import java.util.ArrayList;
import org.lwjgl.opengl.GL11;

public class Organism 
{
	 ArrayList segs;
	 ArrayList legs;
	 float speed ,d;
		  
	 Organism()
	 {}
	  
	  void initialize(Vector3D initialpos, float d_, float speed_)
	  {
		Segment hold;
		Legs holdL;
		Vector3D color, pos;
			color= new Vector3D();
			pos = new Vector3D();
		
	    d=d_;
	    speed=speed_;
		segs = new ArrayList();
		legs = new ArrayList();
		
		for(float i=0; i< 5 ; i=i+1)
	    {
			color.setXYZ(random(.5f),.1f+random(.8f),.1f+random(.8f));
			//pos.setXYZ(initialpos.x()+2*i,initialpos.y(),initialpos.z());
			pos.setXYZ(initialpos.x()+d*i,initialpos.y(),initialpos.z());
			hold = new Segment(pos, d, color);
			segs.add(hold);
			holdL = new Legs(pos);
			legs.add(holdL);
	    }
	  }//END initialize
	 
	  
	  void render()
	  {
		  Segment hold;
		  Legs holdL;
		  
		  for(int i=0; i< segs.size(); i=i+1)
	      {
	        //render segments	        
	    	hold=(Segment) segs.get(i);
	    	hold.render();
	    	//render legs
	    	holdL=(Legs) legs.get(i);
	    	holdL.render();
	      }
	  }//END render
	  
	  
	  void seek(Vector3D target)
	  {
	     int i;
  		 float distm;
	     Vector3D diff;
	     Segment hold1, hold2;
	     Legs holdL;
	     
	     if(segs.size()>0)
	     {
		     i=0;
		     //how deal with updating headpos?
		       hold1=(Segment) segs.get(i);
		       holdL=(Legs) legs.get(i);
		       
		       //MOVE HEAD
			       diff=hold1.XYZ().sub(target);
			       distm=diff.magnitude();
			       diff.normalize();
			       if (distm>d/2)
			       {
			    	   hold1.setXYZ(hold1.XYZ().sub(diff.mult(speed)));
			    	   holdL.setpos(hold1.XYZ().sub(diff.mult(speed)));
			    	   holdL.setdir(hold1.XYZ(), target);
			       }    
		       
		       //BODY FOLLOWS
			       for(i=1; i<segs.size(); i++)
			       {
			    	   hold1=(Segment) segs.get(i-1);
			    	   hold2=(Segment) segs.get(i);
			    	   holdL=(Legs) legs.get(i);
			    	   
			    	   diff=hold2.XYZ().sub(hold1.XYZ());
				       distm=diff.magnitude();
				       if (distm>2*d)
				       {
				    	   hold2.setXYZ(hold2.XYZ().sub(diff.mult((distm-2*d)/distm)));
				    	   holdL.setpos(hold2.XYZ().sub(diff.mult((distm-2*d)/distm)));
				    	   holdL.setdir(hold1.XYZ(), hold2.XYZ());
				       }//else move to within 	    	   
			       }
	     }
	  }//END seek
	  
	  //ALSO HAVE ONE THAT LITERALLY ADDS A SEGMENT CLASS
	  //addsegment: note added at origin but seek will bring it inline
	  void addseg(Vector3D color_)
	  {
		  Segment hold;
		  Legs holdL;
		  Vector3D origin=new Vector3D();
		  
		  hold = new Segment(origin, d, color_);
		  segs.add(hold);
	      holdL = new Legs(origin);
	      legs.add(holdL);		  
	  }
	  
	  //deletesegment: deletes last segment
	  void deleteseg()
	  {
		  segs.remove(segs.size()-1);
		  legs.remove(legs.size()-1);
	  }
	  //setsegcolor
	  
	  //returns the distance of the "head" segs[0] from a target vector
	  float distancefrom(Vector3D target)
	  {
		  Segment hold;
		  
		  if(segs.size()>0)
		  {
			 hold=(Segment) segs.get(0);
			 target.sub(hold.XYZ());
			 return target.magnitude();
		  }
		  else//to cover the case where nothing exsists
		  { return -1;}
	  }
	  
	  
	  //returns -magnitude to +magnitude
	  float random(float magnitude) 
	  {
	    	return ((float)Math.random()-.5f)*2*magnitude;
	  }
	  	  
}//END Organism