Feat: request attendance state

src/main/java/gdsc/konkuk/platformcore/application/attendance/AttendanceService.java

@@ -2,6 +2,7 @@
 
 import static gdsc.konkuk.platformcore.application.attendance.AttendanceServiceHelper.findAttendanceById;
 
+import gdsc.konkuk.platformcore.application.attendance.dtos.AttendanceStatus;
 import gdsc.konkuk.platformcore.application.attendance.exceptions.AttendanceAlreadyExistException;
 import gdsc.konkuk.platformcore.application.attendance.exceptions.AttendanceErrorCode;
 import gdsc.konkuk.platformcore.application.event.exceptions.EventErrorCode;
@@ -56,6 +57,12 @@ public Attendance registerAttendance(AttendanceRegisterRequest registerRequest)
     return newAttendance;
   }
 
+  public AttendanceStatus getAttendanceStatus(Long attendanceId) {
+    List<Participant> totalParticipants = participantRepository.findAllByAttendanceId(attendanceId);
+    List<Participant> attendedParticipants = totalParticipants.stream().filter(Participant::isAttended).toList();
+    return AttendanceStatus.of(attendanceId, totalParticipants.size(), attendedParticipants.size());
+  }
+
   @Transactional
   public void deleteAttendance(Long attendanceId) {
     participantRepository.deleteAllByAttendanceId(attendanceId);

src/main/java/gdsc/konkuk/platformcore/application/attendance/dtos/AttendanceStatus.java

@@ -0,0 +1,22 @@
+package gdsc.konkuk.platformcore.application.attendance.dtos;
+
+import lombok.Builder;
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+@Builder
+public class AttendanceStatus {
+  private Long attendanceId;
+  private int total;
+  private int attended;
+
+  public static AttendanceStatus of(Long attendanceId, int total, int attended) {
+    return AttendanceStatus.builder()
+        .attendanceId(attendanceId)
+        .total(total)
+        .attended(attended)
+        .build();
+  }
+}

src/main/java/gdsc/konkuk/platformcore/controller/attendance/AttendanceController.java

@@ -10,6 +10,7 @@
 import gdsc.konkuk.platformcore.controller.attendance.dtos.AttendSuccessResponse;
 import gdsc.konkuk.platformcore.controller.attendance.dtos.AttendanceRegisterRequest;
 import gdsc.konkuk.platformcore.controller.attendance.dtos.AttendanceResponse;
+import gdsc.konkuk.platformcore.application.attendance.dtos.AttendanceStatus;
 import gdsc.konkuk.platformcore.domain.attendance.entity.Attendance;
 import gdsc.konkuk.platformcore.domain.attendance.entity.Participant;
 import gdsc.konkuk.platformcore.global.responses.SuccessResponse;
@@ -66,6 +67,13 @@ public ResponseEntity<SuccessResponse> registerAttendance(
       .body(SuccessResponse.of(response));
   }
 
+  // TODO: 추후 WebSocket으로 변경 필요
+  @GetMapping("/{attendanceId}/status")
+  public ResponseEntity<SuccessResponse> getAttendance(@PathVariable Long attendanceId) {
+    AttendanceStatus attendanceStatus = attendanceService.getAttendanceStatus(attendanceId);
+    return ResponseEntity.ok(SuccessResponse.of(attendanceStatus));
+  }
+
   @DeleteMapping("/{attendanceId}")
   public ResponseEntity<SuccessResponse> deleteAttendance(@PathVariable Long attendanceId) {
     attendanceService.deleteAttendance(attendanceId);

src/main/java/gdsc/konkuk/platformcore/domain/attendance/repository/ParticipantRepository.java

@@ -25,4 +25,6 @@ public interface ParticipantRepository extends JpaRepository<Participant, Long>
       """)
   List<Participant> findAllByBatchAndStartAtBetween(
       String batch, LocalDateTime st, LocalDateTime en);
+
+  List<Participant> findAllByAttendanceId(Long attendanceId);
 }

src/test/java/gdsc/konkuk/platformcore/controller/attendance/AttendanceControllerTest.java

@@ -4,6 +4,7 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 
 import gdsc.konkuk.platformcore.application.attendance.AttendanceService;
+import gdsc.konkuk.platformcore.application.attendance.dtos.AttendanceStatus;
 import gdsc.konkuk.platformcore.application.event.EventService;
 import gdsc.konkuk.platformcore.application.event.dtos.EventWithAttendance;
 import gdsc.konkuk.platformcore.controller.attendance.dtos.AttendanceRegisterRequest;
@@ -203,6 +204,43 @@ void should_register_attendance_when_pass_event_id() throws Exception {
                         .build())));
   }
 
+  @Test
+  @DisplayName("출석 현황을 조회할 수 있다")
+  @WithMockUser
+  void should_get_attendance_status_when_pass_attendance_id() throws Exception {
+    // given
+    given(attendanceService.getAttendanceStatus(any(Long.class)))
+        .willReturn(AttendanceStatus.of(1L, 10, 6));
+
+    // when
+    ResultActions result =
+        mockMvc.perform(
+            RestDocumentationRequestBuilders.get("/api/v1/attendances/{attendanceId}/status", 1)
+                .with(csrf()));
+
+    // then
+    result
+        .andDo(print())
+        .andExpect(status().isOk())
+        .andDo(
+            document(
+                "getAttendanceStatus",
+                preprocessRequest(prettyPrint()),
+                preprocessResponse(prettyPrint()),
+                resource(
+                    ResourceSnippetParameters.builder()
+                        .description("출석 현황을 조회할 수 있다")
+                        .tag("attendance")
+                        .pathParameters(parameterWithName("attendanceId").description("출석 ID"))
+                        .responseFields(
+                            fieldWithPath("success").description("성공 여부"),
+                            fieldWithPath("message").description("메시지"),
+                            fieldWithPath("data.attendanceId").description("출석 ID"),
+                            fieldWithPath("data.total").description("전체 인원"),
+                            fieldWithPath("data.attended").description("출석 인원"))
+                        .build())));
+  }
+
   @Test
   @DisplayName("이벤트 출석을 삭제할 수 있다")
   @WithMockUser