foopy.js

var groupNode;
var choiceIndex = [];
var choices = [];
var stack = [];

function chooseNegativeResponse() {
    var responses = $('.negative');
    return responses[Math.floor(Math.random() * responses.length)];
}

function updateNegativeResponse() {
    var negative = chooseNegativeResponse();
    $($('.negative.visible')[0]).removeClass('visible');
    $(negative).addClass('visible');  
}

function updateCurrentChoice(lastIndex) {
    var lastChoice = $('.choices li', groupNode)[choices[choices.length - 1][lastIndex]];
    var choice = $('.choices li', groupNode)[choices[choices.length - 1][choiceIndex[choiceIndex.length - 1]]];
    updateNegativeResponse();
    lastChoice.style.display = 'none';
    choice.style.display = 'inline';
    $('#ok')[0].firstChild.href = choice.hasAttribute('next-group') ?
    '' : choice.getAttribute('target');
}

function nextChoice() {
    var lastIndex = choiceIndex[choiceIndex.length - 1];
    choiceIndex[choiceIndex.length - 1]++;
    if (choiceIndex[choiceIndex.length - 1] === $('.choices li', groupNode).length) {
        choiceIndex[choiceIndex.length - 1] = 0;
    }
    updateCurrentChoice(lastIndex);
}

function switchGroup(group) {
    groupNode = document.getElementById(group);
    if (!stack.length || stack[stack.length - 1] !== group) {
        stack.push(group);
        choiceIndex.push(0);

        //+ Jonas Raoni Soares Silva
        //@ http://jsfromhell.com/array/shuffle [rev. #1]
        function shuffle(v) {
            for (var j, x, i = v.length; i; j = parseInt(Math.random() * i), x = v[--i], v[i] = v[j], v[j] = x);
            return v;
        };

        var c = [];
        for (var i = 0; i < $('.choices li', groupNode).length; i++)
            c.push(i);
        choices.push(shuffle(c));
    }
    $('#back')[0].style.display = group == 'proglang' ? 'none' : 'block';
    $('.question', groupNode)[0].style.display = 'block';
    updateCurrentChoice(choiceIndex[choiceIndex.length - 1]);
}

function cleanUpCurrent() {
    if (!groupNode) {
        return;
    }
    $('.question', groupNode)[0].style.display = 'none';
    var lastChoice = $('.choices li', groupNode)[choices[choices.length - 1][choiceIndex[choiceIndex.length - 1]]];
    lastChoice.style.display = 'none';
}

function investigate(ev) {
    ev.preventDefault();
    var choice = $('.choices li', groupNode)[choices[choices.length - 1][choiceIndex[choiceIndex.length - 1]]];
    if (choice.hasAttribute('next-group')) {
        cleanUpCurrent();
        switchGroup(choice.getAttribute('next-group'));
    } else {
        window.open(choice.getAttribute('target'));
    }
}

function takeBack() {
    cleanUpCurrent();
    stack.splice(stack.length - 1, 1);
    choiceIndex.splice(choiceIndex.length - 1, 1);
    choices.splice(choices.length - 1, 1);
    switchGroup(stack[stack.length - 1]);
}

function langChange() {
    document.webL10n.setLanguage(this.value);
}

$(window).load(function() {
    $('#ok')[0].onclick = investigate;
    $('#next')[0].onclick = nextChoice;
    $('#back')[0].onclick = takeBack;
    $('#lang select')[0].onchange = langChange;

    // Detected browser language
    var browserLang = document.webL10n.getLanguage();
    // Default language (value of the selected <option> element)
    var defaultLang = $("#lang option:selected").val();

    if (defaultLang !== browserLang) {
        var option = $('#lang option[value=' + browserLang + ']');
        if (option.length) {
            // If the browser language is supported, select the good option
            option.attr('selected', 'selected');
        } else {
            // Else set the default language
            document.webL10n.setLanguage(defaultLang);
        }
    }

    var query = window.location.hash.substring(1);
    switchGroup('proglang');
    if (query.length == 0) {
      return;
    }

    var node = document.querySelector('li[next-group="' + query + '"]');
    if (!node)
      return;
    node = node.parentNode.parentNode;
    while (node.has) {
      
    }
                 
                 
    cleanUpCurrent();
    switchGroup(query.substring(1));
});