var setname=questionset.name;
var setdescription=questionset.description;
var questions=questionset.questions;

var currentidx=0;
var numcorrect=0;

function clearElement(el){
	while(el.lastChild)el.removeChild(el.lastChild);
}

function shuffle(a){
	var j,v,i;
	for(var i=a.length-1;i>0;i--){
		j=Math.floor(Math.random()*(i+1));
		v=a[i]; a[i]=a[j]; a[j]=v;
	}
}

function startQuiz(){
	currentidx=0;
	numcorrect=0;
	showCurrent();
}

function showCurrent(){
	document.getElementById("qcontainer").classList.remove("invisible");
	document.getElementById("rescontainer").classList.add("invisible");
	document.getElementById("answercontainer").classList.add("invisible");
	document.getElementById("showAnswerButton").classList.remove("invisible");

	var qdiv=document.getElementById("question");
	clearElement(qdiv);
	qdiv.appendChild(document.createTextNode(questions[currentidx].q));
}

function showAnswer(){
	document.getElementById("answercontainer").classList.remove("invisible");
	document.getElementById("showAnswerButton").classList.add("invisible");

	var adiv=document.getElementById("answer");
	clearElement(adiv);
	adiv.appendChild(document.createTextNode(questions[currentidx].a));
}

function finishQuiz(){
	document.getElementById("qcontainer").classList.add("invisible");
	document.getElementById("rescontainer").classList.remove("invisible");
	document.getElementById("numcorrect").innerHTML=numcorrect;
	document.getElementById("numtotal").innerHTML=questions.length;
	if(numcorrect==questions.length){
		document.getElementById("allcorrectp").classList.remove("invisible");
	} else {
		document.getElementById("allcorrectp").classList.add("invisible");
	}
}

function advance(corr){
	if(corr)numcorrect++;
	currentidx++;
	if(currentidx<questions.length){
		showCurrent();
	} else {
		finishQuiz();
	}
}

window.addEventListener("load",function(){
	document.getElementById("qsetname").appendChild(document.createTextNode(setname));
	document.getElementById("qsetdescr").appendChild(document.createTextNode(setdescription));
	if(questions.length==0){
		alert("Deze lijst heeft geen vragen, dus er kan weinig overhoord worden, eerlijk gezegd...");
		return;
	}
	startQuiz();
});