checkout.cs

public class CheckoutSaga :
    Saga<CheckoutSagaData>,
    IAmStartedByMessages<OrderPlaced>,
    IHandleMessages<InventoryReserved>,
    IHandleMessages<PaymentCaptured>,
    IHandleTimeouts<PaymentCaptureTimeout>
{
    protected override void ConfigureHowToFindSaga(
        SagaPropertyMapper<CheckoutSagaData> mapper)
    {
        mapper.MapSaga(saga => saga.OrderId)
            .ToMessage<OrderPlaced>(message => message.OrderId)
            .ToMessage<InventoryReserved>(message => message.OrderId)
            .ToMessage<PaymentCaptured>(message => message.OrderId);
    }

    public async Task Handle(
        OrderPlaced message,
        IMessageHandlerContext context)
    {
        Data.OrderId = message.OrderId;

        await context.Send(new ReserveInventory(
            message.OrderId,
            message.ProductId,
            message.Quantity));
    }
    
    public async Task Handle(
        InventoryReserved message,
        IMessageHandlerContext context)
    {
        Data.InventoryReserved = true;

        await context.Send(new CapturePayment(
            message.OrderId,
            message.Amount));

        await RequestTimeout<PaymentCaptureTimeout>(
            context,
            TimeSpan.FromMinutes(15));
    }
    
    public async Task Handle(
        PaymentCaptured message,
        IMessageHandlerContext context)
    {
        Data.PaymentCaptured = true;

        await context.Send(new ConfirmOrder(message.OrderId));

        MarkAsComplete();
    }

    public async Task Timeout(
        PaymentCaptureTimeout timeout,
        IMessageHandlerContext context)
    {
        if (Data.PaymentCaptured)
        {
            return;
        }

        await context.Send(new RequestPaymentReconciliation(Data.OrderId));
    }
}