import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;

public class GreedSnake implements KeyListener{
  JFrame mainFrame;
  Canvas paintCanvas;
  JLabel labelScore;
  SnakeModel snakeModel = null;

  public static final int canvasWidth = 200;
  public static final int canvasHeight = 300;

  public static final int nodeWidth = 10;
  public static final int nodeHeight = 10;

  public GreedSnake() {
    mainFrame = new JFrame("GreedSnake");

    Container cp = mainFrame.getContentPane();
  
    labelScore = new JLabel("Score:");
    cp.add(labelScore, BorderLayout.NORTH);

    paintCanvas = new Canvas();
    paintCanvas.setSize(canvasWidth+1,canvasHeight+1);
    paintCanvas.addKeyListener(this);
    cp.add(paintCanvas, BorderLayout.CENTER);

    JPanel panelButtom = new JPanel();
    panelButtom.setLayout(new BorderLayout());
    JLabel labelHelp;
    labelHelp = new JLabel("PageUp, PageDown for speed;", JLabel.CENTER);
    panelButtom.add(labelHelp, BorderLayout.NORTH);
    labelHelp = new JLabel("ENTER or R or S for start;", JLabel.CENTER);
    panelButtom.add(labelHelp, BorderLayout.CENTER);
    labelHelp = new JLabel("SPACE or P for pause",JLabel.CENTER);
    panelButtom.add(labelHelp, BorderLayout.SOUTH);
    cp.add(panelButtom,BorderLayout.SOUTH);

    mainFrame.addKeyListener(this);
    mainFrame.pack();
    mainFrame.setResizable(false);
    mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    mainFrame.setVisible(true);
    begin();
  }

  public void keyPressed(KeyEvent e){
    int keyCode = e.getKeyCode();
    if (snakeModel.running)
      switch(keyCode){
        case KeyEvent.VK_UP:
          snakeModel.changeDirection(SnakeModel.UP);
          break;
        case KeyEvent.VK_DOWN:
          snakeModel.changeDirection(SnakeModel.DOWN);
          break;
        case KeyEvent.VK_LEFT:
          snakeModel.changeDirection(SnakeModel.LEFT);
          break;
        case KeyEvent.VK_RIGHT:
          snakeModel.changeDirection(SnakeModel.RIGHT);
          break;
        case KeyEvent.VK_ADD:
        case KeyEvent.VK_PAGE_UP:
          snakeModel.speedUp();
          break;
        case KeyEvent.VK_SUBTRACT:
        case KeyEvent.VK_PAGE_DOWN:
          snakeModel.speedDown();
          break;
        case KeyEvent.VK_SPACE:
        case KeyEvent.VK_P:
          snakeModel.changePauseState();
          break;
        default:
      }

    if (keyCode == KeyEvent.VK_R ||
        keyCode == KeyEvent.VK_S ||
        keyCode == KeyEvent.VK_ENTER){
      snakeModel.running = false;
      begin();
    }
  }

  public void keyReleased(KeyEvent e){
  }

  public void keyTyped(KeyEvent e){
  }


  void repaint(){
    Graphics g = paintCanvas.getGraphics();

    //draw background
    g.setColor(Color.WHITE);
    g.fillRect(0,0,canvasWidth,canvasHeight);

    // draw the snake
    g.setColor(Color.BLACK);
    LinkedList na = snakeModel.nodeArray;
    Iterator it = na.iterator();
    while(it.hasNext()){
      Node n = (Node)it.next();
      drawNode(g,n);
    }

    // draw the food
    g.setColor(Color.RED);
    Node n = snakeModel.food;
    drawNode(g,n);
    
    updateScore();
  }

  private void drawNode(Graphics g, Node n){
    g.fillRect(n.x*nodeWidth,
               n.y*nodeHeight,
               nodeWidth-1,
               nodeHeight-1);
  }
  
  public void updateScore(){
    String s = "Score: " + snakeModel.score;
    labelScore.setText(s);
  }

  void begin(){
    if (snakeModel == null || !snakeModel.running){
      snakeModel = new SnakeModel(this,
                                  canvasWidth/nodeWidth,
                                  canvasHeight/nodeHeight);
      (new Thread(snakeModel)).start();
    }
  }

  public static void main(String[] args){
    GreedSnake gs = new GreedSnake();
  }
}