Task 31 - fix 2

using System;
using System.Collections.Generic;

namespace C_sharp_Light
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.CursorVisible = false;
            TradeRoom tradeRoom = new TradeRoom(new Player());
            tradeRoom.Work();
        }
    }
    public static class RandomStatic
    {
        static private Random _rand = new Random();

        static public int GetNext(int min, int max)
        {
            return _rand.Next(min, max);

        }
        static public int GetNext(int max)
        {
            return _rand.Next(max);
        }
    }

    public static class Messager
    {
        static public void ShowMessageWithColor(string message, ConsoleColor color, bool delay)
        {
            ConsoleColor defaultColor = Console.ForegroundColor;
            Console.ForegroundColor = color;
            Console.WriteLine(message);
            Console.ForegroundColor = defaultColor;
            if (delay)
                Console.ReadKey();
        }
    }

    class Item
    {
        public int Cost { get; private set; }
        public string Name { get; private set; }
        public Item()
        {
            Name = new string[] { "Железный меч", "Рогатый шлем", "Посох огня", "Кожаный сапоги", "Сладкий рулет" }[RandomStatic.GetNext(0, 5)];
            Cost = RandomStatic.GetNext(20, 150);
        }
        public string GetInfo()
        {
            return $"{Name} стоит - {Cost}";
        }
    }
    class Person
    {
        public string Name { get; private set; }
        public int Сash { get { return Money; } }
        protected int Money;
        protected List<Item> Inventory = new List<Item>();
        public Person(string name, int money)
        {
            Money = money;
            Name = name;
            int amountItems = RandomStatic.GetNext(3, 9);
            for (int i = 0; i < amountItems; i++)
            {
                Inventory.Add(new Item());
            }
        }
        public string GetInfoAboutAllItem()
        {
            string result = "";
            for (int i = 0; i < Inventory.Count; i++)
            {
                result += $"{i}:{Inventory[i].GetInfo()}\n";
            }
            return result;
        }
    }
    class Player : Person
    {
        public Player() : base("Player",1500){     }
        public void Buy(Item item)
        {
            Inventory.Add(item);
            Money -= item.Cost;
            Messager.ShowMessageWithColor($"{item.Name} - Куплен", ConsoleColor.Green, true);
        }
        public bool СheckSolvency(Item iten)
        {
            if (Money >= iten.Cost) return true;
            else return false;
        }
        public void ShowInfo()
        {
            Messager.ShowMessageWithColor(Name, ConsoleColor.Green, false);
            Messager.ShowMessageWithColor(GetInfoAboutAllItem(), ConsoleColor.White, false);
            Messager.ShowMessageWithColor($"\nВаши деньги: {Money}", ConsoleColor.Yellow, false);
        }
    }
    class Trader : Person
    {
        public int SelectedIndexItem { get; private set; } = 0;
        public Trader() : base("Торговец",RandomStatic.GetNext(300,900)){}
        public int GetSizeInventory()
        {
            return Inventory.Count;
        }
        public void ChangeActiveItem(int step)
        {
            SelectedIndexItem += step;
            UpdateIndex();
        }
        public Item Sell()
        {
            Item temp = Inventory[SelectedIndexItem];
            Inventory.RemoveAt(SelectedIndexItem);
            Money += temp.Cost;
            UpdateIndex();
            return temp;
        }
        public Item PickItem()
        {
            return Inventory[SelectedIndexItem];
        }
        public void ShowInfo()
        {
            Messager.ShowMessageWithColor(Name, ConsoleColor.Cyan, false);
            Messager.ShowMessageWithColor(GetInfoAboutAllItem(), ConsoleColor.White, false);
            Messager.ShowMessageWithColor($"Выбранный индекс предмета {SelectedIndexItem}", ConsoleColor.Green,false);
        }
        private void UpdateIndex()
        {
            if (SelectedIndexItem < 0)
                SelectedIndexItem = 0;
            else if (SelectedIndexItem > Inventory.Count - 1)
                SelectedIndexItem = Inventory.Count - 1;
        }
    }
    class TradeRoom
    {
        private Player _player;
        private Trader _trader;
        public TradeRoom(Player player)
        {
            _player = player;
            CreateNewTrader();
        }
        public void Work()
        {
            bool isOpen = true;
            bool isTrading = false;
            while (isOpen)
            {
                if (isTrading)
                {
                    Console.Clear();
                    _trader.ShowInfo();
                    Console.WriteLine($"\n\nСтрелка верх или вниз - выбор товара" +
                        $"\n{ConsoleKey.Enter} - Покупка" +
                        $"\n{ConsoleKey.Escape} - Выход из меню торговли");
                    ConsoleKeyInfo key = Console.ReadKey();
                    switch (key.Key)
                    {
                        case ConsoleKey.UpArrow:
                            _trader.ChangeActiveItem(-1);
                            break;
                        case ConsoleKey.DownArrow:
                            _trader.ChangeActiveItem(1);
                            break;
                        case ConsoleKey.Enter:
                            Buy();
                            break;
                        case ConsoleKey.Escape:
                            isTrading = false;
                            break;
                    }
                }
                else
                {
                    Console.Clear();
                    Console.WriteLine("Tab - создать нового торговца \nI - Посмотреть свой инвентарь \nEnter - Попросит торговца показать своей товар \nEsc закрыть");
                    ConsoleKeyInfo key = Console.ReadKey();
                    switch (key.Key)
                    {
                        case ConsoleKey.Tab:
                            CreateNewTrader();
                            break;
                        case ConsoleKey.I:
                            Console.Clear();
                            _player.ShowInfo();
                            Console.ReadKey();
                            break;
                        case ConsoleKey.Enter:
                            isTrading = true;
                            break;
                        case ConsoleKey.Escape:
                            isOpen = false;
                            break;
                    }
                }
            }
        }
        private void Buy()
        {
            if (_trader.GetSizeInventory() > 0)
                if (_player.СheckSolvency(_trader.PickItem()))
                    _player.Buy(_trader.Sell());
                else
                    Messager.ShowMessageWithColor("У ваc больше нет денег.", ConsoleColor.Red, true);
            else
                Messager.ShowMessageWithColor("У торговца больше нет вещей", ConsoleColor.Red, true);
        }
        private void CreateNewTrader()
        {
            _trader = new Trader();
            Messager.ShowMessageWithColor("Торговец создан", ConsoleColor.White, true);
        }
    }
}