public ActionResult Create(CommentModel model)
        {
            if (!ModelState.IsValid)
            {
                return(View(model));
            }

            var comment = model.ToDbModel();

            comment.AuthorId = User.Identity.GetUserId();
            comment.Time     = DateTime.Now;

            db.Comments.Add(comment);
            db.SaveChanges();

            return(RedirectToAction("Details", new { id = comment.Id }));
        }