Asymmetrik/node-rest-starter

import { Socket } from 'socket.io';

import { config, socketIO } from '../../../dependencies';
import { logger } from '../../../lib/logger';
import { SocketConfig } from '../../common/sockets/base-socket.provider';
import { hasAccess } from '../user/user-auth.middleware';

const emitName = 'alert';

/**
 * NotificationSocket Socket Controller that overrides Base Socket Controller
 * methods to handle specifics of Notifications
 */
export class NotificationSocket extends socketIO.SocketProvider {
    _topicName = config.get<string>('notifications.topic');
    _subscriptionCount = 0;

    constructor(socket: Socket, _config: SocketConfig) {
        super(socket, { ..._config, emitName });
    }

    ignorePayload(json) {
        // Ignore any payloads that do not match the current user.
        return (
            !json ||
            !json.user ||
            json.user.toString() !== this.getUserId().toString()
        );
    }

    /**
     * Returns the topic
     */
    getTopic() {
        return this._topicName;
    }

    /**
     * Handle socket disconnects
     */
    onDisconnect() {
        logger.info('NotificationSocket: Disconnected from client.');

        this.unsubscribe(this.getTopic());
    }

    /**
     * Handle socket errors
     */
    onError(err) {
        logger.error(err, 'NotificationSocket: Client connection error');

        this.unsubscribe(this.getTopic());
    }

    /**
     *
     */
    onSubscribe(payload) {
        if (logger.isDebugEnabled()) {
            logger.debug(
                `NotificationSocket: ${emitName}:subscribe event with payload: ${JSON.stringify(
                    payload
                )}`
            );
        }

        // Check that the user account has access
        this.applyMiddleware([hasAccess])
            .then(() => {
                // Subscribe to the user's notification topic
                const topic = this.getTopic();
                this.subscribe(topic);
                this._subscriptionCount++;
            })
            .catch((err) => {
                logger.warn(
                    `Unauthorized access to notifications by inactive user ${this.getUserId()}: ${err}`
                );
            });
    }

    /**
     *
     */
    onUnsubscribe(payload) {
        if (logger.isDebugEnabled()) {
            logger.debug(
                `NotificationSocket: ${emitName}:unsubscribe event with payload: ${JSON.stringify(
                    payload
                )}`
            );
        }

        const topic = this.getTopic();
        this.unsubscribe(topic);

        this._subscriptionCount = Math.max(0, this._subscriptionCount - 1);
        // If we are no longer listening for anything, unsubscribe
        if (this._subscriptionCount === 0) {
            this.unsubscribe(this.getTopic());
        }
    }
}

if (config.get<boolean>('notifications.enabled')) {
    socketIO.registerSocketListener(NotificationSocket);
}

module.exports = NotificationSocket;