using System;

namespace Shop
{
    class Program
    {
        static void Main(string[] args)
        {
            const string ShowSellerGoodsCommand = "1";
            const string SellGoodsCommand = "2";
            const string ShowPlayerInventoryCommand = "3";
            const string ExitCommand = "4";

            bool isWork = true;
            Seller seller = new Seller();
            Player player = new Player();
            Menu menu = new Menu(seller.GetProducts());

            while (isWork)
            {
                Console.Clear();
                Console.WriteLine($"{ShowSellerGoodsCommand}. Показать список товаров." +
                    $"\n{SellGoodsCommand}. Продать товар." +
                    $"\n{ShowPlayerInventoryCommand}. Показать сумку покупателя." +
                    $"\n{ExitCommand}. Выйти");

                switch (Console.ReadLine())
                {
                    case ShowSellerGoodsCommand:
                        seller.ShowAllItems();
                        break;

                    case SellGoodsCommand:
                        menu.Run(seller, player);
                        break;

                    case ShowPlayerInventoryCommand:
                        player.ShowAllItems();
                        break;

                    case ExitCommand:
                        isWork = false;
                        break;

                    default:
                        Console.WriteLine("Ошибка, такого пункта меню нет");
                        break;
                }

                Console.ReadKey();
                Console.Clear();
            }
        }
    }

    class Seller
    {
        private List<Product> _products = new List<Product>();
        private int _money = 0;

        public Seller()
        {
            _products.Add(new Product("Хлеб", 12));
            _products.Add(new Product("Овес", 4));
            _products.Add(new Product("Сыр", 118));
            _products.Add(new Product("Яйца", 32));
            _products.Add(new Product("Чай", 23));
        }

        public List<Product> GetProducts()
        {
            return _products;
        }

        public void TakeMoney(int payment)
        {
            _money+= payment;
        }

        public void Sell(int index)
        {
            Product product = _products[index];
            _products.Remove(product);
            _money += product.Price;
        }

        public void ShowAllItems()
        {
            if (_products.Count > 0)
            {
                foreach (Product _product in _products)
                {
                    _product.ShowInfo();
                }
            }
            else
            {
                Console.WriteLine($"Инвентарь продавца пуст.");
            }
        }
    }

    class Player
    {
        private List<Product> _bag;
        private int _moneyToPay;

        public Player()
        {
            _bag = new List<Product>();
        }

        public int Money { get; private set; } = 50;

        public void AddGoods(Product product)
        {
            _bag.Add(product);
        }

        public bool CheckSolvency(Product product)
        {
            _moneyToPay = product.Price;

            if (Money >= _moneyToPay)
            {
                return true;
            }
            else
            {
                _moneyToPay = 0;
                return false;
            }
        }

        public int Pay()
        {
            Money -= _moneyToPay;
            return _moneyToPay;
        }

        public void ShowAllItems()
        {
            if (_bag.Count > 0)
            {
                foreach (Product item in _bag)
                {
                    item.ShowInfo();
                }
            }
            else
            {
                Console.WriteLine($"Инвентарь покупателя пуст.");
            }
        }
    }

    class Product
    {
        public Product(string name, int price)
        {
            Name = name;
            Price = price;
        }

        public string Name { get; private set; }
        public int Price { get; private set; }

        public void ShowInfo()
        {
            Console.WriteLine($"Название товара: {Name}, цена: {Price}.");
        }
    }

    class Menu
    {
        private List<Product> _items;
        private int _selectedItemIndex;

        public Menu(List<Product> items)
        {
            _items = items;
            _selectedItemIndex = 0;
        }

        private void Display()
        {
            Console.Clear();
            Console.WriteLine("Управление ▲, ▼, Enter, Esc.");

            for (int i = 0; i < _items.Count; i++)
            {
                if (i == _selectedItemIndex)
                {
                    Console.ForegroundColor = ConsoleColor.Black;
                    Console.BackgroundColor = ConsoleColor.Gray;
                    Console.WriteLine($"{i + 1}. {_items[i].Name}, Цена: {_items[i].Price}");
                }
                else
                {
                    Console.WriteLine($"{i + 1}. {_items[i].Name}, Цена: {_items[i].Price}");
                }

                Console.ResetColor();
            }
        }

        public void MoveUp()
        {
            _selectedItemIndex--;

            if (_selectedItemIndex < 0)
            {
                _selectedItemIndex = _items.Count - 1;
            }
        }

        public void MoveDown()
        {
            _selectedItemIndex++;

            if (_selectedItemIndex >= _items.Count)
            {
                _selectedItemIndex = 0;
            }
        }

        public void СhoiceOfGoods(Seller seller, Player player)
        {
            Product product = _items[_selectedItemIndex];

            if (player.CheckSolvency(product))
            {
                seller.Sell(_selectedItemIndex);
                player.AddGoods(product);
                seller.TakeMoney(player.Pay());

                Console.WriteLine($"Осталось денег: {player.Money}.");
                Console.ReadKey();
            }
            else
            {
                Console.WriteLine("Не хватает денег.");
                Console.ReadKey();
            }
        }

        public void Run(Seller seller, Player player)
        {

            bool isWork = true;

            while (isWork)
            {
                Display();
                ConsoleKeyInfo keyInfo;
                keyInfo = Console.ReadKey(true);

                switch (keyInfo.Key)
                {
                    case ConsoleKey.UpArrow:
                        MoveUp();
                        break;

                    case ConsoleKey.DownArrow:
                        MoveDown();
                        break;

                    case ConsoleKey.Enter:
                        СhoiceOfGoods(seller, player);
                        break;

                    case ConsoleKey.Escape:
                        isWork = false;
                        break;
                }
            }
        }
    }
}