import 'dart:async';
import 'dart:convert';
import 'package:flutter/foundation.dart';
import 'package:web_socket_channel/web_socket_channel.dart';

class MeActivityWebSocketClient {
  WebSocketChannel? _channel;
  final StreamController<Map<String, dynamic>> _messageController =
      StreamController<Map<String, dynamic>>.broadcast();
  Timer? _heartbeatTimer;
  Timer? _reconnectTimer;
  bool _isConnecting = false;
  bool _shouldReconnect = true;
  bool _isReady = false;
  int _reconnectAttempts = 0;
  static const int _maxReconnectAttempts = 5;
  static const Duration _reconnectDelay = Duration(seconds: 5);

  final List<int> _radioIds;

  final Completer<void> _readyCompleter = Completer<void>();

  MeActivityWebSocketClient({
    required List<int> radioIds,
  }) : _radioIds = radioIds;

  static const String _wsUrl =
      'wss://api.brandmeister.network/lh/?EIO=4&transport=websocket';

  Stream<Map<String, dynamic>> get messageStream => _messageController.stream;

  bool get isConnected => _channel != null;

  bool get isReady => _isReady;

  Future<void> get ready => _readyCompleter.future;

  List<int> get radioIds => _radioIds;

  Future<void> connect() async {
    if (_isConnecting || isConnected) {
      debugPrint('MeActivity WS: Already connected or connecting');
      return;
    }

    if (_radioIds.isEmpty) {
      debugPrint('MeActivity WS: No radio IDs provided');
      if (!_readyCompleter.isCompleted) {
        _readyCompleter.complete();
      }
      return;
    }

    _isConnecting = true;
    _shouldReconnect = true;

    try {
      debugPrint('MeActivity WS: Connecting to $_wsUrl');

      _channel = WebSocketChannel.connect(Uri.parse(_wsUrl));

      _channel!.stream.listen(
        _handleMessage,
        onError: _handleError,
        onDone: _handleDisconnect,
        cancelOnError: false,
      );

      _reconnectAttempts = 0;
      _isConnecting = false;
      debugPrint('MeActivity WS: WebSocket connected');
    } catch (e) {
      _isConnecting = false;
      debugPrint('MeActivity WS: Connection error: $e');
      _scheduleReconnect();
    }
  }

  void _handleMessage(dynamic message) {
    try {
      final messageStr = message.toString();
      debugPrint('MeActivity WS: Received message: $messageStr');

      if (messageStr.startsWith('0')) {
        _handleOpenPacket(messageStr);
      } else if (messageStr.startsWith('2')) {
        _sendPong();
      } else if (messageStr.startsWith('40')) {
        _handleNamespaceConnect();
      } else if (messageStr.startsWith('42')) {
        _handleDataPacket(messageStr);
      } else if (messageStr.startsWith('4')) {
        debugPrint('MeActivity WS: Received other type 4 message: $messageStr');
      }
    } catch (e) {
      debugPrint('MeActivity WS: Error handling message: $e');
    }
  }

  void _handleOpenPacket(String message) {
    try {
      final jsonStr = message.substring(1);
      final data = jsonDecode(jsonStr) as Map<String, dynamic>;

      final pingInterval = data['pingInterval'] as int? ?? 25000;

      _heartbeatTimer?.cancel();
      _heartbeatTimer = Timer.periodic(
        Duration(milliseconds: pingInterval),
        (_) => _sendPing(),
      );

      debugPrint(
          'MeActivity WS: Open packet received, ping interval: $pingInterval ms');

      _sendNamespaceConnect();
    } catch (e) {
      debugPrint('MeActivity WS: Error parsing open packet: $e');
    }
  }

  void _sendNamespaceConnect() {
    if (isConnected) {
      try {
        _channel!.sink.add('40');
        debugPrint('MeActivity WS: Sent namespace connect (40)');
      } catch (e) {
        debugPrint('MeActivity WS: Error sending namespace connect: $e');
      }
    }
  }

  void _handleNamespaceConnect() {
    debugPrint('MeActivity WS: Namespace connected (received 40)');

    _isReady = true;
    if (!_readyCompleter.isCompleted) {
      _readyCompleter.complete();
    }

    // Send search query to fetch historical activity for user's devices
    _sendSearchQuery();
  }

  void _sendSearchQuery() {
    if (!isConnected || !isReady) {
      debugPrint('MeActivity WS: Cannot send search query, not ready');
      return;
    }

    try {
      // Build SQL query for multiple device IDs: ContextID = 123 OR ContextID = 456
      final sqlParts = _radioIds.map((id) => 'ContextID = $id').toList();
      final sql = sqlParts.join(' OR ');

      final message = '42${jsonEncode([
            'searchMongo',
            {
              'query': {'sql': sql},
              'amount': 50 // Fetch up to 50 historical items
            }
          ])}';
      _channel!.sink.add(message);
      debugPrint('MeActivity WS: Sent search query: $message');
    } catch (e) {
      debugPrint('MeActivity WS: Error sending search query: $e');
    }
  }

  void _handleDataPacket(String message) {
    try {
      String jsonStr = message.substring(1);

      if (jsonStr.startsWith('2')) {
        jsonStr = jsonStr.substring(1);
      }

      final data = jsonDecode(jsonStr);

      Map<String, dynamic>? eventData;

      if (data is Map<String, dynamic>) {
        eventData = data;
      } else if (data is List && data.isNotEmpty) {
        final eventName = data[0] as String;
        if (data.length > 1) {
          eventData = {
            'event': eventName,
            'data': data[1],
          };
        } else {
          eventData = {
            'event': eventName,
          };
        }
      }

      if (eventData != null && !_messageController.isClosed) {
        _messageController.add(eventData);
      }
    } catch (e) {
      debugPrint('MeActivity WS: Error parsing data packet: $e');
    }
  }

  void _sendPing() {
    if (isConnected) {
      try {
        _channel!.sink.add('2');
        debugPrint('MeActivity WS: Sent ping');
      } catch (e) {
        debugPrint('MeActivity WS: Error sending ping: $e');
      }
    }
  }

  void _sendPong() {
    if (isConnected) {
      try {
        _channel!.sink.add('3');
        debugPrint('MeActivity WS: Sent pong');
      } catch (e) {
        debugPrint('MeActivity WS: Error sending pong: $e');
      }
    }
  }

  void _handleError(Object error) {
    debugPrint('MeActivity WS: Stream error: $error');
  }

  void _handleDisconnect() {
    debugPrint('MeActivity WS: Disconnected');
    _cleanup();

    if (_shouldReconnect) {
      _scheduleReconnect();
    }
  }

  void _scheduleReconnect() {
    if (_reconnectAttempts >= _maxReconnectAttempts) {
      debugPrint('MeActivity WS: Max reconnect attempts reached');
      return;
    }

    _reconnectAttempts++;
    debugPrint('MeActivity WS: Scheduling reconnect attempt $_reconnectAttempts');

    _reconnectTimer?.cancel();
    _reconnectTimer = Timer(_reconnectDelay, () {
      if (_shouldReconnect) {
        connect();
      }
    });
  }

  void _cleanup() {
    _heartbeatTimer?.cancel();
    _heartbeatTimer = null;
    _channel = null;
    _isConnecting = false;
  }

  void disconnect() {
    debugPrint('MeActivity WS: Disconnecting');
    _shouldReconnect = false;
    _reconnectTimer?.cancel();
    _heartbeatTimer?.cancel();

    try {
      _channel?.sink.close();
    } catch (e) {
      debugPrint('MeActivity WS: Error closing channel: $e');
    }

    _cleanup();
  }

  void dispose() {
    disconnect();
    _messageController.close();
  }
}