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import { Subject } from '../Subject';
import { Operator } from '../Operator';
import { Subscriber } from '../Subscriber';
import { Observable } from '../Observable';
import { ConnectableObservable, connectableObservableDescriptor } from '../observable/ConnectableObservable';
import { MonoTypeOperatorFunction, OperatorFunction, UnaryFunction, ObservedValueOf, ObservableInput } from '../types';
/* tslint:disable:max-line-length */
export function multicast<T>(subject: Subject<T>): UnaryFunction<Observable<T>, ConnectableObservable<T>>;
export function multicast<T, O extends ObservableInput<any>>(subject: Subject<T>, selector: (shared: Observable<T>) => O): UnaryFunction<Observable<T>, ConnectableObservable<ObservedValueOf<O>>>;
export function multicast<T>(subjectFactory: (this: Observable<T>) => Subject<T>): UnaryFunction<Observable<T>, ConnectableObservable<T>>;
export function multicast<T, O extends ObservableInput<any>>(SubjectFactory: (this: Observable<T>) => Subject<T>, selector: (shared: Observable<T>) => O): OperatorFunction<T, ObservedValueOf<O>>;
/* tslint:enable:max-line-length */
/**
* Returns an Observable that emits the results of invoking a specified selector on items
* emitted by a ConnectableObservable that shares a single subscription to the underlying stream.
*
* 
*
* @param {Function|Subject} subjectOrSubjectFactory - Factory function to create an intermediate subject through
* which the source sequence's elements will be multicast to the selector function
* or Subject to push source elements into.
* @param {Function} [selector] - Optional selector function that can use the multicasted source stream
* as many times as needed, without causing multiple subscriptions to the source stream.
* Subscribers to the given source will receive all notifications of the source from the
* time of the subscription forward.
* @return {Observable} An Observable that emits the results of invoking the selector
* on the items emitted by a `ConnectableObservable` that shares a single subscription to
* the underlying stream.
* @method multicast
* @owner Observable
*/
export function multicast<T, R>(subjectOrSubjectFactory: Subject<T> | (() => Subject<T>),
selector?: (source: Observable<T>) => Observable<R>): OperatorFunction<T, R> {
return function multicastOperatorFunction(source: Observable<T>): Observable<R> {
let subjectFactory: () => Subject<T>;
if (typeof subjectOrSubjectFactory === 'function') {
subjectFactory = <() => Subject<T>>subjectOrSubjectFactory;
} else {
subjectFactory = function subjectFactory() {
return <Subject<T>>subjectOrSubjectFactory;
};
}
if (typeof selector === 'function') {
return source.lift(new MulticastOperator(subjectFactory, selector));
}
const connectable: any = Object.create(source, connectableObservableDescriptor);
connectable.source = source;
connectable.subjectFactory = subjectFactory;
return <ConnectableObservable<R>> connectable;
};
}
export class MulticastOperator<T, R> implements Operator<T, R> {
constructor(private subjectFactory: () => Subject<T>,
private selector: (source: Observable<T>) => Observable<R>) {
}
call(subscriber: Subscriber<R>, source: any): any {
const { selector } = this;
const subject = this.subjectFactory();
const subscription = selector(subject).subscribe(subscriber);
subscription.add(source.subscribe(subject));
return subscription;
}
}
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