tdd-shop

Case - Shopping Cart

Implement an e-commerce shopping cart class.

Rules:

• Product has a title and price.
• Product belong to a category.
• Category may or may not have a parent category.
• Category has a title.
• Products are added to the Cart with quantity info.
• Campaigns exist for product price discounts.
• Campaigns are applicable to a product category.
• Campaign discount vary based on the number of products in the cart
• Coupons exist for cart discounts.
• Coupons have minimum cart amount constraint. If Cart amount is less than minimum, discount is not applied.
• Delivery Cost is Dynamic. Based on the number of deliveries and number of products.

Cart

Implement a class that takes a cart and calculates the delivery cost.

• //sample creating a new category
• Category food = new new Category(“food");  
• //products
• Product apple = new Product(“Apple”, 100.0, category);
• Product almond = new Product(“Almonds”, 150.0, category);  
• //Products can be added to a shopping cart with quantity
• ShoppingCart cart = new ShoppingCart();
• cart.addItem(apple,3);
• cart.addItem(almond,1);  

Discounts

• //you can apply discounts to a category
• //discount rules can be 20% on a category if bought more than 3 items
• Campaign campaign1 = new Campaign(category,20.0,3,DiscountType.Rate);
• //another campaign rule 50% on a category if bought more than 5 items
• Campaign campaign2 = new Campaign(category,50.0,5,DiscountType.Rate);
• //another campaign rule 5 TL amount discount on a category if bought more than  items
• Campaign campaign3 = new Campaign(category,5.0,5,DiscountType.Amount);  
• //Cart should apply the maximum amount of discount to the cart.
• cart.applyDiscounts(discount1,discount2,discount3);

Coupons 

• //You can also apply a coupon to a cart
• //Coupons have minimum amount. If the cart total is less than minimum amount, coupon is not applicable
• //Coupon for 100 TL min purchase amount for a 10% discount
• Coupon coupon = new Coupon(100, 10, DiscountType.Rate)
• cart.applyCoupon(coupon)  
• Campaign Discounts are applied first, Then Coupons.

Delivery

• To optimize our delivery Cost, we want to apply dynamic cargo pricing rules based on the number of deliveries and number of products in the cart.

• Formula is ( CostPerDelivery * NumberOfDeliveries ) + (CostPerProduct * NumberOfProducts) + Fixed Cost

• Fixed cost is 2.99 TL.

• Implement a class that takes a cart and calculates the delivery cost.  

Delivery Calculator

• DeliveryCostCalculator deliveryCostCalculator = new DeliveryCostCalculator(costPerDelivery,costPerProduct,fixedCost);
• double deliveryCostCalculator.calculateFor(cart)  
• NumberOfDeliveries is calculated by the number of distinct categories in the cart. If cart has products that belong to two distinct categories, number of deliveries is 2.  
• NumberOfProducts is the number of different products in the cart. It is not the quantity of products.

Cart Responsibilities

• double cart.getTotalAmountAfterDiscounts()
• double cart.getCouponDiscount()
• double cart.getCampaignDiscount()
• double cart.getDeliveryCost()  

Final

• Group Products by Category and Print the CategoryName, ProductName, Quantity, Unit Price, Total Price, Total Discount(coupon,campaign) applied

• cart.print()  

• At the final line print total amount and the delivery cost.