<?
session_start();

$question = trim($_GET['q']);
$answer = trim($_GET['a']);
if($question == 'start') {
	initialize();
	getNextQuestion();
} else if($question !== '' and $answer !== '') {
	scoreAnswer($question, $answer);
	if(!getNextQuestion()) {
		finish();
	}
} else {
	echo "I have no idea what you're talking about";
}

function initialize() {
	session_destroy();
	session_start();
	$_SESSION['score'] = 0;
	$_SESSION['questions'] = array(
		array('t' => 'What colour is the sky?',
			'c' => array('Red', 'Green', 'Blue', 'Black'),
			'a' => '3'),
		array('t' => 'Why am I here?',
			'c' => array('Because', 'Why not?', 'Good question'),
			'a' => '1'));
	shuffle($_SESSION['questions']);
	$_SESSION['next'] = 0;
}

function getNextQuestion() {
	$next = $_SESSION['next'];
	if($next >= count($_SESSION['questions'])) {
		return false;
	}
	$q = $_SESSION['questions'][$next];
	echo json_encode(array('score' => $_SESSION['score'], 'number' => $next, 'question' => $q));	
	$_SESSION['next'] = $next + 1;
	return true;
}

function scoreAnswer($q, $a) {
	if($_SESSION['questions'][$q]['a'] == $a) {
		$_SESSION['score']++;
	}
}

function finish() {
	echo json_encode(array('score' => $_SESSION['score']));
	session_destroy();
}
?>