[feat] 방 게임 시작 구현

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

@@ -0,0 +1,77 @@
+package io.f1.backend.domain.game.app;
+
+import io.f1.backend.domain.game.dto.GameStartData;
+import io.f1.backend.domain.game.dto.response.GameStartResponse;
+import io.f1.backend.domain.game.event.RoomUpdatedEvent;
+import io.f1.backend.domain.game.model.GameSetting;
+import io.f1.backend.domain.game.model.Player;
+import io.f1.backend.domain.game.model.Room;
+import io.f1.backend.domain.game.model.RoomState;
+import io.f1.backend.domain.game.store.RoomRepository;
+import io.f1.backend.domain.quiz.app.QuizService;
+import io.f1.backend.domain.quiz.entity.Quiz;
+
+import lombok.RequiredArgsConstructor;
+
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.stereotype.Service;
+
+import java.util.Map;
+
+@Service
+@RequiredArgsConstructor
+public class GameService {
+
+    private final QuizService quizService;
+    private final RoomRepository roomRepository;
+    private final ApplicationEventPublisher eventPublisher;
+
+    public GameStartData gameStart(Long roomId, Long quizId) {
+
+        Room room =
+                roomRepository
+                        .findRoom(roomId)
+                        .orElseThrow(() -> new IllegalArgumentException("404 존재하지 않는 방입니다."));
+
+        if (!validateReadyStatus(room)) {
+            throw new IllegalArgumentException("E403004 : 레디 상태가 아닙니다.");
+        }
+
+        // 방의 gameSetting에 설정된 퀴즈랑 요청 퀴즈랑 같은지 체크 후 GameSetting에서 라운드 가져오기
+        Integer round = checkGameSetting(room, quizId);
+
+        Quiz quiz = quizService.getQuizWithQuestionsById(quizId);
+
+        // 라운드 수만큼 랜덤 Question 추출
+        GameStartResponse questions = quizService.getRandomQuestionsWithoutAnswer(quizId, round);
+
+        // 방 정보 게임 중으로 변경
+        room.updateRoomState(RoomState.PLAYING);
+
+        eventPublisher.publishEvent(new RoomUpdatedEvent(room, quiz));
+
+        return new GameStartData(getDestination(roomId), questions);
+    }
+
+    private Integer checkGameSetting(Room room, Long quizId) {
+
+        GameSetting gameSetting = room.getGameSetting();
+
+        if (!gameSetting.checkQuizId(quizId)) {
+            throw new IllegalArgumentException("E409002 : 게임 설정이 다릅니다. (게임을 시작할 수 없습니다.)");
+        }
+
+        return gameSetting.getRound();
+    }
+
+    private boolean validateReadyStatus(Room room) {
+
+        Map<String, Player> playerSessionMap = room.getPlayerSessionMap();
+
+        return playerSessionMap.values().stream().allMatch(Player::isReady);
+    }
+
+    private static String getDestination(Long roomId) {
+        return "/sub/room/" + roomId;
+    }
+}

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

@@ -60,7 +60,7 @@ public class RoomService {
     public RoomCreateResponse saveRoom(RoomCreateRequest request) {
 
         Long quizMinId = quizService.getQuizMinId();
-        Quiz quiz = quizService.getQuizById(quizMinId);
+        Quiz quiz = quizService.getQuizWithQuestionsById(quizMinId);
 
         GameSetting gameSetting = toGameSetting(quiz);
 
@@ -132,7 +132,7 @@ public RoomInitialData initializeRoomSocket(Long roomId, String sessionId) {
         RoomSettingResponse roomSettingResponse = toRoomSettingResponse(room);
 
         Long quizId = room.getGameSetting().getQuizId();
-        Quiz quiz = quizService.getQuizById(quizId);
+        Quiz quiz = quizService.getQuizWithQuestionsById(quizId);
 
         GameSettingResponse gameSettingResponse =
                 toGameSettingResponse(room.getGameSetting(), quiz);
@@ -189,7 +189,7 @@ public RoomListResponse getAllRooms() {
                         .map(
                                 room -> {
                                     Long quizId = room.getGameSetting().getQuizId();
-                                    Quiz quiz = quizService.getQuizById(quizId);
+                                    Quiz quiz = quizService.getQuizWithQuestionsById(quizId);
 
                                     return toRoomResponse(room, quiz);
                                 })

backend/src/main/java/io/f1/backend/domain/game/dto/GameStartData.java

@@ -0,0 +1,5 @@
+package io.f1.backend.domain.game.dto;
+
+import io.f1.backend.domain.game.dto.response.GameStartResponse;
+
+public record GameStartData(String destination, GameStartResponse gameStartResponse) {}

backend/src/main/java/io/f1/backend/domain/game/dto/MessageType.java

@@ -5,4 +5,5 @@ public enum MessageType {
     GAME_SETTING,
     PLAYER_LIST,
     SYSTEM_NOTICE,
+    GAME_START,
 }

backend/src/main/java/io/f1/backend/domain/game/dto/request/GameStartRequest.java

@@ -0,0 +1,3 @@
+package io.f1.backend.domain.game.dto.request;
+
+public record GameStartRequest(Long quizId) {}

backend/src/main/java/io/f1/backend/domain/game/dto/response/GameStartResponse.java

@@ -0,0 +1,7 @@
+package io.f1.backend.domain.game.dto.response;
+
+import io.f1.backend.domain.quiz.dto.GameQuestionResponse;
+
+import java.util.List;
+
+public record GameStartResponse(List<GameQuestionResponse> questions) {}

backend/src/main/java/io/f1/backend/domain/game/model/GameSetting.java

@@ -10,4 +10,11 @@ public class GameSetting {
     private Long quizId;
     private Integer round; // 게임 변경 시 해당 게임의 총 문제 수로 설정
     private int timeLimit = 60;
+
+    public boolean checkQuizId(Long quizId) {
+        if (this.quizId != null && this.quizId.equals(quizId)) {
+            return false;
+        }
+        return true;
+    }
 }

backend/src/main/java/io/f1/backend/domain/game/model/Room.java

@@ -46,6 +46,10 @@ public void updateHost(Player nextHost) {
         this.host = nextHost;
     }
 
+    public void updateRoomState(RoomState newState) {
+        this.state = newState;
+    }
+
     public void removeUserId(Long id) {
         this.userIdSessionMap.remove(id);
     }

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

@@ -1,9 +1,12 @@
 package io.f1.backend.domain.game.websocket;
 
+import io.f1.backend.domain.game.app.GameService;
 import io.f1.backend.domain.game.app.RoomService;
+import io.f1.backend.domain.game.dto.GameStartData;
 import io.f1.backend.domain.game.dto.MessageType;
 import io.f1.backend.domain.game.dto.RoomExitData;
 import io.f1.backend.domain.game.dto.RoomInitialData;
+import io.f1.backend.domain.game.dto.request.GameStartRequest;
 
 import lombok.RequiredArgsConstructor;
 
@@ -19,6 +22,7 @@ public class GameSocketController {
 
     private final MessageSender messageSender;
     private final RoomService roomService;
+    private final GameService gameService;
 
     @MessageMapping("/room/initializeRoomSocket/{roomId}")
     public void initializeRoomSocket(@DestinationVariable Long roomId, Message<?> message) {
@@ -56,6 +60,18 @@ public void exitRoom(@DestinationVariable Long roomId, Message<?> message) {
         }
     }
 
+    @MessageMapping("/room/start/{roomId}")
+    public void gameStart(@DestinationVariable Long roomId, Message<GameStartRequest> message) {
+
+        Long quizId = message.getPayload().quizId();
+
+        GameStartData gameStartData = gameService.gameStart(roomId, quizId);
+
+        String destination = gameStartData.destination();
+
+        messageSender.send(destination, MessageType.GAME_START, gameStartData.gameStartResponse());
+    }
+
     private static String getSessionId(Message<?> message) {
         StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
         return accessor.getSessionId();

backend/src/main/java/io/f1/backend/domain/quiz/app/QuizService.java

@@ -4,8 +4,10 @@
 
 import static java.nio.file.Files.deleteIfExists;
 
+import io.f1.backend.domain.game.dto.response.GameStartResponse;
 import io.f1.backend.domain.question.app.QuestionService;
 import io.f1.backend.domain.question.dto.QuestionRequest;
+import io.f1.backend.domain.question.entity.Question;
 import io.f1.backend.domain.quiz.dao.QuizRepository;
 import io.f1.backend.domain.quiz.dto.QuizCreateRequest;
 import io.f1.backend.domain.quiz.dto.QuizCreateResponse;
@@ -214,12 +216,11 @@ public QuizListPageResponse getQuizzes(String title, String creator, Pageable pa
     }
 
     @Transactional(readOnly = true)
-    public Quiz getQuizById(Long quizId) {
+    public Quiz getQuizWithQuestionsById(Long quizId) {
         Quiz quiz =
                 quizRepository
-                        .findById(quizId)
+                        .findQuizWithQuestionsById(quizId)
                         .orElseThrow(() -> new RuntimeException("E404002: 존재하지 않는 퀴즈입니다."));
-        quiz.getQuestions().size();
         return quiz;
     }
 
@@ -228,6 +229,7 @@ public Long getQuizMinId() {
         return quizRepository.getQuizMinId();
     }
 
+    @Transactional(readOnly = true)
     public QuizQuestionListResponse getQuizWithQuestions(Long quizId) {
         Quiz quiz =
                 quizRepository
@@ -236,4 +238,15 @@ public QuizQuestionListResponse getQuizWithQuestions(Long quizId) {
 
         return quizToQuizQuestionListResponse(quiz);
     }
+
+    @Transactional(readOnly = true)
+    public GameStartResponse getRandomQuestionsWithoutAnswer(Long quizId, Integer round) {
+        quizRepository
+                .findById(quizId)
+                .orElseThrow(() -> new NoSuchElementException("존재하지 않는 퀴즈입니다."));
+
+        List<Question> randomQuestions = quizRepository.findRandQuestionsByQuizId(quizId, round);
+
+        return toGameStartResponse(randomQuestions);
+    }
 }

backend/src/main/java/io/f1/backend/domain/quiz/dao/QuizRepository.java

@@ -1,18 +1,30 @@
 package io.f1.backend.domain.quiz.dao;
 
+import io.f1.backend.domain.question.entity.Question;
 import io.f1.backend.domain.quiz.entity.Quiz;
 
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 
+import java.util.List;
+import java.util.Optional;
+
 public interface QuizRepository extends JpaRepository<Quiz, Long> {
 
     Page<Quiz> findQuizzesByTitleContaining(String title, Pageable pageable);
 
     Page<Quiz> findQuizzesByCreator_NicknameContaining(String creator, Pageable pageable);
 
+    @Query("SELECT q FROM Quiz q LEFT JOIN FETCH q.questions WHERE q.id = :quizId")
+    Optional<Quiz> findQuizWithQuestionsById(Long quizId);
+
     @Query("SELECT MIN(q.id) FROM Quiz q")
     Long getQuizMinId();
+
+    @Query(
+            value = "SELECT * FROM question WHERE quiz_id = :quizId ORDER BY RAND() LIMIT :round",
+            nativeQuery = true)
+    List<Question> findRandQuestionsByQuizId(Long quizId, Integer round);
 }

backend/src/main/java/io/f1/backend/domain/quiz/dto/GameQuestionResponse.java

@@ -0,0 +1,3 @@
+package io.f1.backend.domain.quiz.dto;
+
+public record GameQuestionResponse(Long id, String question) {}

backend/src/main/java/io/f1/backend/domain/quiz/mapper/QuizMapper.java

@@ -1,7 +1,9 @@
 package io.f1.backend.domain.quiz.mapper;
 
+import io.f1.backend.domain.game.dto.response.GameStartResponse;
 import io.f1.backend.domain.question.dto.QuestionResponse;
 import io.f1.backend.domain.question.entity.Question;
+import io.f1.backend.domain.quiz.dto.GameQuestionResponse;
 import io.f1.backend.domain.quiz.dto.QuizCreateRequest;
 import io.f1.backend.domain.quiz.dto.QuizCreateResponse;
 import io.f1.backend.domain.quiz.dto.QuizListPageResponse;
@@ -83,4 +85,16 @@ public static QuizQuestionListResponse quizToQuizQuestionListResponse(Quiz quiz)
                 quiz.getQuestions().size(),
                 questionsToQuestionResponses(quiz.getQuestions()));
     }
+
+    public static List<GameQuestionResponse> toGameQuestionResponseList(List<Question> questions) {
+        return questions.stream().map(QuizMapper::toGameQuestionResponse).toList();
+    }
+
+    public static GameQuestionResponse toGameQuestionResponse(Question question) {
+        return new GameQuestionResponse(question.getId(), question.getTextQuestion().getContent());
+    }
+
+    public static GameStartResponse toGameStartResponse(List<Question> questions) {
+        return new GameStartResponse(toGameQuestionResponseList(questions));
+    }
 }