RocketChat/Rocket.Chat

import { Emitter } from '@rocket.chat/emitter';
import { Random } from '@rocket.chat/random';
import type { ReactPortal } from 'react';

type SubscribedPortal = {
    portal: ReactPortal;
    key: string;
};

type PortalsSubscription = {
    subscribe: (callback: () => void) => () => void;
    getSnapshot: () => SubscribedPortal[];
    has: (key: unknown) => boolean;
    set: (key: unknown, portal: ReactPortal) => void;
    delete: (key: unknown) => void;
};

const createPortalsSubscription = (): PortalsSubscription => {
    const portalsMap = new Map<unknown, SubscribedPortal>();
    let portals = Array.from(portalsMap.values());
    const emitter = new Emitter<{ update: void }>();

    return {
        getSnapshot: (): SubscribedPortal[] => portals,
        subscribe: (callback): (() => void) => emitter.on('update', callback),
        delete: (key): void => {
            portalsMap.delete(key);
            portals = Array.from(portalsMap.values());
            emitter.emit('update');
        },
        set: (key, portal): void => {
            portalsMap.set(key, { portal, key: Random.id() });
            portals = Array.from(portalsMap.values());
            emitter.emit('update');
        },
        has: (key): boolean => portalsMap.has(key),
    };
};

export const portalsSubscription = createPortalsSubscription();

export const unregisterPortal = (key: unknown): void => {
    portalsSubscription.delete(key);
};

export const registerPortal = (key: unknown, portal: ReactPortal): (() => void) => {
    portalsSubscription.set(key, portal);
    return (): void => {
        unregisterPortal(key);
    };
};