class snake{
  //Diámetro de la cabeza
  int myHeadSize;
  //Diámetro de la cola
  int myTailSize;
  //Largo inicial de la cola
  int myTailLength;
  //variables para dirección del bicho
  int myXDirection = 1;
  int myYDirection = 0;
  int mySpeed;
  int bordes;
  //int myXOriginalPosition = 100;
  //int myYOriginalPosition = height/2;
  PVector myInitialPosition = new PVector(100,height/2);
  ArrayList myPositions = new ArrayList();
  //ArrayList myYPositions = new ArrayList();
  boolean dead = false;


  snake(int _hs, int _ts, int _tl, int _s, int _ipX, int _ipY){
    myHeadSize = _hs;
    myTailSize = _ts;
    myTailLength = _tl;
    mySpeed = _s;
    myInitialPosition.x = _ipX;
    myInitialPosition.y = _ipY;
    bordes = _ipX;

    myPositions.add(myInitialPosition);

    for(int i=1; i<tailLength; i++){
      myPositions.add(new PVector(myInitialPosition.x,myInitialPosition.y));
    }

  } 


  void update(){
    if(!dead){
      savePositions();
      move();
      checkBorders();
      drawMe();
    } 
    else {
      background(255,0,0);
    }
  }

  void savePositions(){
    //println(myPositions.size());
    for(int i=myPositions.size()-1; i>0; i--){
      //print("--"+i+"___");
      PVector v2 = (PVector) myPositions.get(i);
      PVector v1 = (PVector) myPositions.get(i-1);
      v2.x=v1.x;
      v2.y=v1.y;
      myPositions.set(i,v2);
    }
    //println("");
  }

  void move(){
    PVector myPos = (PVector) myPositions.get(0);
    myPos.x += mySpeed*myXDirection;
    myPos.y += mySpeed*myYDirection;
    checkNewPosition(myPos);
    myPositions.set(0, myPos);
  }

  void drawMe(){
    PVector myPos = (PVector) myPositions.get(0);
    ellipse(myPos.x,myPos.y,myHeadSize,myHeadSize);
    for(int i=1; i<myPositions.size(); i++){
      // print("**  "+i+" ");
      PVector v = (PVector) myPositions.get(i);
      ellipse(v.x,v.y,myTailSize,myTailSize);
    }   
    //println("");
  }


  void checkBorders(){
    PVector v = (PVector) myPositions.get(0);
    if(v.x < bordes || v.x > width-bordes)die();
    if(v.y < bordes || v.y > height-bordes)die();
  }

  void checkNewPosition(PVector _v){

    //Comprobar si en la posición hay comida, con lo que habrá que CRECER
    boolean theresFoodInThisPosition = false;  
    int indexOfFood = -1;
    for(int i=0; i<foodArray.size(); i++){
      food f = (food) foodArray.get(i);
      PVector vv = f.getPosition();
      if(vv.x==_v.x && vv.y==_v.y){
        theresFoodInThisPosition=true;
        indexOfFood = i; 
      }
    }
    if(theresFoodInThisPosition)eatAndGrow(indexOfFood);

    //Comprobar si en la posición ya hay serpiente, con lo que habrá que morir!
    boolean positionIsOccupied = false;  
    for(int i=1; i<myPositions.size(); i++){
      PVector v = (PVector) myPositions.get(i);
      if(v.x==_v.x && v.y==_v.y)positionIsOccupied=true;
    }
    if(positionIsOccupied)die();
  }

  void eatAndGrow(int _f){
    foodArray.remove(_f);
    myPositions.add(new PVector(-100,-100));
  }

  void die(){
    background(255,127,127);
    dead = true;
  }

  void setDirection(int _d){

    switch(_d) {
    case 1: 
      if(myXDirection!=0 && myYDirection!=1){
        myXDirection = 0;
        myYDirection = -1;
      }
      break;
    case 2: 
      if(myXDirection!=0 && myYDirection!=-1){
        myXDirection = 0;
        myYDirection = 1;
      }
      break;  
    case 3: 
      if(myXDirection!=1 && myYDirection!=0){
        myXDirection = -1;
        myYDirection = 0;
      }
      break;
    case 4: 
      if(myXDirection!=-1 && myYDirection!=0){
        myXDirection = 1;
        myYDirection = 0;
      }
      break;
    default:    
      break;
    }
  }


}