Add Order

src/main/java/org/example/Constants.java

@@ -0,0 +1,8 @@
+package org.example;
+
+public class Constants {
+
+    public static final float lowVat = 0.07f;
+    public static final float highVat = 0.19f;
+
+}

src/main/java/org/example/Order.java

@@ -0,0 +1,94 @@
+package org.example;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Order {
+
+    List<Product> products;
+
+    public Order(List<Product> products) {
+        this.products = products;
+    }
+
+    public float calculateTotalPriceWithVat() {
+        return calculateTotalPrice() + calculateTotalVat();
+    }
+
+    public float calculateTotalPrice() {
+        return getPrice(this.products);
+    }
+
+    public float calculateTotalVat() {
+        return getVat(this.products);
+    }
+
+    public float calculateShippingVat() {
+        float totalWeight = calculateWeight(this.products);
+        float totalPrice = calculateTotalPrice();
+        float baseShippingCost = calculateBaseShippingCost(totalWeight, totalPrice);
+        List<Product> lowVatProducts = filterLowVatProducts(this.products);
+        List<Product> highVatProducts = filterHighVatProducts(this.products);
+        float lowVatPortion = getPrice(lowVatProducts) / totalPrice;
+        float highVatPortion = getPrice(highVatProducts) / totalPrice;
+        return baseShippingCost * lowVatPortion / (1 + Constants.lowVat) + baseShippingCost * highVatPortion / (1 + Constants.highVat);
+    }
+
+    public float calculateBaseShippingCost(float totalWeight, float price) {
+        if (price >= 500f)
+            return 0f;
+        if (totalWeight <= 0.1f)
+            return 3.95f;
+        if (totalWeight <= 1f)
+            return 4.95f;
+        if (totalWeight <= 5f)
+            return 5.95f;
+        return 19.95f;
+    }
+
+
+    private List<Product> filterLowVatProducts(List<Product> products) {
+        List<Product> lowVatProducts = new ArrayList<>();
+        for (Product product : products) {
+            if (product.vatPortion == Constants.lowVat) {
+                lowVatProducts.add(product);
+            }
+        }
+        return lowVatProducts;
+    }
+
+    private List<Product> filterHighVatProducts(List<Product> products) {
+        List<Product> highVatProducts = new ArrayList<>();
+        for (Product product : products) {
+            if (product.vatPortion == Constants.highVat) {
+                highVatProducts.add(product);
+            }
+        }
+        return highVatProducts;
+    }
+
+    private float getPrice(List<Product> products) {
+        float total = 0;
+        for (Product product : products) {
+            total += product.price;
+        }
+        return total;
+    }
+
+    private float getVat(List<Product> products) {
+        float total = 0;
+        for (Product product : products) {
+            total += product.getVat();
+        }
+        return total;
+    }
+
+    private float calculateWeight(List<Product> products) {
+        float totalWeight = 0;
+        for (Product product : products) {
+            totalWeight += product.weight;
+        }
+        return totalWeight;
+    }
+
+}

src/main/java/org/example/ShoppingCart.java

@@ -25,4 +25,16 @@ public class ShoppingCart {
     public void clearProducts() {
         products.clear();
     }
+
+    public Order toOrder() {
+        List<Product> productsInOrder = new ArrayList<>();
+        for (HashMap.Entry<Product, Integer> entry : products.entrySet()) {
+            Product product = entry.getKey();
+            int quantity = entry.getValue();
+            for (int i = 0; i < quantity; i++) {
+                productsInOrder.add(product);
+            }
+        }
+        return new Order(productsInOrder);
+    }
 }