From ae8531ea8101145d4adf2bdda57eee3666adc762 Mon Sep 17 00:00:00 2001
From: Rowan Seymour <rowanseymour@gmail.com>
Date: Tue, 10 Aug 2021 14:56:41 -0500
Subject: [PATCH] Implement asynchronous AMD for Twilio IVR

---
 core/ivr/ivr.go         |  7 ++++++-
 core/ivr/twiml/twiml.go | 18 +++++++++---------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/core/ivr/ivr.go b/core/ivr/ivr.go
index 3738497dd..e2e4fbda5 100644
--- a/core/ivr/ivr.go
+++ b/core/ivr/ivr.go
@@ -417,6 +417,11 @@ func ResumeIVRFlow(
 		return WriteErrorResponse(ctx, rt.DB, client, conn, w, errors.Errorf("active session: %d does not match connection: %d", session.ID(), *session.ConnectionID()))
 	}
 
+	// check connection is still marked as in progress
+	if conn.Status() != models.ConnectionStatusInProgress {
+		return WriteErrorResponse(ctx, rt.DB, client, conn, w, errors.Errorf("connection in invalid state: %s", conn.Status()))
+	}
+
 	// preprocess this request
 	body, err := client.PreprocessResume(ctx, rt.DB, rt.RP, conn, r)
 	if err != nil {
@@ -590,7 +595,7 @@ func HandleIVRStatus(ctx context.Context, rt *runtime.Runtime, oa *models.OrgAss
 		// no associated start? this is a permanent failure
 		if conn.StartID() == models.NilStartID {
 			conn.MarkFailed(ctx, rt.DB, time.Now())
-			return client.WriteEmptyResponse(w, "status updated: F")
+			return client.WriteEmptyResponse(w, "no flow start found, status updated: F")
 		}
 
 		// on errors we need to look up the flow to know how long to wait before retrying
diff --git a/core/ivr/twiml/twiml.go b/core/ivr/twiml/twiml.go
index 577e672ab..f95ba7150 100644
--- a/core/ivr/twiml/twiml.go
+++ b/core/ivr/twiml/twiml.go
@@ -190,7 +190,7 @@ func (c *client) RequestCall(number urns.URN, callbackURL string, statusURL stri
 	form.Set("StatusCallback", statusURL)
 	form.Set("MachineDetection", "Enable")
 	form.Set("AsyncAmd", "true")
-	form.Set("AsyncAmdStatusCallback", callbackURL)
+	form.Set("AsyncAmdStatusCallback", statusURL)
 
 	sendURL := c.baseURL + strings.Replace(callPath, "{AccountSID}", c.accountSID, -1)
 
@@ -289,14 +289,14 @@ func (c *client) ResumeForRequest(r *http.Request) (ivr.Resume, error) {
 
 // StatusForRequest returns the current call status for the passed in status (and optional duration if known)
 func (c *client) StatusForRequest(r *http.Request) (models.ConnectionStatus, int) {
+	// we re-use our status callback for AMD results which will have an AnsweredBy field but no CallStatus field
 	answeredBy := r.Form.Get("AnsweredBy")
-
-	switch answeredBy {
-	case "human", "unknown", "":
-		break
-
-	default:
-		return models.ConnectionStatusErrored, 0
+	if answeredBy != "" {
+		switch answeredBy {
+		case "machine_start", "fax":
+			return models.ConnectionStatusErrored, 0
+		}
+		return models.ConnectionStatusInProgress, 0
 	}
 
 	status := r.Form.Get("CallStatus")
@@ -316,7 +316,7 @@ func (c *client) StatusForRequest(r *http.Request) (models.ConnectionStatus, int
 		return models.ConnectionStatusErrored, 0
 
 	default:
-		logrus.WithField("call_status", status).Error("unknown call status in ivr callback")
+		logrus.WithField("call_status", status).Error("unknown call status in status callback")
 		return models.ConnectionStatusFailed, 0
 	}
 }