Draft pull

pom.xml

@@ -16,19 +16,19 @@
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter</artifactId>
-            <version>5.11.4</version>
+            <version>6.0.1</version>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>org.assertj</groupId>
             <artifactId>assertj-core</artifactId>
-            <version>3.27.3</version>
+            <version>3.27.7</version>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-junit-jupiter</artifactId>
-            <version>5.15.2</version>
+            <version>5.21.0</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
@@ -37,17 +37,17 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.13.0</version>
+                <version>3.14.1</version>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>3.5.2</version>
+                <version>3.5.4</version>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-failsafe-plugin</artifactId>
-                <version>3.5.2</version>
+                <version>3.5.4</version>
                 <executions>
                     <execution>
                         <goals>
@@ -60,7 +60,7 @@
             <plugin>
                 <groupId>org.jacoco</groupId>
                 <artifactId>jacoco-maven-plugin</artifactId>
-                <version>0.8.12</version>
+                <version>0.8.14</version>
                 <configuration>
                     <skip>true</skip>
                 </configuration>

src/main/java/com/example/shop/DiscountService.java

@@ -0,0 +1,7 @@
+package com.example.shop;
+
+import java.math.BigDecimal;
+
+public interface DiscountService {
+    BigDecimal getDiscountMultiplier(String itemName);
+}

src/main/java/com/example/shop/Item.java

@@ -0,0 +1,45 @@
+package com.example.shop;
+
+import java.math.BigDecimal;
+import java.util.Objects;
+
+public class Item {
+
+    private final String name;
+    private final BigDecimal price;
+    private int quantity;
+    private final BigDecimal discountPercentage;
+    public Item(String name, BigDecimal price, int quantity) {
+        this.name = name;
+        this.price = price;
+        this.quantity = quantity;
+        this.discountPercentage = BigDecimal.ZERO;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public BigDecimal getPrice() {
+        return price;
+    }
+
+    public int getQuantity() {
+        return quantity;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (!(o instanceof Item item)) return false;
+        return quantity == item.quantity && Objects.equals(name, item.name) && Objects.equals(price, item.price) && Objects.equals(discountPercentage, item.discountPercentage);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, price, quantity, discountPercentage);
+    }
+
+    public void setQuantity(int quantity) {
+        this.quantity = quantity;
+    }
+}

src/main/java/com/example/shop/ShoppingCart.java

@@ -0,0 +1,51 @@
+package com.example.shop;
+
+import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ShoppingCart {
+    private final List<Item> items = new ArrayList<>();
+    private final DiscountService discountService;
+
+    ShoppingCart(DiscountService discountService) {
+        this.discountService =  discountService;
+    }
+    ShoppingCart() {
+        this.discountService = itemName -> BigDecimal.ONE;
+    }
+
+    public void addItem(Item newItem) {
+        items.stream()
+                .filter(item -> item.getName().equals(newItem.getName()))
+                .findFirst()
+                .ifPresentOrElse(
+                        existing -> existing.setQuantity(existing.getQuantity() + newItem.getQuantity()),
+                        () -> items.add(newItem)
+                );
+    }
+
+    public List<Item> getItems() {
+        return items;
+    }
+
+    public BigDecimal getTotalPrice() {
+        BigDecimal totalPrice = BigDecimal.ZERO;
+        for(Item item : items) {
+            BigDecimal multiplier = discountService.getDiscountMultiplier(item.getName());
+            if (multiplier == null) {
+                multiplier = BigDecimal.ONE;
+            }
+            BigDecimal itemTotal = item.getPrice()
+                    .multiply(BigDecimal.valueOf(item.getQuantity()))
+                    .multiply(multiplier);
+
+            totalPrice = totalPrice.add(itemTotal);
+        }
+        return totalPrice;
+    }
+
+    public void removeItem(Item item) {
+        items.remove(item);
+    }
+}