dont' stop AMD on StoppedSpeaking, wait for tone

lib/utils/amd-utils.js

@@ -247,6 +247,11 @@ module.exports = (logger) => {
     const frequency = Math.floor(fsEvent.getHeader('Frequency'));
     const variance = Math.floor(fsEvent.getHeader('Frequency-variance'));
     task.emit('amd', {type: AmdEvents.ToneDetected, frequency, variance});
+    if (ep.amd?.awaitingTone) {
+      /* partial stop already tore down STT; finish cleanup now that the beep landed */
+      stopAmd(ep, task);
+      return;
+    }
     if (ep.amd) {
       ep.amd.stopToneTimer();
       ep.amd.beepDetected = true;
@@ -387,7 +392,9 @@ module.exports = (logger) => {
       .on(AmdEvents.MachineStoppedSpeaking, () => {
         task.emit('amd', {type: AmdEvents.MachineStoppedSpeaking});
         try {
-          stopAmd(ep, task);
+          /* if the beep already landed during the greeting, nothing left to wait for */
+          const keepAvmd = !ep.amd?.beepDetected;
+          stopAmd(ep, task, {keepAvmd});
         } catch (err) {
           logger.info({err}, 'Error stopping transcription');
         }
@@ -401,11 +408,19 @@ module.exports = (logger) => {
     ep.execute('avmd_start').catch((err) => this.logger.info(err, 'Error starting avmd'));
   };
 
-  const stopAmd = (ep, task) => {
+  const stopAmd = (ep, task, {keepAvmd = false} = {}) => {
     let vendor;
     if (ep.amd) {
       vendor = ep.amd.vendor;
-      ep.amd.stopAllTimers();
+      if (keepAvmd) {
+        /* tear down STT but leave avmd + Beep listener + toneTimer running */
+        ep.amd.stopDecisionTimer();
+        ep.amd.stopNoSpeechTimer();
+        ep.amd.stopGreetingCompletionTimer();
+        ep.amd.awaitingTone = true;
+      } else {
+        ep.amd.stopAllTimers();
+      }
       try {
         ep.removeListener(GoogleTranscriptionEvents.Transcription, ep.amd.transcriptionHandler);
         ep.removeListener(GoogleTranscriptionEvents.EndOfUtterance, ep.amd.EndOfUtteranceHandler);
@@ -421,7 +436,9 @@ module.exports = (logger) => {
       } catch (error) {
         logger.error('Unable to Remove AMD Listener', error);
       }
-      ep.amd = null;
+      if (!keepAvmd) {
+        ep.amd = null;
+      }
     }
 
     if (ep.connected) {
@@ -431,10 +448,14 @@ module.exports = (logger) => {
         gracefulShutdown: false
       })
         .catch((err) => logger.info(err, 'stopAmd: Error stopping transcription'));
-      task.emit('amd', {type: AmdEvents.Stopped});
-      ep.execute('avmd_stop').catch((err) => this.logger.info(err, 'Error stopping avmd'));
+      if (!keepAvmd) {
+        task.emit('amd', {type: AmdEvents.Stopped});
+        ep.execute('avmd_stop').catch((err) => this.logger.info(err, 'Error stopping avmd'));
+      }
+    }
+    if (!keepAvmd) {
+      ep.removeCustomEventListener(AvmdEvents.Beep);
     }
-    ep.removeCustomEventListener(AvmdEvents.Beep);
   };
 
   return {startAmd, stopAmd};