import 'dart:convert';

import 'package:flutter/foundation.dart';

import 'handler_dispatcher.dart';
import 'interface/connection.dart';
import 'interface/handler.dart';
import 'interface/pipeline.dart';

/// 通知中心
abstract class NotificationCenter implements IProcessPipeline {
  bool _isRunning = false;
  final _handlerDispatcher = HandlerDispatcher();

  @override
  bool get isRunning => _isRunning;
  @protected
  set isRunning(bool val) => _isRunning = val;

  /// 消息连接
  IConnection get connection;

  ///消息处理器供应者
  IHandlerProvider get handlerProvider => _handlerDispatcher;

  /// 消息处理器调度员
  @protected
  HandlerDispatcher get handlerDispatcher => _handlerDispatcher;

  @override
  void start() async {
    connection.messageReceived.addListener(_onMessageReceived);
    connection.connect();
    isRunning = true;
  }

  @override
  void stop() {
    connection.messageReceived.removeListener(_onMessageReceived);
    connection.close();
    isRunning = false;
  }

  @protected
  void process(String data);

  void _onMessageReceived(Object sender, dynamic e) {
    if (e is String) {
      process(e);
    } else if (e is Uint8List) {
      final text = const Utf8Decoder().convert(e);
      process(text);
    }
  }
}