import 'dart:async';
import 'package:flutter/foundation.dart';
import 'package:speech_to_text/speech_to_text.dart';
import 'package:mymuseum_visitapp/Services/Glasses/engines/stt_engine.dart';

/// STT via speech_to_text — Google on-device (Android) / Apple (iOS).
/// Gratuit, supporte FR/NL/EN/DE.
class SpeechToTextSttEngine implements SttEngine {
  final SpeechToText _speech = SpeechToText();
  bool _initialized = false;

  Future<void> _ensureInitialized() async {
    if (_initialized) return;
    _initialized = await _speech.initialize();
    debugPrint('[SpeechToTextSttEngine] initialized: $_initialized');
  }

  @override
  Future<String> transcribeOnce({
    required String languageCode,
    Duration timeout = const Duration(seconds: 6),
  }) async {
    await _ensureInitialized();
    if (!_initialized) return '';

    final completer = Completer<String>();
    String lastResult = '';

    // Petit délai pour laisser le micro se réinitialiser après le wake word
    await Future.delayed(const Duration(milliseconds: 200));

    final timer = Timer(timeout, () {
      if (!completer.isCompleted) completer.complete(lastResult);
    });

    await _speech.listen(
      localeId: languageCode,
      onResult: (result) {
        lastResult = result.recognizedWords;
        if (result.finalResult) {
          timer.cancel();
          if (!completer.isCompleted) completer.complete(lastResult);
        }
      },
      listenOptions: SpeechListenOptions(partialResults: true),
    );

    return completer.future;
  }

  @override
  Future<void> cancel() async {
    await _speech.cancel();
  }
}