package command;

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

        TextEditor editor = new TextEditor();
        CommandHistory history = new CommandHistory();

        System.out.println("Initial: " + editor);

        history.execute(new InsertCommand(editor, "Hello", 0));
        System.out.println("After:   " + editor);

        history.execute(new InsertCommand(editor, " World", 5));
        System.out.println("After:   " + editor);

        history.execute(new DeleteCommand(editor, 5, 6));
        System.out.println("After:   " + editor);

        System.out.println("\n-- Undo sequence --");
        history.undo();
        System.out.println("After undo: " + editor);

        history.undo();
        System.out.println("After undo: " + editor);

        history.undo();
        System.out.println("After undo: " + editor);

        history.undo();  // nothing left

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