Attribute Routing for Nimbus

AppServerCommandRouteAttribute.cs

[AttributeUsage(AttributeTargets.Class)]
public class AppServerCommandRouteAttribute : Attribute
{
    public AppServerCommandRouteAttribute(string route)
    {
        if (string.IsNullOrWhiteSpace(route)) throw new ArgumentNullException("route");

        Route = ("appserver." + route).ToLowerInvariant();
    }

    public string Route { get; private set; }
}

AppServerMessageRouter.cs

public class AppServerMessageRouter : IRouter
{
    internal static readonly string AppServerCommandsQueue = "appserver.commands";
    internal static readonly string AppServerRequestsQueue = "appserver.requests";
    //internal static readonly string AppServerEventsTopic = "appserver.events";

    public bool CanRoute(Type messageType)
    {
        return messageType.IsBusMessage();
    }

    public string Route(Type messageType, QueueOrTopic queueOrTopic)
    {
        if (messageType.IsBusCommand())
        {
            var commandRouteAttribute = messageType.GetCustomAttribute<AppServerCommandRouteAttribute>();
            return commandRouteAttribute != null ? commandRouteAttribute.Route : AppServerCommandsQueue;
        }

        if (messageType.IsBusRequest())
            return AppServerRequestsQueue;

        if (messageType.IsBusEvent())
            return PathFactory.TopicPathFor(messageType);
            //return AppServerEventsTopic;

        throw new Exception("Cannot build a route for the message type '{0}'.".FormatWith(messageType.FullName));
    }
}

DelegatingRouter.cs

public class DelegatingRouter : IRouter
{
    private readonly IEnumerable<IRouter> _routers;

    public DelegatingRouter(IEnumerable<IRouter> routers)
    {
        _routers = routers;
    }
     
    public string Route(Type messageType, QueueOrTopic queueOrTopic)
    {
        //Terrible, fix it.
        var router = _routers.FirstOrDefault(x => ((dynamic)x).CanRoute(messageType) == true);

        if (router == null)
            throw new RoutingException("Unable to find a router for message type {0}".FormatWith(messageType.FullName));

        return router.Route(messageType, queueOrTopic);
    }
}

gistfile1.txt

.WithRouter(new DelegatingRouter(new IRouter[] 
                {
                    new AppServerMessageRouter()
                }))

QueuedCommunicationCommandRouteAttribute.cs

public class QueuedCommunicationCommandRouteAttribute : AppServerCommandRouteAttribute
{
    public QueuedCommunicationCommandRouteAttribute()
        : base("queuedcommunication")
    {
    }
}

RoutingException.cs

public class RoutingException : Exception
{
    public RoutingException(string message)
        : base(message)
    {
    }
}