// ==UserScript==
// @name        Github Commit Whitespace
// @namespace   https://github.com/jerone/UserScripts
// @description Adds button to hide whitespaces from commit
// @author      jerone
// @homepage    https://github.com/jerone/UserScripts/tree/master/Github_Commit_Whitespace
// @homepageURL https://github.com/jerone/UserScripts/tree/master/Github_Commit_Whitespace
// @include     https://github.com/*
// @version     1.2.1
// @grant       none
// @downloadURL none
// ==/UserScript==
/* global unsafeWindow */

(function() {

	function addButton() {
		var e;
		if (!(/\/commit\//.test(location.href) || /\/compare\//.test(location.href) || /\/pull\/\d*\/files/.test(location.href)) ||
			!(e = document.querySelector("#toc .explain"))) { return; }

		var r = e.querySelector(".GithubCommitWhitespaceButton");
		if (r) { r.parentElement.removeChild(r); }

		var on = /w=/.test(location.search);

		var b = e.querySelector(".minibutton");

		var s = document.createElement("span");
		s.textContent = " \u2423";
		s.style.color = "#333";  // set color because of css selector `p.explain .octicon`;

		var a = document.createElement("a");
		a.classList.add("GithubCommitWhitespaceButton", "minibutton", "tooltipped", "tooltipped-s");
		if (on) { a.classList.add("selected"); }
		a.setAttribute("href", on ? location.href.replace(location.search, "") : location.href + "?w=1");
		a.setAttribute("title", on ? "Show commit whitespace" : "Hide commit whitespaces");
		a.setAttribute("rel", "nofollow");
		a.setAttribute("aria-label", a.getAttribute("title"));
		a.style.marginLeft = "10px";  // give us some room;
		a.appendChild(s);

		b.parentNode.insertBefore(a, b);
	}

	// init;
	addButton();

	// on pjax;
	unsafeWindow.$(document).on("pjax:success", addButton);

	// on PR files tab;
	var f;
	if ((f = document.querySelector(".js-pull-request-tab[data-container-id='files_bucket']"))) {
		f.addEventListener("click", function() {
			window.setTimeout(addButton, 13);
		});
	}

})();