fix gather

lib/tasks/gather.js

@@ -65,6 +65,11 @@ class TaskGather extends Task {
       const recognizer = this.data.recognizer;
       this.vendor = recognizer.vendor;
       this.language = recognizer.language;
+      this.label = recognizer.label;
+
+      this.fallbackVendor = recognizer.fallbackVendor || 'default';
+      this.fallbackLanguage = recognizer.fallbackLanguage || 'default';
+      this.fallbackLabel = recognizer.fallbackLabel || 'default';
 
       /* let credentials be supplied in the recognizer object at runtime */
       this.sttCredentials = setSpeechCredentialsAtRuntime(recognizer);
@@ -133,11 +138,48 @@ class TaskGather extends Task {
     return s;
   }
 
+  async _initSpeechCredentials(cs, vendor, label) {
+    const {getNuanceAccessToken, getIbmAccessToken} = this.cs.srf.locals.dbHelpers;
+    let credentials = cs.getSpeechCredentials(vendor, 'stt', label);
+
+    if (!credentials) {
+      const {writeAlerts, AlertType} = cs.srf.locals;
+      this.logger.info(`TaskGather:exec - ERROR stt using ${vendor} requested but creds not supplied`);
+      writeAlerts({
+        account_sid: cs.accountSid,
+        alert_type: AlertType.STT_NOT_PROVISIONED,
+        vendor
+      }).catch((err) => this.logger.info({err}, 'Error generating alert for no stt'));
+      // Notify application that STT vender is wrong.
+      this.notifyError({
+        msg: 'ASR error',
+        details: `No speech-to-text service credentials for ${vendor} have been configured`
+      });
+      this.notifyTaskDone();
+      throw new Error(`No speech-to-text service credentials for ${vendor} have been configured`);
+    }
+
+    if (vendor === 'nuance' && credentials.client_id) {
+      /* get nuance access token */
+      const {client_id, secret} = credentials;
+      const {access_token, servedFromCache} = await getNuanceAccessToken(client_id, secret, 'asr tts');
+      this.logger.debug({client_id}, `Gather:exec - got nuance access token ${servedFromCache ? 'from cache' : ''}`);
+      credentials = {...credentials, access_token};
+    }
+    else if (vendor == 'ibm' && credentials.stt_api_key) {
+      /* get ibm access token */
+      const {stt_api_key, stt_region} = credentials;
+      const {access_token, servedFromCache} = await getIbmAccessToken(stt_api_key);
+      this.logger.debug({stt_api_key}, `Gather:exec - got ibm access token ${servedFromCache ? 'from cache' : ''}`);
+      credentials = {...credentials, access_token, stt_region};
+    }
+    return credentials;
+  }
+
   async exec(cs, {ep}) {
     this.logger.debug({options: this.data}, 'Gather:exec');
     await super.exec(cs);
     const {updateSpeechCredentialLastUsed} = require('../utils/db-utils')(this.logger, cs.srf);
-    const {getNuanceAccessToken, getIbmAccessToken} = cs.srf.locals.dbHelpers;
 
     if (cs.hasGlobalSttHints && !this.maskGlobalSttHints) {
       const {hints, hintsBoost} = cs.globalSttHints;
@@ -184,58 +226,61 @@ class TaskGather extends Task {
       this.language = cs.speechRecognizerLanguage;
       if (this.data.recognizer) this.data.recognizer.language = this.language;
     }
+    this.fallbackVendor = this.data.recognizer && this.data.recognizer.fallbackVendor !== 'default' ?
+      this.data.recognizer.fallbackVendor :
+      cs.fallbackSpeechRecognizerVendor;
+
+    this.fallbackLanguage = this.data.recognizer && this.data.recognizer.fallbackLanguage !== 'default' ?
+      this.data.recognizer.fallbackLanguage :
+      cs.fallbackSpeechRecognizerLanguage;
+
+    this.fallbackLabel = this.data.recognizer && this.data.recognizer.fallbackLabel !== 'default' ?
+      this.data.recognizer.fallbackLabel :
+      cs.fallbackSpeechRecognizerLabel;
+
     if (!this.data.recognizer.vendor) {
       this.data.recognizer.vendor = this.vendor;
     }
-    if (this.needsStt && !this.sttCredentials) this.sttCredentials =
-      cs.getSpeechCredentials(this.vendor, 'stt', this.data.recognizer?.label || cs.speechRecognizerLabel);
+
     if (this.needsStt && !this.sttCredentials) {
-      const {writeAlerts, AlertType} = cs.srf.locals;
-      this.logger.info(`TaskGather:exec - ERROR stt using ${this.vendor} requested but creds not supplied`);
-      writeAlerts({
-        account_sid: cs.accountSid,
-        alert_type: AlertType.STT_NOT_PROVISIONED,
-        vendor: this.vendor
-      }).catch((err) => this.logger.info({err}, 'Error generating alert for no stt'));
-      // Notify application that STT vender is wrong.
-      this.notifyError({
-        msg: 'ASR error',
-        details: `No speech-to-text service credentials for ${this.vendor} have been configured`
-      });
-      this.notifyTaskDone();
-      throw new Error(`No speech-to-text service credentials for ${this.vendor} have been configured`);
+      this.sttCredentials = await this._initSpeechCredentials(cs, this.vendor, this.label);
     }
 
-    if (this.vendor === 'nuance' && this.sttCredentials.client_id) {
-      /* get nuance access token */
-      const {client_id, secret} = this.sttCredentials;
-      const {access_token, servedFromCache} = await getNuanceAccessToken(client_id, secret, 'asr tts');
-      this.logger.debug({client_id}, `Gather:exec - got nuance access token ${servedFromCache ? 'from cache' : ''}`);
-      this.sttCredentials = {...this.sttCredentials, access_token};
+    // Fetch credential for fallback recognizer
+    if (this.needsStt && !this.fallbackSttCredentials && this.fallbackVendor) {
+      this.fallbackSttCredentials = await this._initSpeechCredentials(
+        cs, this.fallbackSttCredentials, this.fallbackLabel);
     }
-    else if (this.vendor == 'ibm' && this.sttCredentials.stt_api_key) {
-      /* get ibm access token */
-      const {stt_api_key, stt_region} = this.sttCredentials;
-      const {access_token, servedFromCache} = await getIbmAccessToken(stt_api_key);
-      this.logger.debug({stt_api_key}, `Gather:exec - got ibm access token ${servedFromCache ? 'from cache' : ''}`);
-      this.sttCredentials = {...this.sttCredentials, access_token, stt_region};
-    }
-    const startListening = (cs, ep) => {
+
+    const startListening = async(cs, ep) => {
       this._startTimer();
       if (this.isContinuousAsr && 0 === this.timeout) this._startAsrTimer();
       if (this.input.includes('speech') && !this.listenDuringPrompt) {
-        this._initSpeech(cs, ep)
-          .then(() => {
-            if (this.killed) {
-              this.logger.info('Gather:exec - task was quickly killed so do not transcribe');
-              return;
+        try {
+          await this._initSpeech(cs, ep, this.sttCredentials);
+          if (this.killed) {
+            this.logger.info('Gather:exec - task was quickly killed so do not transcribe');
+            return;
+          }
+          this._startTranscribing(ep, this.vendor, this.language);
+          return updateSpeechCredentialLastUsed(this.sttCredentials.speech_credential_sid);
+        } catch (error) {
+          this.logger.error({error}, 'error in initSpeech');
+          if (this.fallbackSttCredentials) {
+            try {
+              this.logger.info(`fallback to STT provider: ${this.fallbackSttCredentials.vendor}`);
+              await this._initSpeech(cs, ep, this.fallbackSttCredentials);
+              if (this.killed) {
+                this.logger.info('Gather:exec - task was quickly killed so do not transcribe');
+                return;
+              }
+              this._startTranscribing(ep, this.fallbackVendor, this.fallbackLanguage);
+              return updateSpeechCredentialLastUsed(this.fallbackSttCredentials.speech_credential_sid);
+            } catch (err) {
+              this.logger.error({err}, `error in initSpeech for fallback STT provider ${this.fallbackVendor}`);
             }
-            this._startTranscribing(ep);
-            return updateSpeechCredentialLastUsed(this.sttCredentials.speech_credential_sid);
-          })
-          .catch((err) => {
-            this.logger.error({err}, 'error in initSpeech');
-          });
+          }
+        }
       }
     };
 
@@ -363,9 +408,9 @@ class TaskGather extends Task {
     }
   }
 
-  async _initSpeech(cs, ep) {
-    const opts = this.setChannelVarsForStt(this, this.sttCredentials, this.data.recognizer);
-    switch (this.vendor) {
+  async _initSpeech(cs, ep, credentials) {
+    const opts = this.setChannelVarsForStt(this, credentials, this.data.recognizer);
+    switch (credentials.vendor) {
       case 'google':
         this.bugname = 'google_transcribe';
         ep.addCustomEventListener(GoogleTranscriptionEvents.Transcription, this._onTranscription.bind(this, cs, ep));
@@ -451,9 +496,9 @@ class TaskGather extends Task {
           break;
         }
         else {
-          this.notifyError({ msg: 'ASR error', details:`Invalid vendor ${this.vendor}`});
+          this.notifyError({ msg: 'ASR error', details:`Invalid vendor ${credentials.vendor}`});
           this.notifyTaskDone();
-          throw new Error(`Invalid vendor ${this.vendor}`);
+          throw new Error(`Invalid vendor ${credentials.vendor}`);
         }
     }
 
@@ -463,16 +508,16 @@ class TaskGather extends Task {
       .catch((err) => this.logger.info(err, 'Error setting channel variables'));
   }
 
-  _startTranscribing(ep) {
+  _startTranscribing(ep, vendor = this.vendor, language = this.language) {
     this.logger.debug({
-      vendor: this.vendor,
-      locale: this.language,
+      vendor,
+      locale: language,
       interim: this.interim,
       bugname: this.bugname
     }, 'Gather:_startTranscribing');
     ep.startTranscription({
-      vendor: this.vendor,
-      locale: this.language,
+      vendor,
+      locale: language,
       interim: this.interim,
       bugname: this.bugname,
     }).catch((err) => {
@@ -481,7 +526,7 @@ class TaskGather extends Task {
       writeAlerts({
         account_sid: this.cs.accountSid,
         alert_type: AlertType.STT_FAILURE,
-        vendor: this.vendor,
+        vendor,
         detail: err.message
       });
     }).catch((err) => this.logger.info({err}, 'Error generating alert for tts failure'));