Asymmetrik/mean2-starter

import { Injectable } from '@angular/core';
import { AuthenticationService } from '../admin/authentication/authentication.service';
import { UserStateService } from '../admin/authentication/user-state.service';
import { NotificationService } from './notification.service';
import { NotificationStateService } from './notification-state-service';

@Injectable()
export class NotificationHandlerService {
    public subscribed: boolean = false;

    constructor(
        public userStateService: UserStateService,
        public authentication: AuthenticationService,
        public notificationService: NotificationService,
        public notificationStateService: NotificationStateService) {
    }

    public initialize() {

        // Subscribe to state changes
        this.notificationStateService.notificationsCleared$
            .subscribe((clear) => {
                if (clear) {
                    this.notificationService.markAllRead();
                }
            });

        // Subscribe to the user's authentication observable.  When the user signs in,
        // init the websocket and do an initial query for existing notifications
        this.authentication.initializing$
            .subscribe(() => {
                if (this.userStateService.user.isActive()) {
                    if (this.subscribed) {
                        return;
                    }
                    this.subscribed = true;

                    // Initialize the websocket
                    this.notificationService.initialize();
                    this.notificationService.notificationReceived
                        .subscribe((notification: any) => {
                            this.notificationStateService.receiveNotifications([notification]);
                        });

                    // Check for existing unread notifications
                    let notificationsViewed = this.userStateService.user.userModel.notificationsViewed;
                    let query = {};
                    if (undefined !== notificationsViewed) {
                        query = {'created': {'$gte': this.userStateService.user.userModel.notificationsViewed}};
                    }
                    this.notificationService.search(query, null)
                        .subscribe((notifications) => {
                            if (notifications.totalSize === 0) {
                                return;
                            }

                            if (notifications.totalSize > 1) {
                                this.notificationStateService.receiveNotifications(notifications.elements);
                            }
                        });

                }
            });
    }

}