import 'package:flutter/material.dart';
import 'package:tablet_app/Models/AssistantResponse.dart';
import 'package:tablet_app/Models/tabletContext.dart';
import 'package:tablet_app/Services/assistantService.dart';
import 'package:tablet_app/constants.dart';

class AssistantChatView extends StatefulWidget {
  final TabletAppContext tabletAppContext;
  final String? configurationId;
  final void Function(String sectionId, String sectionTitle)? onNavigateToSection;

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

  @override
  State<AssistantChatView> createState() => _AssistantChatViewState();
}

class _AssistantChatViewState extends State<AssistantChatView> {
  late AssistantService _assistantService;
  final TextEditingController _controller = TextEditingController();
  final ScrollController _scrollController = ScrollController();
  final List<Widget> _bubbles = [];
  bool _isLoading = false;

  @override
  void initState() {
    super.initState();
    _assistantService = AssistantService(tabletAppContext: widget.tabletAppContext);
  }

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

    _controller.clear();
    setState(() {
      _bubbles.add(_ChatBubble(text: text, isUser: true));
      _isLoading = true;
    });
    _scrollToBottom();

    try {
      final response = await _assistantService.chat(
        message: text,
        configurationId: widget.configurationId,
      );
      setState(() {
        _bubbles.add(_AssistantMessage(
          response: response,
          onNavigate: widget.onNavigateToSection,
        ));
      });
    } catch (_) {
      setState(() {
        _bubbles.add(_ChatBubble(text: "Une erreur est survenue, réessayez.", isUser: false));
      });
    } finally {
      setState(() => _isLoading = false);
      _scrollToBottom();
    }
  }

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

  @override
  Widget build(BuildContext context) {
    return Container(
      width: 480,
      height: double.infinity,
      decoration: const BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.horizontal(left: Radius.circular(20)),
        boxShadow: [
          BoxShadow(color: Colors.black26, blurRadius: 12, offset: Offset(-4, 0)),
        ],
      ),
      child: Column(
        children: [
          // Header
          Container(
            padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 16),
            decoration: BoxDecoration(
              color: kMainGrey,
              borderRadius: const BorderRadius.only(topLeft: Radius.circular(20)),
            ),
            child: Row(
              children: [
                const Icon(Icons.chat_bubble_outline, color: Colors.white, size: 22),
                const SizedBox(width: 10),
                const Expanded(
                  child: Text(
                    "Assistant",
                    style: TextStyle(color: Colors.white, fontSize: 20, fontWeight: FontWeight.w600),
                  ),
                ),
                IconButton(
                  icon: const Icon(Icons.close, color: Colors.white),
                  onPressed: () => Navigator.of(context).pop(),
                ),
              ],
            ),
          ),
          // Messages
          Expanded(
            child: _bubbles.isEmpty
                ? Center(
                    child: Padding(
                      padding: const EdgeInsets.all(32),
                      child: Text(
                        "Bonjour ! Posez-moi vos questions sur cette visite.",
                        textAlign: TextAlign.center,
                        style: TextStyle(color: Colors.grey[500], fontSize: 18),
                      ),
                    ),
                  )
                : ListView.builder(
                    controller: _scrollController,
                    padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
                    itemCount: _bubbles.length,
                    itemBuilder: (_, i) => _bubbles[i],
                  ),
          ),
          // Loading
          if (_isLoading)
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
              child: Row(
                children: [
                  SizedBox(
                    width: 22, height: 22,
                    child: CircularProgressIndicator(strokeWidth: 2, color: kMainGrey),
                  ),
                  const SizedBox(width: 10),
                  Text("...", style: TextStyle(color: Colors.grey[400], fontSize: 16)),
                ],
              ),
            ),
          // Input
          Padding(
            padding: const EdgeInsets.all(12),
            child: Row(
              children: [
                Expanded(
                  child: TextField(
                    controller: _controller,
                    textCapitalization: TextCapitalization.sentences,
                    style: const TextStyle(fontSize: 16),
                    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: 18, vertical: 12),
                    ),
                    onSubmitted: (_) => _send(),
                  ),
                ),
                const SizedBox(width: 10),
                CircleAvatar(
                  radius: 26,
                  backgroundColor: kMainGrey,
                  child: IconButton(
                    icon: const Icon(Icons.send, color: Colors.white, size: 20),
                    onPressed: _send,
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

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

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

  @override
  Widget build(BuildContext context) {
    return Align(
      alignment: isUser ? Alignment.centerRight : Alignment.centerLeft,
      child: Container(
        margin: const EdgeInsets.symmetric(vertical: 5),
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
        constraints: BoxConstraints(maxWidth: MediaQuery.of(context).size.width * 0.65),
        decoration: BoxDecoration(
          color: isUser ? kMainGrey : Colors.grey[100],
          borderRadius: BorderRadius.only(
            topLeft: const Radius.circular(18),
            topRight: const Radius.circular(18),
            bottomLeft: isUser ? const Radius.circular(18) : const Radius.circular(4),
            bottomRight: isUser ? const Radius.circular(4) : const Radius.circular(18),
          ),
        ),
        child: Text(
          text,
          style: TextStyle(
            color: isUser ? Colors.white : kSecondGrey,
            fontSize: 15,
          ),
        ),
      ),
    );
  }
}

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

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

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 5),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          // Text bubble
          _ChatBubble(text: response.reply, isUser: false),

          // Cards
          if (response.cards != null && response.cards!.isNotEmpty)
            Padding(
              padding: const EdgeInsets.only(top: 6, left: 4, right: 32),
              child: Column(
                children: response.cards!
                    .map((card) => _AiCardWidget(card: card))
                    .toList(),
              ),
            ),

          // Navigation button
          if (response.navigation != null && onNavigate != null)
            Padding(
              padding: const EdgeInsets.only(top: 8, left: 4),
              child: ElevatedButton.icon(
                onPressed: () => onNavigate!(
                  response.navigation!.sectionId,
                  response.navigation!.sectionTitle,
                ),
                icon: const Icon(Icons.arrow_forward, size: 18),
                label: Text(response.navigation!.sectionTitle),
                style: ElevatedButton.styleFrom(
                  backgroundColor: kMainGrey,
                  foregroundColor: Colors.white,
                  shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
                  padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
                ),
              ),
            ),
        ],
      ),
    );
  }
}

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: 14, vertical: 10),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: Colors.grey[200]!),
        boxShadow: [
          BoxShadow(color: Colors.black.withOpacity(0.05), blurRadius: 4, offset: const Offset(0, 2)),
        ],
      ),
      child: Row(
        children: [
          if (card.icon != null) ...[
            Text(card.icon!, style: const TextStyle(fontSize: 20)),
            const SizedBox(width: 10),
          ],
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  card.title,
                  style: TextStyle(fontWeight: FontWeight.w600, fontSize: 14, color: kSecondGrey),
                ),
                if (card.subtitle.isNotEmpty)
                  Text(
                    card.subtitle,
                    style: TextStyle(fontSize: 12, color: Colors.grey[500]),
                  ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}