public ActionResult Buy(Product product)
 {
     IRepository<Product> _productRepository = new ProductRepository();
     Product buyingProduct = _productRepository.GetItem(product.id);
     if (buyingProduct.status == "saled")
     {
         return RedirectToAction("ErrorOfSaledProduct");
     }
     else
     {
         buyingProduct.status = "saled";
         _productRepository.Update(buyingProduct);
         return RedirectToAction("Shop");
     }
 }
        public static void AutoFilling()
        {
            Product[] product = new Product[10];
            Client[] client = new Client[10];
            Manager[] manager = new Manager[10];

            product[0] = new Product(1, "House", "Moskovskaya, 320", "for sale");
            product[1] = new Product(2, "Office", "MOPRa, 30", "for sale");
            product[2] = new Product(3, "House", "Belorusskaya, 10", "for sale");
            product[3] = new Product(4, "Bar", "MOPRa, 3", "for sale");
            product[4] = new Product(5, "House", "Leningradskaya, 35", "for sale");
            product[5] = new Product(6, "Cafe", "Molodogvardeiskaya, 70", "for sale");
            product[6] = new Product(7, "House", "Moskovskaya, 30", "for sale");
            product[7] = new Product(8, "Club", "Zelenaya, 11", "for sale");
            product[8] = new Product(9, "House", "Lugivaja, 11", "for sale");
            product[9] = new Product(10, "Pizzeria", "Pionerskaya, 4", "for sale");

            client[0] = new Client(1, "Fedor Dvinyatin");
            client[1] = new Client(2, "Alexei Volkov");
            client[2] = new Client(3, "Ivan Ivanov");
            client[3] = new Client(4, "Petr Bojko");
            client[4] = new Client(5, "Egor Valedinsky");
            client[5] = new Client(6, "Alexander Evtuh");
            client[6] = new Client(7, "Alexei Lohnitsky");
            client[7] = new Client(8, "Mokin Alexander");
            client[8] = new Client(9, "Pavlovets Sergey");
            client[9] = new Client(10, "Igor Pujko");

            manager[0] = new Manager(1, "Viktor Oniskevich");
            manager[1] = new Manager(2, "Petr Glinskij");
            manager[2] = new Manager(3, "Fedor Yakubuk");
            manager[3] = new Manager(4, "Vasily Sapon");
            manager[4] = new Manager(5, "Igor Ivanovskiy");
            manager[5] = new Manager(6, "Alexander Dubrovsky");
            manager[6] = new Manager(7, "Olga Golub");
            manager[7] = new Manager(8, "Egor Pirozhkov");
            manager[8] = new Manager(9, "Boris Zhukovich");
            manager[9] = new Manager(10, "Igor Stepanchuk");

            IRepository<Client> _clientRepository = new ClientRepository();
            IRepository<Product> _productRepository = new ProductRepository();
            IRepository<Manager> _managerRepository = new ManagerRepository();

            IEnumerable<Client> clientRepository = _clientRepository.GetItems();
            IEnumerable<Product> productRepository = _productRepository.GetItems();
            IEnumerable<Manager> managerRepository = _managerRepository.GetItems();

            foreach (var item in clientRepository)
            {
                _clientRepository.Remove(item);
            }

            foreach (var item in productRepository)
            {
                _productRepository.Remove(item);
            }

            foreach (var item in managerRepository)
            {
                _managerRepository.Remove(item);
            }

            for (int i = 0; i <= 9; i++)
            {
                _clientRepository.Add(client[i]);
                _productRepository.Add(product[i]);
                _managerRepository.Add(manager[i]);
            }
        }