import java.awt.*;
import java.util.Random;

public class Bird {
  private final int GROUNDTOLERANCE = 75;
  int framedelay;
  int delay_counter = 0;
  int curframe = 0;
  int maxframes;
  double x, y, dx, dy, ddx, ddy;
  int groundlevel;
  Graphics g;
  public boolean alive = true;
  Bird prev;
  Bird next;
  
  public Bird(int x, int y, int groundlevel, int maxframes) {
    Random r = new Random();
    this.x = x;
    this.y = y;
    this.dx = (r.nextDouble() * r.nextDouble() - .5) * 20;
    this.dy = (r.nextDouble() * r.nextDouble() + .5) * 10;
    if (r.nextInt() %2 == 1)
      this.dx *= -1;
    if (r.nextInt() %2 == 1)
      this.dy *= -1;
    //    this.dx = (r.nextDouble() * r.nextDouble() - 0.25) * 100; 
    //this.dy = (r.nextDouble() * r.nextDouble() - 0.25) * 100; 
    this.ddx = 0;
    this.ddy = 0;
    this.framedelay = 3;
    //    this.framedelay = (int)(90 - this.dx - this.dy);
    this.maxframes = maxframes;
    this.next = null;
    this.groundlevel = groundlevel;
    //    p("DX: "+dx+", DY:"+dy+".");
  }
  
  public Bird(int x, int y, double dx, double dy, 
	      int groundlevel, int maxframes) {
    this.x = x;
    this.y = y;
    this.dx = dx;
    this.dy = dy;
    this.ddx = 0;
    this.ddy = 0;
    this.framedelay = 3;
    //    this.framedelay = (int)(90 - this.dx - this.dy);
    this.maxframes = maxframes;
    this.next = null;
    this.groundlevel = groundlevel;
  }
  
  public Bird(int x, int y, double dx, double dy, 
	      double ddx, double ddy, int groundlevel, int maxframes) {
    this.x = x;
    this.y = y;
    this.dx = dx;
    this.dy = dy;
    this.ddx = ddx;
    this.ddy = ddy;
    this.framedelay = 3;
    //    this.framedelay = (int)(90 - this.dx - this.dy);
    this.maxframes = maxframes;
    this.next = null;
    this.groundlevel = groundlevel;
  }

  public int getX() {
    return (int)x;
  }

  public int getY() {
    return (int)y;
  }

  public void animate() {
    curframe = ++curframe % maxframes;
  }

  public void motion() {
    if (groundlevel != 0) {
      if (y < groundlevel)
	if ((int)dy <= 0)
	  push(0, (groundlevel - y) / 500);
	else if (y > (groundlevel - 50))
	  push(0, (y - groundlevel - 50) / 500);
	else {}
      else {
	  if (dy > 0) {
	    ddy = 0;
	    ddx = 0;
	    dy = 0;
	    dx = 0;
	  } else {
	  dy = dy * 1.25;
	  }  
      }
    }
    
    if (dy == 0)
      framedelay = 12;
    else if (Math.abs(dy) > 20)
      framedelay = 3;
    else if (Math.abs(dy) > 10)
      framedelay = 5;
      else if (Math.abs(dy) > 1)
	framedelay = 3;
    else
      framedelay = 12;
    //    if (dy != 0)
    //      p("dy: "+dy+"; fd: "+framedelay);
    accelerate();
    move();
  }
  
  public void push(double ddx, double ddy) {
    this.ddx += ddx;
    this.ddy += ddy;
  }

  public void accelerate() {
    dx += ddx;
    dy += ddy;
  }

  public void move() {
    x += dx;
    y += dy;
  }
  
  public void action() {
    motion();
    if ((delay_counter++ % framedelay) == 0) {
      animate();
    }
  }

  public void shoot(int x, int y, boolean silenced) {
    double d;
    if ((d = dist(getX(), getY(), x, y)) < 22) {
      Random r = new Random();
      alive = false;
      dy = 0;
      ddy = 2;
      curframe = 0;
    } else if (!silenced)
	scare(x, y);
  }

  public void scare(int x, int y) {
    double d;
    if ((d = dist(getX(), getY(), x, y)) < 100) {
      Random r = new Random();
      dy -= (r.nextDouble() * r.nextDouble() + .5) * (100 - d) / 2;
      dx = (r.nextDouble() * r.nextDouble() - .5) * (100 - d) / 2;
    }
  }


  public void insertAfter(Bird b) {
    if (next != null) {
      next.prev = b;
      b.next = next;
    }
    next = b;
    b.prev = this;
  }

  public void destroy() {
    if (next != null)
      next.prev = prev;    
    prev.next = next;
  }
  private void p(String s) {
    System.out.println(s);
  }
  
  private void p(Exception e) {
    System.out.println(e);
  }

  private double dist(int x, int y, int xx, int yy) {
    return Math.sqrt((x - xx) * (x - xx) + (y - yy) * (y - yy));
  }


}