import { Operator } from '../Operator';
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import { Subscriber } from '../Subscriber';
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import { Observable } from '../Observable';
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import { Subject } from '../Subject';
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import { Subscription } from '../Subscription';
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import { OuterSubscriber } from '../OuterSubscriber';
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import { InnerSubscriber } from '../InnerSubscriber';
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import { subscribeToResult } from '../util/subscribeToResult';
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import { OperatorFunction } from '../types';
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/**
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* Branch out the source Observable values as a nested Observable starting from
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* an emission from `openings` and ending when the output of `closingSelector`
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* emits.
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*
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* <span class="informal">It's like {@link bufferToggle}, but emits a nested
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* Observable instead of an array.</span>
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*
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* 
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*
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* Returns an Observable that emits windows of items it collects from the source
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* Observable. The output Observable emits windows that contain those items
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* emitted by the source Observable between the time when the `openings`
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* Observable emits an item and when the Observable returned by
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* `closingSelector` emits an item.
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*
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* ## Example
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* Every other second, emit the click events from the next 500ms
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* ```ts
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* import { fromEvent, interval, EMPTY } from 'rxjs';
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* import { windowToggle, mergeAll } from 'rxjs/operators';
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*
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* const clicks = fromEvent(document, 'click');
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* const openings = interval(1000);
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* const result = clicks.pipe(
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* windowToggle(openings, i => i % 2 ? interval(500) : EMPTY),
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* mergeAll()
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* );
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* result.subscribe(x => console.log(x));
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* ```
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*
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* @see {@link window}
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* @see {@link windowCount}
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* @see {@link windowTime}
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* @see {@link windowWhen}
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* @see {@link bufferToggle}
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*
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* @param {Observable<O>} openings An observable of notifications to start new
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* windows.
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* @param {function(value: O): Observable} closingSelector A function that takes
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* the value emitted by the `openings` observable and returns an Observable,
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* which, when it emits (either `next` or `complete`), signals that the
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* associated window should complete.
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* @return {Observable<Observable<T>>} An observable of windows, which in turn
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* are Observables.
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* @method windowToggle
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* @owner Observable
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*/
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export function windowToggle<T, O>(openings: Observable<O>,
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closingSelector: (openValue: O) => Observable<any>): OperatorFunction<T, Observable<T>> {
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return (source: Observable<T>) => source.lift(new WindowToggleOperator<T, O>(openings, closingSelector));
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}
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class WindowToggleOperator<T, O> implements Operator<T, Observable<T>> {
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constructor(private openings: Observable<O>,
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private closingSelector: (openValue: O) => Observable<any>) {
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}
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call(subscriber: Subscriber<Observable<T>>, source: any): any {
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return source.subscribe(new WindowToggleSubscriber(
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subscriber, this.openings, this.closingSelector
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));
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}
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}
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interface WindowContext<T> {
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window: Subject<T>;
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subscription: Subscription;
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}
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/**
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* We need this JSDoc comment for affecting ESDoc.
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* @ignore
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* @extends {Ignored}
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*/
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class WindowToggleSubscriber<T, O> extends OuterSubscriber<T, any> {
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private contexts: WindowContext<T>[] = [];
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private openSubscription: Subscription;
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constructor(destination: Subscriber<Observable<T>>,
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private openings: Observable<O>,
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private closingSelector: (openValue: O) => Observable<any>) {
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super(destination);
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this.add(this.openSubscription = subscribeToResult(this, openings, openings as any));
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}
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protected _next(value: T) {
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const { contexts } = this;
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if (contexts) {
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const len = contexts.length;
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for (let i = 0; i < len; i++) {
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contexts[i].window.next(value);
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}
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}
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}
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protected _error(err: any) {
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const { contexts } = this;
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this.contexts = null;
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if (contexts) {
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const len = contexts.length;
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let index = -1;
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while (++index < len) {
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const context = contexts[index];
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context.window.error(err);
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context.subscription.unsubscribe();
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}
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}
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super._error(err);
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}
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protected _complete() {
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const { contexts } = this;
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this.contexts = null;
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if (contexts) {
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const len = contexts.length;
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let index = -1;
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while (++index < len) {
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const context = contexts[index];
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context.window.complete();
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context.subscription.unsubscribe();
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}
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}
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super._complete();
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}
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/** @deprecated This is an internal implementation detail, do not use. */
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_unsubscribe() {
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const { contexts } = this;
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this.contexts = null;
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if (contexts) {
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const len = contexts.length;
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let index = -1;
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while (++index < len) {
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const context = contexts[index];
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context.window.unsubscribe();
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context.subscription.unsubscribe();
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}
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}
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}
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notifyNext(outerValue: any, innerValue: any,
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outerIndex: number, innerIndex: number,
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innerSub: InnerSubscriber<T, any>): void {
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if (outerValue === this.openings) {
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let closingNotifier;
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try {
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const { closingSelector } = this;
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closingNotifier = closingSelector(innerValue);
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} catch (e) {
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return this.error(e);
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}
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const window = new Subject<T>();
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const subscription = new Subscription();
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const context = { window, subscription };
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this.contexts.push(context);
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const innerSubscription = subscribeToResult(this, closingNotifier, context as any);
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if (innerSubscription.closed) {
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this.closeWindow(this.contexts.length - 1);
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} else {
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(<any>innerSubscription).context = context;
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subscription.add(innerSubscription);
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}
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this.destination.next(window);
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} else {
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this.closeWindow(this.contexts.indexOf(outerValue));
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}
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}
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notifyError(err: any): void {
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this.error(err);
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}
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notifyComplete(inner: Subscription): void {
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if (inner !== this.openSubscription) {
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this.closeWindow(this.contexts.indexOf((<any> inner).context));
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}
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}
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private closeWindow(index: number): void {
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if (index === -1) {
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return;
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}
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const { contexts } = this;
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const context = contexts[index];
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const { window, subscription } = context;
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contexts.splice(index, 1);
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window.complete();
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subscription.unsubscribe();
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}
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}
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