+import java.time.Duration;
+import java.time.LocalDateTime;
+
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.stereotype.Service;
+
+import com.back.web7_9_codecrete_be.domain.concerts.entity.Concert;
+import com.back.web7_9_codecrete_be.domain.concerts.repository.ConcertRepository;
+import com.back.web7_9_codecrete_be.global.error.code.ConcertErrorCode;
+import com.back.web7_9_codecrete_be.global.error.exception.BusinessException;
+
+import lombok.RequiredArgsConstructor;
+
+@Service
+@RequiredArgsConstructor
+public class ChatPolicyService {
+
+	private final RedisTemplate<String, Object> redisTemplate;
+	private final ConcertRepository concertRepository;
+
+	private static final String CHAT_POLICY_KEY_PREFIX = "chat:policy:concert:";
+
+	public boolean isChatAvailable(Long concertId) {
+
+		String key = CHAT_POLICY_KEY_PREFIX + concertId;
+
+		// redis 캐시 조회
+		Boolean cached = (Boolean)redisTemplate.opsForValue().get(key);
+		if (cached != null) {
+			return cached;
+		}
+
+		// 캐시 미스 -> Concert db 조회
+		Concert concert = concertRepository.findById(concertId)
+			.orElseThrow(() -> new BusinessException(ConcertErrorCode.CONCERT_NOT_FOUND));
+
+		LocalDateTime ticketTime = concert.getTicketTime();
+		if (ticketTime == null) {
+			return false;
+		}
+
+		// 정책 기간 계산
+		LocalDateTime now = LocalDateTime.now();
+		boolean available =
+			now.isAfter(ticketTime.minusDays(3)) &&
+				now.isBefore(ticketTime.plusDays(3));
+
+		// TTL 계산 후 캐싱
+		Duration ttl = calculateTtl(now, ticketTime);
+		redisTemplate.opsForValue().set(key, available, ttl);
+
+		return available;
+	}
+
+	private Duration calculateTtl(LocalDateTime now, LocalDateTime ticketTime) {
+
+		LocalDateTime policyStart = ticketTime.minusDays(3);
+		LocalDateTime policyEnd   = ticketTime.plusDays(3);
+
+		// 아직 정책 시작 전
+		if (now.isBefore(policyStart)) {
+			return Duration.between(now, policyStart);
+		}
+
+		// 정책 기간 중
+		if (now.isBefore(policyEnd)) {
+			return Duration.between(now, policyEnd);
+		}
+
+		// 정책 기간 종료 후
+		return Duration.ofMinutes(10);
+	}
+}

src/main/java/com/back/web7_9_codecrete_be/domain/chats/repository/ChatRoomRepository.java

@@ -1,14 +1,62 @@
 package com.back.web7_9_codecrete_be.domain.chats.service;
 
+import org.springframework.dao.DataIntegrityViolationException;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
 
+import com.back.web7_9_codecrete_be.domain.chats.entity.ChatRoom;
 import com.back.web7_9_codecrete_be.domain.chats.repository.ChatRoomRepository;
+import com.back.web7_9_codecrete_be.domain.concerts.entity.Concert;
+import com.back.web7_9_codecrete_be.domain.concerts.repository.ConcertRepository;
+import com.back.web7_9_codecrete_be.global.error.code.ChatErrorCode;
+import com.back.web7_9_codecrete_be.global.error.exception.BusinessException;
 
 import lombok.RequiredArgsConstructor;
 
 @Service
 @RequiredArgsConstructor
+@Transactional
 public class ChatRoomService {
 
 	private final ChatRoomRepository chatRoomRepository;
+	private final ChatPolicyService chatPolicyService;
+	private final ConcertRepository concertRepository;
+
+	/**
+	 * 채팅방 입장
+	 * - 정책 기간 검증 (Redis 캐시 우선)
+	 * - 채팅방 Lazy 생성
+	 */
+	public void joinChatRoom(Long concertId) {
+
+		// 채팅 가능 정책 검증
+		if (!chatPolicyService.isChatAvailable(concertId)) {
+			throw new BusinessException(ChatErrorCode.CHAT_NOT_AVAILABLE);
+		}
+
+		// 채팅방 조회 or Lazy 생성
+		chatRoomRepository.findByConcert_ConcertId(concertId)
+			.orElseGet(() -> createChatRoomSafely(concertId));
+
+		// TODO: 입장 처리 (WebSocket)
+	}
+
+	/**
+	 * 채팅방 Lazy 생성
+	 * - DB UNIQUE(concert_id)로 동시성 처리
+	 */
+	private ChatRoom createChatRoomSafely(Long concertId) {
+
+		try {
+			Concert concert = concertRepository.getReferenceById(concertId);
+
+			return chatRoomRepository.save(ChatRoom.create(concert));
+
+		} catch (DataIntegrityViolationException e) {
+			// 동시에 다른 요청이 먼저 생성한 경우
+			return chatRoomRepository.findByConcert_ConcertId(concertId)
+				.orElseThrow(() ->
+					new IllegalStateException("채팅방 생성 충돌 후 재조회 실패"));
+		}
+	}
 }

src/main/java/com/back/web7_9_codecrete_be/domain/chats/service/ChatPolicyService.java

@@ -0,0 +1,17 @@
+package com.back.web7_9_codecrete_be.global.error.code;
+
+import org.springframework.http.HttpStatus;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+public enum ChatErrorCode implements ErrorCode {
+
+	CHAT_NOT_AVAILABLE(HttpStatus.FORBIDDEN, "CH-100", "채팅 가능 기간이 아닙니다.");
+
+	private final HttpStatus status;
+	private final String code;
+	private final String message;
+}

src/main/java/com/back/web7_9_codecrete_be/domain/chats/service/ChatRoomService.java

@@ -1,15 +1,19 @@
 package com.back.web7_9_codecrete_be.global.error.code;
 
+import org.springframework.http.HttpStatus;
+
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
-import org.springframework.http.HttpStatus;
 
 @Getter
 @RequiredArgsConstructor
 public enum ConcertErrorCode implements ErrorCode {
 
     LIKE_CONFLICT(HttpStatus.CONFLICT,"C131","이미 좋아요를 누른 공연입니다."),
-    NOT_FOUND_CONCERTLIKE(HttpStatus.NOT_FOUND,"C130","좋아요를 누르지 않은 공연입니다.")
+    NOT_FOUND_CONCERTLIKE(HttpStatus.NOT_FOUND,"C130","좋아요를 누르지 않은 공연입니다."),
+
+    CONCERT_NOT_FOUND(HttpStatus.NOT_FOUND, "C-103", "콘서트를 찾을 수 없습니다."),
+    TICKET_TIME_NOT_FOUND(HttpStatus.NOT_FOUND, "C-104", "예매일자가 존재하지 않습니다.")
     ;
 
     private final HttpStatus status;