// PaymentStrategy - interface

public interface PaymentStrategy {
	void pay(int amount);
}

// KAKAOCardStrategy

public class KAKAOCardStrategy implements PaymentStrategy{
	private String name;
	private String cardNumber;
	private String cvv;
	private String dateOfExpiry;

	public KAKAOCardStrategy(String name, String cardNumber, String cvv, String dateOfExpiry) {
		this.name = name;
		this.cardNumber = cardNumber;
		this.cvv = cvv;
		this.dateOfExpiry = dateOfExpiry;
	}

	@Override
	public void pay(int amount) {
		System.out.println(amount + " paid using KAKAOCard.");
	}
}

// LUNACardStrategy

public class LUNACardStrategy implements PaymentStrategy {
	private String emailId;
	private String password;

	public LUNACardStrategy(String emailId, String password) {
		this.emailId = emailId;
		this.password = password;
	}

	@Override
	public void pay(int amount) {
		System.out.println(amount + " paid using LUNACard");
	}
}

// Item

public class Item {
	private String name;
	private int price;
	public Item(String name, int price) {
		this.name = name;
		this.price = price;
	}

	public String getName() {
		return name;
	}

	public int getPrice() {
		return price;
	}
}

// ShoppingCart

import java.util.ArrayList;
import java.util.List;

public class ShoppingCart {
	List<Item> items;

	public ShoppingCart() {
		this.items = new ArrayList<>();
	}

	public void addItem(Item item) {
		this.items.add(item);
	}

	public void removeItem(Item item) {
		this.items.remove(item);
	}

	public int calculateTotal() {
		int sum = 0;
		for (Item item : items) {
			sum += item.getPrice();
		}
		return sum;
	}

	public void pay(PaymentStrategy pamentMethod) {
		int amount = calculateTotal();
		pamentMethod.pay(amount);
	}
}

// Main

import designPattern.strategy.Item;
import designPattern.strategy.KAKAOCardStrategy;
import designPattern.strategy.LUNACardStrategy;
import designPattern.strategy.ShoppingCart;

public class Main {

	public static void main(String[] args) {
		ShoppingCart cart = new ShoppingCart();

		Item A = new Item("A", 100);
		Item B = new Item("B", 300);

		cart.addItem(A);
		cart.addItem(B);

		// pay by LUNACard
		cart.pay(new LUNACardStrategy("kobe@google.com", "1234"));

		// pay by KAKAOCard
		cart.pay(new KAKAOCardStrategy("Minseong Kang", "123456789", "123", "12/01"));
	}
}