findQueueContainer=function($comment){
  // go up and down the DOM until we find either A) a queue container or B) an unqueued comment
  $up=$comment.prevAll(".queue-container, .comment-displayed").first();
  $down=$comment.nextAll(".queue-container, .comment-displayed").first();
  $prev=$comment.prev();
  $next=$comment.next();
  $queuedAncestors=$comment.parents(".comment-queued");
  if($queuedAncestors.exists()){
    // console.log("----------- case 1: Queued Ancestor -----------");
    // 1.
    // our comment has one or more queued ancestor, so we look for the root-most
    // ancestor's queue container
    $container=$queuedAncestors.last().data("queue");
  }else if($prev.hasClass("queue-container")){
    // console.log("----------- case 2: Queued Brother -----------");
    // 2.
    // the comment just above is queued, so we use the same queue container as him
    $container=$prev.data("queue");
  }else if($prev.find(".comment").last().hasClass("comment-queued")){
    // console.log("----------- case 3: Queued Cousin -----------");
    // 3.
    // there are no queued comments going up on the same level,
    // but the bottom-most child of the comment directly above is queued
    $container=$prev.find(".comment").last().data("queue");
  }else if($down.hasClass("queue-container")){
    // console.log("----------- case 4: Queued Sister -----------");
    // 3.
    // the comment just below is queued, so we use the same queue container as him
    $container=$next.data("queue");
  }else if($up.hasClass('comment-displayed') || !$up.exists()){
    // console.log("----------- case 5: No Queue -----------");
    // 4.
    // we've found containers neither above or below, but
    // A) we've hit a displayed comment or
    // B) we've haven't found any comments (i.e. we're at the beginning of the list)
    // so we put our queue container just before the comment
    $container=$('<div class="queue-container"><ul></ul></div>').insertBefore($comment);
    $container.click(function(e){
      e.preventDefault();
      var links=$(this).find("a");
      links.each(function(){
        var target=$(this).attr("href");
        $(target).removeClass("comment-queued").addClass("comment-displayed");
        // add comment ID to global array to avoid queuing it again
        window.openedComments.push(target.substr(1));
      });
      // scrollPageTo(links.first().attr("href"));
      $(this).hide("slow").remove();
    });
  }
  // console.log("comment", $comment);
  // console.log("up", $up);
  // console.log("down", $down);
  // console.log("queuedAncestors", $queuedAncestors);
  // console.log("container", $container);
  return $container;
};

Template.comment_item.created = function() {
  // if comments are supposed to be queued, then queue this comment on create
  this.isQueued = window.queueComments;
}

Template.comment_item.rendered=function(){
  if(this.data){
    var comment=this.data;
    var $comment=$("#"+comment._id);

    if(Meteor.user() && Meteor.user()._id==comment.userId){
      // if user is logged in, and the comment belongs to the user, then never queue it
    }else if(this.isQueued && !$comment.hasClass("comment-queued") && window.openedComments.indexOf(comment._id)==-1){
      // if comment is new and has not already been previously queued
      // note: testing on the class works because Meteor apparently preserves newly assigned CSS classes
      // across template renderings
      // TODO: save scroll position
      
      // get comment author name
      var user=Meteor.users.findOne(comment.userId);
      var author=getDisplayName(user);
      var imgURL=getAvatarUrl(user);
      var $container=findQueueContainer($comment);
      var comment_link='<li class="icon-user"><a href="#'+comment._id+'" class="has-tooltip" style="background-image:url('+imgURL+')"><span class="tooltip"><span>'+author+'</span></span></a></li>';

      $(comment_link).appendTo($container.find("ul"));
      // $(comment_link).appendTo($container.find("ul")).hide().fadeIn("slow");

      $comment.removeClass("comment-displayed").addClass("comment-queued");
      $comment.data("queue", $container);
      // TODO: take the user back to their previous scroll position
    }
  }
}


Template.comment_item.helpers({
  full_date: function(){
    return this.createdAt.toString();
  },
  child_comments: function(){
    // return only child comments
    return Comments.find({parent: this._id });
  },
  author: function(){
    return Meteor.users.findOne(this.userId);
  },
  authorName: function(){
    return getAuthorName(this);
  },
  user_avatar: function(){
    if(author=Meteor.users.findOne(this.userId))
      return getAvatarUrl(author);
  },
  can_edit: function(){
    if(this.userId && Meteor.userId())
      return Meteor.user().isAdmin || (Meteor.userId() === this.userId);
    else
      return false;
  },
  showChildComments: function(){
    // TODO: fix this
    // return Session.get('showChildComments');
    return true;
  },
  ago: function(){
    return moment(this.createdAt).fromNow();
  },
  upvoted: function(){
    return Meteor.user() && _.include(this.upvoters, Meteor.user()._id);
  },
  downvoted: function(){
    return Meteor.user() && _.include(this.downvoters, Meteor.user()._id);
  },
  profileUrl: function(){
    var user = Meteor.users.findOne(this.userId);
    if(user)
      return getProfileUrl(user);
  }  
});

Template.comment_item.events({
  'click .queue-comment': function(e){
    e.preventDefault();
    var current_comment_id=$(event.target).closest(".comment").attr("id");
    var now = new Date();
    var comment_id = Comments.update(current_comment_id,
        {
          $set: {
            postedAt:  new Date().getTime()
          }
        }
      );
    },
  'click .not-upvoted .upvote': function(e, instance){
    e.preventDefault();
    if(!Meteor.user()){
      Router.go('/signin');
      throwError(i18n.t("Please log in first"));
    }
    Meteor.call('upvoteComment', this, function(error, result){
      trackEvent("post upvoted", {'commentId':instance.data._id, 'postId': instance.data.post, 'authorId':instance.data.userId});
    });
  },
  'click .upvoted .upvote': function(e, instance){
    e.preventDefault();
    if(!Meteor.user()){
      Router.go('/signin');
      throwError(i18n.t("Please log in first"));
    }
    Meteor.call('cancelUpvoteComment', this, function(error, result){
      trackEvent("post upvote cancelled", {'commentId':instance.data._id, 'postId': instance.data.post, 'authorId':instance.data.userId});
    });
  },
  'click .not-downvoted .downvote': function(e, instance){
    e.preventDefault();
    if(!Meteor.user()){
      Router.go('/signin');
      throwError(i18n.t("Please log in first"));
    }
    Meteor.call('downvoteComment', this, function(error, result){
      trackEvent("post downvoted", {'commentId':instance.data._id, 'postId': instance.data.post, 'authorId':instance.data.userId});
    });
  },
  'click .downvoted .downvote': function(e, instance){
    e.preventDefault();
    if(!Meteor.user()){
      Router.go('/signin');
      throwError(i18n.t("Please log in first"));
    }
    Meteor.call('cancelDownvoteComment', this, function(error, result){
      trackEvent("post downvote cancelled", {'commentId':instance.data._id, 'postId': instance.data.post, 'authorId':instance.data.userId});
    });
  }
});