/**
* A script to count the comments for each webpage with a given unique id
* Adding this script into a website will turn all the spans with data-talk-id="unique-id" inner HTML to comment count
*/
var hyvorTalkCommentCount = (function() {
if (typeof HYVOR_TALK_WEBSITE === 'undefined' || ! HYVOR_TALK_WEBSITE ) 
    throw Error("HYVOR_TALK_WEBSITE is not defined");
var DOMAIN_TALK = "https://talk.hyvor.com",
    JSONP_URL = DOMAIN_TALK + "/web-api/count/get",
    WEBSITE_ID = HYVOR_TALK_WEBSITE;
var datasetTalkId = "data-talk-id",
    datasetTalkMode = "data-talk-mode";
var Script,
    SpansArray;
/**
* The element should always be a <span>
* with data-talk-id
*/
function trigger() {
    var spanData = findSpans();
    if (!spanData)
        return;
    var	webpageIdentifiers = spanData.webpageIdentifiers;
    if (!webpageIdentifiers)
        return;
    if (Script)
        kill(Script);
    SpansArray = spanData.spansArray; // all spans
    Script = document.createElement("script");
    Script.src = getURL();
    document.body.appendChild(Script);
    function getURL() {
        var getParams = queryString({
            website: WEBSITE_ID,
            webpageIdentifiers: JSON.stringify(webpageIdentifiers),
            time: new Date().getTime()
        });
        var url = JSONP_URL + "?" + getParams;
        return url;
    }
}
function findSpans() {
    var spans = document.getElementsByTagName("span"),
        webpageIdentifiers = [], // collected webpage ids
        spansArray = []; // all selected spans

    for (var i = 0, len = spans.length; i < len; i++) {

        var span = spans[i],
            attr = span.getAttribute(datasetTalkId);
        if (attr) {
            webpageIdentifiers.push(attr);
            spansArray.push(span);
        }

    }

    return webpageIdentifiers.length > 0 ? { 
        webpageIdentifiers: webpageIdentifiers,
        spansArray: spansArray
    } : null;

}
trigger();
/*
* When the server sends the data to the client via JSONOP
* Called from the JSONP script
*/
function receiveData(data) {

    for (var i = 0, len = SpansArray.length; i < len; i++) {
        var span = SpansArray[i],
            id = span.getAttribute(datasetTalkId),
            mode = span.getAttribute(datasetTalkMode) === 'number' ? 'raw' : 'string';
        span.innerHTML = data[id][mode];
    }

}
/* Helper functions */
function kill(el) {
    el.parentElement.removeChild(el);
}
function event(el, event, func) {
    el = el || window;
    if (window.addEventListener) {
        el.addEventListener(event, func);
        return function() {el.removeEventListener(event, func)}
    } else {
        el.attachEvent("on" + event, func);
        return function() {el.detachEvent("on" + event, func)}
    }

}
function queryString(obj) {
    var x, first = true, ret = "";
    for (x in obj) {
        ret += (!first ? "&" : "") +  x + "=" + obj[x];
        first = false;
    }
    return ret;
}
return {
    update: trigger,
    receiveData: receiveData
}
})();