My goal is to create a real-time voice assistant with the following features. (Currently, it is a demo)

Whenever I use the app, I want it to listen

The app listens to what I say perfectly and updates the text based on what I say

As it is a demo, I have set the answer to "You said: $input. This is a dummy response." so it responds to my question.

If I say something, then it will listen to me properly, but when it speaks for a reply, then it will take its own voice, so after that, it will loop.

I would like the assistant to listen and answer after I speak, and in between when I speak and the assistant speaks, the assistant should stop and listen to what I say and answer according to the latest conversation.

I have attached my code here

import 'package:flutter/material.dart';
import 'package:speech_to_text/speech_to_text.dart' as stt;
import 'package:flutter_tts/flutter_tts.dart';

void main() => runApp(VoiceAssistantApp());

class VoiceAssistantApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: VoiceAssistantScreen(),
    );
  }
}

class VoiceAssistantScreen extends StatefulWidget {
  @override
  _VoiceAssistantScreenState createState() => _VoiceAssistantScreenState();
}

class _VoiceAssistantScreenState extends State<VoiceAssistantScreen> {
  stt.SpeechToText _speech = stt.SpeechToText();
  FlutterTts _flutterTts = FlutterTts();
  bool _isListening = false;
  String _lastWords = '';
  String _response = '';

  @override
  void initState() {
    super.initState();
    startListening();
  }

  void startListening() async {
    bool available = await _speech.initialize();
    if (available) {
      setState(() => _isListening = true);
      _speech.listen(
          onResult: (result) {
            if (result.finalResult) {
              setState(() {
                _lastWords = result.recognizedWords;
              });
              processUserInput(_lastWords);
            }
          },
          listenFor: Duration(minutes: 5),
          pauseFor: Duration(seconds: 5),
          listenOptions: stt.SpeechListenOptions(
              cancelOnError: false,
              partialResults: true,
              onDevice: false,
              listenMode: stt.ListenMode.confirmation,
              sampleRate: 0,
              autoPunctuation: true,
              enableHapticFeedback: false));
    }
  }

  void processUserInput(String input) {
    String response = "You said: $input. This is a dummy response.";
    setState(() {
      _response = response; // Update the response text
    });
    speak(response).then((_) {
      startListening(); // Restart listening after speaking
    });
  }

  Future<void> speak(String text) async {
    await _flutterTts.speak(text); // Speak without waiting for completion
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Voice Assistant')),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(
              _isListening ? 'Listening...' : 'Not Listening',
              style: TextStyle(fontSize: 20),
            ),
            SizedBox(height: 20), // Add some spacing
            Text(
              'You said:',
              style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
            ),
            Text(
              _lastWords,
              style: TextStyle(fontSize: 16, color: Colors.blue),
            ),
            SizedBox(height: 20), // Add some spacing
            Text(
              'Response:',
              style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
            ),
            Text(
              _response,
              style: TextStyle(fontSize: 16, color: Colors.green),
            ),
          ],
        ),
      ),
    );
  }
}