[Feature] 스터디 일정 충돌 처리 로직 추가

common/api/src/main/java/kr/spot/code/status/ErrorStatus.java

@@ -74,6 +74,7 @@ public enum ErrorStatus implements BaseErrorCode {
   // 일정 관련
   _SCHEDULE_NOT_FOUND(404, "SCHEDULE404", "일정을 찾을 수 없습니다."),
   _SCHEDULE_ACCESS_DENIED(403, "SCHEDULE403", "해당 스터디에 속하는 일정이 아닙니다."),
+  _SCHEDULE_TIME_CONFLICT(400, "SCHEDULE4001", "동일한 시간대에 이미 일정이 존재합니다."),
   _SCHEDULE_QR_CODE_ALREADY_ASSIGNED(400, "SCHEDULE4000", "이미 출석 QR 코드가 할당된 일정입니다."),
 
   // 출석 관련

modules/study/src/main/java/kr/spot/schedule/application/command/ManageScheduleService.java

@@ -1,6 +1,8 @@
 package kr.spot.schedule.application.command;
 
 import kr.spot.IdGenerator;
+import kr.spot.code.status.ErrorStatus;
+import kr.spot.exception.GeneralException;
 import kr.spot.schedule.domain.Schedule;
 import kr.spot.schedule.infrastructure.jpa.ScheduleRepository;
 import kr.spot.schedule.presentation.command.dto.CreateScheduleRequest;
@@ -17,6 +19,8 @@ public class ManageScheduleService {
   private final ScheduleRepository scheduleRepository;
 
   public long createSchedule(CreateScheduleRequest request, long studyId, long creatorId) {
+    validateScheduleTimeConflict(request, studyId);
+
     long scheduleId = idGenerator.nextId();
     Schedule schedule = Schedule.of(scheduleId, studyId, creatorId, request.title(),
         request.locationInfo(),
@@ -30,4 +34,13 @@ public void deleteSchedule(long studyId, long scheduleId) {
     Schedule schedule = scheduleRepository.getById(scheduleId);
     schedule.delete(studyId);
   }
+
+  private void validateScheduleTimeConflict(CreateScheduleRequest request, long studyId) {
+    boolean hasConflict = scheduleRepository.existsByStudyIdAndStartAtLessThanAndEndAtGreaterThan(
+        studyId, request.endAt(), request.startAt());
+
+    if (hasConflict) {
+      throw new GeneralException(ErrorStatus._SCHEDULE_TIME_CONFLICT);
+    }
+  }
 }

modules/study/src/main/java/kr/spot/schedule/infrastructure/jpa/ScheduleRepository.java

@@ -1,12 +1,16 @@
 package kr.spot.schedule.infrastructure.jpa;
 
+import java.time.LocalDateTime;
 import kr.spot.code.status.ErrorStatus;
 import kr.spot.exception.GeneralException;
 import kr.spot.schedule.domain.Schedule;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 public interface ScheduleRepository extends JpaRepository<Schedule, Long> {
 
+  boolean existsByStudyIdAndStartAtLessThanAndEndAtGreaterThan(
+      Long studyId, LocalDateTime endAt, LocalDateTime startAt);
+
   default Schedule getById(long scheduleId) {
     return findById(scheduleId).orElseThrow(
         () -> new GeneralException(ErrorStatus._SCHEDULE_NOT_FOUND));

modules/study/src/test/java/kr/spot/schedule/application/command/ManageScheduleServiceTest.java

@@ -10,9 +10,11 @@
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import java.time.LocalDateTime;
 import kr.spot.IdGenerator;
 import kr.spot.code.status.ErrorStatus;
 import kr.spot.exception.GeneralException;
@@ -60,6 +62,8 @@ void should_create_schedule_successfully() {
       CreateScheduleRequest request = createScheduleRequest();
 
       when(idGenerator.nextId()).thenReturn(generatedId);
+      when(scheduleRepository.existsByStudyIdAndStartAtLessThanAndEndAtGreaterThan(
+          STUDY_ID, request.endAt(), request.startAt())).thenReturn(false);
       when(scheduleRepository.save(any(Schedule.class)))
           .thenAnswer(invocation -> invocation.getArgument(0));
 
@@ -89,6 +93,8 @@ TITLE, null, createScheduleRequest().startAt(), createScheduleRequest().endAt()
       );
 
       when(idGenerator.nextId()).thenReturn(generatedId);
+      when(scheduleRepository.existsByStudyIdAndStartAtLessThanAndEndAtGreaterThan(
+          STUDY_ID, request.endAt(), request.startAt())).thenReturn(false);
       when(scheduleRepository.save(any(Schedule.class)))
           .thenAnswer(invocation -> invocation.getArgument(0));
 
@@ -101,6 +107,29 @@ TITLE, null, createScheduleRequest().startAt(), createScheduleRequest().endAt()
       Schedule capturedSchedule = scheduleCaptor.getValue();
       assertThat(capturedSchedule.getLocationMemo()).isNull();
     }
+
+    @Test
+    @DisplayName("동일한 시간대에 일정이 있으면 예외가 발생한다")
+    void should_throw_exception_when_schedule_time_conflicts() {
+      // given
+      CreateScheduleRequest request = new CreateScheduleRequest(
+          TITLE,
+          LOCATION_MEMO,
+          LocalDateTime.of(2025, 1, 15, 15, 0),
+          LocalDateTime.of(2025, 1, 15, 17, 0)
+      );
+
+      when(scheduleRepository.existsByStudyIdAndStartAtLessThanAndEndAtGreaterThan(
+          STUDY_ID, request.endAt(), request.startAt())).thenReturn(true);
+
+      // when & then
+      assertThatThrownBy(() -> manageScheduleService.createSchedule(request, STUDY_ID, CREATOR_ID))
+          .isInstanceOf(GeneralException.class)
+          .extracting(ex -> ((GeneralException) ex).getStatus())
+          .isEqualTo(ErrorStatus._SCHEDULE_TIME_CONFLICT);
+
+      verify(scheduleRepository, never()).save(any(Schedule.class));
+    }
   }
 
   @Nested