text: Comments = new Meteor.Collection('comments');
  
  Comments.allow({
      insert: canCommentById
    , update: canEditById
    , remove: canEditById
  });
  
  Comments.deny({
    update: function(userId, post, fieldNames) {
      if(isAdminById(userId))
        return false;
      // may only edit the following fields:
      return (_.without(fieldNames, 'text').length > 0);
    }
  });
  
  Meteor.methods({
    comment: function(postId, parentCommentId, text){
      var user = Meteor.user(),
          post=Posts.findOne(postId),
          postUser=Meteor.users.findOne(post.userId),
          timeSinceLastComment=timeSinceLast(user, Comments),
          cleanText= cleanUp(text),
          commentInterval = Math.abs(parseInt(getSetting('commentInterval',15))),
          properties={
            'commentAuthorId': user._id,
            'commentAuthorName': getDisplayName(user),
            'commentExcerpt': trimWords(stripMarkdown(cleanText),20),
            'postId': postId,
            'postHeadline' : post.headline
          };
  
      // check that user can comment
      if (!user || !canComment(user))
        throw new Meteor.Error('You need to login or be invited to post new comments.');
      
      // check that user waits more than 15 seconds between comments
      if(!this.isSimulation && (timeSinceLastComment < commentInterval))
        throw new Meteor.Error(704, 'Please wait '+(commentInterval-timeSinceLastComment)+' seconds before commenting again');
  
      var comment = {
          post: postId,
          body: cleanText,
          userId: user._id,
          submitted: new Date().getTime(),
          author: getDisplayName(user)
      };
      
      if(parentCommentId)
        comment.parent = parentCommentId;
  
      var newCommentId=Comments.insert(comment);
  
      Posts.update(postId, {$inc: {comments: 1}});
  
      Meteor.call('upvoteComment', newCommentId);
  
      properties.commentId = newCommentId;
  
      if(!this.isSimulation){
        if(parentCommentId){
          // child comment
          var parentComment=Comments.findOne(parentCommentId);
          var parentUser=Meteor.users.findOne(parentComment.userId);
  
          properties.parentCommentId = parentCommentId;
          properties.parentAuthorId = parentComment.userId;
          properties.parentAuthorName = getDisplayName(parentUser);
  
          // do not notify users of their own actions (i.e. they're replying to themselves)
          if(parentUser._id != user._id)
            Meteor.call('createNotification','newReply', properties, parentUser, user);
  
          // if the original poster is different from the author of the parent comment, notify them too
          if(postUser._id != user._id && parentComment.userId != post.userId)
            Meteor.call('createNotification','newComment', properties, postUser, user);
  
        }else{
          // root comment
          // don't notify users of their own comments
          if(postUser._id != user._id)
            Meteor.call('createNotification','newComment', properties, postUser, Meteor.user());
        }
      }
      return properties;
    },
    removeComment: function(commentId){
      var comment=Comments.findOne(commentId);
      // decrement post comment count
      Posts.update(comment.post, {$inc: {comments: -1}});
      // note: should we also decrease user's comment karma ?
      Comments.remove(commentId);
    }
  });
  