SECURE BY DESIGN DAY 03

// 1. Value Object: Address เป็น Immutable และ Conceptual Whole
public final class Address {
    private final String street;
    private final String zipCode;
    private final String city;

    public Address(String street, String zipCode, String city) {
        this.street = notEmpty(street, "Street required");
        this.zipCode = notEmpty(zipCode, "ZipCode required");
        this.city = notEmpty(city, "City required");
    }
    // มีแต่ getters เท่านั้น ไม่มี setters!
}

// 2. Aggregate Root: Customer ปกป้อง Invariants ควบคุมทางเดียว
public class Customer {
    private final CustomerId id; // Identity
    private String name;
    private final List<Address> addresses = new ArrayList<>();

    public Customer(CustomerId id, String name, Address primaryAddress) {
        this.id = notNull(id);
        this.name = notEmpty(name);
        this.addresses.add(notNull(primaryAddress));
    }

    // Encapsulated Domain Operation แทนการเปิด List ให้แก้
    public void updatePrimaryAddress(Address newAddress) {
        notNull(newAddress, "New address cannot be null");
        this.addresses.set(0, newAddress);
    }

    // ส่งออกเฉพาะ Unmodifiable List ป้องกันภายนอกแอบแก้ไข
    public List<Address> addresses() {
        return Collections.unmodifiableList(addresses);
    }
}