Facebook webhook

webhook.php

<?php
require_once __DIR__ . '/config/facebook.php';
require_once __DIR__ . '/vendor/autoload.php';
require_once __DIR__ . '/lib/utility.class.php';

use Facebook\Facebook;
use Facebook\Exceptions\FacebookResponseException;
use Facebook\Exceptions\FacebookSDKException;
use FacebookAds\Object\AdUser;
use FacebookAds\Api;
use FacebookAds\Object\AdAccount;
use FacebookAds\Object\CustomAudience;
use FacebookAds\Object\Fields\CustomAudienceFields;
use FacebookAds\Object\Values\CustomAudienceSubtypes;
use FacebookAds\Object\Values\CustomAudienceTypes;
use Facebook\FacebookRequest;
use Facebook\FacebookSession;

$utility   = new Utility();
$tokenInfo = $utility->readToken();

$fb = new Facebook([
  'app_id'     => $config['app_id'],
  'app_secret' => $config['app_secret'],
]);

//App Access Token
//$fb->setDefaultAccessToken($config['app_access_token']);
$fb->setDefaultAccessToken($tokenInfo->_token);

/*$data = array(
    'object' => 'page',
    'callback_url' => 'http://www.marriagecircle.in/infufb/webhook.php',
    'fields' => 'conversations',
    'verify_token' => 'CAAK3ZCgnFDPABAMnJ',
    'access_token' => $config['app_access_token']
);

try {
    $response = $fb->post('/' . $config['app_id'] . '/subscriptions', $data);

} catch(FacebookResponseException $e) {
    // When Graph returns an error
    echo 'Graph returned an error: ' . $e->getMessage();
    exit;
} catch(FacebookSDKException $e) {
    // When validation fails or other local issues
    echo 'Facebook SDK returned an error: ' . $e->getMessage();
    exit;
}*/

// Verifying the verify_token ensures nobody else can
// subscribe random things to your application.
if (isset($_REQUEST['hub_verify_token']) && $_REQUEST['hub_verify_token'] === 'CAAK3ZCgnFDPABAMnJ') {
  echo $_REQUEST['hub_challenge'];
  exit;
}

Api::init(
    $config['app_id'], // App ID
    $config['app_secret'],
    $tokenInfo->_token
);
$accounts = Api::instance()->call('/me/accounts');

$response  = $fb->get('/me/accounts');
$accounts  = $response->getDecodedBody();
$pageToken = $accounts['data'][0]['access_token'];
$pageId    = $accounts['data'][0]['id'];
$pageName  = $accounts['data'][0]['name'];

/*$fb->setDefaultAccessToken($pageToken);

$response = $fb->post('/' . $pageId . '/subscribed_apps', array(
    'access_token' => $pageToken
));*/

//echo '<pre>';
//var_dump($response);
//exit;

try {

    $fb->setDefaultAccessToken($tokenInfo->_token);

    $response = $fb->post('/' . $config['app_id'] . '/subscriptions_sample', array(
        'object_id'     => $pageId,
        'object'        => 'page',
        'field'         => 'leadgen',
        'access_token'  => $tokenInfo->_token,
        'custom_fields' => json_encode(array(
            'page_id' => $pageId
        ))
    ));

} catch(FacebookResponseException $e) {
    // When Graph returns an error
    echo 'Graph returned an error: ' . $e->getMessage();
    exit;
} catch(FacebookSDKException $e) {
    // When validation fails or other local issues
    echo 'Facebook SDK returned an error: ' . $e->getMessage();
    exit;
}

echo '<pre>';
var_dump($response);

$inputJSON = file_get_contents('php://input');
//$input = json_decode($inputJSON, true);

//var_dump($inputJSON);
$utility = new Utility();

$ret  = $utility->writeToFile('webhook.txt', $inputJSON);
var_dump($ret);

/*$page_id = $input['entry'][0]['changes'][0]['value']['page_id'];

$conversation_id = $input['entry'][0]['changes'][0]['value']['conversation_id'];
$field = $input['entry'][0]['changes'][0]['value']['field'];


switch ($field) {
  case 'conversations':
    $request = new FacebookRequest(
      $session,
      'GET',
      '/' . $page_id . '/conversations'
    );
    $response = $request->execute();
    $conversations = $response->getGraphObjectList();

    foreach ($conversations as $conversation) {
      $messages = $conversation->getProperty('messages')->asArray();
      foreach ($messages['data'] as $message) {
        // Again just using error_log so I can tail my log file.
        error_log(sprintf(
          "%s sent by %s (%s)",
          $message->message,
          $message->from->name,
          $message->from->id
        ));
      }
    }
    break;
}
*/

Do you not verify the incoming requests are valid?