Actions.cs

[HttpPost("{orderId}/prepare")]
public async Task<ActionResult<OrderWithStatus>> Preparing(int orderId, [FromServices] ICapPublisher capPublisher)
{
    var order = await _db.Orders
        .Where(o => o.OrderId == orderId)
        .SingleOrDefaultAsync();

    if (order == null)
    {
        return NotFound();
    }

    order.OrderStatus = OrderStatus.Preparing;
    await _db.SaveChangesAsync();

    await capPublisher.PublishAsync(nameof(OrderBeingPreparedEvent), new OrderBeingPreparedEvent(orderId));

    return NoContent();
}

[HttpPost("{orderId}/outForDelivery")]
public async Task<ActionResult<OrderWithStatus>> OutForDelivery(int orderId, [FromServices] ICapPublisher capPublisher)
{
    var order = await _db.Orders
        .Where(o => o.OrderId == orderId)
        .SingleOrDefaultAsync();

    if (order == null)
    {
        return NotFound();
    }

    order.OrderStatus = OrderStatus.OutForDelivery;
    await _db.SaveChangesAsync();

    await capPublisher.PublishAsync(nameof(OrderPickedUpForDeliveryEvent), new OrderPickedUpForDeliveryEvent(orderId));

    return NoContent();
}

[HttpPost("{orderId}/deliver")]
public async Task<ActionResult<OrderWithStatus>> Deliver(int orderId, [FromServices] ICapPublisher capPublisher)
{
    var order = await _db.Orders
        .Where(o => o.OrderId == orderId)
        .SingleOrDefaultAsync();

    if (order == null)
    {
        return NotFound();
    }

    order.OrderStatus = OrderStatus.Delivered;
    await _db.SaveChangesAsync();

    await capPublisher.PublishAsync(nameof(OrderDeliveredEvent), new OrderDeliveredEvent(orderId));

    return NoContent();
}