// My first applet...cut me some slack. Suggestions welcome.
//
// guichard@whitman.edu

import java.awt.*;
import java.applet.*;
import java.net.URL;

public class merlin extends java.applet.Applet
{
  
  merlin_display the_display;
  boolean[] current_board = new boolean[9];
  boolean[] goal_board = {true,true,true,true,false,true,true,true,true};
  boolean[] start_board = new boolean[9];
  Label label;
  framed_canvas framedArea;
  Image backBuffer;
  Graphics backGC;
  Button hint_button, target_button,sound_button;
  Thread button_thread;
  SoundList soundList;
  String successFile = "success.au";
  String beepFile = "beep.au";
  blinkThread blinker;
  boolean sounds, buttons;
  boolean sound_loading = false;

  final int PLAY = -1;
  final int BOX0 =  0;
  final int BOX1 =  1;
  final int BOX2 =  2;
  final int BOX3 =  3;
  final int BOX4 =  4;
  final int BOX5 =  5;
  final int BOX6 =  6;
  final int BOX7 =  7;
  final int BOX8 =  8;
  final int RESTART =  9;
  final int NEWGAME = 10;
  final int SETGOAL = 11;
  final int SETSTART= 12;
  final int HINT    = 13;
  final int QUIT    = 14;

  int mode=PLAY;

  public void init() // Init all the variables and classes
  { 
    String str;

    GridBagLayout gridBag = new GridBagLayout();
    GridBagConstraints c = new GridBagConstraints();

    try
      {
	backBuffer = createImage(size().width, size().height);
      }
    catch (Exception e) {}

    the_display = new merlin_display(backBuffer,goal_board);
    framedArea = new framed_canvas(the_display);

    sounds = getboolean("sound",false);
    buttons = getboolean("buttons",true);

    setLayout(gridBag);

    c.fill = GridBagConstraints.BOTH;
    c.weighty = 5.0;
    c.weightx = 10.0;
    c.gridheight = 5;
    c.gridwidth = 1;
    gridBag.setConstraints(framedArea, c);
    add(framedArea);

    if (buttons) {
      c.fill = GridBagConstraints.HORIZONTAL;
      c.insets = new Insets(4,20,0,15);
      c.weighty = 0.0;
      c.weightx = 0.4;
      c.gridheight = 1;
      c.gridwidth = GridBagConstraints.REMAINDER; //end row
      hint_button = new Button("Hint");
      gridBag.setConstraints(hint_button,c);
      add(hint_button);

      c.fill = GridBagConstraints.HORIZONTAL;
      target_button = new Button("Set");
      gridBag.setConstraints(target_button,c);
      add(target_button);

      c.fill = GridBagConstraints.HORIZONTAL;
      sound_button = new Button();
      if (sounds) {
	sound_button.setLabel("Sound Off");
      } else {
	sound_button.setLabel("Sound On");
      }
      gridBag.setConstraints(sound_button,c);
      add(sound_button);

      //    label = new Label("Click within the framed area.");
      //    c.fill = GridBagConstraints.HORIZONTAL;
      //    c.weightx = 1.0;
      //    c.weighty = 0.0;
      //    gridBag.setConstraints(label, c);
      //    add(label);
    }

    validate();
    if (sounds) {
      startLoadingSounds();
    }
  }

  public boolean action(Event e, Object arg) {
    Object target = e.target;
    int h;

    if (target == hint_button) {
      if ((h = hint()) >= 0) {
	blinker = new blinkThread(the_display,h); blinker.start();
      }
      else beep(beepFile);
      return true;
    }
    if (target == target_button) {
      if (mode == PLAY) {
	hint_button.disable();
	target_button.setLabel("Play");
	mode = SETGOAL;
      } else {
	hint_button.enable();
	target_button.setLabel("Set");
	mode = PLAY;
      }
      return true;
    }
    if (target == sound_button) {
      sounds = !sounds;
      if (sounds) {
	if (!sound_loading) startLoadingSounds();
	sound_button.setLabel("Sound Off");
      } else {
	sound_button.setLabel("Sound On");
      }
      return true;
    }
    return false;
  }  

  public boolean getboolean (String att, boolean def) 
  {
    String parm = getParameter(att);
    if (parm != null) {
      if (parm.equals("true")) return true;
      else if (parm.equals("false")) return false;
      else return def;
    }
    return def;
  } 

  void startLoadingSounds() {
    //Start asynchronous sound loading.
    sound_loading = true;
    soundList = new SoundList(this, getCodeBase());
    soundList.startLoading(successFile);
    soundList.startLoading(beepFile);
  }

  public void
  toggle_box(int i)
  {
    if (current_board[i] = !current_board[i]) 
      the_display.square_on(i);
    else the_display.square_off(i);
  }

  public void
  do_move(int i)
  { 
    toggle_box(i);
    switch(i) {
    case BOX0 :           
      toggle_box(1);
      toggle_box(3);
      toggle_box(4);
      break;
    case BOX1 :
      toggle_box(0);
      toggle_box(2);
      break;
    case BOX2 :
      toggle_box(1);
      toggle_box(4);
      toggle_box(5);
      break;
    case BOX3 :
      toggle_box(0);
      toggle_box(6);
      break;
    case BOX4 :
      toggle_box(1);
      toggle_box(3);
      toggle_box(5);
      toggle_box(7);
      break;
    case BOX5 :
      toggle_box(2);
      toggle_box(8);
      break;
    case BOX6 :
      toggle_box(3);
      toggle_box(4);
      toggle_box(7);
      break;
    case BOX7 :
      toggle_box(6);
      toggle_box(8);
      break;
    case BOX8 :
      toggle_box(5);
      toggle_box(4);
      toggle_box(7);
      break;
    }
  }

  public boolean rand01()
  { 
    if (Math.random() > 0.5) return(true);
    else return(false);
  }

  public boolean
  goal_reached()
  { int i;

  for (i=0; i<=BOX8; i++)
    if (current_board[i] != goal_board[i]) return(false);
  return(true);
  }

  public void
  toggle_start(int i)
  {
    if (start_board[i] = !start_board[i]) the_display.square_on(i);
    else the_display.square_off(i); 
  }

  public void
  toggle_goal(int i)
  {
    if (goal_board[i] = !goal_board[i]) the_display.setgoal(i);
    else the_display.offgoal(i); 
    the_display.repaint(); 
  }

  public void start()
  {
    //    label.setText("Starting game");
    start_game();
    repaint();   
  }

  public void
  start_game()
  { 
    int i;

    for (i=0; i<=BOX8; i++) {
      if (current_board[i] = start_board[i] =  rand01()) 
	the_display.square_on(i);
      else the_display.square_off(i);
    }
  }

  public void
  restart_game()
  { int i;

  for (i=0; i<=BOX8; i++)
    if (current_board[i] = start_board[i]) the_display.square_on(i);
    else the_display.square_off(i);
  }

  private boolean XOR (boolean x,boolean y)
  {
    return( (x || y) && !(x && y) );
  }

  public int
  hint()
  { boolean stat=false;
  int i;

  for (i=0; i<6; i++) stat = XOR(stat,XOR( goal_board[i],current_board[i]) );
  if (stat) return(1);

  stat = false;
  for (i=0; i<3; i++)
    stat = XOR(stat,XOR(goal_board[3*i], current_board[3*i]));

  for (i=0; i<3; i++) 
    stat = XOR(stat,XOR(goal_board[3*i+1], current_board[3*i+1]));
  
  if (stat) return(3);

  stat = false;
  for (i=0; i<3; i++) 
    stat = XOR(stat,XOR(goal_board[3*i+2], current_board[3*i+2]));

  for (i=0; i<3; i++) 
    stat = XOR(stat,XOR(goal_board[3*i+1], current_board[3*i+1]));

  if (stat) return(5);

  stat = false;

  for (i=3; i<9; i++) stat = XOR(stat,XOR(goal_board[i], current_board[i]));

  if (stat) return(7);

  if ( XOR(goal_board[0], current_board[0]) ) return(0);
  if ( XOR(goal_board[2], current_board[2]) ) return(2);
  if ( XOR(goal_board[6], current_board[6]) ) return(6);
  if ( XOR(goal_board[8], current_board[8]) ) return(8);
  if ( XOR(goal_board[4], current_board[4]) ) return(4);

  return(-1);
  }

  private void beep(String which_clip)
  {
    if (sounds) {
      AudioClip clip;

      clip = soundList.getClip(which_clip);

      if (clip != null) {  //If the sound is loaded:
	clip.play();
      }
    }
  }

  public boolean gotFocus(Event e, Object what) {
    if (size().width != backBuffer.getWidth(this)) {
      try
	{
	  backBuffer = createImage(size().width, size().height);
	}
      catch (Exception exc) {}
      the_display.newscratch(backBuffer);
    }
    return(true);
  }

  public boolean mouseDown(java.awt.Event evt, int x,int y)
  { int i,h;
  int action=0;
  boolean return_value=false;

  //  label.setText("Click occurred at coordinate ("
  // + x + ", " + y + ").");

  if (blinker != null) { blinker.hangon(); }

  action = the_display.getevent(x-4,y-4);
  switch(action) {
  case BOX0:    
  case BOX1:    
  case BOX2:    
  case BOX3:    
  case BOX4:    
  case BOX5:    
  case BOX6:    
  case BOX7:    
  case BOX8:
    switch(mode) {
    case PLAY:
      do_move(action);    
      if (goal_reached()) beep(successFile);
      break;
    case SETGOAL:
      toggle_goal(action);
      break;
    case SETSTART:
      toggle_start(action);
      break;
    }
    return_value = true;
    break;
  }
  the_display.repaint(); 
  return(return_value);
  }
}

class blinkThread extends Thread {
  private  int box;
  private merlin_display the_display;
  private boolean hinting = false;

  public blinkThread(merlin_display d, int i) {
    super();
    box = i;
    the_display = d;
  }

  public synchronized void run() {
      int duration = 200;
      int i;
      int flashes = 2;

      hinting = true;
      the_display.flip(box);
      the_display.repaint();
      for (i=0; i<2*flashes - 1 ; i++) {
	try {
	  Thread.currentThread().sleep(duration);
	} catch (InterruptedException e){}
	the_display.flip(box);
	the_display.repaint();
      }
      hinting = false;
      notify();
  }

  public synchronized void hangon() {
    while (hinting == true) {
      try {
	wait();
      } catch (InterruptedException e){}
    }
  }

}   // end blinkThread

class framed_canvas extends Panel {
  public framed_canvas(Canvas the_display) {
    super();

    //Set layout to one that makes its contents as big as possible.
    setLayout(new GridLayout(1,0));

    add(the_display);
    validate();
  }

  public Insets insets() {
    return new Insets(4,4,4,4);
  }

  public void paint(Graphics g) {
    Dimension d = size();
    Color bg = getBackground();
 
    g.setColor(bg);
    g.draw3DRect(0, 0, d.width - 1, d.height - 1, true);
    g.draw3DRect(3, 3, d.width - 7, d.height - 7, false);
  }
}

class merlin_display extends java.awt.Canvas
{
  merlin_square[] current_board = new merlin_square[9];
  Color background_col=Color.white;
  Image backBuffer;
  Graphics backGC;
  boolean background_in=false;
  int width,height,gutter;

  public merlin_display(Image img,boolean[] gb)
  {
    int i;
    backBuffer = img;
    for (i=0; i<9; i++) 
      {
	current_board[i] = new merlin_square(i,gb[i]);
      }
  }

  public void paint(Graphics g)
  {
    update(g);
  }

  public void newscratch(Image img)
  {
    backBuffer = img;
  }

  public void update(Graphics g)
  {
    int i,w,h;
    Graphics backGC;

    w = size().width;
    h = size().height;

    gutter = w/10;
    width = (w-gutter)/3;
    height = (h-gutter)/3;
    gutter = gutter/4;

    backGC = backBuffer.getGraphics();
    backGC.setColor(Color.lightGray);
    backGC.fillRect(0,0,w,h);
    for (i=0; i<9; i++) {
      current_board[i].draw(backGC,width,height,gutter);
    }
    g.drawImage(backBuffer, 0, 0, this);
  }

  public int  getevent(int x, int y)
  { 
    int i;
    
    for (i=0; i<9; i++) {
      if (current_board[i].is_me(x,y,width,height,gutter)) return(i);
    }
    return(-1);
  }

  public void flip(int i)
  { 
    current_board[i].flip();
  }

  public void setgoal(int i)
  { 
    current_board[i].setgoal(true);
  }

  public void offgoal(int i)
  { 
    current_board[i].setgoal(false);
  }

  public void square_on(int i)
  { 
    current_board[i].square_on();
  }

  public void square_off(int i)
  { 
    current_board[i].square_off();
  }

}

class merlin_square
{
  private int number,width,height,gutter;
  private Color on_color=Color.red;
  private Color off_color=Color.blue;
  private Color my_color;
  private boolean goal;

  public merlin_square(int i, boolean g)
  {
    number = i;
    goal = g;
  }

  public boolean is_me(int x, int y,int width,int height,int gutter)
  {
    if ( ( (number%3)*(gutter+width) + gutter <= x ) && 
	 ( x <= (1+number%3)*(gutter+width) ) &&
	 ( (number/3)*(gutter+height) + gutter <= y ) && 
	 ( y <= (1+number/3)*(gutter+height) ) )
      return(true);
    else return(false);
  }

  public void draw (Graphics g,int width,int height,int gutter)
  {
//    g.setColor(my_color);
//    g.fillRect(gutter+(number%3)*(gutter+width),
//		 gutter+(number/3)*(gutter+height),width,height);
//    if (goal) {
//	g.setColor(Color.black);
//    } else {
//	g.setColor(Color.lightGray);
//    }      
//    g.drawRect(gutter+(number%3)*(gutter+width)-2,
//		 gutter+(number/3)*(gutter+height)-2,width+3,height+3);
//    g.drawRect(gutter+(number%3)*(gutter+width)-1,
//		 gutter+(number/3)*(gutter+height)-1,width+1,height+1);
    if (goal) {                   
      g.setColor(on_color);
    } else {                      
      g.setColor(off_color);
    }
    g.fillRect(gutter+(number%3)*(gutter+width),
		 gutter+(number/3)*(gutter+height),width,height);
    g.setColor(my_color);
    g.fillOval(gutter+(number%3)*(gutter+width),
	       gutter+(number/3)*(gutter+height),width,height);
  }

  public void flip ()
  {
    if (my_color == on_color) { my_color = off_color; }
    else { my_color = on_color; }
  }

  public void setgoal (boolean b)
  {
    goal = b;
  }

  public void square_on ()
  {
    my_color= on_color;
  }

  public void square_off () 
  {
     my_color= off_color;
  }

}

class SoundLoader extends Thread {
    Applet applet;
    SoundList soundList;
    URL baseURL;
    String relativeURL;

  public SoundLoader(Applet applet, SoundList soundList,
		     URL baseURL, String relativeURL) {
    this.applet = applet;
    this.soundList = soundList;
    this.baseURL = baseURL;
    this.relativeURL = relativeURL;
    setPriority(MIN_PRIORITY);
    start();
  }

  public void run() {
    AudioClip audioClip = applet.getAudioClip(baseURL, relativeURL);

    //AudioClips load too fast for me!
    //Simulate slow loading by adding a delay of up to 10 seconds.
    //	  try {
    //	      sleep((int)(Math.random()*10000));
    //	  } catch (InterruptedException e) {}

    soundList.putClip(audioClip, relativeURL);
  }
}

class SoundList extends java.util.Hashtable {
    Applet applet;
    URL baseURL;

    public SoundList(Applet applet, URL baseURL) {
        super(5); //Initialize Hashtable with capacity of 5 entries.
        this.applet = applet;
        this.baseURL = baseURL;
    }

    public void startLoading(String relativeURL) {
        new SoundLoader(applet, this,
                        baseURL, relativeURL);
    }

    public AudioClip getClip(String relativeURL) {
        return (AudioClip)get(relativeURL);
    }

    public void putClip(AudioClip clip, String relativeURL) {
        put(relativeURL, clip);
    }
}