Flat-Disqus-Comments

// ==UserScript==
// @include http://disqus.com/*
// @include https://disqus.com/*
// ==/UserScript==

var postListElement = null;
var millsecInterval = 500;

console.log("Flat-Disqus-Comments starting");
try {
  //don't run on frames or iframes
  if (window.top != window.self)
    return;

  //
  flattenAndSortPosts();
  setInterval(flattenAndSortPosts, millsecInterval);
}catch(err){
  console.log("Flat-Disqus-Comments: top level error: " + err);
}


return undefined;
// ****
// ****

function flattenAndSortPosts() {
  try {
    if (null == postListElement) {
      postListElement = document.getElementById("post-list");
      if (postListElement == null)
        return;
    }

    //get all comments
    var allComments = getAllComments(postListElement);
    var allCommentsSorted = allComments.slice();
    allCommentsSorted.sort(byIdComparator);

    if (true == arrayEqual(allComments, allCommentsSorted) && true != existsNestedPost(allComments))
      return;

    //clear children of comments
    for (var i = 0; i < allCommentsSorted.length; ++i) {
      var comment = allCommentsSorted[i];
      var childrenNode = getChildrenNode(comment);
      while (childrenNode.childNodes.length > 0)
        childrenNode.removeChild(childrenNode.childNodes[0]);
    }

    //clear post-list node
    while (postListElement.childNodes.length > 0)
      postListElement.removeChild(postListElement.childNodes[0]);

    //add comments in proper order to post-list node
    for (var i = 0; i < allCommentsSorted.length; ++i)
      postListElement.appendChild(allCommentsSorted[i]);
  }catch(err) {
    console.log("Flat-Disqus-Comments: flattenAndSortPosts error: " + err);
  }
}

function getAllComments(postListElement) {
  var result = new Array();
  getAllComments2(result, postListElement);
  return result;
}
function getAllComments2(result, ele) {
  var cl = getClassAttribute(ele);
  if (cl === "post")
    result.push(ele);
  for (var i = 0; i < ele.childNodes.length; ++i) {
    var child = ele.childNodes[i];
    var cl = getClassAttribute(child);
    if (cl === "post" || cl === "children")
      getAllComments2(result, child);
  }
}

function getClassAttribute(x) {
  if (x.class)
    return x.class;
   if (x.getAttribute)
    return x.getAttribute("class");
  return "";
}


function byIdComparator(a,b) {
  a = a.id;
  b = b.id;
  a = a.substring(5, a.length);
  b = b.substring(5, b.length);
  a = Number(a);
  b = Number(b);
  return a - b;
}

function arrayEqual(a, b) {
  if ( ! Array.isArray(a) || ! Array.isArray(b))
    throw "Invalid input to arrayEqual()";
  if (a.length != b.length)
    return false;
  for (var i = 0; i < a.length; ++i) {
    if (a[i] != b[i])
      return false;
  }
  return true;
}

function existsNestedPost(posts) {
  for (var i = 0; i < posts.length; ++i) {
    var post = posts[i];
    var childrenNode = getChildrenNode(post);
    if (childrenNode.childNodes.length > 0)
      return true;
  }
  return false;
}

function getChildrenNode(ele) {
  for (var i = 0; i < ele.childNodes.length; ++i) {
    var child = ele.childNodes[i];
    var cl = getClassAttribute(child);
    if (cl === "children")
      return child;
  }
}