/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
import {Injectable} from '@angular/core';
import {ActivatedRouteSnapshot, CanActivate, Router, RouterStateSnapshot} from '@angular/router';
import {Observable} from 'rxjs/Observable';
import * as fromRoot from '../../../store';
import {Store} from '@ngrx/store';

@Injectable()
export class AuthGuard implements CanActivate {

  constructor(private store: Store<fromRoot.State>, private router: Router) {
  }

  waitForAuthentication(): Observable<boolean> {
    return this.store.select(fromRoot.getAuthenticationLoading)
      .filter(loading => !loading)
      .take(1);
  }

  canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {
    return this.waitForAuthentication()
      .switchMap(() => this.store.select(fromRoot.getAuthentication)
        .map(authentication => {
          if (!authentication) {
            this.router.navigate(['/login']);
            return false;
          }
          return true;
        })
      );

  }
}