import 'dart:async';

import 'package:fl_lib/fl_lib.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:server_box/data/model/opencode/models.dart';
import 'package:server_box/data/provider/opencode/opencode.dart';
import 'package:server_box/data/provider/server/single.dart';
import 'package:server_box/data/res/store.dart';

/// Opencode 聊天页面
class OpencodeChatPage extends ConsumerStatefulWidget {
  final String serverId;
  final String? sessionId;

  const OpencodeChatPage({
    super.key,
    required this.serverId,
    this.sessionId,
  });

  @override
  ConsumerState<OpencodeChatPage> createState() => _OpencodeChatPageState();
}

class _OpencodeChatPageState extends ConsumerState<OpencodeChatPage> {
  final TextEditingController _messageController = TextEditingController();
  final ScrollController _scrollController = ScrollController();
  final List<OpencodeMessage> _messages = [];
  bool _isSending = false;
  StreamSubscription? _outputSubscription;
  String _streamingContent = '';

  @override
  void initState() {
    super.initState();
    _initSession();
    _listenToOutput();
  }

  @override
  void dispose() {
    _messageController.dispose();
    _scrollController.dispose();
    _outputSubscription?.cancel();
    super.dispose();
  }

  void _initSession() {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final sessionManager = ref.read(opencodeSessionManagerProvider.notifier);
      
      if (widget.sessionId != null) {
        sessionManager.loadSession(widget.sessionId!);
      } else {
        final serverState = ref.read(serverProvider(widget.serverId));
        sessionManager.createSession(
          serverId: widget.serverId,
          serverName: serverState.spi.name,
        );
      }
    });
  }

  void _listenToOutput() {
    final outputStream = ref.read(opencodeOutputStreamProvider);
    _outputSubscription = outputStream.listen((data) {
      setState(() {
        _streamingContent += data;
      });
      _scrollToBottom();
    });
  }

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

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

    _messageController.clear();
    
    final message = OpencodeMessage.user(text);
    
    setState(() {
      _messages.add(message);
      _isSending = true;
      _streamingContent = '';
    });

    await ref.read(opencodeSessionManagerProvider.notifier).addMessage(message);

    try {
      final connection = ref.read(opencodeConnectionProvider.notifier);
      await connection.sendMessage(message, _messages);
      
      await Future.delayed(const Duration(seconds: 2));
      
      if (_streamingContent.isNotEmpty) {
        final responseMessage = OpencodeMessage.assistant(_streamingContent);
        setState(() {
          _messages.add(responseMessage);
        });
        await ref.read(opencodeSessionManagerProvider.notifier).addMessage(responseMessage);
      }
    } catch (e) {
      final errorMessage = OpencodeMessage.assistant('Error: $e');
      setState(() {
        _messages.add(errorMessage);
      });
    } finally {
      setState(() {
        _isSending = false;
        _streamingContent = '';
      });
      _scrollToBottom();
    }
  }

  @override
  Widget build(BuildContext context) {
    final sessionState = ref.watch(opencodeSessionManagerProvider);
    final connectionState = ref.watch(opencodeConnectionProvider);

    return Scaffold(
      appBar: CustomAppBar(
        title: Text(sessionState.currentSession?.title ?? 'Opencode Chat'),
        actions: [
          IconButton(
            icon: const Icon(Icons.history),
            onPressed: _showSessionHistory,
          ),
          IconButton(
            icon: const Icon(Icons.settings),
            onPressed: _showSettings,
          ),
        ],
      ),
      body: Column(
        children: [
          if (connectionState.status != OpencodeConnectionStatus.connected)
            _buildStatusBar(connectionState),
          
          Expanded(
            child: _buildMessageList(sessionState),
          ),
          
          _buildInputArea(),
        ],
      ),
    );
  }

  Widget _buildStatusBar(OpencodeConnectionState state) {
    Color color;
    String text;
    IconData icon;

    switch (state.status) {
      case OpencodeConnectionStatus.connecting:
        color = Colors.orange;
        text = 'Connecting...';
        icon = Icons.sync;
      case OpencodeConnectionStatus.checkingInstallation:
        color = Colors.blue;
        text = 'Checking Opencode...';
        icon = Icons.search;
      case OpencodeConnectionStatus.installing:
        color = Colors.purple;
        text = 'Installing Opencode...';
        icon = Icons.download;
      case OpencodeConnectionStatus.startingServer:
        color = Colors.teal;
        text = 'Starting API server...';
        icon = Icons.play_arrow;
      case OpencodeConnectionStatus.error:
        color = Colors.red;
        text = state.error ?? 'Connection error';
        icon = Icons.error;
      default:
        return const SizedBox.shrink();
    }

    return Container(
      width: double.infinity,
      padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 16),
      color: color.withOpacity(0.1),
      child: Row(
        children: [
          Icon(icon, color: color, size: 18),
          const SizedBox(width: 8),
          Expanded(
            child: Text(
              text,
              style: TextStyle(color: color, fontSize: 13),
            ),
          ),
          if (state.status == OpencodeConnectionStatus.error)
            TextButton(
              onPressed: _retryConnection,
              child: const Text('Retry'),
            ),
        ],
      ),
    );
  }

  Widget _buildMessageList(OpencodeSessionState sessionState) {
    final allMessages = [...sessionState.currentSession?.messages ?? [], ..._messages];
    
    if (allMessages.isEmpty) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(
              Icons.chat_bubble_outline,
              size: 64,
              color: Colors.grey[400],
            ),
            const SizedBox(height: 16),
            Text(
              'Start a conversation with Opencode',
              style: TextStyle(
                color: Colors.grey[600],
                fontSize: 16,
              ),
            ),
          ],
        ),
      );
    }

    return ListView.builder(
      controller: _scrollController,
      padding: const EdgeInsets.all(16),
      itemCount: allMessages.length + (_isSending ? 1 : 0),
      itemBuilder: (context, index) {
        if (index == allMessages.length) {
          return _buildStreamingIndicator();
        }
        
        final message = allMessages[index];
        return _buildMessageBubble(message);
      },
    );
  }

  Widget _buildMessageBubble(OpencodeMessage message) {
    final isUser = message.role == 'user';
    final isSystem = message.role == 'system';

    if (isSystem) {
      return const SizedBox.shrink();
    }

    return Align(
      alignment: isUser ? Alignment.centerRight : Alignment.centerLeft,
      child: Container(
        margin: const EdgeInsets.only(bottom: 12),
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
        constraints: BoxConstraints(
          maxWidth: MediaQuery.of(context).size.width * 0.8,
        ),
        decoration: BoxDecoration(
          color: isUser ? UIs.primaryColor : Colors.grey[200],
          borderRadius: BorderRadius.circular(16).copyWith(
            bottomRight: isUser ? const Radius.circular(4) : null,
            bottomLeft: !isUser ? const Radius.circular(4) : null,
          ),
        ),
        child: Text(
          message.content,
          style: TextStyle(
            color: isUser ? Colors.white : Colors.black87,
            fontSize: 15,
          ),
        ),
      ),
    );
  }

  Widget _buildStreamingIndicator() {
    return Align(
      alignment: Alignment.centerLeft,
      child: Container(
        margin: const EdgeInsets.only(bottom: 12),
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
        decoration: BoxDecoration(
          color: Colors.grey[200],
          borderRadius: BorderRadius.circular(16).copyWith(
            bottomLeft: const Radius.circular(4),
          ),
        ),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(
              _streamingContent.isEmpty ? 'Thinking' : _streamingContent,
              style: TextStyle(
                color: Colors.black87,
                fontSize: 15,
              ),
            ),
            if (_streamingContent.isEmpty) ...[
              const SizedBox(width: 4),
              SizedBox(
                width: 12,
                height: 12,
                child: CircularProgressIndicator(
                  strokeWidth: 2,
                  valueColor: AlwaysStoppedAnimation<Color>(
                    Colors.grey[600]!,
                  ),
                ),
              ),
            ],
          ],
        ),
      ),
    );
  }

  Widget _buildInputArea() {
    return Container(
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: Colors.white,
        boxShadow: [
          BoxShadow(
            color: Colors.black.withOpacity(0.05),
            blurRadius: 10,
            offset: const Offset(0, -5),
          ),
        ],
      ),
      child: SafeArea(
        child: Row(
          children: [
            Expanded(
              child: TextField(
                controller: _messageController,
                decoration: InputDecoration(
                  hintText: 'Message Opencode...',
                  filled: true,
                  fillColor: Colors.grey[100],
                  border: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(24),
                    borderSide: BorderSide.none,
                  ),
                  contentPadding: const EdgeInsets.symmetric(
                    horizontal: 20,
                    vertical: 14,
                  ),
                ),
                onSubmitted: (_) => _sendMessage(),
              ),
            ),
            const SizedBox(width: 8),
            FloatingActionButton(
              mini: true,
              onPressed: _isSending ? null : _sendMessage,
              child: _isSending
                  ? const SizedBox(
                      width: 20,
                      height: 20,
                      child: CircularProgressIndicator(
                        strokeWidth: 2,
                        valueColor: AlwaysStoppedAnimation<Color>(Colors.white),
                      ),
                    )
                  : const Icon(Icons.send),
            ),
          ],
        ),
      ),
    );
  }

  void _showSessionHistory() {
    final sessionManager = ref.read(opencodeSessionManagerProvider.notifier);
    final sessions = ref.read(opencodeSessionManagerProvider).sessions
        .where((s) => s.serverId == widget.serverId)
        .toList();

    showModalBottomSheet(
      context: context,
      builder: (context) => Container(
        padding: const EdgeInsets.all(16),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              'Session History',
              style: Theme.of(context).textTheme.titleLarge,
            ),
            const SizedBox(height: 16),
            Expanded(
              child: ListView.builder(
                itemCount: sessions.length,
                itemBuilder: (context, index) {
                  final session = sessions[index];
                  return ListTile(
                    title: Text(session.title ?? 'Untitled Session'),
                    subtitle: Text(
                      '${session.messages.length} messages • ${_formatDate(session.updatedAt)}',
                    ),
                    onTap: () {
                      Navigator.pop(context);
                      sessionManager.loadSession(session.id);
                    },
                    trailing: IconButton(
                      icon: const Icon(Icons.delete, size: 20),
                      onPressed: () async {
                        await sessionManager.deleteSession(session.id);
                        Navigator.pop(context);
                      },
                    ),
                  );
                },
              ),
            ),
            const SizedBox(height: 8),
            SizedBox(
              width: double.infinity,
              child: ElevatedButton.icon(
                onPressed: () {
                  Navigator.pop(context);
                  final serverState = ref.read(serverProvider(widget.serverId));
                  sessionManager.createSession(
                    serverId: widget.serverId,
                    serverName: serverState.spi.name,
                  );
                },
                icon: const Icon(Icons.add),
                label: const Text('New Session'),
              ),
            ),
          ],
        ),
      ),
    );
  }

  void _showSettings() {
    context.push('/opencode/settings/${widget.serverId}');
  }

  void _retryConnection() {
    final connection = ref.read(opencodeConnectionProvider.notifier);
    final serverState = ref.read(serverProvider(widget.serverId));
    
    final pki = serverState.spi.keyId != null
        ? Stores.key.get(serverState.spi.keyId!)
        : null;

    connection.connect(
      serverState.spi,
      privateKey: pki?.key,
      passphrase: pki?.password,
    );
  }

  String _formatDate(DateTime date) {
    final now = DateTime.now();
    final diff = now.difference(date);
    
    if (diff.inDays == 0) {
      return '${date.hour.toString().padLeft(2, '0')}:${date.minute.toString().padLeft(2, '0')}';
    } else if (diff.inDays == 1) {
      return 'Yesterday';
    } else {
      return '${date.month}/${date.day}';
    }
  }
}