using System; using System.Collections.Generic;

class Product { public int Id { get; set; } public string Name { get; set; } public int Quantity { get; set; } public decimal Price { get; set; }

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

public void DisplayProduct()
{
    Console.WriteLine($"ID: {Id}, Name: {Name}, Quantity: {Quantity}, Price: {Price:C}");
}

}

class Inventory { private List products = new List(); private int nextId = 1;

public void AddProduct(string name, int quantity, decimal price)
{
    Product product = new Product(nextId++, name, quantity, price);
    products.Add(product);
    Console.WriteLine($"Product '{name}' added successfully!");
}

public void DisplayInventory()
{
    Console.WriteLine("\n--- Inventory ---");
    if (products.Count == 0)
    {
        Console.WriteLine("Inventory is empty.");
    }
    else
    {
        foreach (var product in products)
        {
            product.DisplayProduct();
        }
    }
    Console.WriteLine("-----------------\n");
}

public void UpdateStock(int id, int newQuantity)
{
    Product product = products.Find(p => p.Id == id);
    if (product != null)
    {
        product.Quantity = newQuantity;
        Console.WriteLine($"Product '{product.Name}' updated with new quantity: {newQuantity}");
    }
    else
    {
        Console.WriteLine("Product not found!");
    }
}

public void RemoveProduct(int id)
{
    Product product = products.Find(p => p.Id == id);
    if (product != null)
    {
        products.Remove(product);
        Console.WriteLine($"Product '{product.Name}' removed successfully.");
    }
    else
    {
        Console.WriteLine("Product not found!");
    }
}

}

class Program { static void Main(string[] args) { Inventory inventory = new Inventory(); bool running = true;

    while (running)
    {
        Console.WriteLine("Inventory Management System");
        Console.WriteLine("1. Add Product");
        Console.WriteLine("2. View Inventory");
        Console.WriteLine("3. Update Product Quantity");
        Console.WriteLine("4. Remove Product");
        Console.WriteLine("5. Exit");
        Console.Write("Choose an option: ");
        string choice = Console.ReadLine();

        switch (choice)
        {
            case "1":
                Console.Write("Enter product name: ");
                string name = Console.ReadLine();
                Console.Write("Enter quantity: ");
                int quantity = int.Parse(Console.ReadLine());
                Console.Write("Enter price: ");
                decimal price = decimal.Parse(Console.ReadLine());
                inventory.AddProduct(name, quantity, price);
                break;
            case "2":
                inventory.DisplayInventory();
                break;
            case "3":
                Console.Write("Enter product ID to update: ");
                int idToUpdate = int.Parse(Console.ReadLine());
                Console.Write("Enter new quantity: ");
                int newQuantity = int.Parse(Console.ReadLine());
                inventory.UpdateStock(idToUpdate, newQuantity);
                break;
            case "4":
                Console.Write("Enter product ID to remove: ");
                int idToRemove = int.Parse(Console.ReadLine());
                inventory.RemoveProduct(idToRemove);
                break;
            case "5":
                running = false;
                Console.WriteLine("Exiting the system...");
                break;
            default:
                Console.WriteLine("Invalid option, please try again.");
                break;
        }

        Console.WriteLine();
    }
}

}