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

import com.sun.j3d.utils.universe.*;

public class NavigationBehavior extends Behavior {


  protected static final double FAST_SPEED = 2.0;
  protected static final double NORMAL_SPEED = 1.0;
  protected static final double SLOW_SPEED = 0.5;

  private TransformGroup transformGroup;
  private Transform3D transform3D;
  private WakeupCondition keyCriterion;

  private final static double TWO_PI = (2.0 * Math.PI);
  private double rotateXAmount = Math.PI / 16.0;
  private double rotateYAmount = Math.PI / 16.0;
  private double rotateZAmount = Math.PI / 16.0;

  private double moveRate = 0.3;
  private double speed = NORMAL_SPEED;

  private int forwardKey = KeyEvent.VK_UP;
  private int backKey = KeyEvent.VK_DOWN;
  private int leftKey = KeyEvent.VK_LEFT;
  private int rightKey = KeyEvent.VK_RIGHT;

  public NavigationBehavior( TransformGroup tg )
  {
    transformGroup = tg;
    transform3D = new Transform3D();
  }

  public void initialize()
  {
    WakeupCriterion[] keyEvents = new WakeupCriterion[2];

    keyEvents[0] = new WakeupOnAWTEvent( KeyEvent.KEY_PRESSED );
    keyEvents[1] = new WakeupOnAWTEvent( KeyEvent.KEY_RELEASED );
   keyCriterion = new WakeupOr( keyEvents );
    wakeupOn( keyCriterion );
  }



  public void processStimulus( Enumeration criteria )
  {
    WakeupCriterion wakeup;
    AWTEvent[] event;

    while( criteria.hasMoreElements() )
    {
      wakeup = (WakeupCriterion) criteria.nextElement();
      if( !(wakeup instanceof WakeupOnAWTEvent) )
        continue;

      event = ((WakeupOnAWTEvent)wakeup).getAWTEvent();
      for( int i = 0; i < event.length; i++ )
      {
        if( event[i].getID() == KeyEvent.KEY_PRESSED )
        {
          processKeyEvent((KeyEvent)event[i]);
        }
      }
    }
    wakeupOn( keyCriterion );
  }

  protected void processKeyEvent(KeyEvent event)
  {
    int keycode = event.getKeyCode();

    if(event.isShiftDown()) speed = FAST_SPEED;
    else speed = NORMAL_SPEED;
    if( event.isAltDown() )
      altMove(keycode);
    else if( event.isControlDown())
      controlMove(keycode);
    else
      standardMove(keycode);
  }



  //moves forward backward or rotates left right
  private void standardMove(int keycode)
  {
    if(keycode == forwardKey)
      moveForward();
    else if(keycode == backKey)
      moveBackward();
    else if(keycode == leftKey)
      rotLeft();
    else if(keycode == rightKey)
      rotRight();
  }

  //moves left right, rotate up down
  protected void altMove(int keycode)
  {
    if(keycode == forwardKey)
      rotUp();
    else if(keycode == backKey)
      rotDown();
    else if(keycode == leftKey)
      moveLeft();
    else if(keycode == rightKey)
      moveRight();
  }

  //move up down, rot left right
  protected void controlMove(int keycode)
  {
    if(keycode == forwardKey)
      moveUp();
    else if(keycode == backKey)
      moveDown();
    else if(keycode == leftKey)
      rollLeft();
    else if(keycode == rightKey)
      rollRight();
  }

  private void moveForward()
  {
    doMove(new Vector3d(0.0,0.0, -getMovementRate()));
  }

  private void moveBackward()
  {
    doMove(new Vector3d(0.0,0.0, getMovementRate()));
  }

  private void moveLeft()
  {
    doMove(new Vector3d( -getMovementRate() ,0.0,0.0));
  }

  private void moveRight()
  {
    doMove(new Vector3d(getMovementRate(),0.0,0.0));
  }

  private void moveUp()
  {
    doMove(new Vector3d(0.0, getMovementRate() ,0.0));
  }

  private void moveDown()
  {
    doMove(new Vector3d(0.0, -getMovementRate() ,0.0));
  }

  protected void rotRight()
  {
    doRotateY(getRotateRightAmount());
  }

  protected void rotUp()
  {
    doRotateX(getRotateUpAmount());
  }

  protected void rotLeft()
  {
    doRotateY(getRotateLeftAmount());
  }

  protected void rotDown()
  {
    doRotateX(getRotateDownAmount());
  }

  protected void rollLeft()
  {
     doRotateZ(getRollLeftAmount());
  }

  protected void rollRight()
  {
     doRotateZ(getRollRightAmount());
  }

  protected void doRotateY(double radians)
  {
    transformGroup.getTransform(transform3D);
    Transform3D toMove = new Transform3D();
    toMove.rotY(radians);
    transform3D.mul(toMove);
    transformGroup.setTransform(transform3D);
  }
  protected void doRotateX(double radians)
  {
    transformGroup.getTransform(transform3D);
    Transform3D toMove = new Transform3D();
    toMove.rotX(radians);
    transform3D.mul(toMove);
    transformGroup.setTransform(transform3D);
  }

  protected void doRotateZ(double radians)
  {
    transformGroup.getTransform(transform3D);
    Transform3D toMove = new Transform3D();
    toMove.rotZ(radians);
    transform3D.mul(toMove);
    transformGroup.setTransform(transform3D);
  }
  protected void doMove(Vector3d theMove)
  {
    transformGroup.getTransform(transform3D);
    Transform3D toMove = new Transform3D();
    toMove.setTranslation(theMove);
    transform3D.mul(toMove);
    transformGroup.setTransform(transform3D);
  }
  protected double getMovementRate()
  {
    return moveRate * speed;
  }

  protected double getRollLeftAmount()
  {
    return rotateZAmount * speed;
  }
  protected double getRollRightAmount()
  {
    return -rotateZAmount * speed;
  }

  protected double getRotateUpAmount()
  {
    return rotateYAmount * speed;
  }

  protected double getRotateDownAmount()
  {
    return -rotateYAmount * speed;
  }

  protected double getRotateLeftAmount()
  {
    return rotateYAmount * speed;
  }

  protected double getRotateRightAmount()
  {
    return -rotateYAmount * speed;
  }

  public void setRotateXAmount(double radians)
  {
    rotateXAmount = radians;
  }

  public void setRotateYAmount(double radians)
  {
    rotateYAmount = radians;
  }

  public void setRotateZAmount(double radians)
  {
    rotateZAmount = radians;
  }

  public void setMovementRate(double meters)
  {
    moveRate = meters; // Travel rate in meters/frame
  }

  public void setForwardKey(int key)
  {
    forwardKey = key;
  }

  public void setBackKey(int key)
  {
    backKey = key;
  }

  public void setLeftKey(int key)
  {
    leftKey = key;
  }

  public void setRightKey(int key)
  {
    rightKey = key;
  }
}