ДЗ Магазин

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
            Dealer dealer = new Dealer(1000);
            Player player = new Player(90);

            dealer.ReceiveGoods();
            dealer.ShowGoods();
            player.ShowGoods();

            dealer.AskAboutTrading(player);
            dealer.ShowGoods();
            player.ShowGoods();
        }

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

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

            public string Info {
                get
                {
                    return $"{Name}\t{Price}";
                }
            }
        }

        class Person
        {
            protected Thing[] _goods;
            public int Money { get; protected set; }

            public Person(int money)
            {
                _goods = new Thing[] { };
                Money = money;
            }

            public void AddThing(Thing thing)
            {
                Array.Resize(ref _goods, _goods.Length + 1);
                _goods[_goods.Length - 1] = thing;
            }

            public Thing RemoveThing(int index)
            {
                Thing thing = _goods[index];
                for (int i = index; i < _goods.Length - 1; i++)
                {
                    _goods[i] = _goods[i + 1];
                }
                Array.Resize(ref _goods, _goods.Length - 1);
                return thing;

            }

            public void ShowGoods(string header)
            {
                Console.WriteLine(header);
                if (_goods.Length == 0)
                {
                    Console.WriteLine("-Пусто-");
                }
                else
                {
                    Console.WriteLine("N\tТовар\tЦена");
                    for (int i = 0; i < _goods.Length; i++)
                    {
                        Console.WriteLine($"{i}\t{_goods[i].Info}");
                    }
                }
                Console.WriteLine();
            }
        }

        class Player : Person
        {
            public Player(int money) : base(money) { }

            internal void BuyThing(Thing product)
            {
                Money -= product.Price;
                AddThing(product);
            }

            public void ShowGoods()
            {
                base.ShowGoods("Инвентарь игрока:");
            }
        }

        class Dealer : Person
        {
            public Dealer(int money) : base(money) { }

            public void ReceiveGoods()
            {
                AddThing(new Thing("Меч", 100));
                AddThing(new Thing("Щит", 20));
                AddThing(new Thing("Факел", 2));
            }

            public void AskAboutTrading(Player player)
            {
                int productID;
                Console.WriteLine("Товар в какой позиции вы хотите приобрести?");
                productID = Convert.ToInt32(Console.ReadLine());

                if(productID >= _goods.Length)
                {
                    Console.WriteLine("У меня нет такого товара");
                }
                else if (player.Money < _goods[productID].Price)
                {
                    Console.WriteLine("У тебя недостаточно денег");
                }
                else
                {
                    Thing product = SellThing(productID);
                    player.BuyThing(product);
                }
            }

            private Thing SellThing(int productID)
            {
                Thing thingForSell = RemoveThing(productID);
                Money += thingForSell.Price;
                return thingForSell;
            }

            public void ShowGoods()
            {
                base.ShowGoods("Инвентарь торговца:");
            }
        }
    }
}