!7

// Goes well with a headphone detector like #1027532

cmodule AudioFeedbackPreventer > DynPrintLogAndEnabled {

  // from end of talking to recognition coming in

  switchable double expectedDelay = 3.0;

  transient long talkingSince;

  transient LongRange lastTalked;

  start {

    dm_registerAs_direct audioFeedbackPreventer();

    dm_vmBus_onMessage talking(r { talkingSince = sysNow() });

    dm_vmBus_onMessage doneTalking(r {

      lastTalked = longRange(talkingSince, sysNow());

      talkingSince = 0;

    });

  }

  // API

  bool recognizedSpeechIsProbablyMyOwnUtterance(O... _) {

    if (isTrue(dm_haveHeadphones())) {

      // Voice output goes to headphones, so we can't hear it

      print("Assuming I can't hear myself (headphones)");

      false;

    }

    if (talkingSince != 0) true;

    if (lastTalked == null) false;

    double elapsed = elapsedSeconds_sysNow(lastTalked.end);

    bool b = elapsed <= expectedDelay;

    if (nempty(_)) print(asList(_));

    print("Time since my last utterance: " + formatDouble(elapsed, 1) + "s, guessing it is " + (b ? "" : "not ") + " my utterance");

    ret b;

  }

}