[FEATURE] 예약 가능 날짜/시간 조회 API

src/main/java/com/kernellabs/kernellabs/application/PlaceService.java

@@ -1,12 +1,19 @@
 package com.kernellabs.kernellabs.application;
 
 import com.kernellabs.kernellabs.domain.Place;
+import com.kernellabs.kernellabs.domain.Reservation;
 import com.kernellabs.kernellabs.global.exception.CustomException;
 import com.kernellabs.kernellabs.global.exception.ErrorCode;
 import com.kernellabs.kernellabs.infrastructure.repository.PlaceRepository;
+import com.kernellabs.kernellabs.infrastructure.repository.ReservationRepository;
+import com.kernellabs.kernellabs.presentation.dto.response.PlaceDetailResponse;
 import com.kernellabs.kernellabs.presentation.dto.response.PlaceListResponse;
-import com.kernellabs.kernellabs.presentation.dto.response.PlaceViewResponse;
+import com.kernellabs.kernellabs.presentation.dto.response.TimeSlotResponse;
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
@@ -18,17 +25,56 @@
 public class PlaceService {
 
     private final PlaceRepository placeRepository;
+    private final ReservationRepository reservationRepository;
 
     public List<PlaceListResponse> getAllPlace() {
         return placeRepository.findAll().stream()
             .map(PlaceListResponse::from)
             .collect(Collectors.toList());
     }
 
-    public PlaceViewResponse getPlaceDetail(Long placeId) {
+    public PlaceDetailResponse getPlaceDetailWithDate(Long placeId, LocalDate date) {
+        // 1. 장소 정보 조회
         Place place = placeRepository.findById(placeId)
             .orElseThrow(() -> new CustomException(ErrorCode.PLACE_NOT_FOUND));
 
-        return PlaceViewResponse.from(place);
+        // 2. 해당 날짜 실제 운영 시간 확인
+        LocalTime openTime = place.getOpenTime();
+        LocalTime closeTime = place.getCloseTime();
+
+        // 3. 해당 날짜에 이미 예약된 시간 목록 조회
+        List<Reservation> reservations = reservationRepository.findByPlaceIdAndReservationDate(placeId, date);
+        Set<LocalTime> reservedSlots = getReservedSlots(reservations);
+
+        // 4. 전체 시간 슬롯 생성 및 예약 가능 여부 판단
+        List<TimeSlotResponse> timeSlots = generateTimeSlots(openTime, closeTime, reservedSlots);
+
+        // 5. 최종 응답 DTO 생성 및 반환
+        return PlaceDetailResponse.of(place, timeSlots);
+    }
+
+    private List<TimeSlotResponse> generateTimeSlots(LocalTime openTime, LocalTime closeTime, Set<LocalTime> reservedSlots) {
+        List<TimeSlotResponse> slots = new ArrayList<>();
+        LocalTime currentTime = openTime;
+        while (!currentTime.isAfter(closeTime.minusHours(1))) {
+            boolean isAvailable = !reservedSlots.contains(currentTime);
+            slots.add(new TimeSlotResponse(currentTime.toString(), isAvailable));
+            currentTime = currentTime.plusHours(1);
+        }
+        return slots;
+    }
+
+    private Set<LocalTime> getReservedSlots(List<Reservation> reservations) {
+        return reservations.stream()
+            .flatMap(reservation -> {
+                List<LocalTime> slots = new ArrayList<>();
+                LocalTime current = reservation.getStartTime();
+                while (current.isBefore(reservation.getEndTime())) {
+                    slots.add(current);
+                    current = current.plusHours(1);
+                }
+                return slots.stream();
+            })
+            .collect(Collectors.toSet());
     }
 }

src/main/java/com/kernellabs/kernellabs/infrastructure/repository/ReservationRepository.java

@@ -27,4 +27,6 @@ boolean existsByPlaceIdAndReservationDateAndIdNotAndStartTimeBeforeAndEndTimeAft
         LocalTime endTime,
         LocalTime startTime
     );
+
+    List<Reservation> findByPlaceIdAndReservationDate(Long placeId, LocalDate date);
 }

src/main/java/com/kernellabs/kernellabs/presentation/controller/PlaceController.java

@@ -2,14 +2,18 @@
 
 import com.kernellabs.kernellabs.application.PlaceService;
 import com.kernellabs.kernellabs.global.common.ApiResponse;
+import com.kernellabs.kernellabs.presentation.dto.response.PlaceDetailResponse;
 import com.kernellabs.kernellabs.presentation.dto.response.PlaceListResponse;
-import com.kernellabs.kernellabs.presentation.dto.response.PlaceViewResponse;
+import java.time.LocalDate;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
+import org.springframework.format.annotation.DateTimeFormat;
+import org.springframework.format.annotation.DateTimeFormat.ISO;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
@@ -26,8 +30,12 @@ public ResponseEntity<?> getAllPlaces() {
     }
 
     @GetMapping("/{placeId}")
-    public ResponseEntity<ApiResponse<PlaceViewResponse>> getPlace(@PathVariable Long placeId) {
-        PlaceViewResponse response = placeService.getPlaceDetail(placeId);
+    public ResponseEntity<ApiResponse<PlaceDetailResponse>> getPlace(@PathVariable Long placeId,
+        @RequestParam(required = false) @DateTimeFormat(iso = ISO.DATE) LocalDate date) {
+        // 날짜 파라미터가 없으면 오늘 날짜 기본값
+        LocalDate targetDate = (date == null) ? LocalDate.now() : date;
+
+        PlaceDetailResponse response = placeService.getPlaceDetailWithDate(placeId, targetDate);
         return ResponseEntity.ok(ApiResponse.success(response));
     }
 }

src/main/java/com/kernellabs/kernellabs/presentation/dto/response/PlaceViewResponse.java → src/main/java/com/kernellabs/kernellabs/presentation/dto/response/PlaceDetailResponse.java

@@ -2,33 +2,34 @@
 
 import com.kernellabs.kernellabs.domain.Place;
 import java.time.LocalTime;
+import java.util.List;
 import lombok.Builder;
 import lombok.Getter;
 
 @Getter
 @Builder
-public class PlaceViewResponse {
+public class PlaceDetailResponse {
+    private Long id;
+    private String name;
+    private String address;
+    private String thumbnailUrl;
+    private String description;
+    private LocalTime openTime;
+    private LocalTime closeTime;
+    private Integer unitPrice;
+    private List<TimeSlotResponse> timeSlots; // 시간표 정보
 
-    private final Long id;
-    private final String thumbnailUrl;
-    private final String name;
-    private final String address;
-    private final LocalTime openTime;
-    private final LocalTime closeTime;
-    private final Integer unitPrice;
-    private final String description;
-
-    public static PlaceViewResponse from(Place place) {
-        return PlaceViewResponse.builder()
+    public static PlaceDetailResponse of(Place place, List<TimeSlotResponse> timeSlots) {
+        return PlaceDetailResponse.builder()
             .id(place.getId())
-            .thumbnailUrl(place.getThumbnailUrl())
             .name(place.getName())
             .address(place.getAddress())
+            .thumbnailUrl(place.getThumbnailUrl())
+            .description(place.getDescription())
             .openTime(place.getOpenTime())
             .closeTime(place.getCloseTime())
             .unitPrice(place.getUnitPrice())
-            .description(place.getDescription())
+            .timeSlots(timeSlots)
             .build();
     }
-
 }

src/main/java/com/kernellabs/kernellabs/presentation/dto/response/TimeSlotResponse.java

@@ -0,0 +1,13 @@
+package com.kernellabs.kernellabs.presentation.dto.response;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public class TimeSlotResponse {
+
+    private String time;
+    private boolean isAvailable;
+
+}