// ### @@ httpclient.ts
// ### @@

import {Injectable} from '@angular/core';
import {
  Http,
  Headers
} from '@angular/http';
import {UserService} from './user.service';

@Injectable()
export class HttpClient {
  constructor(private http: Http,
              private userService: UserService) {
  }

  sessionToken(headers: Headers) {
    headers.append('Accept', '*/*');
    headers.append('X-Requested-With', 'XMLHttpRequest');
    headers.append('SESSION', localStorage.getItem('session_token'));

    if (this.userService.loggedIn()) {
      headers.append('Authorization', 'Bearer' + localStorage.getItem('token'));
    }
    if (!this.userService.loggedIn()) {
      headers.append('Authorization', 'Bearer' + localStorage.getItem('refresh_token'));
    }
  }

  get(url) {
    const headers = new Headers();
    this.token(headers);
    return this.http.get(url, {
      headers: headers
    });
  }

  post(url, data) {
    const headers = new Headers();
    this.token(headers);
    return this.http.post(url, data, {
      headers: headers
    });
  }
}


// ### @@ user.service.ts
// ### @@

import {Injectable} from '@angular/core';

import {User} from '../models/user.model';

import {AppConfig} from '../../app.config';
import {HttpClient} from './httpclient';
import {tokenNotExpired, JwtHelper} from "angular2-jwt";

@Injectable()
export class UserService {
  jwtHelper: JwtHelper = new JwtHelper();
  session_token: any;
  token: string;
  refresh_token: string;

  constructor(private httpClient: HttpClient) {
  }
    ...
  // Check if the User is loggedIn
  // Return True; if token is not expired
  // Return False; if token is expired
  loggedIn() {
    let token = localStorage.getItem('token');
    console.log(this.jwtHelper.getTokenExpirationDate(token));

    return tokenNotExpired('token');
  };
}