import 'package:flutter/material.dart';
import 'dart:ui';
import '../g4f/client.dart';
import '../g4f/models.dart';
import '../services/settings_repository.dart';

class OracleChatScreen extends StatefulWidget {
  const OracleChatScreen({Key? key}) : super(key: key);

  @override
  State<OracleChatScreen> createState() => _OracleChatScreenState();
}

class ChatMessage {
  final String text;
  final bool isUser;

  ChatMessage({required this.text, required this.isUser});
}

class _OracleChatScreenState extends State<OracleChatScreen> {
  final TextEditingController _controller = TextEditingController();
  final ScrollController _scrollController = ScrollController();
  final G4FClient _client = G4FClient();
  
  late final List<ChatMessage> _messages;
  bool _isLoading = false;

  @override
  void initState() {
    super.initState();
    _messages = [
      ChatMessage(
        text: SettingsRepository().persona.chatGreeting,
        isUser: false,
      ),
    ];
  }

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

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

    setState(() {
      _messages.add(ChatMessage(text: text, isUser: true));
      _messages.add(ChatMessage(text: '', isUser: false));
      _isLoading = true;
    });
    _controller.clear();
    _scrollToBottom();

    final apiMessages = <Message>[
      Message(
        role: Role.system,
        content:
            '${SettingsRepository().persona.systemPrompt}\n'
            'Отвечай на языке вопрошающего. Не упоминай модели, провайдеров и технические сбои.',
      ),
      for (final m in _messages)
        if (m.text.trim().isNotEmpty)
          Message(
            role: m.isUser ? Role.user : Role.assistant,
            content: m.text,
          ),
    ];

    try {
      final reply = await _client.chat.completions.create(
        model: G4FModels.gpt4o,
        messages: apiMessages,
      );
      if (!mounted) return;
      _setLastOracleText(
        reply.trim().isEmpty
            ? 'Мой взор затуманен. Знаки молчат. Спроси ещё раз.'
            : reply.trim(),
      );
    } catch (_) {
      if (!mounted) return;
      _setLastOracleText('Мой взор затуманен. Связь прервалась.');
    } finally {
      if (mounted) {
        setState(() => _isLoading = false);
        _scrollToBottom();
      }
    }
  }

  void _setLastOracleText(String text) {
    setState(() {
      _messages[_messages.length - 1] = ChatMessage(text: text, isUser: false);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFF060B19),
      appBar: AppBar(
        title: const Text("Оракул", style: TextStyle(color: Color(0xFFFFD700), fontWeight: FontWeight.w300, letterSpacing: 2.0)),
        backgroundColor: Colors.transparent,
        elevation: 0,
        centerTitle: true,
        iconTheme: const IconThemeData(color: Color(0xFFFFD700)),
      ),
      extendBodyBehindAppBar: true,
      body: Container(
        decoration: const BoxDecoration(
          gradient: LinearGradient(
            begin: Alignment.topCenter,
            end: Alignment.bottomCenter,
            colors: [Color(0xFF0D0415), Color(0xFF060B19)],
          ),
        ),
        child: SafeArea(
          child: Column(
            children: [
              Expanded(
                child: ListView.builder(
                  controller: _scrollController,
                  padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 20),
                  itemCount: _messages.length,
                  itemBuilder: (context, index) {
                    final msg = _messages[index];
                    return _buildMessageBubble(msg);
                  },
                ),
              ),
              if (_isLoading)
                const Padding(
                  padding: EdgeInsets.all(8.0),
                  child: SizedBox(
                    width: 20,
                    height: 20,
                    child: CircularProgressIndicator(
                      color: Color(0xFFFFD700),
                      strokeWidth: 2,
                    ),
                  ),
                ),
              _buildInputArea(),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildMessageBubble(ChatMessage message) {
    return Align(
      alignment: message.isUser ? Alignment.centerRight : Alignment.centerLeft,
      child: Container(
        margin: const EdgeInsets.only(bottom: 16.0),
        constraints: BoxConstraints(maxWidth: MediaQuery.of(context).size.width * 0.8),
        child: ClipRRect(
          borderRadius: BorderRadius.only(
            topLeft: const Radius.circular(20),
            topRight: const Radius.circular(20),
            bottomLeft: Radius.circular(message.isUser ? 20 : 5),
            bottomRight: Radius.circular(message.isUser ? 5 : 20),
          ),
          child: BackdropFilter(
            filter: ImageFilter.blur(sigmaX: 10, sigmaY: 10),
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 18, vertical: 14),
              decoration: BoxDecoration(
                color: message.isUser 
                    ? const Color(0xFF1E293B).withOpacity(0.6)
                    : const Color(0xFF2E1A47).withOpacity(0.4),
                border: Border.all(
                  color: message.isUser 
                      ? Colors.white.withOpacity(0.1)
                      : const Color(0xFFFFD700).withOpacity(0.2),
                  width: 1,
                ),
              ),
              child: SelectableText(
                message.text,
                style: TextStyle(
                  color: message.isUser ? Colors.white : const Color(0xFFE5E7EB),
                  fontSize: 16,
                  height: 1.4,
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildInputArea() {
    return Container(
      padding: const EdgeInsets.only(left: 16, right: 16, top: 12, bottom: 24),
      decoration: BoxDecoration(
        color: const Color(0xFF0D0415).withOpacity(0.8),
        border: Border(
          top: BorderSide(
            color: const Color(0xFFFFD700).withOpacity(0.2),
            width: 1,
          ),
        ),
      ),
      child: Row(
        children: [
          Expanded(
            child: Container(
              decoration: BoxDecoration(
                color: Colors.white.withOpacity(0.05),
                borderRadius: BorderRadius.circular(30),
                border: Border.all(color: Colors.white.withOpacity(0.1)),
              ),
              child: TextField(
                controller: _controller,
                style: const TextStyle(color: Colors.white),
                decoration: const InputDecoration(
                  hintText: "Спроси Оракула...",
                  hintStyle: TextStyle(color: Colors.white38),
                  border: InputBorder.none,
                  contentPadding: EdgeInsets.symmetric(horizontal: 20, vertical: 14),
                ),
                textInputAction: TextInputAction.send,
                onSubmitted: (_) => _sendMessage(),
              ),
            ),
          ),
          const SizedBox(width: 12),
          GestureDetector(
            onTap: _isLoading ? null : _sendMessage,
            child: Container(
              padding: const EdgeInsets.all(14),
              decoration: BoxDecoration(
                shape: BoxShape.circle,
                gradient: const RadialGradient(
                  colors: [Color(0xFFFFD700), Color(0xFFB8860B)],
                  center: Alignment.topLeft,
                  radius: 1.0,
                ),
                boxShadow: [
                  BoxShadow(
                    color: const Color(0xFFFFD700).withOpacity(0.3),
                    blurRadius: 12,
                    spreadRadius: 2,
                  ),
                ],
              ),
              child: const Icon(
                Icons.auto_awesome, 
                color: Color(0xFF2E1A47),
                size: 24,
              ),
            ),
          ),
        ],
      ),
    );
  }
}