‫بررسی تغییرات نحوه‌ی تعریف خواص در C# 13

1. اگر محصول در تخفیف باشد، قیمت نهایی شامل تخفیف می‌شود.
2. اگر مشتری VIP باشد، درصد تخفیف بیشتری اعمال می‌شود.
3. اگر مالیات (Tax) فعال باشد، به قیمت نهایی اضافه می‌شود.
4. تمامی این منطق باید از هم جدا باشد تا نگهداری و گسترش پروژه ساده‌تر شود.

// File1.cs
public partial class Product
{
    public string Name { get; set; }              // Product name
    public decimal BasePrice { get; set; }        // Base price of the product
    public decimal Discount { get; set; }         // Discount percentage
    public bool IsOnSale { get; set; }            // Indicates if the product is on sale
    public bool IsVipCustomer { get; set; }       // Indicates if the customer is VIP
    public bool TaxApplicable { get; set; }       // Indicates if tax is applicable

    // Partial property declaration for final price calculation
    public partial decimal FinalPrice { get; }
}

// File2.cs
public partial class Product
{
    public partial decimal FinalPrice
    {
        get
        {
            // Apply discount if the product is on sale
            if (IsOnSale)
            {
                return BasePrice - (BasePrice * Discount / 100);
            }
            return BasePrice; // Return base price if no discount applies
        }
    }
}

// File3.cs
public partial class Product
{
    public partial decimal FinalPrice
    {
        get
        {
            // Apply additional discount for VIP customers
            if (IsVipCustomer)
            {
                decimal vipDiscount = Discount + 10; // Add an extra 10% discount for VIPs
                return BasePrice - (BasePrice * vipDiscount / 100);
            }
            return BasePrice; // Return base price if not a VIP
        }
    }
}

// File4.cs
public partial class Product
{
    public partial decimal FinalPrice
    {
        get
        {
            decimal price = BasePrice;

            // Add tax if applicable
            if (TaxApplicable)
            {
                decimal taxRate = 0.15m; // 15% tax rate
                price += BasePrice * taxRate;
            }

            return price;
        }
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        // Product 1: On sale with general discount
        var product1 = new Product
        {
            Name = "Laptop",
            BasePrice = 100_000_000, // 100,000,000 IRR
            Discount = 10,          // 10% general discount
            IsOnSale = true,
            IsVipCustomer = false,
            TaxApplicable = false
        };

        Console.WriteLine($"Product 1 ({product1.Name}) Final Price: {product1.FinalPrice:N0} IRR");

        // Product 2: VIP customer with additional discount
        var product2 = new Product
        {
            Name = "Smartphone",
            BasePrice = 80_000_000, // 80,000,000 IRR
            Discount = 5,           // 5% general discount
            IsOnSale = true,
            IsVipCustomer = true,
            TaxApplicable = false
        };

        Console.WriteLine($"Product 2 ({product2.Name}) Final Price: {product2.FinalPrice:N0} IRR");

        // Product 3: Product with tax applied
        var product3 = new Product
        {
            Name = "Tablet",
            BasePrice = 50_000_000, // 50,000,000 IRR
            Discount = 0,
            IsOnSale = false,
            IsVipCustomer = false,
            TaxApplicable = true
        };

        Console.WriteLine($"Product 3 ({product3.Name}) Final Price: {product3.FinalPrice:N0} IRR");
    }
}

Product 1 (Laptop) Final Price: 90,000,000 IRR
Product 2 (Smartphone) Final Price: 68,000,000 IRR
Product 3 (Tablet) Final Price: 54,500,000 IRR