Store application (buyer, trader, product)

iJunior_C#_Lesson_56

namespace iJuniorPractice
{
    class Program
    {
        static void Main(string[] args)
        {
            List<Product> productsInStore = new List<Product>
            {
                new Product(1, 20, "Apple"),
                new Product(2, 100, "Coconut"),
                new Product(3, 10, "Cucumber"),
                new Product(4, 40, "Pineapple")
            };
            Trader trader = new Trader(100, productsInStore);
            Buyer buyer = new Buyer(50, new List<Product>());
            Shop shop = new Shop(trader, buyer);
            shop.Play();
        }
    }

    static class Utils
    {
        public static int ReadInt(string message = "")
        {
            int number;
            string input;

            Console.WriteLine(message);
            input = Console.ReadLine();
            
            while (int.TryParse(input, out number) == false)
            {
                Console.WriteLine("Incorrect input. Try again.");
                input = Console.ReadLine();
            }

            return number;
        }

        public static string ReadString(string message = "")
        {
            string input;

            Console.WriteLine(message);
            input = Console.ReadLine();
            
            while (input == "")
            {
                Console.WriteLine("Incorrect input, line is empty. Try again.");
                input = Console.ReadLine();
            }

            return input;
        }
    }

    class Shop
    {
        private const int CommandShowStoreInfo = 1;
        private const int CommandBuyProduct = 2;
        private const int CommandShowBuyerInventory = 3;
        private const int CommandExit = 0;

        private Trader _trader;
        private Buyer _buyer;
        private bool _isWork;

        public Shop(Trader trader,  Buyer buyer, bool isWork = true)
        {
            _trader = trader;
            _buyer = buyer;
            _isWork = isWork;
        }

        public void Play()
        {
            while (_isWork)
            {
                ShowMenu();
                int input = Utils.ReadInt("Please enter command: ");

                switch (input)
                {
                    case CommandShowStoreInfo:
                        _trader.ShowInfo();
                        break;

                    case CommandBuyProduct:
                        Trade(_buyer, _trader);
                        break;

                    case CommandShowBuyerInventory:
                        _buyer.ShowInfo();
                        break;

                    case CommandExit:
                        _isWork = false;
                        break;

                    default:
                        Console.WriteLine("Incorrect input.");
                        break;
                }

                Console.WriteLine("Press any key to continue...");
                Console.ReadKey();
                Console.Clear();
            }

            Console.WriteLine("Exiting...");
        }

        private void ShowMenu()
        {
            Console.WriteLine($"Main Menu:");
            Console.WriteLine($"{CommandShowStoreInfo} - See the products in the shop");
            Console.WriteLine($"{CommandBuyProduct} - Buy a product");
            Console.WriteLine($"{CommandShowBuyerInventory} - Show Inventory");
            Console.WriteLine($"{CommandExit} - Exit");
        }

        private void Trade(Buyer buyer, Trader trader)
        {
            trader.ShowInfo();

            int productId = buyer.GetProductIdToBuy();
            
            if (trader.TryGetProductById(productId, out Product product)) 
            { 
                if (buyer.TryToBuy(product) && trader.TryToSell(product)) 
                { 
                    Console.WriteLine("Purchase successful!");
                }
                else
                {
                    Console.WriteLine("Purchase failed!");
                }
            }
        }
    }

    class Character
    {
        protected List<Product> Products;
        
        protected Character(int moneyAmount, List<Product> products)
        {
            MoneyAmount = moneyAmount;
            Products = products;
        }
        
        public int MoneyAmount { get; protected set; }
        
        public void ShowInfo()
        {
            Console.WriteLine($"Balance: {MoneyAmount}, Product list:");
            
            if (Products.Count == 0)
            {
                Console.WriteLine("Inventory is empty.");
            }
            else
            {
                foreach (var product in Products)
                {
                    product.WriteInfo();
                }
            }
        }
    }

    class Buyer : Character
    {
        public Buyer(int moneyAmount, List<Product> products) : base(moneyAmount, products)
        {
        }

        public int GetProductIdToBuy()
        {
            int productId;
            
            productId = Utils.ReadInt("Please enter product ID: ");
            return productId;
        }

        public bool TryToBuy(Product product)
        {
            if (MoneyAmount >= product.Price)
            {
                MoneyAmount -= product.Price;
                Products.Add(product);
                
                return true;
            }
            
            Console.WriteLine("Not enough money."); 
            return false;
        }
    }

    class Trader : Character
    {
        public Trader(int moneyAmount, List<Product> products) : base(moneyAmount, products)
        {
        }

        public bool TryGetProductById(int productId,  out Product product)
        {
            foreach (Product productInInventory in Products)
            {
                if (productInInventory.Id == productId)
                {
                    product = productInInventory;
                    return true;
                }
            }
            
            Console.WriteLine("Incorrect product id. Try again.");
            product = null;
            return false;
        }

        public bool TryToSell(Product product)
        {
            if (product == null)
            {
                Console.WriteLine("Product is null.");
                return false;
            }
            
            MoneyAmount += product.Price;
            Products.Remove(product);
            
            return true;
        }
    }

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

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

        public void WriteInfo()
        {
            Console.WriteLine($"ID: {Id}, Title: {Name}, Price: {Price}");
        }
    }
}