[sally4405/#19] Feat: 숙소 예약 요금 상세 조회 API 개발

- 주 단위, 월 단위, 연 단위 할인 정책 enum 클래스를 만들어 예약한 날짜를 계산하여 할인을 적용할 수 있는 로직 추가

BE/src/main/java/louie/dong/airbnb/accommodation/AccommodationController.java

@@ -42,7 +42,7 @@ public AccommodationDetailResponse getAccommodationDetail(@PathVariable Long id)
 	@GetMapping("/{id}/detail-price")
 	public AccommodationDetailPriceResponse getDetailPrice(@PathVariable Long id,
 		AccommodationDetailPriceRequest accommodationDetailPriceRequest) {
-		return mockAccommodationService.findDetailPrice(id, accommodationDetailPriceRequest);
+		return accommodationService.findDetailPrice(id, accommodationDetailPriceRequest);
 	}
 
 }

BE/src/main/java/louie/dong/airbnb/accommodation/AccommodationService.java

@@ -1,5 +1,12 @@
 package louie.dong.airbnb.accommodation;
 
+import static louie.dong.airbnb.accommodation.DiscountPolicy.MONTHLY;
+import static louie.dong.airbnb.accommodation.DiscountPolicy.NONE;
+import static louie.dong.airbnb.accommodation.DiscountPolicy.WEEKLY;
+import static louie.dong.airbnb.accommodation.DiscountPolicy.YEARLY;
+
+import java.time.LocalDate;
+import java.time.temporal.ChronoUnit;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
@@ -26,22 +33,54 @@ public AccommodationPriceResponse findPrices(String country) {
 	}
 
 	public AccommodationDetailResponse findById(Long id) {
-		Accommodation accommodation = accommodationRepository.findById(id)
-			.orElseThrow(() -> new IllegalArgumentException("유효하지 않은 id입니다."));
+		Accommodation accommodation = getAccommodation(id);
 		boolean wish = wishRepository.existsByAccommodationId(id);
 		return new AccommodationDetailResponse(accommodation, wish);
 	}
 
+	public AccommodationDetailPriceResponse findDetailPrice(Long id,
+		AccommodationDetailPriceRequest accommodationDetailPriceRequest) {
+		Accommodation accommodation = getAccommodation(id);
+		LocalDate checkIn = accommodationDetailPriceRequest.getCheckIn();
+		LocalDate checkOut = accommodationDetailPriceRequest.getCheckOut();
+
+		int date = (int) checkIn.until(checkOut, ChronoUnit.DAYS);
+		int totalPrice = accommodation.getPrice() * date;
+		double discountRate = getDiscountRate(date) * 0.01;
+		int discountPrice = (int) (totalPrice * discountRate);
+		int finalPrice = totalPrice - discountPrice + accommodation.getCleaningFee()
+			+ accommodation.getServiceFee() + accommodation.getAccommodationFee();
+
+		return new AccommodationDetailPriceResponse(accommodation.getPrice(), date, totalPrice,
+			WEEKLY.getDiscountRate(), discountPrice, accommodation.getCleaningFee(),
+			accommodation.getServiceFee(), accommodation.getAccommodationFee(), finalPrice);
+	}
+
+	private Accommodation getAccommodation(Long id) {
+		return accommodationRepository.findById(id)
+			.orElseThrow(() -> new IllegalArgumentException("유효하지 않은 id입니다."));
+	}
+
+	private int getDiscountRate(int date) {
+		if (date < 7) {
+			return NONE.getDiscountRate();
+		}
+
+		if (date < 30) {
+			return WEEKLY.getDiscountRate();
+		}
+
+		if (date < 365) {
+			return MONTHLY.getDiscountRate();
+		}
+		return YEARLY.getDiscountRate();
+	}
+
 	private int calculateAverage(List<Integer> prices) {
 		int sum = 0;
 		for (Integer price : prices) {
 			sum += price;
 		}
 		return sum / prices.size();
 	}
-
-	public AccommodationDetailPriceResponse findDetailPrice(Long id,
-		AccommodationDetailPriceRequest accommodationDetailPriceRequest) {
-		return null;
-	}
 }

BE/src/main/java/louie/dong/airbnb/accommodation/DiscountPolicy.java

@@ -0,0 +1,12 @@
+package louie.dong.airbnb.accommodation;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Getter
+public enum DiscountPolicy {
+	WEEKLY(4), MONTHLY(7), YEARLY(10), NONE(0);
+
+	private final int discountRate;
+}