feat: Add CustomizedRoomRepository (#52)

- 필터링 된 방을 조회하기 위한 findFilteredRooms 메서드 구현

BE/airbnb/src/main/java/airbnb/repository/CustomizedRoomRepository.java

@@ -0,0 +1,11 @@
+package airbnb.repository;
+
+import airbnb.domain.Room;
+import airbnb.request.SearchRequest;
+import airbnb.response.RoomResponse;
+
+import java.util.List;
+
+public interface CustomizedRoomRepository {
+    List<Room> findFilteredRooms(SearchRequest searchRequest);
+}

BE/airbnb/src/main/java/airbnb/repository/CustomizedRoomRepositoryImpl.java

@@ -0,0 +1,56 @@
+package airbnb.repository;
+
+import airbnb.domain.Room;
+import airbnb.request.SearchRequest;
+import com.querydsl.core.types.dsl.BooleanExpression;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import lombok.RequiredArgsConstructor;
+
+import java.time.LocalDate;
+import java.util.List;
+
+import static airbnb.domain.QBooking.booking;
+import static airbnb.domain.QRoom.room;
+import static org.springframework.util.StringUtils.hasText;
+
+@RequiredArgsConstructor
+public class CustomizedRoomRepositoryImpl implements CustomizedRoomRepository {
+
+    private final JPAQueryFactory queryFactory;
+
+    @Override
+    public List<Room> findFilteredRooms(SearchRequest searchRequest) {
+        return queryFactory
+                .selectFrom(room)
+                .leftJoin(booking).on(room.id.eq(booking.id))
+                .where(placeIdEquals(searchRequest.getPlaceId()),
+                        dateNotBetween(searchRequest.getCheckIn(), searchRequest.getCheckOut()),
+                        priceBetween(searchRequest.getPriceMin(), searchRequest.getPriceMax()),
+                        maximumNumberOfGuestsGoeSumOf(searchRequest.getAdults(), searchRequest.getChildren(), searchRequest.getInfants()))
+                .fetch();
+    }
+
+    private BooleanExpression placeIdEquals(String placeId) {
+        return hasText(placeId) ? room.location.placeId.eq(placeId) : null;
+    }
+
+    private BooleanExpression dateNotBetween(LocalDate checkIn, LocalDate checkOut) {
+        return ((checkIn != null) && (checkOut != null)) ?
+                booking.checkOut.loe(checkIn).or(booking.checkIn.goe(checkOut)) : null;
+    }
+
+    private BooleanExpression priceBetween(Integer priceMin, Integer priceMax) {
+        return ((priceMin != null) && (priceMax != null)) ?
+                room.pricePerNight.goe(priceMin).and(room.pricePerNight.loe(priceMax)) : null;
+    }
+
+    private BooleanExpression maximumNumberOfGuestsGoeSumOf(Integer adults, Integer children, Integer infants) {
+        if (children == null) {
+            children = 0;
+        }
+        if (infants == null) {
+            infants = 0;
+        }
+        return adults != null ? room.maximumNumberOfGuests.goe(adults + children + infants) : null;
+    }
+}