// import { Subject, Observable, isObservable } from 'rxjs';
// import { filter, mergeMap, map } from 'rxjs/operators';

// export interface Action<T = any> {
//     id?: string;
//     type: string;
//     args: T;
// }

// export interface ActionResult {
//     id: string;
//     result: any;
// }

// type ActionHandler<T = any> = (args: T) => any;

// const actionStream = new Subject<Action>();
// const responseStream = new Subject<ActionResult>();

// export const actionOf = <T = any>(type: string, handler: ActionHandler<T>) => {
//     return actionStream
//         .pipe<Action, ActionResult>(
//             filter(action => action.type === type),
//             mergeMap(action => {
//                 const { id, args } = action;
//                 const response = handler(args);

//                 return new Observable<ActionResult>(obs => {
//                     if (isObservable(response)) {
//                         const sub = response.subscribe(result => {
//                             obs.next({ id, result });
//                             sub.unsubscribe();
//                         });
//                     } else {
//                         obs.next({ id, result: response });
//                     }
//                 });
//             }),
//         )
//         .subscribe(result => responseStream.next(result));
// };

// export const dispatch = <T = any>(type: string, args?: T) => {
//     const action: Action = {
//         id: (Math.random() * 1000000 << 0).toString(16),
//         type, args
//     };

//     const res = responseStream.pipe(
//         filter(r => r.id === action.id),
//         map(r => r.result)
//     );

//     actionStream.next(action);

//     return res;
// };