BookManagement.Controllers.BookController.Categories C# (CSharp) Метод

        public ActionResult Categories(int id=-1, string category="All",int page =1)
        {
            ViewBag.category = category;
            ViewBag.id = id;
            var model = from m in db.Books
                        select m;
            if (!category.ToLower().Equals("all"))
                model = model.Where(q => q.CategoryID == id);

            model = model.OrderByDescending(p => p.Date);
            int CountPage = ((model.Count() - 1) / CountInPage) + 1;
            ViewBag.CountPage = CountPage;

            ViewBag.CurrPage = page;

            model = model.Skip((page - 1) * CountInPage).Take(CountInPage);

            return View(model);
        }