import 'package:flutter/material.dart';
import 'package:flutter_widget_from_html/flutter_widget_from_html.dart';
import 'package:mymuseum_visitapp/Components/VisitorPrivacyNotice.dart';
import 'package:mymuseum_visitapp/Helpers/assistantSuggestions.dart';
import 'package:mymuseum_visitapp/Helpers/translationHelper.dart';
import 'package:mymuseum_visitapp/Models/AssistantResponse.dart';
import 'package:mymuseum_visitapp/Models/visitContext.dart';
import 'package:mymuseum_visitapp/Services/assistantService.dart';
import 'package:mymuseum_visitapp/Services/Glasses/glasses_orchestrator.dart';
import 'package:mymuseum_visitapp/Services/meta_glasses_service.dart';
import 'package:mymuseum_visitapp/constants.dart';
import 'package:speech_to_text/speech_to_text.dart';

String _stripHtml(String html) => html.replaceAll(RegExp(r'<[^>]*>'), '').trim();

class AssistantChatSheet extends StatefulWidget {
  final VisitAppContext visitAppContext;
  final String? configurationId;
  final void Function(String sectionId, String sectionTitle)? onNavigateToSection;

  const AssistantChatSheet({
    Key? key,
    required this.visitAppContext,
    this.configurationId,
    this.onNavigateToSection,
  }) : super(key: key);

  static void show(
    BuildContext context, {
    required VisitAppContext visitAppContext,
    String? configurationId,
    void Function(String sectionId, String sectionTitle)? onNavigateToSection,
  }) {
    showGeneralDialog(
      context: context,
      barrierDismissible: true,
      barrierLabel: '',
      barrierColor: Colors.black54,
      transitionDuration: const Duration(milliseconds: 280),
      pageBuilder: (dialogContext, _, __) => AssistantChatSheet(
        visitAppContext: visitAppContext,
        configurationId: configurationId,
        onNavigateToSection: onNavigateToSection,
      ),
      transitionBuilder: (_, animation, __, child) => SlideTransition(
        position: Tween<Offset>(begin: const Offset(0, 1), end: Offset.zero)
            .animate(CurvedAnimation(parent: animation, curve: Curves.easeOut)),
        child: child,
      ),
    );
  }

  @override
  State<AssistantChatSheet> createState() => _AssistantChatSheetState();
}

class _AssistantChatSheetState extends State<AssistantChatSheet> {
  late AssistantService _assistantService;
  final TextEditingController _controller = TextEditingController();
  final ScrollController _scrollController = ScrollController();
  bool _isLoading = false;

  final SpeechToText _speech = SpeechToText();
  bool _speechAvailable = false;
  bool _isListening = false;

  @override
  void initState() {
    super.initState();
    // Conversation partagée avec le vocal et le proactif : à l'ouverture, la feuille
    // affiche déjà ce qui s'est dit aux lunettes, et se met à jour en direct si le
    // guide parle pendant qu'elle est ouverte.
    _assistantService = widget.visitAppContext.assistant;
    _assistantService.addListener(_onConversationChanged);
    _initSpeech();
  }

  void _onConversationChanged() {
    if (!mounted) return;
    setState(() {});
    _scrollToBottom();
  }

  Future<void> _initSpeech() async {
    final available = await _speech.initialize();
    if (mounted) setState(() => _speechAvailable = available);
  }

  Future<void> _toggleListening() async {
    if (_isListening) {
      await _speech.stop();
      setState(() => _isListening = false);
    } else {
      final locale = widget.visitAppContext.language?.toLowerCase() ?? 'fr';
      setState(() => _isListening = true);
      await _speech.listen(
        localeId: locale,
        onResult: (result) {
          setState(() => _controller.text = result.recognizedWords);
          if (result.finalResult) {
            setState(() => _isListening = false);
          }
        },
        listenOptions: SpeechListenOptions(partialResults: true),
      );
    }
  }

  @override
  void dispose() {
    // Le service survit à la feuille — il porte la conversation, pas l'écran. On se
    // désabonne, on ne le dispose pas.
    _assistantService.removeListener(_onConversationChanged);
    _speech.cancel();
    super.dispose();
  }

  Future<void> _send() async {
    final text = _controller.text.trim();
    if (text.isEmpty || _isLoading) return;

    _controller.clear();
    // Le tour du visiteur est ajouté par le service, qui prévient ses écouteurs :
    // rien à empiler ici, sinon il s'afficherait deux fois.
    setState(() => _isLoading = true);
    _scrollToBottom();

    try {
      final response = await _assistantService.chat(
        message: text,
        configurationId: widget.configurationId,
      );

      // Pipe TTS vers les lunettes si connectées
      if (MetaGlassesService.instance.isConnected && response.reply.isNotEmpty) {
        final lang = widget.visitAppContext.language ?? 'FR';
        activeVoiceOrchestrator?.ttsEngine.speak(
          response.reply,
          languageCode: _toLangCode(lang),
        );
      }
    } on AssistantUnavailableException {
      // Quota épuisé : surtout ne pas inviter à réessayer, le visiteur boucterait.
      _assistantService.addServiceMessage(
          "Le guide se repose pour aujourd'hui. Revenez demain.");
    } catch (e) {
      debugPrint('AssistantChatSheet error: $e');
      _assistantService.addServiceMessage("Une erreur est survenue, réessayez.");
    } finally {
      setState(() => _isLoading = false);
      _scrollToBottom();
    }
  }

  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';
    }
  }

  void _scrollToBottom() {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (_scrollController.hasClients) {
        _scrollController.animateTo(
          _scrollController.position.maxScrollExtent,
          duration: const Duration(milliseconds: 300),
          curve: Curves.easeOut,
        );
      }
    });
  }

  /// Nom du lieu affiché sous le titre — le visiteur sait à qui il parle.
  String get _venueName {
    final configuration = widget.visitAppContext.configuration;
    if (configuration == null) return '';
    final title = _stripHtml(
        TranslationHelper.get(configuration.title, widget.visitAppContext));
    return title.isNotEmpty ? title : (configuration.label ?? '');
  }

  @override
  Widget build(BuildContext context) {
    final height = MediaQuery.of(context).size.height * 0.9;
    return Align(
      alignment: Alignment.bottomCenter,
      child: Material(
        borderRadius: const BorderRadius.vertical(top: Radius.circular(20)),
        clipBehavior: Clip.antiAlias,
        child: SizedBox(
          height: height,
          child: Column(
          children: [
            // Header
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
              child: Row(
                children: [
                  Container(
                    width: 32,
                    height: 32,
                    decoration: BoxDecoration(
                      color: kMainColor1,
                      shape: BoxShape.circle,
                    ),
                    child: const Icon(Icons.chat_bubble_outline,
                        color: Colors.white, size: 17),
                  ),
                  const SizedBox(width: 10),
                  Flexible(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        Text("Votre guide",
                            style: TextStyle(
                                fontSize: 16,
                                fontWeight: FontWeight.w600,
                                height: 1.15,
                                color: kSecondGrey)),
                        if (_venueName.isNotEmpty)
                          Text(_venueName,
                              maxLines: 1,
                              overflow: TextOverflow.ellipsis,
                              style: TextStyle(
                                  fontSize: 11.5,
                                  height: 1.2,
                                  color: Colors.grey[500])),
                      ],
                    ),
                  ),
                  const SizedBox(width: 8),
                  ValueListenableBuilder<GlassesState>(
                    valueListenable: MetaGlassesService.instance.state,
                    builder: (_, glassesState, __) {
                        final connected = glassesState == GlassesState.connected ||
                            glassesState == GlassesState.streaming;
                        // Rien à montrer tant qu'aucune paire n'est entrée en scène :
                        // l'ancienne garde `glassesEnabled` n'était jamais vraie, donc
                        // cette pastille n'a jamais été affichée à personne.
                        if (glassesState == GlassesState.disconnected) {
                          return const SizedBox.shrink();
                        }
                        return Row(
                          mainAxisSize: MainAxisSize.min,
                          children: [
                            Icon(
                              Icons.smart_toy_outlined,
                              size: 14,
                              color: connected ? Colors.green : Colors.grey[400],
                            ),
                            const SizedBox(width: 3),
                            Text(
                              connected ? 'Lunettes' : 'Déconnecté',
                              style: TextStyle(
                                fontSize: 11,
                                color: connected ? Colors.green : Colors.grey[400],
                              ),
                            ),
                          ],
                        );
                    },
                  ),
                  const Spacer(),
                  // §8.3 des CGU : la mention doit être accessible depuis l'assistant
                  // lui-même, c'est-à-dire là où la collecte a lieu — pas seulement dans
                  // la politique de confidentialité du lieu.
                  IconButton(
                    icon: const Icon(Icons.privacy_tip_outlined, size: 20),
                    tooltip: VisitorPrivacyNotice.textFor(widget.visitAppContext.language).title,
                    onPressed: () =>
                        VisitorPrivacyNotice.show(context, widget.visitAppContext),
                  ),
                  IconButton(
                    icon: const Icon(Icons.close),
                    onPressed: () => Navigator.of(context).pop(),
                  ),
                ],
              ),
            ),
            const Divider(height: 1),
            // Messages — lus depuis la conversation partagée, donc ce qui a été dit
            // aux lunettes est déjà là à l'ouverture.
            Expanded(
              child: _assistantService.turns.isEmpty
                  ? Center(
                      child: Padding(
                        padding: const EdgeInsets.all(24),
                        child: Column(
                          mainAxisSize: MainAxisSize.min,
                          children: [
                            Text(
                              "Bonjour ! Posez-moi vos questions sur cette visite.",
                              textAlign: TextAlign.center,
                              style: TextStyle(color: Colors.grey[500], fontSize: 15),
                            ),
                            const SizedBox(height: 16),
                            // Suggestions dérivées du contenu réel de la configuration :
                            // face à un champ vide, peu de visiteurs savent quoi demander.
                            Wrap(
                              alignment: WrapAlignment.center,
                              spacing: 8,
                              runSpacing: 8,
                              children: AssistantSuggestions
                                  .build(widget.visitAppContext)
                                  .map((suggestion) => ActionChip(
                                        label: Text(
                                          suggestion,
                                          style: const TextStyle(fontSize: 12.5),
                                        ),
                                        backgroundColor: Colors.white,
                                        side: BorderSide(color: Colors.grey[300]!),
                                        onPressed: () {
                                          _controller.text = suggestion;
                                          _send();
                                        },
                                      ))
                                  .toList(),
                            ),
                          ],
                        ),
                      ),
                    )
                  : ListView.builder(
                      controller: _scrollController,
                      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
                      itemCount: _assistantService.turns.length,
                      itemBuilder: (_, i) {
                        final turn = _assistantService.turns[i];
                        if (turn.response != null) {
                          return _AssistantMessage(
                            response: turn.response!,
                            isVoice: turn.isVoice,
                            onNavigate: widget.onNavigateToSection,
                          );
                        }
                        return _ChatBubble(
                          text: turn.text,
                          isUser: turn.isUser,
                          isVoice: turn.isVoice,
                        );
                      },
                    ),
            ),
            // Le guide rédige — trois points plutôt qu'un spinner : la réponse
            // arrive, elle ne « charge » pas.
            if (_isLoading)
              Align(
                alignment: Alignment.centerLeft,
                child: Padding(
                  padding: const EdgeInsets.fromLTRB(16, 4, 16, 4),
                  child: Semantics(
                    label: 'Le guide rédige',
                    child: Container(
                      padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
                      decoration: BoxDecoration(
                        color: Colors.grey[100],
                        borderRadius: const BorderRadius.only(
                          topLeft: Radius.circular(16),
                          topRight: Radius.circular(16),
                          bottomLeft: Radius.circular(4),
                          bottomRight: Radius.circular(16),
                        ),
                      ),
                      child: const _TypingDots(),
                    ),
                  ),
                ),
              ),

            // Écoute en cours — le micro rouge seul ne dit pas qu'on enregistre.
            if (_isListening)
              Padding(
                padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
                child: Container(
                  padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 9),
                  decoration: BoxDecoration(
                    color: Colors.red.withValues(alpha: 0.09),
                    borderRadius: BorderRadius.circular(999),
                  ),
                  child: Row(
                    children: [
                      const Icon(Icons.mic, color: Colors.red, size: 15),
                      const SizedBox(width: 8),
                      const Text(
                        "Je vous écoute…",
                        style: TextStyle(
                            color: Colors.red, fontSize: 13, fontWeight: FontWeight.w600),
                      ),
                      const Spacer(),
                      const _ListeningWave(),
                    ],
                  ),
                ),
              ),
            // Input
            Padding(
              padding: EdgeInsets.only(
                  left: 12,
                  right: 12,
                  bottom: MediaQuery.of(context).viewInsets.bottom + 8,
                  top: 8),
              child: Row(
                children: [
                  Expanded(
                    child: TextField(
                      controller: _controller,
                      textCapitalization: TextCapitalization.sentences,
                      decoration: InputDecoration(
                        hintText: "Votre question...",
                        filled: true,
                        fillColor: Colors.grey[100],
                        border: OutlineInputBorder(
                          borderRadius: BorderRadius.circular(24),
                          borderSide: BorderSide.none,
                        ),
                        contentPadding:
                            const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
                      ),
                      onSubmitted: (_) => _send(),
                    ),
                  ),
                  const SizedBox(width: 8),
                  if (_speechAvailable)
                    AnimatedContainer(
                      duration: const Duration(milliseconds: 200),
                      decoration: BoxDecoration(
                        color: _isListening ? Colors.red : Colors.grey[200],
                        shape: BoxShape.circle,
                      ),
                      child: IconButton(
                        icon: Icon(
                          _isListening ? Icons.mic : Icons.mic_none,
                          color: _isListening ? Colors.white : Colors.grey[600],
                          size: 20,
                        ),
                        onPressed: _toggleListening,
                      ),
                    ),
                  const SizedBox(width: 8),
                  CircleAvatar(
                    backgroundColor: kMainColor1,
                    child: IconButton(
                      icon: const Icon(Icons.send, color: Colors.white, size: 18),
                      onPressed: _send,
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
        ),
      ),
    );
  }
}

/// Trois points qui pulsent en décalé, pendant que la réponse se prépare.
class _TypingDots extends StatefulWidget {
  const _TypingDots();

  @override
  State<_TypingDots> createState() => _TypingDotsState();
}

class _TypingDotsState extends State<_TypingDots>
    with SingleTickerProviderStateMixin {
  late final AnimationController _controller = AnimationController(
    vsync: this,
    duration: const Duration(milliseconds: 1300),
  )..repeat();

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _controller,
      builder: (_, __) => Row(
        mainAxisSize: MainAxisSize.min,
        children: List.generate(3, (i) {
          // Chaque point est décalé d'un sixième de cycle sur le précédent.
          final phase = (_controller.value - i * 0.14) % 1.0;
          final lift = phase < 0.3 ? Curves.easeInOut.transform(phase / 0.3) : 0.0;
          return Padding(
            padding: EdgeInsets.only(right: i < 2 ? 4 : 0),
            child: Transform.translate(
              offset: Offset(0, -3 * lift),
              child: Container(
                width: 6,
                height: 6,
                decoration: BoxDecoration(
                  shape: BoxShape.circle,
                  color: Colors.grey[500]!.withValues(alpha: 0.3 + 0.7 * lift),
                ),
              ),
            ),
          );
        }),
      ),
    );
  }
}

/// Onde sonore de la dictée — cinq barres qui respirent.
class _ListeningWave extends StatefulWidget {
  const _ListeningWave();

  @override
  State<_ListeningWave> createState() => _ListeningWaveState();
}

class _ListeningWaveState extends State<_ListeningWave>
    with SingleTickerProviderStateMixin {
  static const _heights = [8.0, 14.0, 20.0, 11.0, 16.0];

  late final AnimationController _controller = AnimationController(
    vsync: this,
    duration: const Duration(milliseconds: 1000),
  )..repeat();

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _controller,
      builder: (_, __) => Row(
        mainAxisSize: MainAxisSize.min,
        children: List.generate(_heights.length, (i) {
          final phase = (_controller.value + i * 0.12) % 1.0;
          final scale = 0.5 + 0.5 * (1 - (phase * 2 - 1).abs());
          return Padding(
            padding: EdgeInsets.only(right: i < _heights.length - 1 ? 2 : 0),
            child: Container(
              width: 3,
              height: _heights[i] * scale,
              decoration: BoxDecoration(
                color: Colors.red,
                borderRadius: BorderRadius.circular(2),
              ),
            ),
          );
        }),
      ),
    );
  }
}

class _ChatBubble extends StatelessWidget {
  final String text;
  final bool isUser;

  /// Le tour est passé par la voix. Une petite icône le signale — sans elle, le
  /// visiteur qui ouvre le chat ne comprend pas d'où sortent des messages qu'il
  /// n'a jamais tapés.
  final bool isVoice;

  const _ChatBubble({required this.text, required this.isUser, this.isVoice = false});

  @override
  Widget build(BuildContext context) {
    return Align(
      alignment: isUser ? Alignment.centerRight : Alignment.centerLeft,
      child: Column(
        crossAxisAlignment: isUser ? CrossAxisAlignment.end : CrossAxisAlignment.start,
        children: [
          if (isVoice)
            Padding(
              padding: const EdgeInsets.only(top: 4, left: 6, right: 6),
              child: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  Icon(Icons.graphic_eq, size: 11, color: Colors.grey[500]),
                  const SizedBox(width: 3),
                  Text('À voix haute',
                      style: TextStyle(fontSize: 10.5, color: Colors.grey[500])),
                ],
              ),
            ),
          _bubble(context),
        ],
      ),
    );
  }

  Widget _bubble(BuildContext context) {
    return Container(
        margin: const EdgeInsets.symmetric(vertical: 4),
        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 10),
        constraints: BoxConstraints(maxWidth: MediaQuery.of(context).size.width * 0.78),
        decoration: BoxDecoration(
          color: isUser ? kMainColor1 : Colors.grey[100],
          borderRadius: BorderRadius.only(
            topLeft: const Radius.circular(16),
            topRight: const Radius.circular(16),
            bottomLeft: isUser ? const Radius.circular(16) : const Radius.circular(4),
            bottomRight: isUser ? const Radius.circular(4) : const Radius.circular(16),
          ),
        ),
        child: isUser
            ? Text(
                text,
                style: const TextStyle(color: Colors.white, fontSize: 14),
              )
            : HtmlWidget(
                text,
                textStyle: TextStyle(color: kSecondGrey, fontSize: 14),
              ),
    );
  }
}

class _AssistantMessage extends StatelessWidget {
  final AssistantResponse response;
  final bool isVoice;
  final void Function(String sectionId, String sectionTitle)? onNavigate;

  const _AssistantMessage({
    required this.response,
    this.isVoice = false,
    this.onNavigate,
  });

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          if (response.reply.isNotEmpty)
            _ChatBubble(text: response.reply, isUser: false, isVoice: isVoice),

          if (response.cards != null && response.cards!.isNotEmpty)
            Padding(
              padding: const EdgeInsets.only(top: 6, left: 4, right: 24),
              child: Column(
                children: response.cards!.map((card) => _AiCardWidget(card: card)).toList(),
              ),
            ),

          if (response.navigation != null && onNavigate != null)
            GestureDetector(
              onTap: () {
                Navigator.of(context).pop();
                onNavigate!(
                  response.navigation!.sectionId,
                  _stripHtml(response.navigation!.sectionTitle),
                );
              },
              child: Container(
                margin: const EdgeInsets.only(top: 8, left: 4, right: 24),
                padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
                decoration: BoxDecoration(
                  color: kMainColor1.withValues(alpha: 0.08),
                  borderRadius: BorderRadius.circular(12),
                  border: Border.all(color: kMainColor1.withValues(alpha: 0.35)),
                ),
                child: Row(
                  children: [
                    ClipRRect(
                      borderRadius: BorderRadius.circular(8),
                      child: response.navigation!.imageUrl != null
                          ? Image.network(
                              response.navigation!.imageUrl!,
                              width: 48,
                              height: 48,
                              fit: BoxFit.cover,
                              errorBuilder: (_, __, ___) => Container(
                              width: 48,
                              height: 48,
                              decoration: BoxDecoration(
                                color: kMainColor1,
                                borderRadius: BorderRadius.circular(8),
                              ),
                              child: const Icon(Icons.place_outlined, color: Colors.white, size: 22),
                            ),
                            )
                          : Container(
                              width: 48,
                              height: 48,
                              decoration: BoxDecoration(
                                color: kMainColor1,
                                borderRadius: BorderRadius.circular(8),
                              ),
                              child: const Icon(Icons.place_outlined, color: Colors.white, size: 22),
                            ),
                    ),
                    const SizedBox(width: 10),
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            _stripHtml(response.navigation!.sectionTitle),
                            style: TextStyle(
                              fontWeight: FontWeight.w600,
                              fontSize: 13,
                              color: kSecondGrey,
                            ),
                          ),
                          Text(
                            "Voir cette section",
                            style: TextStyle(fontSize: 11, color: Colors.grey[500]),
                          ),
                        ],
                      ),
                    ),
                    Icon(Icons.chevron_right, color: kMainColor1, size: 20),
                  ],
                ),
              ),
            ),
        ],
      ),
    );
  }
}

class _AiCardWidget extends StatelessWidget {
  final AiCard card;

  const _AiCardWidget({required this.card});

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: const EdgeInsets.only(bottom: 6),
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(10),
        border: Border.all(color: Colors.grey[200]!),
        boxShadow: [
          BoxShadow(
              color: Colors.black.withValues(alpha: 0.05),
              blurRadius: 3,
              offset: const Offset(0, 1)),
        ],
      ),
      child: Row(
        children: [
          if (card.icon != null) ...[
            Text(card.icon!, style: const TextStyle(fontSize: 18)),
            const SizedBox(width: 8),
          ],
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(card.title,
                    style: TextStyle(
                        fontWeight: FontWeight.w600, fontSize: 13, color: kSecondGrey)),
                if (card.subtitle.isNotEmpty)
                  Text(card.subtitle,
                      style: const TextStyle(fontSize: 12, color: Colors.grey)),
              ],
            ),
          ),
        ],
      ),
    );
  }
}