[feat] 구매자는 카트를 조회할 수 있다 (#137)

* [feat] 조회하고자 하는 카트가 없을 때 발생시킬 예외 구현

* [feat] 구매자의 카트를 조회하는 Dao

* [feat] 카트 조회 앤드포인트

* [feat] 카트를 조회할 수 있는 Dao를 Redis를 이용해서 구현 (#135)

* [test] menu 더미를 저장하고 반환하는 메서드 추가 및 상점을 24시간 열려있도록 수정

* [feat] getter 및 생성자 추가

* [feat] redis용 dao를 임시로 inMemoryCartRepository를 이용해서 구현

* [test] RedisCartDao 테스트코드 추가

* [feat] CartItemInfo에도 getter 추가

* [fix] 테스트 이후 데이터를 롤백시키기 위해 @transactional 추가

* [fix] CartResponse의 amount를 Integer로 수정

* [feat] Jpa를 이용한 카트 조회 dao

---------

Co-authored-by: 김현욱 <43038815+Hyeon-Uk@users.noreply.github.com>

src/main/java/camp/woowak/lab/cart/exception/CartErrorCode.java

@@ -7,7 +7,8 @@
 public enum CartErrorCode implements ErrorCode {
 	MENU_NOT_FOUND(HttpStatus.NOT_FOUND, "ca_1_1", "해당 메뉴가 존재하지 않습니다."),
 	OTHER_STORE_MENU(HttpStatus.BAD_REQUEST, "ca_1_2", "다른 매장의 메뉴는 등록할 수 없습니다."),
-	STORE_NOT_OPEN(HttpStatus.BAD_REQUEST, "ca_1_3", "주문 가능한 시간이 아닙니다.");
+	STORE_NOT_OPEN(HttpStatus.BAD_REQUEST, "ca_1_3", "주문 가능한 시간이 아닙니다."),
+	NOT_FOUND(HttpStatus.BAD_REQUEST, "ca_2_1", "카트에 담긴 상품이 없습니다.");
 
 	private final int status;
 	private final String errorCode;

src/main/java/camp/woowak/lab/cart/exception/NotFoundCartException.java

@@ -0,0 +1,9 @@
+package camp.woowak.lab.cart.exception;
+
+import camp.woowak.lab.common.exception.BadRequestException;
+
+public class NotFoundCartException extends BadRequestException {
+	public NotFoundCartException(String message) {
+		super(CartErrorCode.NOT_FOUND, message);
+	}
+}

src/main/java/camp/woowak/lab/web/api/cart/CartApiController.java

@@ -6,12 +6,15 @@
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
+import camp.woowak.lab.cart.exception.NotFoundCartException;
 import camp.woowak.lab.cart.service.CartService;
 import camp.woowak.lab.cart.service.command.AddCartCommand;
 import camp.woowak.lab.cart.service.command.CartTotalPriceCommand;
 import camp.woowak.lab.web.authentication.LoginCustomer;
 import camp.woowak.lab.web.authentication.annotation.AuthenticationPrincipal;
+import camp.woowak.lab.web.dao.cart.CartDao;
 import camp.woowak.lab.web.dto.request.cart.AddCartRequest;
+import camp.woowak.lab.web.dto.response.CartResponse;
 import camp.woowak.lab.web.dto.response.cart.AddCartResponse;
 import camp.woowak.lab.web.dto.response.cart.CartTotalPriceResponse;
 import lombok.extern.slf4j.Slf4j;
@@ -21,9 +24,11 @@
 @Slf4j
 public class CartApiController {
 	private final CartService cartService;
+	private final CartDao cartDao;
 
-	public CartApiController(CartService cartService) {
+	public CartApiController(CartService cartService, CartDao cartDao) {
 		this.cartService = cartService;
+		this.cartDao = cartDao;
 	}
 
 	@PostMapping
@@ -47,4 +52,13 @@ public CartTotalPriceResponse getCartTotalPrice(
 		log.info("Customer({})'s total price in cart is {}", loginCustomer.getId(), totalPrice);
 		return new CartTotalPriceResponse(totalPrice);
 	}
+
+	@GetMapping
+	public CartResponse getMyCart(@AuthenticationPrincipal LoginCustomer loginCustomer) {
+		CartResponse cartResponse = cartDao.findByCustomerId(loginCustomer.getId());
+		if (cartResponse == null) {
+			throw new NotFoundCartException(loginCustomer.getId() + "의 카트가 조회되지 않았습니다.");
+		}
+		return cartResponse;
+	}
 }

src/main/java/camp/woowak/lab/web/dao/cart/CartDao.java

@@ -0,0 +1,12 @@
+package camp.woowak.lab.web.dao.cart;
+
+import java.util.UUID;
+
+import camp.woowak.lab.web.dto.response.CartResponse;
+
+public interface CartDao {
+	/**
+	 * @throws camp.woowak.lab.cart.exception.NotFoundCartException
+	 */
+	CartResponse findByCustomerId(UUID customerId);
+}

src/main/java/camp/woowak/lab/web/dao/cart/JpaCartDao.java

@@ -0,0 +1,57 @@
+package camp.woowak.lab.web.dao.cart;
+
+import static camp.woowak.lab.cart.persistence.jpa.entity.QCartEntity.*;
+import static camp.woowak.lab.cart.persistence.jpa.entity.QCartItemEntity.*;
+import static camp.woowak.lab.menu.domain.QMenu.*;
+import static camp.woowak.lab.store.domain.QStore.*;
+
+import java.util.UUID;
+
+import org.springframework.stereotype.Repository;
+
+import com.querydsl.core.types.Projections;
+import com.querydsl.core.types.dsl.BooleanExpression;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+
+import camp.woowak.lab.web.dto.response.CartResponse;
+
+@Repository
+public class JpaCartDao implements CartDao {
+	private final JPAQueryFactory queryFactory;
+
+	public JpaCartDao(JPAQueryFactory queryFactory) {
+		this.queryFactory = queryFactory;
+	}
+
+	@Override
+	public CartResponse findByCustomerId(UUID customerId) {
+		CartResponse cartResponse = queryFactory
+			.select(Projections.constructor(CartResponse.class,
+				store.id,
+				store.name,
+				store.minOrderPrice,
+				Projections.list(
+					Projections.constructor(CartResponse.CartItemInfo.class,
+						menu.id,
+						menu.name,
+						menu.price,
+						cartItemEntity.amount,
+						menu.stockCount
+					)
+				)
+			))
+			.from(cartEntity)
+			.leftJoin(cartEntity.cartItems, cartItemEntity)
+			.join(menu).on(menu.id.eq(cartItemEntity.menuId))
+			.join(store).on(store.id.eq(cartItemEntity.storeId))
+			.where(
+				eqCustomerId(customerId)
+			)
+			.fetchOne();
+		return cartResponse;
+	}
+
+	private BooleanExpression eqCustomerId(UUID customerId) {
+		return cartEntity.customerId.eq(customerId);
+	}
+}

src/main/java/camp/woowak/lab/web/dao/cart/RedisCartDao.java

@@ -0,0 +1,93 @@
+package camp.woowak.lab.web.dao.cart;
+
+import static camp.woowak.lab.menu.domain.QMenu.*;
+import static camp.woowak.lab.store.domain.QStore.*;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.stereotype.Repository;
+
+import com.querydsl.core.Tuple;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+
+import camp.woowak.lab.cart.domain.Cart;
+import camp.woowak.lab.cart.repository.CartRepository;
+import camp.woowak.lab.web.dto.response.CartResponse;
+
+@Repository
+public class RedisCartDao implements CartDao {
+	private final CartRepository cartRepository;
+	private final JPAQueryFactory queryFactory;
+
+	public RedisCartDao(@Qualifier("inMemoryCartRepository") CartRepository cartRepository,
+						JPAQueryFactory queryFactory) {
+		this.cartRepository = cartRepository;
+		this.queryFactory = queryFactory;
+	}
+
+	@Override
+	public CartResponse findByCustomerId(UUID customerId) {
+		Optional<Cart> optionalCart = cartRepository.findByCustomerId(customerId.toString());
+		if (optionalCart.isEmpty()) {
+			return new CartResponse();
+		}
+		Cart cart = optionalCart.get();
+
+		if (cart.getCartItems().isEmpty()) {
+			return new CartResponse();
+		}
+
+		Long sId = cart.getCartItems().stream().findAny().get().getStoreId();
+		Map<Long, Integer> menuIdsCount = new HashMap<>();
+		Set<Long> menuIds = cart.getCartItems().stream()
+			.map((cartItem) -> {
+				int amount = cartItem.getAmount();
+				menuIdsCount.put(cartItem.getMenuId(), amount);
+				return cartItem.getMenuId();
+			})
+			.collect(Collectors.toSet());
+
+		List<Tuple> results = queryFactory
+			.select(
+				store.id,
+				store.name,
+				store.minOrderPrice,
+				menu.id,
+				menu.name,
+				menu.price,
+				menu.stockCount
+			)
+			.from(store)
+			.join(menu).on(menu.store.id.eq(store.id))
+			.where(store.id.eq(sId).and(menu.id.in(menuIds)))
+			.fetch();
+
+		if (results.isEmpty()) {
+			return null; // 또는 적절한 예외 처리
+		}
+
+		Tuple firstResult = results.get(0);
+		Long storeId = firstResult.get(store.id);
+		String storeName = firstResult.get(store.name);
+		Integer minOrderPrice = firstResult.get(store.minOrderPrice);
+
+		List<CartResponse.CartItemInfo> menuList = results.stream()
+			.map(tuple -> new CartResponse.CartItemInfo(
+				tuple.get(menu.id),
+				tuple.get(menu.name),
+				tuple.get(menu.price),
+				menuIdsCount.get(tuple.get(menu.id)), // amount 대신 stockCount 사용
+				tuple.get(menu.stockCount)
+			))
+			.collect(Collectors.toList());
+
+		return new CartResponse(storeId, storeName, minOrderPrice, menuList);
+	}
+}

src/main/java/camp/woowak/lab/web/dto/response/CartResponse.java

@@ -0,0 +1,41 @@
+package camp.woowak.lab.web.dto.response;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import lombok.Getter;
+
+@Getter
+public class CartResponse {
+	private Long storeId;
+	private String storeName;
+	private Integer minOrderPrice;
+	private List<CartItemInfo> menus = new ArrayList<>();
+
+	public CartResponse() {
+	}
+
+	public CartResponse(Long storId, String storeName, Integer minOrderPrice, List<CartItemInfo> menus) {
+		this.storeId = storId;
+		this.storeName = storeName;
+		this.minOrderPrice = minOrderPrice;
+		this.menus = menus;
+	}
+
+	@Getter
+	public static class CartItemInfo {
+		private Long menuId;
+		private String menuName;
+		private Long menuPrice;
+		private Integer amount;
+		private Long leftAmount;
+
+		public CartItemInfo(Long menuId, String menuName, Long menuPrice, Integer amount, Long leftAmount) {
+			this.menuId = menuId;
+			this.menuName = menuName;
+			this.menuPrice = menuPrice;
+			this.amount = amount;
+			this.leftAmount = leftAmount;
+		}
+	}
+}

src/test/java/camp/woowak/lab/web/dao/cart/RedisCartDaoTest.java

@@ -0,0 +1,84 @@
+package camp.woowak.lab.web.dao.cart;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.util.List;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.transaction.annotation.Transactional;
+
+import camp.woowak.lab.cart.domain.Cart;
+import camp.woowak.lab.cart.repository.CartRepository;
+import camp.woowak.lab.customer.domain.Customer;
+import camp.woowak.lab.customer.repository.CustomerRepository;
+import camp.woowak.lab.menu.domain.Menu;
+import camp.woowak.lab.menu.domain.MenuCategory;
+import camp.woowak.lab.menu.repository.MenuCategoryRepository;
+import camp.woowak.lab.menu.repository.MenuRepository;
+import camp.woowak.lab.order.repository.OrderRepository;
+import camp.woowak.lab.payaccount.repository.PayAccountRepository;
+import camp.woowak.lab.store.domain.Store;
+import camp.woowak.lab.store.repository.StoreCategoryRepository;
+import camp.woowak.lab.store.repository.StoreRepository;
+import camp.woowak.lab.vendor.repository.VendorRepository;
+import camp.woowak.lab.web.dao.store.StoreDummiesFixture;
+import camp.woowak.lab.web.dto.response.CartResponse;
+
+@SpringBootTest
+@Transactional
+class RedisCartDaoTest extends StoreDummiesFixture {
+	private final CartRepository cartRepository;
+	@Autowired
+	private RedisCartDao redisCartDao;
+
+	@Autowired
+	public RedisCartDaoTest(StoreRepository storeRepository,
+							StoreCategoryRepository storeCategoryRepository,
+							VendorRepository vendorRepository,
+							PayAccountRepository payAccountRepository,
+							OrderRepository orderRepository,
+							CustomerRepository customerRepository,
+							MenuRepository menuRepository,
+							MenuCategoryRepository menuCategoryRepository,
+							CartRepository cartRepository) {
+		super(storeRepository, storeCategoryRepository, vendorRepository, payAccountRepository, orderRepository,
+			  customerRepository, menuRepository, menuCategoryRepository);
+		this.cartRepository = cartRepository;
+	}
+
+	private Customer customer;
+	private Store store;
+	private MenuCategory menuCategory;
+	private List<Menu> menus;
+
+	@BeforeEach
+	void setUp() {
+		customer = createDummyCustomers(1).get(0);
+		store = createDummyStores(1).get(0);
+		menuCategory = createDummyMenuCategories(store,1).get(0);
+		menus = createDummyMenus(store,menuCategory,5);
+	}
+
+	@Test
+	@DisplayName("findByCustomerId 메서드는 장바구니에 담긴 메뉴의 아이템을 가져온다.")
+	void findByCustomerIdTest(){
+		//given
+		Cart cart = new Cart(customer.getId().toString());
+		cartRepository.save(cart);
+		menus.stream()
+			.forEach(cart::addMenu);
+		Cart save = cartRepository.save(cart);
+
+		//when
+		CartResponse response = redisCartDao.findByCustomerId(customer.getId());
+
+		//then
+		assertThat(response.getStoreId()).isEqualTo(store.getId());
+		assertThat(response.getStoreName()).isEqualTo(store.getName());
+		assertThat(response.getMinOrderPrice()).isEqualTo(store.getMinOrderPrice());
+	}
+}