package command;

import java.util.ArrayDeque;
import java.util.Deque;

/**
 * Invoker — holds command history and triggers execute/undo.
 * It doesn't know what the commands do; it just calls execute() and undo().
 */
public class CommandHistory {
    private final Deque<Command> history = new ArrayDeque<>();

    public void execute(Command cmd) {
        cmd.execute();
        history.push(cmd);
        System.out.println("  Executed: " + cmd.getDescription());
    }

    public void undo() {
        if (history.isEmpty()) {
            System.out.println("  Nothing to undo.");
            return;
        }
        Command cmd = history.pop();
        cmd.undo();
        System.out.println("  Undone: " + cmd.getDescription());
    }
}