import java.awt.AWTEvent;
import java.awt.Dimension;
import java.awt.event.MouseEvent;
import java.util.Enumeration;
import javax.media.j3d.*;
import javax.vecmath.*;

public class FreeViewBehavior extends Behavior
{
	private TransformGroup target;

	private WakeupCondition mouseCriterion;
	private long lastTime,stopCounter;

	private Point3d position;
	private double tx,ty;
	private double speed;

	private double mouseX,mouseY;
	private boolean mouseButton;
	private boolean inversion;

	public FreeViewBehavior(TransformGroup target)
	{
		this.target=target;
		
		position=new Point3d(0.0,5.0,5.0*Math.sqrt(3.0));
		tx=-Math.PI/6.0;
		ty=0.0;
	}

	public void initialize()
	{
		WakeupCriterion[] events;
	
		events=new WakeupCriterion[7];
		events[0]=new WakeupOnElapsedFrames(0);
		events[1]=new WakeupOnAWTEvent(MouseEvent.MOUSE_PRESSED);
		events[2]=new WakeupOnAWTEvent(MouseEvent.MOUSE_RELEASED);
		events[3]=new WakeupOnAWTEvent(MouseEvent.MOUSE_MOVED);
		events[4]=new WakeupOnAWTEvent(MouseEvent.MOUSE_DRAGGED);
		events[5]=new WakeupOnAWTEvent(MouseEvent.MOUSE_ENTERED);
		events[6]=new WakeupOnAWTEvent(MouseEvent.MOUSE_EXITED);
		mouseCriterion=new WakeupOr(events);
		
		mouseX=0;
		mouseY=0;
		mouseButton=false;
		inversion  =false;
		
		lastTime=0;
		stopCounter=-1;
		
		wakeupOn(mouseCriterion);
	}

	public void processStimulus(Enumeration criteria)
	{
		WakeupCriterion criterion;
		AWTEvent[] events;
	
		while (criteria.hasMoreElements())
		{
			criterion=(WakeupCriterion)(criteria.nextElement());
			
			if (criterion instanceof WakeupOnElapsedFrames)
			{
				process((WakeupOnElapsedFrames)(criterion));
			}
			else if (criterion instanceof WakeupOnAWTEvent)
			{
				events=((WakeupOnAWTEvent)(criterion)).getAWTEvent();
				
				for (int i=0;i<events.length;i++)
				{
					if (events[i] instanceof MouseEvent)
					{
						processMouseEvent((MouseEvent)(events[i]));
					}
				}
			}
		}
		
		wakeupOn(mouseCriterion);
	}

	private void process(WakeupOnElapsedFrames event)
	{
		long delay;
	
		if (lastTime==0)
		{
			lastTime=System.currentTimeMillis();
		}
		
		delay=System.currentTimeMillis()-lastTime;
		lastTime=System.currentTimeMillis();
		
		if (stopCounter>=0)
		{
			stopCounter+=delay;
			if (stopCounter>1000)
			{
				mouseX=0;
				mouseY=0;
			}
		}
		
		move(delay);
		setTransform();
	}

	private void processMouseEvent(MouseEvent event)
	{
		Dimension size;
	
		if (event.getID()==MouseEvent.MOUSE_PRESSED)
		{
			mouseButton=true;
			inversion=((event.getModifiers() & MouseEvent.BUTTON3_MASK)!=0);
		}
		else if (event.getID()==MouseEvent.MOUSE_RELEASED)
		{
			mouseButton=false;
		}
		else if (event.getID()==MouseEvent.MOUSE_MOVED ||
		         event.getID()==MouseEvent.MOUSE_DRAGGED)
		{
			size=event.getComponent().getSize();
			mouseX=((event.getX()-size.width /2.0)/(size.width /2.0))%1.0;
			mouseY=((event.getY()-size.height/2.0)/(size.height/2.0))%1.0;
		}
		else if (event.getID()==MouseEvent.MOUSE_ENTERED)
		{
			stopCounter=-1;
		}
		else if (event.getID()==MouseEvent.MOUSE_EXITED)
		{
			stopCounter=0;
		}
	}

	private void move(long delay)
	{
		Transform3D transform;
		Vector3d velocity;
		double frame;
	
		frame=delay/1000.0;
		
		tx=tx+frame*(Math.acos(mouseY)-Math.PI/2.0)*2.0/3.0;
		tx=Math2.trimRadian(tx);
		ty=ty+frame*(Math.acos(mouseX)-Math.PI/2.0)*2.0/3.0;
		ty=Math2.trimRadian(ty);
		
		for (double i=0.0;i<frame;i+=1.0/24.0)
		{
			if (mouseButton)
			{
				speed+=1.0/8.0*(inversion ? -1.0 : 1.0);
			}
			speed-=Math2.signum(speed)*Math.max(0.01,Math.abs(speed/7.0));
		}
		
		setTransform();
		target.getTransform(transform=new Transform3D());
		transform.transform(velocity=new Vector3d(0.0,0.0,-speed));
		position.add(velocity);
	}

	private void setTransform()
	{
		Transform3D transform;
		Transform3D rotationX,rotationY;
		Vector3d translation;
	
		rotationY=new Transform3D();
		rotationY.rotY(ty);
		rotationX=new Transform3D();
		rotationX.rotX(tx);
		translation=new Vector3d();
		translation.set(position);
		transform=new Transform3D();
		transform.mul(rotationY,rotationX);
		transform.setTranslation(translation);
		
		target.setTransform(transform);
	}
}