// ==UserScript==
// @id          Github_Pages_Linker@https://github.com/jerone/UserScripts
// @name        Github Pages Linker
// @namespace   https://github.com/jerone/UserScripts/
// @description Add a link to Github Pages (gh-pages) when available.
// @author      jerone
// @copyright   2014+, jerone (https://github.com/jerone)
// @license     CC-BY-NC-SA-4.0; https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode
// @license     GPL-3.0-or-later; http://www.gnu.org/licenses/gpl-3.0.txt
// @homepage    https://github.com/jerone/UserScripts/tree/master/Github_Pages_Linker
// @homepageURL https://github.com/jerone/UserScripts/tree/master/Github_Pages_Linker
// @supportURL  https://github.com/jerone/UserScripts/issues
// @contributionURL https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=VCYMHWQ7ZMBKW
// @icon        https://github.githubassets.com/pinned-octocat.svg
// @version     1.2.4
// @grant       none
// @run-at      document-end
// @include     https://github.com/*
// @downloadURL none
// ==/UserScript==

(function() {

	String.format = function(string) {
		var args = Array.prototype.slice.call(arguments, 1, arguments.length);
		return string.replace(/{(\d+)}/g, function(match, number) {
			return typeof args[number] !== "undefined" ? args[number] : match;
		});
	};
  
  var DELAY = 800;

  var triggerEventClick = new MouseEvent('click', {
     view: window,
     bubbles: true,
     cancelable: true
  });

  function addLink() {
	if(document.getElementById("GithubPagesLinker")) {
	  return;
    }

    var meta = document.querySelector('.file-navigation');
    if (!meta) {
      return;
    }
    
    var closeDropdown = () => {
      document.querySelector('[data-toggle-for="branch-select-menu"]').dispatchEvent(triggerEventClick);
    }

    var dropdown = document.querySelector('[data-hotkey="w"]');
    dropdown.dispatchEvent(triggerEventClick); // open menu to load data

    setTimeout(() => {
      var branch = document.querySelector('.SelectMenu-item[href$="/tree/gh-pages"]');
      if (!branch) {
        closeDropdown();
        return;
      }

      var tree = branch.getAttribute("href").split("/"); // `/{user}/{repo}/tree/gh-pages`;
      var url = String.format("{0}//{1}.github.io/{2}/", tree[0], tree[3], tree[4]);

      var div = document.createElement("div");
      div.id = "GithubPagesLinker";
      div.style.margin = "-10px 0px 10px";
      meta.parentNode.insertBefore(div, meta.nextSibling);

      var img = document.createElement("img");
      img.setAttribute("src", "https://github.githubassets.com/images/icons/emoji/octocat.png");
      img.setAttribute("align", "absmiddle");
      img.classList.add("emoji");
      img.style.height = "16px";
      img.style.width = "16px";
      div.appendChild(img);

      div.appendChild(document.createTextNode(" "));

      var a = document.createElement("a");
      a.setAttribute("href", "{https}://pages.github.com");
      a.setAttribute("title", "More info about gh-pages...");
      a.style.color = "inherit";
      a.appendChild(document.createTextNode("Github Pages"));
      div.appendChild(a);

      div.appendChild(document.createTextNode(": "));

      var aa = document.createElement("a");
      aa.setAttribute("href", url);
      aa.appendChild(document.createTextNode(url));
      div.appendChild(aa);
      
      closeDropdown();
      
    }, DELAY);
	}

	// Init;
	addLink();

	// On pjax;
  document.addEventListener('pjax:end', addLink);

})();