Orders.java

package com.example.cleancoder.splitphase;

record Product(double basePrice, double discountThreshold, double discountRate) {}

record ShippingMethod(double discountThreshold, double discountedFee, Double feePerCase) {}

record PricingData(double basePrice, double discount, int quantity) {}

public class Orders {
    double priceOrder(Product product, int quantity, ShippingMethod shippingMethod) {
        PricingData pricingData = calculatePricingData(product, quantity);
        return applyShippingCost(shippingMethod, pricingData);
    }

    private static PricingData calculatePricingData(Product product, int quantity) {
        double basePrice = product.basePrice() * quantity;
        double discount = Math.max(quantity - product.discountThreshold(), 0)
                * product.basePrice() * product.discountRate();

        return new PricingData(basePrice, discount, quantity);
    }

    private static double applyShippingCost(ShippingMethod shippingMethod, PricingData pricingData) {
        double shippingPerCase = (pricingData.basePrice() > shippingMethod.discountThreshold())
                ? shippingMethod.discountedFee() : shippingMethod.feePerCase();
        double shippingCost = pricingData.quantity() * shippingPerCase;
        return pricingData.basePrice() - pricingData.discount() * shippingCost;
    }
}