SOLID [O] - Deciding implementations

solid-O-deciding-implementations.cs

// sample enum for payment.Type
public enum PaymentType
{
    CreditCard,
    DebitCard,
    BankInvoice,
    Pix
} 

// simple factory
public static class PaymentServiceFactory
{
    public IPaymentService GetProcessor(PaymentType type)
    {
        switch (type)
        {
            case PaymentType.CreditCard:
                return new CreditCardPaymentService();
            case PaymentType.DebitCard:
                return new DebitCardPaymentService();
            case PaymentType.BankInvoice:
                return new BankInvoicePaymentService();
            case PaymentType.Pix:
                return new PixPaymentService();
            default:
                throw new NotImplementedException("Payment type not implemented");
        }
    }
}

// example calling by action into controller

[HttpPost("payments")]
public IActionResult ProcessPayment([FromBody] CreatePaymentRequest request)
{
    // do something

    var payment = request.Map<Payment>();
    var paymentProcessor = PaymentServiceFactory.GetProcessor(payment.Type);

    var result = paymentProcessor.ProcessPayment(payment);

    // return something
}