<?php
/*
 * Copyright 2011 Google Inc.
 *
 * Licensed 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.
 */

include_once __DIR__ . '/../vendor/autoload.php';
include_once "templates/base.php";

echo pageHeader("Retrieving An Id Token");

/*************************************************
 * Ensure you've downloaded your oauth credentials
 ************************************************/
if (!$oauth_credentials = getOAuthCredentialsFile()) {
  echo missingOAuth2CredentialsWarning();
  exit;
}

/************************************************
 * NOTICE:
 * The redirect URI is to the current page, e.g:
 * http://localhost:8080/idtoken.php
 ************************************************/
$redirect_uri = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'];

$client = new Google_Client();
$client->setAuthConfig($oauth_credentials);
$client->setRedirectUri($redirect_uri);
$client->setScopes('email');

/************************************************
 * If we're logging out we just need to clear our
 * local access token in this case
 ************************************************/
if (isset($_REQUEST['logout'])) {
  unset($_SESSION['id_token']);
}


/************************************************
 * If we have a code back from the OAuth 2.0 flow,
 * we need to exchange that with the
 * Google_Client::fetchAccessTokenWithAuthCode()
 * function. We store the resultant access token
 * bundle in the session, and redirect to ourself.
 ************************************************/
if (isset($_GET['code'])) {
  $token = $client->fetchAccessTokenWithAuthCode($_GET['code']);
  $client->setAccessToken($token);

  // store in the session also
  $_SESSION['id_token'] = $token;

  // redirect back to the example
  header('Location: ' . filter_var($redirect_uri, FILTER_SANITIZE_URL));
}

/************************************************
  If we have an access token, we can make
  requests, else we generate an authentication URL.
 ************************************************/
if (
  !empty($_SESSION['id_token'])
  && isset($_SESSION['id_token']['id_token'])
) {
  $client->setAccessToken($_SESSION['id_token']);
} else {
  $authUrl = $client->createAuthUrl();
}

/************************************************
  If we're signed in we can go ahead and retrieve
  the ID token, which is part of the bundle of
  data that is exchange in the authenticate step
  - we only need to do a network call if we have
  to retrieve the Google certificate to verify it,
  and that can be cached.
 ************************************************/
if ($client->getAccessToken()) {
  $token_data = $client->verifyIdToken();
}
?>

<div class="box">
<?php if (isset($authUrl)): ?>
  <div class="request">
    <a class='login' href='<?= $authUrl ?>'>Connect Me!</a>
  </div>
<?php else: ?>
  <div class="data">
    <p>Here is the data from your Id Token:</p>
    <pre><?php var_export($token_data) ?></pre>
  </div>
<?php endif ?>
</div>

<?php echo pageFooter(__FILE__) ?>
