import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.Set;
import java.util.TreeSet;

public class Words {
    public static final int HEIGHT = 700;
    public static final int WIDTH = 440;
    private static int outputX = 15;
    private static int outputY = 150;
    private static int numPrinted = 0;
    private static DrawingPanel panel;
    private static String part;
    private static boolean paused = false;
    
    /* Given methods: print, choose, unchoose */
    private static void words(String acc, int length) {
        String[] choices = { "a", "b", "c", "d" };
        if (length == 0) {
            add(acc);
        }
        else {
            for (String c : choices) {
                //acc += c;                                           //choose(c);
                words(acc + c, length - 1);
                //acc = acc.substring(0, acc.length() - 1);           //unchoose();
            }
        }
    }
    public static void words(int length) {
        words("", length);
    }
    
    
    
    
    
    
    
   
    
    
    
    
    
    
    

    public static void main(String[] args) {
        panel = new DrawingPanel(WIDTH, HEIGHT);
        panel.addMouseListener((MouseListener) new MouseAdapter() {
            public void mouseClicked(MouseEvent e) {
                Words.paused = !Words.paused;
            }
        });

        drawUnderline();
        placePartial("");
        words(4);
    }
    public static void drawUnderline() {
        Graphics g = panel.getGraphics();
        g.setColor(Color.RED);
        Font font = new Font("Arial", Font.PLAIN, 100);
        g.setFont(font);
        g.drawString("____", 100, 80);

    }
    public static void placePartial(String x) {
        if (x.length() == 0) {
            return;
        }
        Graphics g = panel.getGraphics();
        g.setColor(Color.BLACK);
        Font font = new Font("Arial", Font.PLAIN, 100);
        g.setFont(font);
        g.setColor(Color.WHITE);
        g.fillRect(10, 5, 100 + 55 * (4), 80);

        if (x.length() > 1) {
            g.setColor(Color.BLACK);
            g.drawString(x.substring(0, x.length() - 1), 100, 80);
        }
        g.setColor(Color.BLUE);
        g.drawString(x.substring(x.length() - 1), 100 + 57 * (x.length() - 1),
                80);
        g.setColor(Color.BLACK);
        pause();
    }
    public static void add(String x) {
        Graphics g = panel.getGraphics();
        Font font = new Font("Arial", Font.PLAIN, 20);
        g.setFont(font);
        g.drawString(x + ", ", outputX, outputY);
        outputX += 60;
        numPrinted++;
        if (numPrinted % 7 == 0) {
            outputY += 30;
            outputX = 15;
        }
    }
    public static void choose(String choice) {
        if (part == null) {
            part = "";
        }
        part += choice;
        placePartial(part);
    }
    public static void unchoose() {
        part = part.substring(0, part.length() - 1);
        placePartial(part);
    }
    public static void print() {
        add(part);
    }
    public static void pause() {
        panel.sleep(800);
        while (paused) {
            panel.sleep(200);
        }
    }
}