// Project: Recursion
// Module: hanoi2
// Source code file: DiskDispay.java
// Solve Towers of Hanoi puzzle graphically.

// Display three pegs and maximum of
// eight disks for Towers of Hanoi puzzle.

import javax.swing.*;

import java.awt.*;
import java.awt.event.*;
import java.io.*;

public class MyPanel extends JPanel
{
    private JButton run, reset;
    private JComboBox<String> cb;
    private DiskDisplay dd;
    private int nDisks;
    private Timer timer;
    private BufferedReader br;
    private PrintWriter pw;

    public MyPanel()
    {
        String[] numbers = {"1", "2", "3", "4",
                "5", "6", "7", "8"};
        cb = new JComboBox<String>(numbers);
        dd = new DiskDisplay(3, timer);
        cb.setSelectedIndex(2);
        nDisks = 3;
        setBackground(Color.white);
        run = new JButton("Run");
        reset = new JButton("Reset");
        setLayout(new FlowLayout());
        add(cb);
        add(reset);
        add(run);
        ResetD rd = new ResetD();
        cb.addActionListener(rd);
        reset.addActionListener(rd);
        run.addActionListener(new RunD());
        timer = new Timer(1000, new TimerD());
        timer.stop();
        try
        {
            pw = new PrintWriter("hanoi.txt");
        }
        catch(IOException ex)
        {
            System.out.println(ex);
        }

    }

    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        dd.display(g);
    }

    public void hanoi(int n, int from, int to, int aux)
    {
        if (n >= 1)
        {
            hanoi(n - 1, from, aux, to);
            pw.println(from + " " + to);
            hanoi(n - 1, aux, to, from);
        }
    }
    private class RunD implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            hanoi(nDisks, 0, 1, 2);
            pw.close();
            try
            {
                br = new BufferedReader(
                        new FileReader("hanoi.txt"));
            }
            catch(IOException ex)
            {
                System.out.println(ex);
            }
            timer.start();
        }
    }

    private class ResetD implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            String item;
            item = (String) cb.getSelectedItem();
            nDisks = Integer.parseInt(item);
            dd = new DiskDisplay(nDisks, timer);
            repaint();
            try
            {
                br.close();
                pw = new PrintWriter("hanoi.txt");
            }
            catch(IOException ex)
            {
                System.out.println(ex);
            }
            timer.stop();
        }
    }

    private class TimerD implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            int from, to;
            String line;
            try
            {
                if ((line = br.readLine()) != null)
                {
                    from = Integer.parseInt(
                            line.substring(0, 1));
                    to = Integer.parseInt(
                            line.substring(2));
                    dd.move(from, to);
                    repaint();
                }
            }
            catch(IOException ex)
            {
                System.out.println(ex);
            }
        }
    }
}