package mediator;

/**
 * Mediator Design Pattern — Runnable Demo
 * Run: javac mediator/*.java -d out/mediator && java -cp out/mediator mediator.Main
 * Article: https://ankurm.com/mediator-design-pattern-java/
 */
public class Main {
    public static void main(String[] args) {
        System.out.println("=== Mediator Design Pattern Demo ===\n");

        ChatRoom room = new ChatRoom();

        User alice = new User("Alice", room);
        User bob   = new User("Bob",   room);
        User carol = new User("Carol", room);

        room.addUser(alice);
        room.addUser(bob);
        room.addUser(carol);

        System.out.println();
        alice.send("Hey everyone!");
        System.out.println();
        bob.send("Hi Alice and Carol!");
        System.out.println();
        carol.send("Good morning!");

        System.out.println("\n-- Connections without Mediator: " + 3 + " users need " + (3 * 2) + " direct links --");
        System.out.println("-- With Mediator: " + 3 + " users each connect only to the room --");
        System.out.println("-- With N users: O(N) connections instead of O(N²) --");

        System.out.println("\n=== Demo complete ===");
    }
}