package ballworld;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.Timer;
import command.*;


/**
 * The "Controller" in a Model-View-Controller architecture
 * Sets up the appropriate wiring between the model and the view.
 * Uses event handlers to respond to user input and notifies the model and the view to update accordingly.
 * Uses a Timer object to update the model and the view at a regular time slice.  This will give the effect of animation.  
 * @dependency ballModel.IStrategy uses
 * @dependency javax.swing.Timer uses
 */
public class BallControl
{
  private IRandomizer _rand ;
  private int _MaxRadius = 20;
  private int _MinRadius = 5;
  private int _MaxSpeed = 20;
  
  private Rectangle _MaxVel = new Rectangle(-_MaxSpeed,-_MaxSpeed, _MaxSpeed, _MaxSpeed);
  
  private BallGUI _frame;
  private Dispatcher _dispatcher = new Dispatcher();
  private SwitcherStrategy _switcher = new SwitcherStrategy();
  
  private ILambda _paintCmd = new ILambda() {
    public Object apply(Object g) {
      _dispatcher.notifyAll(g);
      return null;
    }
  };
  
  private ILambda _makeBallCmd =  new ILambda(){
    public Object apply(Object classname) {
      _dispatcher.addObserver(loadBall(loadStrategy((String)classname)));
      return null;
    }
  };

  
  private ILambda _makeSwitcherCmd =  new ILambda(){
    public Object apply(Object nu) {
      _dispatcher.addObserver(loadBall(_switcher));
      return null;
    }
  };

  private ILambda _switchCmd =  new ILambda(){
    public Object apply(Object classname) {
      _switcher.setStrategy(loadStrategy((String) classname));
      return null;
    }
  };

  private ILambda _clearBallsCmd =  new ILambda(){
    public Object apply(Object nu) {
      _dispatcher.deleteObservers();
      return null;
    }
  }; 
  
  private int TimeSlice = 50;
  private Timer _timer = new  Timer (TimeSlice, new ActionListener ()                                       {
    public void actionPerformed (ActionEvent e) {
      _frame.getContainer().repaint();
      //      _frame.repaint();
    }
  });
  
  /**
   * Constructor for the BallControl class
   * Instantiates the BallGUI frame with the required ILambdas for 
   * making a ball, clearing the balls from the screen and for 
   * painting the balls onto the Container
   * Starts the timer up.
   */
  public BallControl (IRandomizer rand)
  {
    _rand = rand;
    _frame = new BallGUI (_makeBallCmd, _clearBallsCmd, _paintCmd, _makeSwitcherCmd, _switchCmd);
    
    _frame.validate ();
    _frame.setVisible (true);
    _timer.start ();
  }
  
  
  private Ball loadBall(IUpdateStrategy strategy) {
    return new Ball(_rand.randomLoc(_frame.getContainer().getSize()), 
                    _rand.randomInt(_MinRadius, _MaxRadius), 
                    _rand.randomVel(_MaxVel), 
                    _rand.randomColor(), 
                    _frame.getContainer(),
                    strategy);
  }
  
  /**
   * Uses dynamic class loading to load and instantiate an ABall subclass, given
   * its class name.
   */
  private IUpdateStrategy loadStrategy(String className) {
    try {
      java.lang.reflect.Constructor c =  Class.forName(className).getConstructors()[0];
      Object []args = new Object[]{
      };
      return (IUpdateStrategy) c.newInstance(args);
    }
    catch(Exception ex) {
      System.err.println("Class "+className+" not found!  Using StraightStrategy instead.");
      return new StraightStrategy();
    }
  }
  
  
  /**
   * Entry point to the program. Instantiates a BallControl object and goes away.
   */
  public static void main(String[] args)
  {
    try
    {
      UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    }
    catch(Exception e)
    {
    }
    new BallControl(Randomizer.Singleton);
  }
}