/* POLL OBJECT
 * Requires: HttpRequest.js
 * Arguments:
 * id    - the id of the container
 * path  - the path of the poll
 * [tmpl] - the template for display poll and results
 * [lang] - the language to use
 */

function Poll(id, path, tmpl, lang)
{
    p_ = this;
    tmpl = tmpl || 'default';
    lang = lang || 'en';
    var q, a, haveResults;
    var url = '/ncp_polls/xml/display.do';
    this.url = url;
    var msgs = new Object();
    if (lang == 'fr')
    {
        msgs.loading = 'Chargement...';
        msgs.voted = 'Vous avez d'+String.fromCharCode(233)+'j'+String.fromCharCode(224)+' vot' + String.fromCharCode(233);
        msgs.select = 'Vous devez d\'abord s'+String.fromCharCode(233)+'lectionner un choix pour voter';
    }
    else
    {
        msgs.loading = 'Loading...';
        msgs.voted = 'You have already voted';
        msgs.select = 'To vote, please select an answer';
    }

    var container = document.getElementById(id);

    var pollBox = document.createElement('div');
    pollBox.id = id+"Box";
    pollBox.style.display = 'none';
    container.appendChild(pollBox);

    var pollResults = document.createElement('div');
    pollResults.id = id+"Results";
    pollResults.style.display = 'none';
    container.appendChild(pollResults);

    var pollLoading = document.createElement('div');
    pollLoading.style.display = 'none';
    pollLoading.innerHTML = '<div class="poll-loading">' + msgs.loading + '</div>';
    container.appendChild(pollLoading);

    Poll.prototype.setUrl = function(newUrl)
        {
            this.url = newUrl;
        }

    Poll.prototype.display = function()
        {
            var data = 'path=' + path + '&tmpl=' + tmpl + '&lang=' + lang;
            var http = new HttpRequestHandler(true, displayContent);

            displayLoading();
            
            http.post(this.url, data, 'text/xml');
        }

    function displayContent(url, xml)
    {
        // Check for Error
        if (xml.getElementsByTagName('error').length > 0)
        {
            var errMsg = xml.getElementsByTagName('error').item(0).firstChild.nodeValue;
            pollLoading.innerHTML = errMsg;
            return;
        }
        q = getQuestion(xml);
        a = getAnswers(xml);
        pollBox.innerHTML = xml.getElementsByTagName('content').item(0).firstChild.nodeValue;
        pollResults.innerHTML = xml.getElementsByTagName('results').item(0).firstChild.nodeValue;

        // Add Event Listener
        document.getElementById('poll'+q.id+'Vote').onclick = submit;
        document.getElementById('poll'+q.id+'Results').onclick = displayResults;
        document.getElementById('poll'+q.id+'Back').onclick = displayPoll;
        (q.canVote == 1) ? displayPoll() : displayResults();

        // Calculate Height
        pollLoading.style.height = pollBox.scrollHeight + "px";
    }

    function submit(e)
    {
        if (q.canVote == 0)
        {
            alert(msgs.voted);
            return false;
        }
        var answerId
        var f = document.getElementById('poll'+q.id+'Form');
        var inputs = f.answerId;
        for (var i = 0; i < inputs.length; i++)
        {
            if (inputs[i].checked == true)
            {
                answerId = inputs[i].value;
                break;
            }
        }
        if (answerId == null)
        {
            alert(msgs.select);
            return false;
        }
        displayLoading();
        
        var data = 'path=' + path + '&QId=' + q.id + '&AId=' + answerId + '&tmpl=' + tmpl + '&lang=' + lang;
        var http = new HttpRequestHandler(true, displaySubmit);
        http.post(p_.url, data, 'text/xml');

        function displaySubmit(url, xml)
        {
            displayContent(url, xml);
            displayResults();
            return false;
        }
        return false;
    }
    function displayLoading()
    {
        pollBox.style.display = 'none';
        pollResults.style.display = 'none';
        pollLoading.style.display= 'block';
    }
    function displayPoll(e)
    {
        pollBox.style.display = 'block';
        pollResults.style.display = 'none';
        pollLoading.style.display= 'none';
        return false;
    }
    function displayResults(e)
    {
        pollBox.style.display = 'none';
        if (q.canVote == 0)
            document.getElementById('poll'+q.id+'Back').style.display = 'none';
        pollResults.style.display = 'block';
        pollLoading.style.display= 'none';
        return false;
    }
    function getQuestion(xml)
    {
        var question = new Object();
        var qNode = xml.getElementsByTagName('question').item(0);
        question.id = qNode.getAttribute('id');
        question.value = getChildValue(qNode, 'value');
        question.voteOnce = getChildValue(qNode, 'voteonce');
        question.canVote = getChildValue(qNode, 'canvote');
        return question
    }
    function getAnswers(xml)
    {
        var answers = new Array();
        var totalVotes = 0;
        var aNodes = xml.getElementsByTagName('answer');
        for (var i = 0; i < aNodes.length; i++)
        {
            var answer = new Object();
            answer.id = aNodes[i].getAttribute('id');
            answer.value = getChildValue(aNodes[i], 'value');
            answer.votes = getChildValue(aNodes[i], 'votes');
            answers.push(answer);
            totalVotes += parseInt(answer.votes);
        }
        for (var i = 0; i < answers.length; i++)
            answers[i].percent = Math.round(answers[i].votes/totalVotes*100);
        return answers;
    }
    function getChildValue(xmlNode, name)
    {
        try
        {
            return xmlNode.getElementsByTagName(name).item(0).firstChild.nodeValue;
        }
        catch(e)
        {
            return null;
        }
    }
}