/// <summary>
/// Process the intent based on the intent context
/// </summary>
/// <param name="turnContext">turn context</param>
/// <param name="intentContext">intent context</param>
/// <param name="cancellationToken"></param>
/// <returns>task</returns>
public Task ProcessIntentAsync(
ITurnContext turnContext,
IntentContext intentContext,
CancellationToken cancellationToken)
{
if (!(intentContext is T))
{
throw new InvalidOperationException($"intentContext of {intentContext.GetType().Name} is not allowed");
}
return(this.ProcessIntentInternalAsync(turnContext, intentContext as T, cancellationToken));
}
/// <summary>
/// Get handler type for the given intent context.
/// Uses local cache first to avoid unnecessary reflection.
/// </summary>
/// <param name="intentContext"></param>
/// <returns></returns>
private Type GetHandlerType(IntentContext intentContext)
{
var intentContextType = intentContext.GetType();
var result = this.HandlerTypeMap.GetOrAdd(
intentContextType,
x =>
{
// Not in the map before. Use reflection to get it.
var handlerGenericType = typeof(IntentHandler <>);
var handlerType = handlerGenericType.MakeGenericType(intentContextType);
return(handlerType);
});
return(result);
}
/// <summary>
/// Get the intent handler given the intent context
/// </summary>
/// <param name="intentContext">intent context</param>
/// <returns>task</returns>
public IIntentHandler GetIntentHandler(IntentContext intentContext)
{
intentContext = intentContext ?? throw new ArgumentNullException(nameof(intentContext));
// NOTE - we use service provider and reflection to dynamically locate the intent handler - which can be scoped or transient
// and depend on other scoped/transient services.
// We cannot direclty resolve them since intents are singletons.
var handlerType = this.GetHandlerType(intentContext);
var handler = (IIntentHandler)this.serviceProvider.GetService(handlerType);
if (handler == null)
{
var error = $"No handler registered for {intentContext.GetType().Name}.";
this.logger.LogError(error);
throw new InvalidOperationException(error);
}
return(handler);
}