public async Task <ActionResult> Buy(Guid ebookId)
        {
            using (var db = new EbookManagerDbContext())
            {
                var catalogRepository = new CatalogRepository(db);

                var userId = ClaimsPrincipal.Current.Claims.First(c => c.Type == ClaimTypes.NameIdentifier).Value;
                await catalogRepository.BuyEbookAsync(userId, ebookId);

                TempData["Success"] = "Votre achat a été pris en compte !";

                return(RedirectToAction("Index", "MySpace"));
            }
        }