// must load ot.js first

'use strict';

let nQuestions = 10;

for( let i=0; i<allQuestions.length; i++ ) {
	allQuestions[i].i = i;
}

console.log(`using ${nQuestions} out of ${allQuestions.length} questions`)


function remove(a,i) {
	return a.splice(i,1)[0];
}

function removeRandom(a) {
	let i = Math.floor( Math.random() * a.length );
	return remove(a,i);
}

let questions = [];
let allQuestions2 = JSON.parse(JSON.stringify(allQuestions));
for( let i=0; i<nQuestions; i++ ) {
	let p = removeRandom(allQuestions2);
	let a = [];
	while( p.a.length > 0 ) {
		a.push( removeRandom(p.a) );
	}
	p.a = a;
	questions.push(p);
}

let encoder = document.createElement('span');

function htmlEncode(s) {
	encoder.textContent = s;
	return encoder.innerHTML;
}

function checkTest() {
	let divs = document.querySelectorAll('div[q]');
	let nCorrect = 0;
	for( let div of divs ) {
		let answer = allQuestions[div.getAttribute('q')].a[0];
		let selected = div.querySelector('input[type=radio]:checked');
		if( selected.value === answer ) {
			selected.parentNode.insertAdjacentHTML( 'afterend', ' <span correct></span>' );
			nCorrect++;
		} else {
			selected.parentNode.insertAdjacentHTML( 'afterend', ' <span wrong></span>' );
			let correct = div.querySelector(`input[type=radio][value="${htmlEncode(answer)}"]`);
			correct.parentNode.insertAdjacentHTML( 'afterend', ' <span correct></span>' );
		}
	}
	document.querySelector('div[end]').innerHTML = `\
		<p>${nCorrect} of ${divs.length} correct</p>
		<p><a href="/test.html">Try again</a></p>
`	;
}