import 'dart:async';
import 'dart:io';
import 'package:flutter/foundation.dart';
import 'package:mymuseum_visitapp/Helpers/translationHelper.dart';
import 'package:just_audio/just_audio.dart';
import 'package:mobile_scanner/mobile_scanner.dart';
import 'package:mymuseum_visitapp/Models/visitContext.dart';
import 'package:mymuseum_visitapp/Services/Glasses/engines/llm_client.dart';
import 'package:mymuseum_visitapp/Services/Glasses/engines/stt_engine.dart';
import 'package:mymuseum_visitapp/Services/Glasses/engines/tts_engine.dart';
import 'package:mymuseum_visitapp/Services/Glasses/engines/wake_word_engine.dart';
import 'package:mymuseum_visitapp/Services/meta_glasses_service.dart';

/// Instance active de l'orchestrateur, accessible globalement.
/// Gérée par VoiceController — ne pas modifier directement.
VoiceOrchestrator? activeVoiceOrchestrator;

/// Orchestre le pipeline complet mains-libres :
///   WakeWord → STT → dispatch → LLM ou QR scan → TTS
///
/// Toutes les dépendances sont injectées via les interfaces abstraites
/// pour pouvoir swapper chaque maillon indépendamment.
class VoiceOrchestrator {
  final VisitAppContext visitAppContext;
  final WakeWordEngine wakeWordEngine;
  final SttEngine sttEngine;
  final TtsEngine ttsEngine;
  final LlmClient llmClient;

  bool _running = false;
  bool _inConversation = false;

  final ValueNotifier<String> lastTranscription = ValueNotifier('');
  final ValueNotifier<bool> isListeningForCommand = ValueNotifier(false);
  final ValueNotifier<String> lastTtsText = ValueNotifier('');
  final ValueNotifier<List<String>> visitPhotosNotifier = ValueNotifier([]);
  final ValueNotifier<String?> lastQrScanPhoto = ValueNotifier(null);

  final List<String> visitPhotos = [];

  static const String _wakeSound     = 'assets/sounds/wake_detected.mp3';
  static const String _thinkingSound = 'assets/sounds/thinking.mp3';
  static const String _doneSound     = 'assets/sounds/done.mp3';
  final AudioPlayer _soundPlayer   = AudioPlayer();
  final AudioPlayer _thinkingPlayer = AudioPlayer();

  final Map<String, int> _lastQrTime = {};
  static const int _qrCooldownMs = 10000;

  static final RegExp _urlPattern1 =
      RegExp(r'https://web\.mymuseum\.be/([^/]+)/([^/]+)/([^/\s]+)');
  static final RegExp _urlPattern2 =
      RegExp(r'https://web\.myinfomate\.be/([^/]+)/([^/]+)/([^/\s]+)');

  VoiceOrchestrator({
    required this.visitAppContext,
    required this.wakeWordEngine,
    required this.sttEngine,
    required this.ttsEngine,
    required this.llmClient,
  });

  Future<void> start() async {
    if (_running) return;
    _running = true;
    await wakeWordEngine.start(
      onDetected: _onWakeWord,
      onDetectedWithCommand: _onWakeWordWithCommand,
    );
    debugPrint('[VoiceOrchestrator] Started');
  }

  Future<void> stop() async {
    await wakeWordEngine.stop();
    await sttEngine.cancel();
    await ttsEngine.stop();
    _running = false;
    debugPrint('[VoiceOrchestrator] Stopped');
  }

  bool get isRunning => _running;
  bool get isInConversation => _inConversation;
  bool get isListening => _running && !_inConversation;

  Future<void> restartWakeWord() async {
    if (!_running || _inConversation) return;
    await wakeWordEngine.start(
      onDetected: _onWakeWord,
      onDetectedWithCommand: _onWakeWordWithCommand,
    );
  }

  Future<void> triggerConversation() => _handleConversation();
  Future<void> dispatchCommand(String command) => _dispatch(command);

  Future<void> triggerQrScan(String imagePath) async {
    final qr = await _tryDecodeQr(imagePath);
    if (qr != null) await explainSection(qr.sectionId, configurationId: qr.configId);
  }

  // ── Wake word ──────────────────────────────────────────────────────────────

  void _onWakeWord() async {
    if (_inConversation) return;
    _inConversation = true;
    await wakeWordEngine.stop();
    await _stopThinkingLoop();
    _playWakeSound();
    await Future.delayed(const Duration(milliseconds: 200));
    try {
      await _handleConversation();
    } finally {
      _inConversation = false;
      if (_running) await wakeWordEngine.start(
        onDetected: _onWakeWord,
        onDetectedWithCommand: _onWakeWordWithCommand,
      );
    }
  }

  void _onWakeWordWithCommand(String inlineCommand) async {
    if (_inConversation) return;
    _inConversation = true;
    await wakeWordEngine.stop();
    await _stopThinkingLoop();
    _playWakeSound();
    await Future.delayed(const Duration(milliseconds: 200));
    try {
      if (inlineCommand.isNotEmpty) {
        debugPrint('[VoiceOrchestrator] Inline command: "$inlineCommand"');
        await _dispatch(inlineCommand);
      } else {
        await _handleConversation();
      }
    } finally {
      _inConversation = false;
      if (_running) await wakeWordEngine.start(
        onDetected: _onWakeWord,
        onDetectedWithCommand: _onWakeWordWithCommand,
      );
    }
  }

  Future<void> _playSound(String asset) async {
    try {
      await _soundPlayer.setAsset(asset);
      await _soundPlayer.play();
    } catch (_) {
      debugPrint('[VoiceOrchestrator] Sound not found: $asset');
    }
  }

  Future<void> _playWakeSound() => _playSound(_wakeSound);
  Future<void> _playDoneSound() => _playSound(_doneSound);

  Future<void> _startThinkingLoop() async {
    try {
      await _thinkingPlayer.setAsset(_thinkingSound);
      await _thinkingPlayer.setLoopMode(LoopMode.one);
      _thinkingPlayer.play();
    } catch (_) {
      debugPrint('[VoiceOrchestrator] Thinking sound not found');
    }
  }

  Future<void> _stopThinkingLoop() async {
    await _thinkingPlayer.stop();
  }

  // ── Conversation vocale ────────────────────────────────────────────────────

  Future<void> _handleConversation() async {
    final lang = visitAppContext.language ?? 'FR';
    final langCode = _toLangCode(lang);
    isListeningForCommand.value = true;
    final command = await sttEngine.transcribeOnce(languageCode: langCode);
    isListeningForCommand.value = false;
    debugPrint('[VoiceOrchestrator] Command: "$command"');
    if (command.isEmpty) return;
    lastTranscription.value = command;
    await _dispatch(command);
  }

  Future<void> _dispatch(String command, {bool continueConversation = true}) async {
    final lang = visitAppContext.language ?? 'FR';
    final langCode = _toLangCode(lang);

    if (_isStopCommand(command)) {
      debugPrint('[VoiceOrchestrator] Annulé: "$command"');
      await _stopThinkingLoop();
      return;
    }

    if (_isQrScanCommand(command)) { await _handleQrScan(); return; }
    if (_isPhotoCommand(command)) { await _handlePhotoCapture(); return; }

    if (_isRepeatCommand(command)) {
      await ttsEngine.replay();
    } else {
      bool expectsReply = true;
      try {
        await _startThinkingLoop();
        final result = await llmClient.chat(
          command,
          configurationId: visitAppContext.configuration?.id,
          languageCode: lang,
        );
        expectsReply = result.expectsReply;
        await _stopThinkingLoop();
        if (result.reply.isNotEmpty) {
          lastTtsText.value = result.reply;
          await _playDoneSound();
          await ttsEngine.speak(result.reply, languageCode: langCode);
        }
      } catch (e) {
        await _stopThinkingLoop();
        debugPrint('[VoiceOrchestrator] LLM error: $e');
        return;
      }
      if (!expectsReply) return;
    }

    if (continueConversation) await _listenForFollowUp();
  }

  Future<void> _listenForFollowUp() async {
    final lang = visitAppContext.language ?? 'FR';
    final langCode = _toLangCode(lang);
    isListeningForCommand.value = true;
    final followUp = await sttEngine.transcribeOnce(
      languageCode: langCode,
      timeout: const Duration(seconds: 5),
    );
    isListeningForCommand.value = false;
    if (followUp.isNotEmpty) lastTranscription.value = followUp;
    if (followUp.isEmpty || _isStopCommand(followUp)) return;
    await _dispatch(followUp, continueConversation: true);
  }

  // ── QR scan ───────────────────────────────────────────────────────────────

  Future<void> _handleQrScan() async {
    final lang = _toLangCode(visitAppContext.language ?? 'FR');
    final completer = Completer<String?>();
    final prevCallback = MetaGlassesService.instance.onPhotoCaptured;
    MetaGlassesService.instance.onPhotoCaptured = (path) {
      if (!completer.isCompleted) completer.complete(path.isEmpty ? null : path);
      prevCallback?.call(path);
    };
    Timer(const Duration(seconds: 25), () {
      if (!completer.isCompleted) completer.complete(null);
    });
    unawaited(MetaGlassesService.instance.requestPhotoCapture());
    final photoPath = await completer.future;
    MetaGlassesService.instance.onPhotoCaptured = prevCallback;

    if (photoPath == null) {
      lastTtsText.value = TranslationHelper.getFromLocale('voice.cameraUnavailable', visitAppContext);
      await ttsEngine.speak(lastTtsText.value, languageCode: lang);
      return;
    }

    if (lastQrScanPhoto.value != null && lastQrScanPhoto.value != photoPath) {
      try { File(lastQrScanPhoto.value!).deleteSync(); } catch (_) {}
    }
    lastQrScanPhoto.value = photoPath;

    final qr = await _tryDecodeQr(photoPath);
    if (qr != null) {
      await explainSection(qr.sectionId, configurationId: qr.configId);
    } else {
      lastTtsText.value = TranslationHelper.getFromLocale('voice.noQrFound', visitAppContext);
      await ttsEngine.speak(lastTtsText.value, languageCode: lang);
    }
  }

  Future<void> _handlePhotoCapture() async {
    final completer = Completer<String?>();
    final prevCallback = MetaGlassesService.instance.onPhotoCaptured;
    MetaGlassesService.instance.onPhotoCaptured = (path) {
      if (!completer.isCompleted) completer.complete(path);
      prevCallback?.call(path);
    };
    Timer(const Duration(seconds: 25), () {
      if (!completer.isCompleted) completer.complete(null);
    });
    unawaited(MetaGlassesService.instance.requestPhotoCapture());
    final photoPath = await completer.future;
    MetaGlassesService.instance.onPhotoCaptured = prevCallback;

    if (photoPath == null || photoPath.isEmpty) {
      final lang = _toLangCode(visitAppContext.language ?? 'FR');
      lastTtsText.value = TranslationHelper.getFromLocale('voice.photoFailed', visitAppContext);
      await ttsEngine.speak(lastTtsText.value, languageCode: lang);
      return;
    }

    final qr = await _tryDecodeQr(photoPath);
    if (qr != null) {
      await explainSection(qr.sectionId, configurationId: qr.configId);
    } else {
      visitPhotos.add(photoPath);
      visitPhotosNotifier.value = List.unmodifiable(visitPhotos);
      final lang = _toLangCode(visitAppContext.language ?? 'FR');
      lastTtsText.value = TranslationHelper.getFromLocale('voice.photoCaptured', visitAppContext);
      await ttsEngine.speak(lastTtsText.value, languageCode: lang);
    }
  }

  Future<({String sectionId, String? configId})?> _tryDecodeQr(String imagePath) async {
    final controller = MobileScannerController();
    ({String sectionId, String? configId})? result;
    try {
      final completer = Completer<({String sectionId, String? configId})?>();
      final sub = controller.barcodes.listen((capture) {
        for (final barcode in capture.barcodes) {
          final raw = barcode.rawValue;
          if (raw != null) {
            final ids = _extractQrIds(raw);
            if (ids != null && !completer.isCompleted) completer.complete(ids);
          }
        }
      });
      await controller.analyzeImage(imagePath);
      Timer(const Duration(seconds: 2), () {
        if (!completer.isCompleted) completer.complete(null);
      });
      result = await completer.future;
      await sub.cancel();
    } catch (e) {
      debugPrint('[VoiceOrchestrator] QR decode error: $e');
    } finally {
      controller.dispose();
    }
    return result;
  }

  ({String sectionId, String? configId})? _extractQrIds(String raw) {
    final m1 = _urlPattern1.firstMatch(raw);
    if (m1 != null) return (sectionId: m1.group(3)!, configId: m1.group(2));
    final m2 = _urlPattern2.firstMatch(raw);
    if (m2 != null) return (sectionId: m2.group(3)!, configId: m2.group(2));
    if (visitAppContext.sectionIds != null) {
      return visitAppContext.sectionIds!.contains(raw)
          ? (sectionId: raw, configId: visitAppContext.configuration?.id)
          : null;
    }
    return (sectionId: raw, configId: null);
  }

  Future<void> explainSection(String sectionId, {String? configurationId}) async {
    final now = DateTime.now().millisecondsSinceEpoch;
    if ((now - (_lastQrTime[sectionId] ?? 0)) < _qrCooldownMs) return;
    _lastQrTime[sectionId] = now;
    final cfgId = configurationId ?? visitAppContext.configuration?.id;
    final lang = visitAppContext.language ?? 'FR';
    try {
      final result = await llmClient.chat(
        'Le visiteur vient de scanner le QR code de la section "$sectionId". '
        'Appelle GetSectionDetail avec cet ID, puis présente le contenu de façon engageante en 2-3 phrases.',
        configurationId: cfgId,
        languageCode: lang,
      );
      if (result.reply.isNotEmpty) {
        lastTtsText.value = result.reply;
        await ttsEngine.speak(result.reply, languageCode: _toLangCode(lang));
      }
    } catch (e) {
      debugPrint('[VoiceOrchestrator] explainSection error: $e');
    }
  }

  // ── Helpers ────────────────────────────────────────────────────────────────

  bool _isStopCommand(String text) {
    final t = text.toLowerCase().trim();
    return t == 'non' || t == 'rien' || t == 'non rien' || t == 'rien merci' ||
        t == 'non merci' || t == 'laisse tomber' || t == 'annule' || t == 'annuler' ||
        t.contains('stop') || t.contains('arrête') || t.contains('au revoir') ||
        t.contains('c\'est bon') || t.contains('ok merci') || t.contains('laisse tomber') ||
        (t.length < 10 && (t.contains('non') || t.contains('rien')));
  }

  bool _isQrScanCommand(String text) {
    final t = text.toLowerCase();
    return t.contains('scan') || t.contains('qr') || t.contains('code') || t.contains('regarde');
  }

  bool _isPhotoCommand(String text) {
    final t = text.toLowerCase();
    return t.contains('photo') || t.contains('prends') || t.contains('capture');
  }

  bool _isRepeatCommand(String text) {
    final t = text.toLowerCase();
    return t.contains('répète') || t.contains('repete') || t.contains('encore');
  }

  String _toLangCode(String lang) {
    switch (lang.toUpperCase()) {
      case 'FR': return 'fr-FR';
      case 'NL': return 'nl-NL';
      case 'EN': return 'en-US';
      case 'DE': return 'de-DE';
      default:   return 'fr-FR';
    }
  }
}