/**
 * Periodic BBS Demo (SVG version)
 * by Kazuki Maeda
 * Last-Modified: May 26, 2013
 */

var WIDTH=900, HEIGHT=50;

var boxWidth;
var boxNumber;
var state;
var box, ball;
var thread;
var rootSVG;
var defs;
var animationThread;

window.onload = function(){
    init();
}

function init(){
    document.getElementById("startstop").addEventListener("click", startstop, true);
    document.getElementById("prev").addEventListener("click", prev, true);
    document.getElementById("next").addEventListener("click", next, true);
    document.getElementById("random").addEventListener("click", random, true);
    document.getElementById("clear").addEventListener("click", reset, true);
    document.getElementById("number").addEventListener("keypress", setSize, true);
    document.getElementById("set").addEventListener("click", init2, true);

    init2();
}

function init2(){
    document.getElementById("canvas").removeChild(document.getElementById("canvas").firstChild);
    rootSVG = document.createElementNS("http://www.w3.org/2000/svg", "svg");
    rootSVG.setAttribute("width", WIDTH);
    rootSVG.setAttribute("height", HEIGHT);
    document.getElementById("canvas").appendChild(rootSVG);

    boxNumber = document.getElementById("number").value;
    if(boxNumber < 3){
	boxNumber = 3;
	document.getElementById("number").value = 3;
    }
    if(boxNumber > 300){
	boxNumber = 300;
	document.getElementById("number").value = 100;
    }
    boxWidth = Math.floor(WIDTH/boxNumber);
    if(boxWidth > HEIGHT)
	boxWidth = HEIGHT;

    state = new Array(boxNumber);
    for(var i = 0; i < boxNumber; ++i)
	state[i] = 0;

    if(document.getElementById("startstop").value == "Stop") {
	clearInterval(thread);
	document.getElementById("startstop").value = "Start";
	document.getElementById("next").disabled = false;
	document.getElementById("prev").disabled = false;
	document.getElementById("random").disabled = false;
	document.getElementById("clear").disabled = false;
	document.getElementById("set").disabled = false;
	document.getElementById("number").disabled = false;
	document.getElementById("fps").disabled = false;
	document.getElementById("effect").disabled = false;
    }

    // create box images
    box = new Array(boxNumber);
    for(var i = 0; i < boxNumber; ++i){
	box[i] = document.createElementNS("http://www.w3.org/2000/svg", "rect");
	box[i].setAttribute("id", "box"+i);
	box[i].setAttribute("x", ""+(i*boxWidth));
	box[i].setAttribute("y", ""+((HEIGHT-boxWidth)/2));
	box[i].setAttribute("width", ""+boxWidth);
	box[i].setAttribute("height", ""+boxWidth);
	box[i].setAttribute("stroke", "#000000");
	box[i].setAttribute("stroke-width", "1.0");
	if(Math.floor(i/5)%2)
	    box[i].setAttribute("fill", "#DDDDFF");
	else
	    box[i].setAttribute("fill", "#FFFFFF");


	box[i].addEventListener("click", setBallClicked, true);
	rootSVG.appendChild(box[i]);
    }

    // create ball images
    defs = document.createElementNS("http://www.w3.org/2000/svg", "defs");
    rootSVG.appendChild(defs);

    var grad = document.createElementNS("http://www.w3.org/2000/svg", "radialGradient");
    grad.setAttribute("id", "grad");
    grad.setAttribute("cx", "50%");
    grad.setAttribute("cy", "50%");
    grad.setAttribute("r", "50%");
    grad.setAttribute("fx", "30%");
    grad.setAttribute("fy", "30%");
    var stop0 = document.createElementNS("http://www.w3.org/2000/svg", "stop");
    stop0.setAttribute("offset", "0%");
    stop0.setAttribute("stop-color", "#FFFFFF");
    grad.appendChild(stop0);
    var stop1 = document.createElementNS("http://www.w3.org/2000/svg", "stop");
    stop1.setAttribute("offset", "100%");
    stop1.setAttribute("stop-color", "#000000");
    grad.appendChild(stop1);
    defs.appendChild(grad);

    ball = new Array(boxNumber);
    for(var i = 0; i < boxNumber; ++i){
	ball[i] = document.createElementNS("http://www.w3.org/2000/svg", "circle");
	ball[i].setAttribute("id", "bal"+i);
	ball[i].setAttribute("cx", ""+((i+0.5)*boxWidth));
	ball[i].setAttribute("cy", ""+(HEIGHT/2));
	ball[i].setAttribute("r", ""+0);
	ball[i].setAttribute("fill", "url(#grad)");
	ball[i].addEventListener("click", setBallClicked, true);
	rootSVG.appendChild(ball[i]);
    }

    animationThread = new Array(boxNumber);

}


function startstop() {
    if(document.getElementById("startstop").value == "Start") {
	var timeInterval = parseInt(document.getElementById("fps").value);
	if(timeInterval < 1)
	    timeInterval = 1000;
	else if(timeInterval > 60)
	    timeInterval = 1000/60;
	else
	    timeInterval = 1000/timeInterval;
	thread = setInterval("next();", timeInterval);
	document.getElementById("startstop").value = "Stop";
	document.getElementById("random").disabled = true;
	document.getElementById("clear").disabled = true;
	document.getElementById("next").disabled = true;
	document.getElementById("prev").disabled = true;
	document.getElementById("set").disabled = true;
	document.getElementById("number").disabled = true;
	document.getElementById("fps").disabled = true;
	document.getElementById("effect").disabled = true;
    } else {
	clearInterval(thread);
	document.getElementById("startstop").value = "Start";
	document.getElementById("random").disabled = false;
	document.getElementById("clear").disabled = false;
	document.getElementById("next").disabled = false;
	document.getElementById("prev").disabled = false;
	document.getElementById("set").disabled = false;
	document.getElementById("number").disabled = false;
	document.getElementById("fps").disabled = false;
	document.getElementById("effect").disabled = false;
    }
}


function random(){
    reset();
    var sum = 0;
    for(var i = 0; i < boxNumber; ++i)
	if(sum < boxNumber/2 && Math.random()>0.8){
	    setBall(i, true);
	    ++sum;
	}
}

function reset(){
    for(var i = 0; i < boxNumber; ++i)
	if(state[i])
	    setBall(i, true);
}

function resetNoAnimate(){
    for(var i = 0; i < boxNumber; ++i)
	if(state[i])
	    setBall(i, false);
}

function next(){
    var newState = new Array(boxNumber);
    var car = 0;
    for(var i = 0; i < boxNumber; ++i){
	if(state[i]){
	    newState[i] = 0;
	    ++car;
	} else if(car > 0){
	    newState[i] = 1;
	    --car;
	} else {
	    newState[i] = 0;
	}
    }

    // periodicity
    for(var i = 0; i < boxNumber; ++i)
	if(!state[i] && !newState[i] && car){
	    newState[i] = 1;
	    --car;
	}

    resetNoAnimate();
    for(var i = 0; i < boxNumber; ++i)
	if(newState[i])
	    setBall(i, false);
}

function prev(){
    var newState = new Array(boxNumber);
    var car = 0;
    for(var i = boxNumber-1; i >= 0; --i){
	if(state[i]){
	    newState[i] = 0;
	    ++car;
	} else if(car > 0){
	    newState[i] = 1;
	    --car;
	} else {
	    newState[i] = 0;
	}
    }

    // periodicity
    for(var i = boxNumber-1; i >= 0; --i)
	if(!state[i] && !newState[i] && car){
	    newState[i] = 1;
	    --car;
	}

    resetNoAnimate();
    for(var i = 0; i < boxNumber; ++i)
	if(newState[i])
	    setBall(i, false);
}

function setBallClicked(e){
    if(document.getElementById("startstop").value == "Start"){
	var str = e.target.id;
	var n = parseInt(str.substr(3, str.length-3));

	setBall(n, true);
    }
}

function animateSet(n) {
    var r = parseFloat(ball[n].getAttribute("r"))+(boxWidth/20);
    if(r > boxWidth/2*0.8) {
	r = boxWidth/2*0.8;
	clearInterval(animationThread[n]);
    }
    ball[n].setAttribute("r", ""+r);
}

function animateRemove(n) {
    var r = parseFloat(ball[n].getAttribute("r"))-(boxWidth/20);
    if(r < 0) {
	r = 0;
	clearInterval(animationThread[n]);
    }
    ball[n].setAttribute("r", ""+r);
}

function setBall(n, animate){
    if(state[n]){
	if(document.getElementById("effect").checked && animate){
	    clearInterval(animationThread[n]);
	    animationThread[n] = setInterval("animateRemove("+n+");", 1000/60);
	} else {
	    ball[n].setAttribute("r", "0");
	}
	state[n]=0;
    } else {
	var sum = 0;
	for(var i = 0; i < boxNumber; ++i)
	    if(state[i])
		++sum;

	if(sum<Math.floor(boxNumber/2)){
	    if(document.getElementById("effect").checked && animate) {
		clearInterval(animationThread[n]);
		animationThread[n] = setInterval("animateSet("+n+");", 1000/60);
	    } else {
		ball[n].setAttribute("r", ""+boxWidth/2*0.8);
	    }
	    state[n]=1;
	}
    }
}

function setSize(e){
    if(e.keyCode == 13)
	init2();
}