fix(datachannel): checkpoint lobby token refresh and llm resubscribe …

packages/@webex/plugin-meetings/src/meeting/index.ts

@@ -3734,7 +3734,7 @@ export default class Meeting extends StatelessWebexPlugin {
       });
       this.updateLLMConnection();
     });
-    this.locusInfo.on(LOCUSINFO.EVENTS.SELF_ADMITTED_GUEST, async (payload) => {
+    this.locusInfo.on(LOCUSINFO.EVENTS.SELF_ADMITTED_GUEST, (payload) => {
       this.stopKeepAlive();
 
       if (payload) {
@@ -3760,6 +3760,15 @@ export default class Meeting extends StatelessWebexPlugin {
         });
       }
       this.rtcMetrics?.sendNextMetrics();
+
+      this.ensureDefaultDatachannelTokenAfterAdmit().catch((error) => {
+        LoggerProxy.logger.warn(
+          `Meeting:index#setUpLocusInfoSelfListener --> failed post-admit token prefetch flow: ${
+            error?.message || String(error)
+          }`
+        );
+      });
+
       this.updateLLMConnection();
     });
 
@@ -5960,6 +5969,30 @@ export default class Meeting extends StatelessWebexPlugin {
     );
   }
 
+  /**
+   * Restores LLM subchannel subscriptions after reconnect when captions are active.
+   * @returns {void}
+   */
+  private restoreLLMSubscriptionsIfNeeded(): void {
+    try {
+      // @ts-ignore
+      const isCaptionBoxOn = this.webex.internal.voicea?.getIsCaptionBoxOn?.();
+
+      if (!isCaptionBoxOn) {
+        return;
+      }
+
+      // @ts-ignore
+      this.webex.internal.voicea.updateSubchannelSubscriptions({subscribe: ['transcription']});
+    } catch (error) {
+      const msg = error?.message || String(error);
+
+      LoggerProxy.logger.warn(
+        `Meeting:index#restoreLLMSubscriptionsIfNeeded --> failed to restore subscriptions after LLM online: ${msg}`
+      );
+    }
+  }
+
   /**
    * This is a callback for the LLM event that is triggered when it comes online
    * This method in turn will trigger an event to the developers that the LLM is connected
@@ -5968,8 +6001,8 @@ export default class Meeting extends StatelessWebexPlugin {
    * @returns {null}
    */
   private handleLLMOnline = (): void => {
-    // @ts-ignore
-    this.webex.internal.llm.off('online', this.handleLLMOnline);
+    this.restoreLLMSubscriptionsIfNeeded();
+
     Trigger.trigger(
       this,
       {
@@ -6200,6 +6233,8 @@ export default class Meeting extends StatelessWebexPlugin {
         this.saveDataChannelToken(join);
         // @ts-ignore - config coming from registerPlugin
         if (this.config.enableAutomaticLLM) {
+          // @ts-ignore
+          this.webex.internal.llm.off('online', this.handleLLMOnline);
           // @ts-ignore
           this.webex.internal.llm.on('online', this.handleLLMOnline);
           this.updateLLMConnection()
@@ -6343,6 +6378,52 @@ export default class Meeting extends StatelessWebexPlugin {
     }
   }
 
+  /**
+   * Ensures default-session data channel token exists after lobby admission.
+   * Some lobby users do not receive a token until they are admitted.
+   * @returns {Promise<boolean>} true when a new token is fetched and cached
+   */
+  private async ensureDefaultDatachannelTokenAfterAdmit(): Promise<boolean> {
+    try {
+      // @ts-ignore
+      const datachannelToken = this.webex.internal.llm.getDatachannelToken();
+      // @ts-ignore
+      const isDataChannelTokenEnabled = await this.webex.internal.llm.isDataChannelTokenEnabled();
+
+      if (!isDataChannelTokenEnabled || datachannelToken) {
+        return false;
+      }
+
+      const response = await this.meetingRequest.fetchDatachannelToken({
+        locusUrl: this.locusUrl,
+        requestingParticipantId: this.members.selfId,
+        isPracticeSession: false,
+      });
+      const fetchedDatachannelToken = response?.body?.datachannelToken;
+
+      if (!fetchedDatachannelToken) {
+        return false;
+      }
+
+      // @ts-ignore
+      this.webex.internal.llm.setDatachannelToken(
+        fetchedDatachannelToken,
+        DataChannelTokenType.Default
+      );
+
+      return true;
+    } catch (error) {
+      const msg = error?.message || String(error);
+
+      LoggerProxy.logger.warn(
+        `Meeting:index#ensureDefaultDatachannelTokenAfterAdmit --> failed to proactively fetch default data channel token after admit: ${msg}`,
+        {statusCode: error?.statusCode}
+      );
+
+      return false;
+    }
+  }
+
   /**
    * Connects to low latency mercury and reconnects if the address has changed
    * It will also disconnect if called when the meeting has ended

packages/@webex/plugin-meetings/src/webinar/index.ts

@@ -154,12 +154,63 @@ const Webinar = WebexPlugin.extend({
     );
   },
 
+  /**
+   * Ensures practice-session token exists before registering the practice LLM channel.
+   * @param {object} meeting
+   * @returns {Promise<string|undefined>}
+   */
+  async ensurePracticeSessionDatachannelToken(meeting) {
+    // @ts-ignore
+    const isDataChannelTokenEnabled = await this.webex.internal.llm.isDataChannelTokenEnabled();
+
+    if (!isDataChannelTokenEnabled) {
+      return undefined;
+    }
+
+    // @ts-ignore
+    const cachedToken = this.webex.internal.llm.getDatachannelToken(
+      DataChannelTokenType.PracticeSession
+    );
+
+    if (cachedToken) {
+      return cachedToken;
+    }
+
+    try {
+      const refreshResponse = await meeting.refreshDataChannelToken();
+      const {datachannelToken, dataChannelTokenType} = refreshResponse?.body ?? {};
+
+      if (!datachannelToken) {
+        return undefined;
+      }
+
+      // @ts-ignore
+      this.webex.internal.llm.setDatachannelToken(
+        datachannelToken,
+        dataChannelTokenType || DataChannelTokenType.PracticeSession
+      );
+
+      return datachannelToken;
+    } catch (error) {
+      LoggerProxy.logger.warn(
+        `Webinar:index#ensurePracticeSessionDatachannelToken --> failed to proactively refresh practice-session token: ${
+          error?.message || String(error)
+        }`
+      );
+
+      return undefined;
+    }
+  },
+
   /**
    * Connects to low latency mercury and reconnects if the address has changed
    * It will also disconnect if called when the meeting has ended
    * @returns {Promise}
    */
   async updatePSDataChannel() {
+    this._updatePSDataChannelSequence = (this._updatePSDataChannelSequence || 0) + 1;
+    const invocationSequence = this._updatePSDataChannelSequence;
+
     const meeting = this.webex.meetings.getMeetingByType(_ID_, this.meetingId);
     const isPracticeSession = meeting?.isJoined() && this.isJoinPracticeSessionDataChannel();
 
@@ -174,7 +225,7 @@ const Webinar = WebexPlugin.extend({
       meeting?.locusInfo || {};
 
     // @ts-ignore
-    const practiceSessionDatachannelToken = this.webex.internal.llm.getDatachannelToken(
+    let practiceSessionDatachannelToken = this.webex.internal.llm.getDatachannelToken(
       DataChannelTokenType.PracticeSession
     );
 
@@ -229,6 +280,29 @@ const Webinar = WebexPlugin.extend({
       this._pendingOnlineListener = null;
     }
 
+    const refreshedPracticeSessionToken = await this.ensurePracticeSessionDatachannelToken(meeting);
+
+    const latestPracticeSessionDatachannelUrl = get(
+      meeting,
+      'locusInfo.info.practiceSessionDatachannelUrl'
+    );
+    const isStillPracticeSession = meeting?.isJoined() && this.isJoinPracticeSessionDataChannel();
+
+    // Skip stale invocations after async refresh to avoid reconnecting a session
+    // that was already updated/cleaned by a newer state transition.
+    if (
+      invocationSequence !== this._updatePSDataChannelSequence ||
+      !isStillPracticeSession ||
+      !latestPracticeSessionDatachannelUrl ||
+      latestPracticeSessionDatachannelUrl !== practiceSessionDatachannelUrl
+    ) {
+      return undefined;
+    }
+
+    if (refreshedPracticeSessionToken) {
+      practiceSessionDatachannelToken = refreshedPracticeSessionToken;
+    }
+
     // @ts-ignore - Fix type
     return this.webex.internal.llm
       .registerAndConnect(