// ==UserScript==
// @name       Detect new comments on Hashtable's blog
// @namespace  http://h16free.pltplp.net/
// @version    0.2
// @description Detect new comments since last visit on h16free.com blog. This version supports comments on multiple pages
// @match      http://h16free.com/*
// @copyright  2013, Etienne Bernard
// ==/UserScript==

// a function that loads jQuery and calls a callback function when jQuery has finished loading
function addJQuery(callback) {
    var script = document.createElement("script");
    script.setAttribute("src", "//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js");
    script.addEventListener('load', function() {
        var script = document.createElement("script");
        script.textContent = "window.jQ=jQuery.noConflict(true);(" + callback.toString() + ")();";
        document.body.appendChild(script);
    }, false);
    document.body.appendChild(script);
}

// the guts of this userscript
function main() {

    var cookies;
    var readCookie = function(name,c,C,i){
        if(cookies){ return cookies[name]; }
        c = document.cookie.split('; ');
        cookies = {};
        for(i=c.length-1; i>=0; i--){
            C = c[i].split('=');
            cookies[C[0]] = C[1];
        }
        return cookies[name];
    };

    var articleId = jQ('article.entry-plain').attr('id');
    if (articleId) {
        articleId = articleId.substr(5);
        // Get comments' page
        var hr = jQ('article.comment-block:first header a').attr('href');
        var commentPage = parseInt(hr.replace(/#.*/, '').replace(/^.*comment-page-/, ''), 10);
        var cookieName = 'lastVisits';
        // Check if we have a cookie for this article
        var cookie = readCookie('lastVisits');
        var lastVisits = {};
        if (cookie !== undefined) {
            lastVisits = JSON.parse(cookie);
        }
        // Get last visit time
        var key = 'p' + articleId + '-' + commentPage;
        var lastViewed = lastVisits[key];
        if (lastViewed !== undefined) {
            // Mark as new
            jQ('article.comment-block > header > a > time').each(function() {
                var t = new Date(jQ(this).attr('datetime'));
                t = t.getTime() - 7200000; // Fix timezone
                if (t > lastViewed) {
                    jQ(this).parents('article').parent('li').css('outline', '2px dotted red');
                }
            });
        }
        lastVisits[key] = new Date().getTime();
        // Set cookie for next time
        document.cookie = cookieName + '=' + JSON.stringify(lastVisits) + ';path=/;expires=Tue, 31 Dec 2019 23:00:00 GMT';
    }
}

// load jQuery and execute the main function
addJQuery(main);