import { Observable, Subject } from 'rxjs';
import { ServiceBusEvent, ServiceBus } from '../interface/service-bus.type';

/**
 * serviceBus 通讯服务器端，用来监听其他子应用发来的请求
 *
 * @export
 */
export class ServiceBusServer {
  /**
   * 应用的名称
   *
   */
  appName: string;

  /**
   * 应用的事件
   *
   */
  get events(): Observable<ServiceBusEvent> {
    return this._events;
  }

  /**
   * 应用的请求处理
   *
   */
  requestHandler!:  null | ((event: ServiceBusEvent) => Observable<ServiceBusEvent>);

  private _serviceBus: ServiceBus;

  private _events: Subject<ServiceBusEvent> = new Subject<ServiceBusEvent>();

  /**
   * Creates an instance of ServiceBusServer.
   * @param  appName server所在应用名称
   * @param  serviceBusService serviceBusServer
   */
  constructor(appName: string, serviceBusService: ServiceBus) {
    this._serviceBus = serviceBusService;
    this.appName = appName;
  }

  /**
   * 注册server
   *
   */
  register(): void {
    this._serviceBus.registerServer(this);
  }

  /**
   * 发布事件
   *
   */
  publishEvent(event: ServiceBusEvent): void {
    this._events.next(event);
  }

  /**
   * 销毁
   *
   */
  destroy() {
    this.requestHandler = null;
    this._events.error('destroyed');
  }
}