♻️ refactor: gameStart 리팩토링

- 방장만 게임 시작 가능
- 이미 플레이 중인 방의 중복 게임시작 방지

Author: LimKangHyun

backend/src/main/java/io/f1/backend/domain/game/app/GameService.java

@@ -13,10 +13,11 @@
 import io.f1.backend.domain.question.entity.Question;
 import io.f1.backend.domain.quiz.app.QuizService;
 import io.f1.backend.domain.quiz.entity.Quiz;
+import io.f1.backend.domain.user.dto.UserPrincipal;
 import io.f1.backend.global.exception.CustomException;
-import io.f1.backend.global.exception.errorcode.GameErrorCode;
 import io.f1.backend.global.exception.errorcode.RoomErrorCode;
 
+import java.util.Objects;
 import lombok.RequiredArgsConstructor;
 
 import org.springframework.context.ApplicationEventPublisher;
@@ -33,53 +34,54 @@ public class GameService {
     private final RoomRepository roomRepository;
     private final ApplicationEventPublisher eventPublisher;
 
-    public GameStartResponse gameStart(Long roomId, GameStartRequest gameStartRequest) {
-
-        Long quizId = gameStartRequest.quizId();
+    public GameStartResponse gameStart(Long roomId, UserPrincipal principal) {
 
         Room room =
                 roomRepository
                         .findRoom(roomId)
                         .orElseThrow(() -> new CustomException(RoomErrorCode.ROOM_NOT_FOUND));
 
-        if (!validateReadyStatus(room)) {
-            throw new CustomException(RoomErrorCode.PLAYER_NOT_READY);
-        }
-
-        // 방의 gameSetting에 설정된 퀴즈랑 요청 퀴즈랑 같은지 체크 후 GameSetting에서 라운드 가져오기
-        Integer round = checkGameSetting(room, quizId);
+        validateRoomStart(room, principal);
 
+        Long quizId = room.getGameSetting().getQuizId();
         Quiz quiz = quizService.getQuizWithQuestionsById(quizId);
+        List<Question> questions = prepareQuestions(room, quiz);
 
-        // 라운드 수만큼 랜덤 Question 추출
-        List<Question> questions = quizService.getRandomQuestionsWithoutAnswer(quizId, round);
         room.updateQuestions(questions);
 
-        GameStartResponse gameStartResponse = toGameStartResponse(questions);
-
         // 방 정보 게임 중으로 변경
         room.updateRoomState(RoomState.PLAYING);
 
         eventPublisher.publishEvent(new RoomUpdatedEvent(room, quiz));
 
-        return gameStartResponse;
+        return toGameStartResponse(questions);
     }
 
-    private Integer checkGameSetting(Room room, Long quizId) {
-
-        GameSetting gameSetting = room.getGameSetting();
+    private boolean validateReadyStatus(Room room) {
 
-        if (!gameSetting.validateQuizId(quizId)) {
-            throw new CustomException(GameErrorCode.GAME_SETTING_CONFLICT);
-        }
+        Map<String, Player> playerSessionMap = room.getPlayerSessionMap();
 
-        return gameSetting.getRound();
+        return playerSessionMap.values().stream().allMatch(Player::isReady);
     }
 
-    private boolean validateReadyStatus(Room room) {
+    private void validateRoomStart(Room room, UserPrincipal principal) {
+        if (!Objects.equals(principal.getUserId(), room.getHost().getId())) {
+            throw new CustomException(RoomErrorCode.NOT_ROOM_OWNER);
+        }
 
-        Map<String, Player> playerSessionMap = room.getPlayerSessionMap();
+        if (!validateReadyStatus(room)) {
+            throw new CustomException(RoomErrorCode.PLAYER_NOT_READY);
+        }
 
-        return playerSessionMap.values().stream().allMatch(Player::isReady);
+        if (room.getState() == RoomState.PLAYING) {
+            throw new CustomException(RoomErrorCode.GAME_ALREADY_PLAYING);
+        }
+    }
+
+    // 라운드 수만큼 랜덤 Question 추출
+    public List<Question> prepareQuestions(Room room, Quiz quiz) {
+        Long quizId = quiz.getId();
+        Integer round = room.getGameSetting().getRound();
+        return quizService.getRandomQuestionsWithoutAnswer(quizId, round);
     }
 }

backend/src/main/java/io/f1/backend/domain/game/websocket/GameSocketController.java

@@ -8,7 +8,6 @@
 import io.f1.backend.domain.game.dto.RoomInitialData;
 import io.f1.backend.domain.game.dto.RoundResult;
 import io.f1.backend.domain.game.dto.request.DefaultWebSocketRequest;
-import io.f1.backend.domain.game.dto.request.GameStartRequest;
 import io.f1.backend.domain.game.dto.response.GameStartResponse;
 import io.f1.backend.domain.game.dto.response.PlayerListResponse;
 import io.f1.backend.domain.user.dto.UserPrincipal;
@@ -18,10 +17,11 @@
 import org.springframework.messaging.Message;
 import org.springframework.messaging.handler.annotation.DestinationVariable;
 import org.springframework.messaging.handler.annotation.MessageMapping;
-import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
-import org.springframework.security.core.Authentication;
 import org.springframework.stereotype.Controller;
 
+import static io.f1.backend.domain.game.websocket.WebSocketUtils.getSessionId;
+import static io.f1.backend.domain.game.websocket.WebSocketUtils.getSessionUser;
+
 @Controller
 @RequiredArgsConstructor
 public class GameSocketController {
@@ -72,11 +72,11 @@ public void exitRoom(@DestinationVariable Long roomId, Message<?> message) {
 
     @MessageMapping("/room/start/{roomId}")
     public void gameStart(
-            @DestinationVariable Long roomId,
-            Message<DefaultWebSocketRequest<GameStartRequest>> message) {
+            @DestinationVariable Long roomId, Message<?> message) {
+
+        UserPrincipal principal = getSessionUser(message);
 
-        GameStartResponse gameStartResponse =
-                gameService.gameStart(roomId, message.getPayload().getMessage());
+        GameStartResponse gameStartResponse = gameService.gameStart(roomId, principal);
 
         String destination = getDestination(roomId);
 
@@ -112,17 +112,6 @@ public void playerReady(@DestinationVariable Long roomId, Message<?> message) {
         messageSender.send(getDestination(roomId), MessageType.PLAYER_LIST, playerListResponse);
     }
 
-    private static String getSessionId(Message<?> message) {
-        StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
-        return accessor.getSessionId();
-    }
-
-    private static UserPrincipal getSessionUser(Message<?> message) {
-        StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
-        Authentication auth = (Authentication) accessor.getUser();
-        return (UserPrincipal) auth.getPrincipal();
-    }
-
     private String getDestination(Long roomId) {
         return "/sub/room/" + roomId;
     }

backend/src/main/java/io/f1/backend/domain/game/websocket/WebSocketUtils.java

@@ -0,0 +1,20 @@
+package io.f1.backend.domain.game.websocket;
+
+import io.f1.backend.domain.user.dto.UserPrincipal;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
+import org.springframework.security.core.Authentication;
+
+public class WebSocketUtils {
+
+    public static String getSessionId(Message<?> message) {
+        StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
+        return accessor.getSessionId();
+    }
+
+    public static UserPrincipal getSessionUser(Message<?> message) {
+        StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
+        Authentication auth = (Authentication) accessor.getUser();
+        return (UserPrincipal) auth.getPrincipal();
+    }
+}

backend/src/main/java/io/f1/backend/global/exception/errorcode/RoomErrorCode.java

@@ -14,7 +14,9 @@ public enum RoomErrorCode implements ErrorCode {
     ROOM_NOT_FOUND("E404005", HttpStatus.NOT_FOUND, "존재하지 않는 방입니다."),
     WRONG_PASSWORD("E401006", HttpStatus.UNAUTHORIZED, "비밀번호가 일치하지않습니다."),
     PLAYER_NOT_FOUND("E404007", HttpStatus.NOT_FOUND, "존재하지 않는 플레이어입니다."),
-    SOCKET_SESSION_NOT_FOUND("E404006", HttpStatus.NOT_FOUND, "존재하지 않는 소켓 세션입니다.");
+    SOCKET_SESSION_NOT_FOUND("E404006", HttpStatus.NOT_FOUND, "존재하지 않는 소켓 세션입니다."),
+    GAME_ALREADY_PLAYING("E400015", HttpStatus.BAD_REQUEST, "이미 게임이 진행 중 입니다."),
+    NOT_ROOM_OWNER("E403005", HttpStatus.FORBIDDEN, "방장만 게임 시작이 가능합니다.");
 
     private final String code;