/**

* @license

* Copyright Google LLC All Rights Reserved.

*

* Use of this source code is governed by an MIT-style license that can be

* found in the LICENSE file at https://angular.dev/license

*/

import {Events, MessageBus, Parameters} from '../projects/protocol';

export class IFrameMessageBus extends MessageBus<Events> {

private listeners: any[] = [];

constructor(

private readonly source: string,

private readonly destination: string,

private readonly docWindow: () => Window,

) {

super();

}

override on<E extends keyof Events>(topic: E, cb: Events[E]): () => void {

const listener = (e: MessageEvent) => {

if (!e.data || e.data.source !== this.destination || !e.data.topic) {

return;

}

if (e.data.topic === topic) {

(cb as () => void).apply(null, e.data.args);

}

};

window.addEventListener('message', listener);

this.listeners.push(listener);

return () => {

this.listeners.splice(this.listeners.indexOf(listener), 1);

window.removeEventListener('message', listener);

};

}

override once<E extends keyof Events>(topic: E, cb: Events[E]): void {

const listener = (e: MessageEvent) => {

if (!e.data || e.data.source !== this.destination || !e.data.topic) {

return;

}

if (e.data.topic === topic) {

(cb as any).apply(null, e.data.args);

window.removeEventListener('message', listener);

}

};

window.addEventListener('message', listener);

}

override emit<E extends keyof Events>(topic: E, args?: Parameters<Events[E]>): boolean {

this.docWindow().postMessage(

{

source: this.source,

topic,

args,

// Since both the devtools app and the demo app use IframeMessageBus,

// we want to only ignore the ngZone for the demo app. This will let us

// prevent infinite change detection loops triggered by message

// event listeners but also not prevent the NgZone in the devtools app

// from updating its UI.

__ignore_ng_zone__: this.source === 'angular-devtools',

__NG_DEVTOOLS_EVENT__: true,

},

'*',

);

return true;

}

override destroy(): void {

this.listeners.forEach((l) => window.removeEventListener('message', l));

this.listeners = [];

}

}