import { Injectable } from '@angular/core';
import { ConfigurationService } from './config.service';
import { Authentication } from './configuration';
import { Http, Headers, Response } from '@angular/http';
import { Observable } from 'rxjs/Rx';
import { Output, EventEmitter } from '@angular/core';
import { JwtHelper } from 'angular2-jwt';

const OAUTH_REFRESH_URL = '/oauth/refresh';
const OAUTH_GETTOKEN_URL = '/oauth/get_auth_token';
const PSERVER_AUTHCODE_URL = '/@oauthgetcode';
const ATLASENSE_LOGIN_URL = '@login';
const ATLASENSE_REFRESH_URL = '@refresh';


@Injectable()
export class AuthService {

  timerRefreshToken: any;
  auth: Authentication;
  jwtHelper: JwtHelper = new JwtHelper();
  @Output() loggedin = new EventEmitter();

  constructor(
    public http: Http,
    public config: ConfigurationService) {
      let local_auth = localStorage.getItem('atlasense_auth');
      if (local_auth) {
        this.auth = JSON.parse(local_auth);
      } else {
        this.auth = new Authentication();
      }
      this.loggedin.subscribe(
        data => this.saveUserToken(data.data, data.refresh)
      );
  }

  save_auth() {
    localStorage.setItem('atlasense_auth', JSON.stringify(this.auth));
  }

  // Oauth functions for atlasense.oauth

  login_oauth(user, password) {
    let endpoint = this.config.getCanonicalURL() + PSERVER_AUTHCODE_URL +
      '?client_id=' + this.config.config.client_id + '&scope=' + this.config.config.account;
    let headers = new Headers();
    headers.append('Content-Type', 'application/json');
    this.http.options(
      endpoint,
      {headers: headers}
    ).subscribe(
      res => this.call_real_oauth(res, user, password),
      err => console.log(err)
    );
  }

  call_real_oauth(response, user, password) {
    let endpoint = this.config.getAuthURL() + OAUTH_GETTOKEN_URL;
    let body = JSON.stringify(
      {
        "grant_type": 'user',
        "code": response.json().auth_code,
        "username":user,
        "password": password,
        "scopes": [this.config.config.account],
        "client_id": this.config.config.client_id
      }

    );
    let headers = new Headers();
    headers.append('Content-Type', 'application/json');
    let refresh = this.auth.oauth + OAUTH_REFRESH_URL;
    this.http.post(
      endpoint,
      body,
      {headers: headers}
    ).subscribe(
      res => this.saveUserToken(res, refresh),
      err => console.log(err)
    );
  }

  // User token management

  saveUserToken(res, refresh) {
    this.auth.jwt = res;
    let decoded = this.jwtHelper.decodeToken(res._body);
    this.auth.token = decoded.token;
    this.auth.username = decoded.login;
    let expiration = this.jwtHelper.getTokenExpirationDate(res._body).getTime();
    let now = new Date().getTime();
    let timeout = expiration - now - 3600000;
    console.log('Refresh again in ' + timeout);
    this.save_auth();
    this.timerRefreshToken = Observable.timer(timeout);
    this.timerRefreshToken.subscribe(
      x => this.refreshToken(refresh)
    );
  }

  refreshToken(endpoint) {
    let headers = new Headers();
    headers.append('Content-Type', 'application/json');
    let body = JSON.stringify(
      {
        'token': this.auth.token,
        'user': this.auth.username,
        'cliend_id': this.config.config.client_id
      }
    );
    this.http.post(
      endpoint,
      body,
      {headers: headers}
    ).subscribe(
      res => this.saveUserToken(res, endpoint),
      err => console.log(err)
    );
  }

}