public ActionResult ArticleDetails(Guid?id)
        {
            IArticleBLL articleBLL = new ArticleBLL();

            if (id == null || !articleBLL.ExistArticle(id.Value))
            {
                return(RedirectToAction(nameof(ArticleList)));
            }

            ViewBag.Comments = articleBLL.GetCommentsByArticleId(id.Value);

            return(View(articleBLL.GetOneArticleById(id.Value)));
        }
        public ActionResult EditArticle(Guid id)
        {
            IArticleBLL          articleBLL           = new ArticleBLL();
            var                  article              = articleBLL.GetOneArticleById(id);
            EditArticleViewModel editArticleViewModel = new EditArticleViewModel
            {
                Title       = article.Title,
                Content     = article.Content,
                CategoryIds = article.CategoryIds,
                ArticleId   = article.Id
            };

            // all user's categories
            var userId = Guid.Parse(Session["loginUserId"].ToString());

            ViewBag.CategoryIds = new ArticleBLL().GetAllCategories(userId);

            return(View(editArticleViewModel));
        }