import 'dart:ui';
import 'package:flutter/material.dart';
import 'dart:convert';
import 'package:http/http.dart' as http;
import 'dart:async';
import 'package:flutter_markdown/flutter_markdown.dart';

class ChatScreen extends StatefulWidget {
  const ChatScreen({super.key});

  @override
  State<ChatScreen> createState() => _ChatScreenState();
}

class ChatMessage {
  final String text;
  final bool isAssistant;

  ChatMessage({required this.text, this.isAssistant = false});
}

class _ChatScreenState extends State<ChatScreen> with TickerProviderStateMixin {
  final List<ChatMessage> _messages = [];
  final TextEditingController _textController = TextEditingController();
  final ScrollController _scrollController = ScrollController();
  bool _isTyping = false;
  late AnimationController _typingController;

  @override
  void initState() {
    super.initState();
    _typingController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 1200),
    )..repeat();

    Timer(const Duration(seconds: 2), () => _checkAvailableModels());
  }

  Future<void> _checkAvailableModels() async {
    try {
      final response = await http.get(
        Uri.parse('http://89.114.196.110:11434/api/tags'),
      ).timeout(const Duration(seconds: 15));

      if (response.statusCode == 200) {
        final data = jsonDecode(response.body);
        print("--- MODELOS DISPONÍVEIS ---");
        if (data['models'] != null) {
          for (var m in data['models']) {
            print("- ${m['name']}");
          }
        }
      }
    } catch (e) {
      print("Erro ao listar modelos: $e");
    }
  }

  @override
  void dispose() {
    _typingController.dispose();
    _textController.dispose();
    _scrollController.dispose();
    super.dispose();
  }

  void _clearChat() {
    setState(() {
      _messages.clear();
      _isTyping = false;
    });
  }

  Future<void> _handleSubmitted(String text) async {
    if (text.trim().isEmpty || _isTyping) return;

    _textController.clear();

    setState(() {
      _messages.insert(0, ChatMessage(text: text));
      _isTyping = true;
    });

    try {
      final url = Uri.parse('http://89.114.196.110:11434/api/chat');

      final response = await http
          .post(
        url,
        headers: {
          'Content-Type': 'application/json',
        },
        body: jsonEncode({
          'model': 'qwen3:4b',
          'messages': [{'role': 'user', 'content': text}],
          'stream': false, 
        }),
      )
          .timeout(const Duration(seconds: 60));

      if (response.statusCode == 200) {
        final data = jsonDecode(response.body);
        final reply = data['message']?['content'] ?? 'Sem resposta.';

        if (mounted) {
          setState(() {
            _isTyping = false;
            _messages.insert(0, ChatMessage(text: reply, isAssistant: true));
          });
        }
      } else {
        throw Exception('Erro HTTP ${response.statusCode}: ${response.body}');
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _isTyping = false;
          _messages.insert(
            0,
            ChatMessage(text: "Erro: $e", isAssistant: true),
          );
        });
      }
    }
  }

  Widget _buildMessage(ChatMessage message) {
    bool isAssistant = message.isAssistant;
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 12.0, horizontal: 16.0),
      child: Row(
        mainAxisAlignment: isAssistant ? MainAxisAlignment.start : MainAxisAlignment.end,
        crossAxisAlignment: CrossAxisAlignment.end,
        children: [
          if (isAssistant) _buildAvatar(Icons.auto_awesome),
          Flexible(
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 10.0),
              decoration: BoxDecoration(
                gradient: isAssistant
                    ? const LinearGradient(colors: [Color(0xFFF1F5F9), Color(0xFFE2E8F0)])
                    : const LinearGradient(colors: [Color(0xFF8ad5c9), Color(0xFF57a7ed)]),
                borderRadius: BorderRadius.only(
                  topLeft: const Radius.circular(20),
                  topRight: const Radius.circular(20),
                  bottomLeft: Radius.circular(isAssistant ? 4 : 20),
                  bottomRight: Radius.circular(isAssistant ? 20 : 4),
                ),
              ),
              child: isAssistant 
                ? MarkdownBody(
                    data: message.text,
                    styleSheet: MarkdownStyleSheet(
                      p: const TextStyle(color: Colors.black87, fontSize: 15, height: 1.4),
                      strong: const TextStyle(color: Colors.black, fontWeight: FontWeight.bold),
                      listBullet: const TextStyle(color: Colors.black87),
                    ),
                  )
                : Text(
                    message.text,
                    style: const TextStyle(color: Colors.white, fontSize: 15, height: 1.4),
                  ),
            ),
          ),
          if (!isAssistant) _buildAvatar(Icons.person),
        ],
      ),
    );
  }

  Widget _buildAvatar(IconData icon) {
    return Container(
      margin: EdgeInsets.only(left: icon == Icons.person ? 12 : 0, right: icon == Icons.auto_awesome ? 12 : 0),
      decoration: const BoxDecoration(
        shape: BoxShape.circle,
        gradient: LinearGradient(colors: [Color(0xFF8ad5c9), Color(0xFF57a7ed)]),
      ),
      child: CircleAvatar(backgroundColor: Colors.transparent, radius: 16, child: Icon(icon, color: Colors.white, size: 18)),
    );
  }

  Widget _buildTypingIndicator() {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 12.0, horizontal: 16.0),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.start,
        children: [
          _buildAvatar(Icons.auto_awesome),
          Container(
            padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 12.0),
            decoration: BoxDecoration(
              color: const Color(0xFFF1F5F9),
              borderRadius: const BorderRadius.only(topLeft: Radius.circular(20), topRight: Radius.circular(20), bottomLeft: Radius.circular(4), bottomRight: Radius.circular(20)),
            ),
            child: Row(
              mainAxisSize: MainAxisSize.min,
              children: [_buildAnimatedDot(0), const SizedBox(width: 4), _buildAnimatedDot(1), const SizedBox(width: 4), _buildAnimatedDot(2)],
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildAnimatedDot(int index) {
    return AnimatedBuilder(
      animation: _typingController,
      builder: (context, child) {
        double value = (_typingController.value + (index * 0.15)) % 1.0;
        double intensity = 1.0 - (value - 0.5).abs() * 2;
        return Opacity(
          opacity: 0.3 + (0.7 * intensity),
          child: Transform.translate(offset: Offset(0, -3 * intensity), child: Container(width: 6, height: 6, decoration: const BoxDecoration(color: Colors.black54, shape: BoxShape.circle))),
        );
      },
    );
  }

  Widget _buildTextComposer() {
    return ClipRRect(
      child: BackdropFilter(
        filter: ImageFilter.blur(sigmaX: 10, sigmaY: 10),
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 12.0),
          decoration: BoxDecoration(
            color: Colors.white.withOpacity(0.8),
            border: Border(top: BorderSide(color: Colors.black.withOpacity(0.05), width: 0.5)),
          ),
          child: SafeArea(
            child: Row(
              children: [
                IconButton(
                  icon: const Icon(Icons.delete_sweep_rounded, color: Colors.redAccent),
                  onPressed: _isTyping ? null : _clearChat,
                ),
                Expanded(
                  child: Container(
                    decoration: BoxDecoration(
                      color: const Color(0xFFF1F5F9),
                      borderRadius: BorderRadius.circular(30.0),
                      border: Border.all(color: Colors.black.withOpacity(0.05)),
                    ),
                    child: TextField(
                      controller: _textController,
                      enabled: !_isTyping,
                      onSubmitted: _handleSubmitted,
                      decoration: InputDecoration(
                        hintText: _isTyping ? "Aguarde a resposta..." : "Mensagem EPVChat...",
                        border: InputBorder.none,
                        contentPadding: const EdgeInsets.symmetric(horizontal: 24.0, vertical: 14.0),
                      ),
                    ),
                  ),
                ),
                const SizedBox(width: 8),
                Container(
                  decoration: BoxDecoration(
                    gradient: LinearGradient(
                      colors: _isTyping
                          ? [Colors.grey, Colors.grey]
                          : [const Color(0xFF8ad5c9), const Color(0xFF57a7ed)],
                      begin: Alignment.topLeft,
                      end: Alignment.bottomRight,
                    ),
                    shape: BoxShape.circle,
                  ),
                  child: IconButton(
                    icon: const Icon(Icons.send_rounded, color: Colors.white),
                    onPressed: _isTyping ? null : () => _handleSubmitted(_textController.text),
                  ),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final screenWidth = MediaQuery.of(context).size.width;

    return Scaffold(
      backgroundColor: Colors.white,
      body: Column(
        children: [
          Expanded(
            child: ListView(
              controller: _scrollController,
              reverse: true,
              children: [
                ...(_isTyping ? [_buildTypingIndicator()] : []),
                ..._messages.map((msg) => _buildMessage(msg)),
                Padding(
                  padding: const EdgeInsets.only(bottom: 50, top: 20),
                  child: Stack(
                    alignment: Alignment.center,
                    children: [
                      Container(
                        height: screenWidth * 0.8,
                        decoration: BoxDecoration(
                          shape: BoxShape.circle,
                          gradient: RadialGradient(
                            colors: [
                              const Color(0xFF8ad5c9).withOpacity(0.4),
                              const Color(0xFF8ad5c9).withOpacity(0.0),
                            ],
                          ),
                        ),
                      ),
                      Image.asset(
                        'assets/logo.png',
                        height: 170,
                        fit: BoxFit.contain,
                      ),
                    ],
                  ),
                ),
              ],
            ),
          ),
          _buildTextComposer(),
        ],
      ),
    );
  }
}