org.eclipse.mdm.application/src/main/webapp/src/app/authentication/authentication.service.ts

/********************************************************************************
 * Copyright (c) 2015-2018 Contributors to the Eclipse Foundation
 *
 * See the NOTICE file(s) distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 ********************************************************************************/

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Router, ResolveStart } from '@angular/router';
import { PropertyService } from '../core/property.service';
import { Observable } from 'rxjs';
import { publishReplay, refCount, map, tap } from 'rxjs/operators';

export class User {
  username: string;
  roles: string[];
}

export enum Role {
  Admin = 'Admin',
  User = 'DescriptiveDataAuthor',
  Guest = 'Guest',
}

@Injectable({
  providedIn: 'root'
})
export class AuthenticationService {
  readonly loginURL: string;
  readonly logoutURL: string;
  readonly currentUserURL: string;

  private loginUser: Observable<User>;

  constructor(private http: HttpClient,
    private _prop: PropertyService) {
    this.currentUserURL = _prop.getUrl('mdm/user/current');
  }

  isLoggedIn() {
    return this.getLoginUser().pipe(map(user => user !== null));
  }

  getLoginUser() {
    if (!this.loginUser) {
      this.loginUser = this.loadUser().pipe(
        publishReplay(1),
        refCount()
      );
    }

    return this.loginUser;
  }

  isUserInRole(roles: string | string[]) {
    if (roles === undefined) {
      return Observable.of(true);
    } else if (typeof roles === 'string') {
      roles = [ roles ];
    }

    return this.getLoginUser().pipe(
          map(user => user.roles.filter(x => roles.includes(x)).length > 0)
      );
  }

  private loadUser() {
    return this.http.get<User>(this.currentUserURL, {
      params: {
        roles: Object.values(Role).join(',')
      }
    });
  }
}