import { Injectable } from '@angular/core';

import * as Rx from 'rxjs/RX';

@Injectable()
export class Message {
  listeners
  events
  eventsSubject
  constructor() {
    this.listeners = {};
    this.eventsSubject = new Rx.Subject();

    this.events = Rx.Observable.from(this.eventsSubject);

    this.events.subscribe(
      ({name, args}) => {
        if (this.listeners[name]) {
          for (let listener of this.listeners[name]) {
            listener(...args);
          }
        }
      });
  }

  // 推送数据
  send = (name, ...args) => {
    this.eventsSubject.next({
      name,
      args
    });
  }

  // 添加监听事件，listener为函数
  receive = (name, listener) => {
    if (!this.listeners[name]) {
      this.listeners[name] = [];
    }

    this.listeners[name].push(listener);
  }
}