auth.guard.ts

import { Inject, Injectable } from '@angular/core';
import { CanActivate } from '@angular/router';
import { DOCUMENT } from '@angular/common';
import { Actions, ofActionCompleted, Select, Store } from '@ngxs/store';
import { Observable, of } from 'rxjs';
import { map, switchMap } from 'rxjs/operators';
import { ReadUser } from '@dasch-swiss/dsp-js';
import { AuthService } from '@dasch-swiss/vre/shared/app-session';
import {
    CurrentPageSelectors,
    SetUserAction,
    UserSelectors,
} from '@dasch-swiss/vre/shared/app-state';

@Injectable({
    providedIn: 'root',
})
export class AuthGuard implements CanActivate {
    @Select(UserSelectors.user) user$: Observable<ReadUser>;

    constructor(
        private store: Store,
        private _authService: AuthService,
        private actions$: Actions,
        @Inject(DOCUMENT) private document: Document
    ) {}

    canActivate(): Observable<boolean> {
        return this.user$.pipe(
            switchMap((user) => {
                if (user) return of(null);

                if (this.store.selectSnapshot(UserSelectors.isLoading)) {
                    return this.actions$.pipe(ofActionCompleted(SetUserAction));
                } else {
                    return this.store.dispatch(new SetUserAction(user));
                }
            }),
            switchMap(() => this._authService.isLoggedIn$),
            map((isLoggedIn) => {
                if (isLoggedIn) {
                    return true;
                } else {
                    this._goToHomePage();
                    return false;
                }
            })
        );
    }

    private _goToHomePage() {
        this.document.defaultView.location.href =
            `${this.document.defaultView.location.href}?` +
            `returnLink=${this.store.selectSnapshot(
                CurrentPageSelectors.loginReturnLink
            )}`;
    }
}