// ==UserScript==
// @name           Sluggy.net "Like" button
// @namespace      http://robert.walkertribe.com
// @description    Adds a "Like" button to the sluggy.net forums
// @include        http://www.sluggy.net/forum/viewtopic.php?*
// ==/UserScript==

var ACA_THREAD = "http://www.sluggy.net/forum/posting.php?mode=reply&f=7&t=11681";
var LIKE_BUTTON_URL = "url(http://i54.tinypic.com/vhzvk4.gif)";
var LIKE_DESCRIPTION = "Like (quote in \"Awesome Comment Award\" thread)";

var likeClick = function(event) {
   var postEl = event.target.parentNode.parentNode.parentNode.parentNode.parentNode;
   var quoteEl = document.evaluate("//div[@id='" + postEl.id + "']//li[@class='quote-icon']/a", document, null,
     XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
   var permalinkEl = document.evaluate("//div[@id='" + postEl.id + "']//p[@class='author']/a", document, null,
     XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
   var threadTitleEl = document.evaluate("//h2/a", document, null,
     XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
   var iframe = document.getElementById("likeFrame");
   iframe.permalink = permalinkEl.href;
   iframe.threadTitle = threadTitleEl.textContent;
   iframe.src = quoteEl.href;
};
var likeFrameLoad = function(permalink, threadName) {
   var iframe = document.getElementById("likeFrame");

   if (iframe.src != "about:blank") {
     var doc = window.frames[0].document;
     var quoteText = doc.getElementById("message").value;
     var linkText = "From the [url=" + iframe.permalink + "]" + iframe.threadTitle + "[/url] thread";
     var newTab = window.open(ACA_THREAD, "_newtab");
     newTab.addEventListener("load", function() {
       var textarea = newTab.document.getElementById("message");
       textarea.textContent = quoteText + linkText;
       textarea.focus();
     }, true);
   }
};
var likeHover = function(event) {
   event.target.style.backgroundPosition = "0 20px";
};
var likeUnhover = function(event) {
   event.target.style.backgroundPosition = "0 0";
};

var iframe = document.createElement("iframe");
iframe.id = "likeFrame";
iframe.src = "about:blank";
iframe.style.position = "absolute";
iframe.style.visibility = "hidden";
iframe.addEventListener("load", likeFrameLoad, true);
document.body.appendChild(iframe);

var posts = document.evaluate("//div[@class='postbody']/ul[@class='profile-icons']", document, null,
     XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);

for (var i = 0; i < posts.snapshotLength; i++) {
   var post = posts.snapshotItem(i);
   var li = document.createElement("li");
   li.className = "like-icon";
   li.style.backgroundImage = LIKE_BUTTON_URL;
   var a = document.createElement("a");
   a.title = LIKE_DESCRIPTION;
   a.href = "javascript:void(null)";
   a.addEventListener("click", likeClick, true);
   a.addEventListener("mouseover", likeHover, true);
   a.addEventListener("mouseout", likeUnhover, true);
   a.style.backgroundImage = LIKE_BUTTON_URL;
   a.style.width = "39px";
   a.style.height = "20px";
   var span = document.createElement("span");
   span.appendChild(document.createTextNode(LIKE_DESCRIPTION));
   a.appendChild(span);
   li.appendChild(a);
   post.appendChild(li);
}