/// <summary>
/// Create an observable service from the specified message.
/// </summary>
/// <returns>The create.</returns>
/// <param name="message">Message.</param>
public async Task <MessagingResult> Create(CreateServiceObservableMessage message)
{
// lookup the existing service, it MUST exist
var service = _serviceRepository[message.Service];
if (service == null)
{
throw new InvalidOperationException($"No Service associated with {message.Service.Value}");
}
// get the target for the creation of the service and invoke it
var target = InvocationTarget.Create((service as ClassServiceInstance).Instance, message.Method, message.Parameters);
var result = await target.Invoke();
if (!target.IsObservable)
{
throw new InvalidOperationException($"Service {message.Service.Value} Method {message.Method} doesn't return an Observable");
}
// now then, we need to spin up our observable proxy with our resultant observable (which we should have)
var interfaces = result.GetType().GetInterfaces();
var i = interfaces.FirstOrDefault(ii => ii.IsConstructedGenericType && typeof(IObservable <>) == ii.GetGenericTypeDefinition());
var genericType = i.GetGenericArguments()[0];
var genericOwType = typeof(ObservableProxy <>);
var gen = genericOwType.MakeGenericType(genericType);
var serviceKey = ObservableServiceInstance.CreateKeyFor(service, message.Method);
var eventStream = _factory.CreateFor(serviceKey);
var observableProxy = (ObservableProxy)Activator.CreateInstance(gen, new object[] { result, eventStream, serviceKey });
// create the service instance, store it away
var si = new ObservableServiceInstance((ClassServiceInstance)service, observableProxy, serviceKey);
_serviceRepository.Add(si);
// and return a message with the key of the observable instance
return(new MessagingResult(si.Key));
}
