;

var cells = [];

var cellX=0, cellY=0;



var score = 0;

var snake = [];

var initlen;

var snakelen = initlen;

var nextdir = 'u';

var snakedir = 'u';

var snakemoved = false;

var snakeorient = 'vertical';

var snakepause = false;



function snakePart(x,y){

	this.x = x;

	this.y = y;

	this.o = snakeorient;

}



function initSnake(length){

	initlen = length;

	snake = "";

	snake = [];

	for(i=0; i<initlen; i++){

		snake[i] = new snakePart(20 , 15 + (length - i) );

		cells[snake[i].y][snake[i].x] = "snake";

	}

	

	snakelen = initlen;

}



function initCells(){

	for(y=0; y < 30; y++){

		cells[y] = [];

		for(x=0; x < 40; x++){

			cells[y][x] = false;

		}

	}

}



function cellOn(x, y, color){

	// if(!color)color = "transparent";

	if(!color)color = "ground";

	$('#cell_'+y+'_'+x).removeClass('ground snake apple vertical horizontal  nexus up-left up-right down-left down-right left-up right-up left-down right-down');

	$('#cell_'+y+'_'+x).toggleClass(color);

	

}



function cellOff(x, y){

	$('#cell_'+y+'_'+x).removeClass('snake apple ground vertical horizontal nexus up-left up-right down-left down-right  left-up right-up left-down right-down');

	$('#cell_'+y+'_'+x).toggleClass('ground');

}





function renderCells(){				

	for(y=0; y<30; y++){

		for(x=0; x<40; x++){

			if(cells[y][x]) cellOn(x,y,cells[y][x]); else cellOff(x,y);

		}

	}

}	



function genDot(){

	var x = 1+parseInt(Math.random()*38);

	var y = 1+parseInt(Math.random()*28);

	cells[y][x] = 'apple';

	

	for(i=0; i<snakelen; i++){

		if((snake[i].x == x) && (snake[i].y == y)) return genDot();

	}

}



function addScore(x){

	score += x;	

}

function setScore(x){

	score = x;

	

	var i=0;

	var digits = [];

	$('#digits span').each(function(){

		digits[i] = $(this);

		i++;

	});

	

	var scorestr = score.toString();

	while(scorestr.length < digits.length){

		scorestr = "0"+scorestr;

	}

	

	var scoreStarted = false;

	var digit;

	for(i=0; i<digits.length; i++){		

		digits[i].removeClass();

		if((!scoreStarted)&&(i<digits.length-1)){

			if(scorestr[i] == '0') continue;

			scoreStarted = true;

		} 

		digits[i].toggleClass('_'+scorestr[i]);		

	}

}



function snakeReset(){				

	initCells();

	

	initSnake(4);



	nextdir = 'u';

	snakedir = 'u';

	snakeorient = 'vertical';

	

	setScore(0);

	

	$('body').find('.cell').each(function(i){

		$(this).removeClass("snake apple ground vertical horizontal nexus up-left up-right down-left down-right  left-up right-up left-down right-down");

		$(this).toggleClass('ground');

	});

	

	/*level*/

	genDot();				

}



function snakeMoveTo(x, y){				



	/*check self collission*/

	for(i=0; i < snakelen; i++){

		for(t=0; t < snakelen; t++){

			/*skip self check!*/

			if(i==t)continue

			if((snake[t].x == snake[i].x)&&(snake[t].y == snake[i].y)){

				snakeReset();

				return;

			}

		}

	}

	

	/*lose 'energy'*/

	if(score > 0)setScore(score-1);

	

	/* handle border wrap*/

	if(y < 0) y = 29;

	if(y >= 30) y = 0;

	if(x < 0) x = 39;

	if(x >= 40) x = 0;

	

	/*erase from cell memory*/

	for(i=0; i<snakelen; i++){

		cells[snake[i].y][snake[i].x] = false;

	}

	

	/*move body*/

	for(i=0; i < snakelen-1; i++){

		snake[i].x = snake[i+1].x;

		snake[i].y = snake[i+1].y;

		snake[i].o = snake[i+1].o;

	}

	

	/*move head */

	snake[snakelen-1].x = x;

	snake[snakelen-1].y = y;

	if((snakeorient!='vertical')&&(snakeorient!='horizontal')){

		snake[snakelen-2].o = snakeorient;

		snakeorient = ((snakedir == 'u') || (snakedir == 'd')) ? 'vertical':'horizontal';

	}

	snake[snakelen-1].o = snakeorient;

	

	/*grow*/

	if(cells[y][x]){

		addScore(100);

		

		var newx = snake[snakelen-2].x - snake[snakelen-1].x;

		var newy = snake[snakelen-2].y - snake[snakelen-1].y;

		var tx = snake[snakelen-1].x - newx;

		var ty = snake[snakelen-1].y - newy;

		snake[snakelen] = new snakePart(tx,ty); 

		snakelen++;

		

		/*gen new dot*/

		genDot();

	}				

	

	

	/*draw on cell memory*/

	for(i=0; i<snakelen; i++){

		cells[snake[i].y][snake[i].x] = "snake "+snake[i].o;

	}

	snakemoved = false;

}



function snakeNotifyScore(name, score){

	$.post('index.php', {name: name, score:score, key:'0xdeadbabe'}, function(data){

		console.log(data);

	});

}



function snakeWalk(){				

	if(snakepause)return;



	switch(snakedir){

		case 'u':	snakeMoveTo(snake[snakelen-1].x, 	snake[snakelen-1].y-1);	break;						

		case 'l':	snakeMoveTo(snake[snakelen-1].x-1,	snake[snakelen-1].y);	break;						

		case 'd':	snakeMoveTo(snake[snakelen-1].x, 	snake[snakelen-1].y+1); break;						

		case 'r':	snakeMoveTo(snake[snakelen-1].x+1, 	snake[snakelen-1].y); 	break;

	}

	

	renderCells();

}



$(function() {

	snakeReset();				

	

	$('body').keydown(function (key) {

		if(snakemoved)return;

			snakemoved = true;

		switch(key.which){

			case 38: nextdir = 'u'; break;

			case 40: nextdir = 'd'; break;

			case 37: nextdir = 'l'; break;

			case 39: nextdir = 'r'; break;					

			case 13: snakemoved = false; snakepause ^= 1;break;

		}	



		lastorient = ((snakedir == 'u') || (snakedir == 'd')) ? 'vertical':'horizontal';

		lastdir = snakedir;

		

		switch(snakedir){

			case 'u':case 'd': snakedir = (nextdir == 'l'?'l':nextdir == 'r'?'r':snakedir);break;

			case 'l':case 'r': snakedir = (nextdir == 'u'?'u':nextdir == 'd'?'d':snakedir);break;

		}

		

		snakeorient = ((snakedir == 'u') || (snakedir == 'd')) ? 'vertical':'horizontal';

		if(snakeorient != lastorient){

			snakeorient = 'nexus ';

				  if((lastdir == 'u') && (snakedir == 'l'))snakeorient = 'nexus up-left' 

			else if((lastdir == 'u') && (snakedir == 'r'))snakeorient = 'nexus up-right' ;

			else if((lastdir == 'd') && (snakedir == 'l'))snakeorient = 'nexus down-left' ;

			else if((lastdir == 'd') && (snakedir == 'r'))snakeorient = 'nexus down-right' ;

			else if((lastdir == 'l') && (snakedir == 'd'))snakeorient = 'nexus left-down' ;

			else if((lastdir == 'l') && (snakedir == 'u'))snakeorient = 'nexus left-up' ;

			else if((lastdir == 'r') && (snakedir == 'd'))snakeorient = 'nexus right-down' ;

			else if((lastdir == 'r') && (snakedir == 'u'))snakeorient = 'nexus right-up' ;

		}

		

	});		

	

	setInterval(snakeWalk, 60);								

});