feat(basket): add basket items entity and repository

src/main/java/cat/udl/eps/softarch/demo/domain/Basket.java

@@ -7,6 +7,8 @@
 import lombok.EqualsAndHashCode;
 
 import java.time.ZonedDateTime;
+import java.util.ArrayList;
+import java.util.List;
 
 @Entity
 @Data
@@ -22,6 +24,9 @@ public class Basket extends UriEntity<Long> {
     @JsonIdentityReference(alwaysAsId = true)
     private Customer customer;
 
+    @OneToMany(mappedBy = "basket", cascade = CascadeType.ALL, orphanRemoval = true)
+    private List<BasketItem> items = new ArrayList<>();
+
     @Column(nullable = false, updatable = false)
     private ZonedDateTime createdAt;
 
@@ -39,4 +44,5 @@ protected void onCreate() {
     protected void onUpdate() {
         this.updatedAt = ZonedDateTime.now();
     }
-}
+}
+

src/main/java/cat/udl/eps/softarch/demo/domain/BasketItem.java

@@ -0,0 +1,33 @@
+package cat.udl.eps.softarch.demo.domain;
+
+import com.fasterxml.jackson.annotation.JsonIdentityReference;
+import jakarta.persistence.*;
+import jakarta.validation.constraints.Min;
+import jakarta.validation.constraints.NotNull;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+@Entity
+@Data
+@EqualsAndHashCode(callSuper = true)
+public class BasketItem extends UriEntity<Long> {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @NotNull
+    @ManyToOne
+    @JsonIdentityReference(alwaysAsId = true)
+    private Basket basket;
+
+    @NotNull
+    @ManyToOne
+    @JsonIdentityReference(alwaysAsId = true)
+    private Product product;
+
+    @NotNull
+    @Min(1)
+    private Integer quantity = 1;
+}
+

src/main/java/cat/udl/eps/softarch/demo/handler/BasketItemEventHandler.java

@@ -0,0 +1,32 @@
+package cat.udl.eps.softarch.demo.handler;
+
+import cat.udl.eps.softarch.demo.domain.BasketItem;
+import cat.udl.eps.softarch.demo.repository.BasketRepository;
+import org.springframework.data.rest.core.annotation.*;
+import org.springframework.stereotype.Component;
+
+@Component
+@RepositoryEventHandler
+public class BasketItemEventHandler {
+
+    private final BasketRepository basketRepository;
+
+    public BasketItemEventHandler(BasketRepository basketRepository) {
+        this.basketRepository = basketRepository;
+    }
+
+    @HandleBeforeCreate
+    @HandleBeforeSave
+    public void handleBasketItemSave(BasketItem item) {
+        if (item.getBasket() != null) {
+            basketRepository.save(item.getBasket()); // Updates basket updatedAt
+        }
+    }
+
+    @HandleBeforeDelete
+    public void handleBasketItemDelete(BasketItem item) {
+        if (item.getBasket() != null) {
+            basketRepository.save(item.getBasket());
+        }
+    }
+}

src/main/java/cat/udl/eps/softarch/demo/repository/BasketItemRepository.java

@@ -0,0 +1,16 @@
+package cat.udl.eps.softarch.demo.repository;
+
+import cat.udl.eps.softarch.demo.domain.Basket;
+import cat.udl.eps.softarch.demo.domain.BasketItem;
+import cat.udl.eps.softarch.demo.domain.Product;
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.PagingAndSortingRepository;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface BasketItemRepository extends CrudRepository<BasketItem, Long>, PagingAndSortingRepository<BasketItem, Long> {
+
+    List<BasketItem> findByBasket(Basket basket);
+    Optional<BasketItem> findByBasketAndProduct(Basket basket, Product product);
+}