AuthManager.ts

// Copyright (c) Microsoft.
// Licensed under the MIT license.

import AsyncStorage from '@react-native-async-storage/async-storage';
import {authorize, refresh, AuthConfiguration} from 'react-native-app-auth';
import {compareAsc, parseISO, sub} from 'date-fns';

import {AuthConfig} from './AuthConfig';

const config: AuthConfiguration = {
  clientId: AuthConfig.appId,
  redirectUrl: 'graph-sample://react-native-auth/',
  scopes: AuthConfig.appScopes,
  additionalParameters: {prompt: 'select_account'},
  serviceConfiguration: {
    authorizationEndpoint:
      'https://login.microsoftonline.com/common/oauth2/v2.0/authorize',
    tokenEndpoint: 'https://login.microsoftonline.com/common/oauth2/v2.0/token',
  },
};

export class AuthManager {
  static signInAsync = async () => {
    const result = await authorize(config);

    console.log(result.accessToken);

    // Store the access token, refresh token, and expiration time in storage
    await AsyncStorage.setItem('userToken', result.accessToken);
    await AsyncStorage.setItem('refreshToken', result.refreshToken);
    await AsyncStorage.setItem('expireTime', result.accessTokenExpirationDate);
  };

  static signOutAsync = async () => {
    // Clear storage
    await AsyncStorage.removeItem('userToken');
    await AsyncStorage.removeItem('refreshToken');
    await AsyncStorage.removeItem('expireTime');
  };

  static getAccessTokenAsync = async () => {
    const expireTime = await AsyncStorage.getItem('expireTime');

    if (expireTime !== null) {
      // Get expiration time - 5 minutes
      // If it's <= 5 minutes before expiration, then refresh
      const expire = sub(parseISO(expireTime), {minutes: 5});
      const now = new Date();

      if (compareAsc(now, expire) >= 0) {
        // Expired, refresh
        console.log('Refreshing token');
        const refreshToken = await AsyncStorage.getItem('refreshToken');
        console.log(`Refresh token: ${refreshToken}`);
        const result = await refresh(config, {
          refreshToken: refreshToken || '',
        });

        // Store the new access token, refresh token, and expiration time in storage
        await AsyncStorage.setItem('userToken', result.accessToken);
        await AsyncStorage.setItem('refreshToken', result.refreshToken || '');
        await AsyncStorage.setItem(
          'expireTime',
          result.accessTokenExpirationDate,
        );

        return result.accessToken;
      }

      // Not expired, just return saved access token
      const accessToken = await AsyncStorage.getItem('userToken');
      return accessToken;
    }

    return null;
  };
}