/// <summary>
/// Handle a DialogFlow conversation request.
/// An instance of this class handles just one conversation,
/// which is tracked external to this class, using the DialogFlow sessionID.
/// </summary>
/// <param name="req">Conversation request</param>
/// <returns>A JSON response which is passed back to DialogFlow</returns>
public async Task <string> HandleAsync(ConvRequest req)
{
// Use reflection to find the handler method for the requested DialogFlow intent
var handler = FindHandler(req.IntentName);
if (handler == null)
{
return(DialogflowApp.Tell($"Sorry, no handler found for intent: {req.IntentName}"));
}
try
{
using (_tracer.StartSpan(req.IntentName))
{
// Call the sync handler, if there is one. If not, call the async handler.
// Otherwise, it's an error.
return(handler.Handle(req) ??
await handler.HandleAsync(req) ??
DialogflowApp.Tell("Error. Handler did not return a valid response."));
}
}
catch (Exception e) when(req.IntentName != "exception.throw")
{
_exceptionLogger.Log(e);
var msg = (e as GoogleApiException)?.Error.Message ?? e.Message;
return(DialogflowApp.Tell($"Sorry, there's a problem: {msg}"));
}
}
/// <summary>
/// Handles received HTTP request. For details of the expected request,
/// please see Dialogflow fulfillment doc: https://dialogflow.com/docs/fulfillment
/// </summary>
/// <param name="httpRequest">HTTP request</param>
/// <returns>A response to the request which usually includes a spoken fulfillment</returns>
public async Task <string> HandleRequest(HttpRequest httpRequest)
{
using (_tracer.StartSpan(nameof(DialogflowApp)))
{
var request = await ConvRequest.ParseAsync(httpRequest);
_logger.LogInformation($"Intent: '{request.IntentName}', QueryText: '{request.QueryText}'");
var conversation = GetOrCreateConversation(request);
using (_tracer.StartSpan("Conversation"))
{
return(await conversation.HandleAsync(request));
}
}
}
/// <summary>
/// Given a conversation request with a session id, either get the existing
/// conversation or create a new one.
/// </summary>
/// <param name="convRequest">Conversation request</param>
/// <returns>Conversation</returns>
private Conversation GetOrCreateConversation(ConvRequest convRequest)
{
Conversation conversation;
lock (conversations)
{
var sessionId = convRequest.SessionId;
if (!conversations.TryGetValue(sessionId, out conversation))
{
_logger.LogInformation($"Creating new conversation with sessionId: {sessionId}");
conversation = new Conversation(_exceptionLogger, _tracer);
conversations.Add(sessionId, conversation);
}
}
return(conversation);
}