ДЗ: Магазин

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Reflection;

internal class Program
{
    static void Main(string[] args)
    {
        Shop shop = new Shop();

        shop.Work();
    }
}

public 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 override string ToString()
    {
        return $"{Name}. Цена: {Price} руб.";
    }
}

public class Person
{
    protected List<Product> Products;

    public Person(int money, string role)
    {
        Money = money;
        Role = role;
    }

    public string Role { get; private set; }
    public int Money { get; protected set; }

    public void ShowInfo()
    {
        Console.WriteLine($"{Role}. Денег: {Money} руб.");

        ShowProducts();

        Console.ReadKey();
    }

    public void ShowProducts()
    {
        Console.WriteLine("Товары: ");

        if (Products.Count > 0)
        {
            for (int i = 0; i < Products.Count; i++)
            {
                Console.WriteLine(i + 1 + ". " + Products[i]);
            }
        }
        else
        {
            Console.WriteLine("Пусто.");
        }
    }
}

public class Seller : Person
{
    public Seller(int money, string role) : base(money, role)
    {
        Products = new List<Product>
        {
            new Product("Яблоко", 50),
            new Product("Банан", 40),
            new Product("Молоко", 80),
            new Product("Хлеб", 30),
            new Product("Сыр", 150),
            new Product("Колбаса", 200),
            new Product("Шоколад", 100),
            new Product("Кофе", 300),
            new Product("Чай", 120),
            new Product("Яйца", 90)
        };
    }

    public bool TryGetProduct(out Product product)
    {
        product = SetProduct();

        if (product != null)
            return true;
        else return false;
    }

    public void AddMoney(int money)
    {
        Money += money;
    }

    private Product SetProduct()
    {
        ShowProducts();

        Console.Write("\nВыбере товар: ");

        int ProductNumber = ReadInt();

        if (ProductNumber > 0 && ProductNumber < Products.Count)
        {
            return Products[ProductNumber - 1];
        }

        return null;
    }

    private int ReadInt()
    {
        int number;

        while (int.TryParse(Console.ReadLine(), out number) == false)
        {
            Console.Write("Ошибка ввода. Повторите: ");
        }

        return number;
    }
}

public class Buyer : Person
{
    public Buyer(int money, string role) : base(money, role)
    {
        Products = new List<Product>();
    }

    public void Buy(Product product)
    {
        Money -= product.Price;

        Products.Add(product);
    }

    public bool CanAfford(Product product)
    {
        return Money >= product.Price;
    }
}

public class Shop
{
    private Seller _seller = new Seller(10000, "Продавец");
    private Buyer _buyer = new Buyer(1000, "Покупатель");

    public void Work()
    {
        const string CommandSellInfoBuyer = "1";
        const string CommandSellInfoSeller = "2";
        const string CommandConductSale = "3";
        const string CommandExit = "Exit";

        bool isRun = true;

        while (isRun)
        {
            Console.Clear();
            Console.WriteLine($"{CommandSellInfoBuyer} - Информация о покупателе.\n" +
            $"{CommandSellInfoSeller} - Информация о продавце.\n" +
            $"{CommandConductSale} - Провести продажу.\n" +
            $"{CommandExit} - Выход.");

            switch (Console.ReadLine())
            {
                case CommandSellInfoBuyer:
                    ShowInfoBuyer();
                    break;

                case CommandSellInfoSeller:
                    ShowInfoSeller();
                    break;

                case CommandConductSale:
                    ConductSale();
                    break;

                case CommandExit:
                    isRun = false;
                    break;

                default:
                    Console.WriteLine("Ошибка ввода");
                    Console.ReadKey();
                    break;
            }
        }

        Console.WriteLine("Программа завершена.");
        Console.ReadKey();
    }

    private void ConductSale()
    {
        if (_seller.TryGetProduct(out Product product))
        {
            if (_buyer.CanAfford(product))
            {
                _seller.AddMoney(product.Price);
                _buyer.Buy(product);
                Console.WriteLine($"{_buyer.Role} купил {product.Name}.");
                Console.ReadKey();
            }
            else
            {
                Console.WriteLine($"У {_buyer.Role} не достаточно денег.");
                Console.ReadKey();
            }
        }
        else
        {
            Console.WriteLine("Нет товара под этим номером.");
            Console.ReadKey();
        }
    }

    private void ShowInfoSeller()
    {
        _seller.ShowInfo();
    }

    private void ShowInfoBuyer()
    {
        _buyer.ShowInfo();
    }
}