// ==UserScript==
// @name        Explain XKCD
// @namespace   Alice
// @include     https://xkcd.com/*
// @version     1
// @require     http://code.jquery.com/jquery-2.1.4.min.js
// @description Adds Explain XKCD links to each XKCD comic page
// @grant       none
// @downloadURL none
// ==/UserScript==

var explain = "http://www.explainxkcd.com/wiki/index.php/";
var curPage = document.location.toString();
var pageTitle = $('#ctitle').text();
pageTitle = pageTitle.replace(/ /, "_");

if (curPage.match(/\d+/) === null) {
  curPage = $('#middleContainer').text();
  curPage = curPage.replace(/[\u0000-\uffff\n]*(Permanent link to this comic: )(http:\/\/xkcd\.com\/\d+\/)[\u0000-\uffff\n]*/gm, "$2");
}

curPage = curPage.replace(/(https?:\/\/xkcd\.com\/)(\d+)(\/)/, "$2");
explain = explain + curPage + ":_" + pageTitle;

$('#ctitle').append("<br><a href=\""+explain+"\">Explain XKCD</a>");