import {Observable, Subject, AsyncSubject} from 'rxjs';
import EndlessSubject from './endlessSubject';

export interface NewableSubject<U extends Subject<T>, T> {
  new (): U;
}

export type RequestOptions<T, U extends Subject<R>, R> = {
  topic: string;
  data: T;
  Subject?: NewableSubject<U, R>;
};

declare interface BaseChannel {
  new (plugins: Object[]): this;
  registerPlugin(plugin: Object): void;
}

declare interface Channel<T> extends BaseChannel {
  observe(topic: String): Observable<T>;
  subject(topic: String, subject?: EndlessSubject<T>): Subject<T>;
}

declare interface RequestResponseChannel<Req, Res> extends BaseChannel {
  observe(topic: String): Observable<{data: Req; replySubject: Subject<Res>}>;
  request<S extends Subject<Res>>(options: RequestOptions<Req, S, Res>): Subject<Res>;
  subject(topic: String, subject?: EndlessSubject<Res>): Subject<Res>;
}

export {Channel, RequestResponseChannel};