Round3 ecommerce implementation

.docs/design/01-requirements.md

@@ -114,7 +114,7 @@
 ### 4.2 좋아요
 
 - 이미 좋아요한 상품에 다시 좋아요를 누를 경우 오류로 처리한다.
-- 좋아요하지 않은 상품에 좋아요 취소를 요청할 경우 오류로 처리한다.
+- 좋아요하지 않은 상품에 좋아요 취소를 요청할 경우 아무 동작 없이 성공으로 처리한다. (멱등)
 - 삭제된 상품에 대한 좋아요는 목록에서 제외한다.
 
 ### 4.3 주문

apps/commerce-api/src/main/java/com/loopers/application/brand/BrandFacade.java

@@ -0,0 +1,25 @@
+package com.loopers.application.brand;
+
+import com.loopers.application.like.LikeService;
+import com.loopers.application.product.ProductService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+@RequiredArgsConstructor
+@Service
+public class BrandFacade {
+    private final BrandService brandService;
+    private final ProductService productService;
+    private final LikeService likeService;
+
+    @Transactional
+    public void delete(Long brandId) {
+        List<Long> productIds = productService.getProductIdsByBrandId(brandId);
+        likeService.deleteAllByProductIds(productIds);
+        productService.deleteAllByBrandId(brandId);
+        brandService.delete(brandId);
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/brand/BrandInfo.java

@@ -0,0 +1,25 @@
+package com.loopers.application.brand;
+
+import com.loopers.domain.brand.Brand;
+
+import java.time.ZonedDateTime;
+
+public record BrandInfo(
+        Long id,
+        String name,
+        String description,
+        ZonedDateTime createdAt,
+        ZonedDateTime updatedAt,
+        ZonedDateTime deletedAt
+) {
+    public static BrandInfo from(Brand brand) {
+        return new BrandInfo(
+                brand.getId(),
+                brand.getName(),
+                brand.getDescription(),
+                brand.getCreatedAt(),
+                brand.getUpdatedAt(),
+                brand.getDeletedAt()
+        );
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/brand/BrandService.java

@@ -0,0 +1,74 @@
+package com.loopers.application.brand;
+
+import com.loopers.domain.brand.Brand;
+import com.loopers.domain.brand.BrandRepository;
+import com.loopers.support.error.CoreException;
+import com.loopers.support.error.ErrorType;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+@RequiredArgsConstructor
+@Service
+public class BrandService {
+    private final BrandRepository brandRepository;
+
+    @Transactional
+    public BrandInfo register(String name, String description) {
+        Brand brand = Brand.create(name, description);
+        return BrandInfo.from(brandRepository.save(brand));
+    }
+
+    @Transactional(readOnly = true)
+    public BrandInfo getBrand(Long id) {
+        Brand brand = findById(id);
+        if (brand.getDeletedAt() != null) {
+            throw new CoreException(ErrorType.NOT_FOUND, "[brandId = " + id + "] 를 찾을 수 없습니다.");
+        }
+        return BrandInfo.from(brand);
+    }
+
+    @Transactional(readOnly = true)
+    public Page<BrandInfo> getBrands(Pageable pageable) {
+        return brandRepository.findAllByDeletedAtIsNull(pageable).map(BrandInfo::from);
+    }
+
+    @Transactional
+    public BrandInfo update(Long id, String name, String description) {
+        Brand brand = findNonDeletedById(id);
+        brand.update(name, description);
+        return BrandInfo.from(brand);
+    }
+
+    @Transactional(readOnly = true)
+    public Map<Long, String> getBrandNameMap(Collection<Long> brandIds) {
+        return brandRepository.findAllByIdIn(brandIds).stream()
+                              .collect(Collectors.toMap(Brand::getId, Brand::getName));
+    }
+
+    @Transactional
+    public void delete(Long id) {
+        Brand brand = findById(id);
+        brand.delete();
+    }
+
+    private Brand findNonDeletedById(Long id) {
+        Brand brand = findById(id);
+        if (brand.getDeletedAt() != null) {
+            throw new CoreException(ErrorType.NOT_FOUND, "[brandId = " + id + "] 를 찾을 수 없습니다.");
+        }
+        return brand;
+    }
+
+    private Brand findById(Long id) {
+        return brandRepository.findById(id)
+                              .orElseThrow(() -> new CoreException(ErrorType.NOT_FOUND,
+                                                                   "[brandId = " + id + "] 를 찾을 수 없습니다."));
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/like/LikeFacade.java

@@ -0,0 +1,47 @@
+package com.loopers.application.like;
+
+import com.loopers.application.product.ProductInfo;
+import com.loopers.application.product.ProductService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+@RequiredArgsConstructor
+@Service
+public class LikeFacade {
+    private final LikeService likeService;
+    private final ProductService productService;
+
+    @Transactional
+    public LikeInfo register(Long userId, Long productId) {
+        LikeInfo like = likeService.register(userId, productId);
+        productService.increaseLikeCount(productId);
+        return like;
+    }
+
+    @Transactional
+    public void cancel(Long userId, Long productId) {
+        if (likeService.cancel(userId, productId)) {
+            productService.decreaseLikeCount(productId);
+        }
+    }
+
+    public List<LikedProductInfo> getLikedProductsByUserId(Long userId) {
+        List<LikeInfo> likes = likeService.getLikesByUserId(userId);
+        if (likes.isEmpty()) return List.of();
+
+        List<Long> productIds = likes.stream().map(LikeInfo::productId).toList();
+        Map<Long, ProductInfo> productMap = productService.getActiveProductsByIds(productIds)
+                                                          .stream()
+                                                          .collect(Collectors.toMap(ProductInfo::id, p -> p));
+
+        return likes.stream()
+                    .filter(like -> productMap.containsKey(like.productId()))
+                    .map(like -> new LikedProductInfo(like.id(), productMap.get(like.productId()), like.createdAt()))
+                    .toList();
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/like/LikeInfo.java

@@ -0,0 +1,21 @@
+package com.loopers.application.like;
+
+import com.loopers.domain.like.Like;
+
+import java.time.ZonedDateTime;
+
+public record LikeInfo(
+        Long id,
+        Long userId,
+        Long productId,
+        ZonedDateTime createdAt
+) {
+    public static LikeInfo from(Like like) {
+        return new LikeInfo(
+                like.getId(),
+                like.getUserId(),
+                like.getProductId(),
+                like.getCreatedAt()
+        );
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/like/LikeService.java

@@ -0,0 +1,49 @@
+package com.loopers.application.like;
+
+import com.loopers.domain.like.Like;
+import com.loopers.domain.like.LikeRepository;
+import com.loopers.support.error.CoreException;
+import com.loopers.support.error.ErrorType;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+@RequiredArgsConstructor
+@Service
+public class LikeService {
+    private final LikeRepository likeRepository;
+
+    @Transactional
+    public LikeInfo register(Long userId, Long productId) {
+        likeRepository.findByUserIdAndProductId(userId, productId).ifPresent(like -> {
+            throw new CoreException(ErrorType.ALREADY_LIKED, "이미 좋아요한 상품입니다.");
+        });
+
+        Like like = Like.create(userId, productId);
+        return LikeInfo.from(likeRepository.save(like));
+    }
+
+    @Transactional
+    public boolean cancel(Long userId, Long productId) {
+        return likeRepository.deleteByUserIdAndProductId(userId, productId) > 0;
+    }
+
+    @Transactional(readOnly = true)
+    public List<LikeInfo> getLikesByUserId(Long userId) {
+        return likeRepository.findByUserId(userId)
+                             .stream()
+                             .map(LikeInfo::from)
+                             .toList();
+    }
+
+    @Transactional
+    public void deleteAllByProductIds(List<Long> productIds) {
+        if (productIds.isEmpty()) {
+            return;
+        }
+
+        likeRepository.deleteAllByProductIdIn(productIds);
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/like/LikedProductInfo.java

@@ -0,0 +1,11 @@
+package com.loopers.application.like;
+
+import com.loopers.application.product.ProductInfo;
+
+import java.time.ZonedDateTime;
+
+public record LikedProductInfo(
+        Long likeId,
+        ProductInfo product,
+        ZonedDateTime likedAt
+) {}

apps/commerce-api/src/main/java/com/loopers/application/order/OrderCreateCommand.java

@@ -0,0 +1,6 @@
+package com.loopers.application.order;
+
+import java.util.List;
+
+public record OrderCreateCommand(Long userId, List<OrderItemCommand> items) {
+}

apps/commerce-api/src/main/java/com/loopers/application/order/OrderFacade.java

@@ -0,0 +1,39 @@
+package com.loopers.application.order;
+
+import com.loopers.application.product.ProductService;
+import com.loopers.application.product.ProductInfo;
+import com.loopers.domain.order.OrderItemSnapshot;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+@RequiredArgsConstructor
+@Service
+public class OrderFacade {
+    private final OrderService orderService;
+    private final ProductService productService;
+
+    @Transactional
+    public OrderInfo createOrder(OrderCreateCommand command) {
+        orderService.validateItems(command.items());
+        List<Long> productIds = command.items().stream()
+                                       .map(OrderItemCommand::productId)
+                                       .toList();
+        List<ProductInfo> products = productService.getActiveProductsByIdsOrThrow(productIds);
+        productService.decreaseStock(command.items());
+
+        Map<Long, ProductInfo> productMap = products.stream()
+                                                    .collect(Collectors.toMap(ProductInfo::id, p -> p));
+        List<OrderItemSnapshot> snapshots = command.items().stream()
+                                                   .map(item -> {
+                                                       ProductInfo p = productMap.get(item.productId());
+                                                       return new OrderItemSnapshot(p.id(), p.name(), p.price(), item.quantity());
+                                                   })
+                                                   .toList();
+        return orderService.placeOrder(command.userId(), snapshots);
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/order/OrderInfo.java

@@ -0,0 +1,23 @@
+package com.loopers.application.order;
+
+import com.loopers.domain.order.Order;
+
+import java.time.ZonedDateTime;
+
+public record OrderInfo(
+        Long id,
+        Long userId,
+        Order.Status status,
+        Long totalAmount,
+        ZonedDateTime createdAt
+) {
+    public static OrderInfo from(Order order) {
+        return new OrderInfo(
+                order.getId(),
+                order.getUserId(),
+                order.getStatus(),
+                order.getTotalAmount(),
+                order.getCreatedAt()
+        );
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/order/OrderItemCommand.java

@@ -0,0 +1,3 @@
+package com.loopers.application.order;
+
+public record OrderItemCommand(Long productId, Integer quantity) {}

apps/commerce-api/src/main/java/com/loopers/application/order/OrderItemInfo.java

@@ -0,0 +1,23 @@
+package com.loopers.application.order;
+
+import com.loopers.domain.order.OrderItem;
+
+public record OrderItemInfo(
+        Long id,
+        Long orderId,
+        Long productId,
+        String productName,
+        Long price,
+        Integer quantity
+) {
+    public static OrderItemInfo from(OrderItem item) {
+        return new OrderItemInfo(
+                item.getId(),
+                item.getOrderId(),
+                item.getProductId(),
+                item.getProductName(),
+                item.getUnitPrice(),
+                item.getQuantity()
+        );
+    }
+}