import 'dart:async';
import 'package:flutter/foundation.dart';
import 'package:flutter/services.dart';
import 'package:mymuseum_visitapp/Services/Glasses/engines/wake_word_engine.dart';

/// Wake word via OpenWakeWord — service Android natif (foreground service).
/// Supporte plusieurs modèles en parallèle : un seul AudioRecord + pipeline
/// mel→embedding partagée, N classifieurs TFLite tournant simultanément.
///
/// Événements reçus : "detected:hey_marco", "detected:hey_alba", etc.
/// → onDetectedWithCommand("hey_marco") si fourni, sinon onDetected()
///
/// iOS non supporté — fallback sur SpeechToTextWakeWordEngine.
class OpenWakeWordEngine implements WakeWordEngine {
  static const _methodChannel = MethodChannel('be.unov.mymuseum/wake_word');
  static const _eventChannel = EventChannel('be.unov.mymuseum/wake_word_events');

  /// Un ou plusieurs modèles .tflite dans assets/files (sans extension).
  /// Ex: ['hey_marco'] ou ['hey_alba', 'hey_marco', 'hey_vasco']
  final List<String> modelNames;

  StreamSubscription<dynamic>? _subscription;
  void Function()? _onDetected;
  void Function(String modelName)? _onModelDetected;
  bool _running = false;

  OpenWakeWordEngine({
    List<String>? modelNames,
    String? modelName,
  }) : modelNames = modelNames ?? (modelName != null ? [modelName] : ['hey_visit']);

  @override
  Future<void> start({
    required void Function() onDetected,
    void Function(String command)? onDetectedWithCommand,
  }) async {
    if (_running) return;
    if (!_isAndroid) {
      debugPrint('[OpenWakeWordEngine] Android only — no-op on this platform');
      return;
    }

    _onDetected = onDetected;
    _onModelDetected = onDetectedWithCommand;
    _running = true;

    _subscription = _eventChannel.receiveBroadcastStream().listen(
      (event) {
        if (!_running || event is! String) return;
        if (event.startsWith('detected:')) {
          final name = event.substring('detected:'.length);
          debugPrint('[OpenWakeWordEngine] Wake word detected: $name');
          if (_onModelDetected != null) {
            _onModelDetected!(name);
          } else {
            _onDetected?.call();
          }
        }
      },
      onError: (e) => debugPrint('[OpenWakeWordEngine] Event error: $e'),
    );

    await _methodChannel.invokeMethod('start', {
      'modelNames': modelNames.join(','),
    });
    debugPrint('[OpenWakeWordEngine] Service started (models: $modelNames)');
  }

  @override
  Future<void> stop() async {
    if (!_running) return;
    _running = false;
    await _subscription?.cancel();
    _subscription = null;
    if (_isAndroid) await _methodChannel.invokeMethod('stop');
    debugPrint('[OpenWakeWordEngine] Service stopped');
  }

  bool get _isAndroid => defaultTargetPlatform == TargetPlatform.android;
}