Php how to add Notify Subscribers when uploading video Youtube Api - php

Question

I have the below code working perfectly, i use it to upload videos to my youtube channel but i want to add Notify Subscribers everytime i upload new video, what piece of code do i need to add to my code, i did a lot of research online but couldn't find any solution.
<?php
/**
* Library Requirements
*
* 1. Install composer (https://getcomposer.org)
* 2. On the command line, change to this directory (api-samples/php)
* 3. Require the google/apiclient library
* $ composer require google/apiclient:~2.0
*/
if (!file_exists(__DIR__ . '/vendor/autoload.php')) {
throw new \Exception('please run "composer require google/apiclient:~2.0" in "' . __DIR__ .'"');
}
require_once __DIR__ . '/vendor/autoload.php';
session_start();
/*
* You can acquire an OAuth 2.0 client ID and client secret from the
* {{ Google Cloud Console }} <{{ https://cloud.google.com/console }}>
* For more information about using OAuth 2.0 to access Google APIs, please see:
* <https://developers.google.com/youtube/v3/guides/authentication>
* Please ensure that you have enabled the YouTube Data API for your project.
*/
$OAUTH2_CLIENT_ID = 'xxxxxxx';
$OAUTH2_CLIENT_SECRET = 'xxxxxxx';
$client = new Google_Client();
$client->setClientId($OAUTH2_CLIENT_ID);
$client->setClientSecret($OAUTH2_CLIENT_SECRET);
$client->setScopes('https://www.googleapis.com/auth/youtube');
$redirect = filter_var('http://' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'],
FILTER_SANITIZE_URL);
$client->setRedirectUri($redirect);
// Define an object that will be used to make all API requests.
$youtube = new Google_Service_YouTube($client);
// Check if an auth token exists for the required scopes
$tokenSessionKey = 'token-' . $client->prepareScopes();
if (isset($_GET['code'])) {
if (strval($_SESSION['state']) !== strval($_GET['state'])) {
die('The session state did not match.');
}
$client->authenticate($_GET['code']);
$_SESSION[$tokenSessionKey] = $client->getAccessToken();
header('Location: ' . $redirect);
}
if (isset($_SESSION[$tokenSessionKey])) {
$client->setAccessToken($_SESSION[$tokenSessionKey]);
}
// Check to ensure that the access token was successfully acquired.
if ($client->getAccessToken()) {
$htmlBody = '';
try{
// REPLACE this value with the path to the file you are uploading.
$videoPath = __DIR__ . '/video.mp4';
// Create a snippet with title, description, tags and category ID
// Create an asset resource and set its snippet metadata and type.
// This example sets the video's title, description, keyword tags, and
// video category.
$snippet = new Google_Service_YouTube_VideoSnippet();
$snippet->setTitle("Test title");
$snippet->setDescription("Test description");
$snippet->setTags(array("tag1", "tag2"));
// Numeric video category. See
// https://developers.google.com/youtube/v3/docs/videoCategories/list
$snippet->setCategoryId("22");
// Set the video's status to "public". Valid statuses are "public",
// "private" and "unlisted".
$status = new Google_Service_YouTube_VideoStatus();
$status->privacyStatus = "public";
// Associate the snippet and status objects with a new video resource.
$video = new Google_Service_YouTube_Video();
$video->setSnippet($snippet);
$video->setStatus($status);
// Specify the size of each chunk of data, in bytes. Set a higher value for
// reliable connection as fewer chunks lead to faster uploads. Set a lower
// value for better recovery on less reliable connections.
$chunkSizeBytes = 1 * 1024 * 1024;
// Setting the defer flag to true tells the client to return a request which can be called
// with ->execute(); instead of making the API call immediately.
$client->setDefer(true);
// Create a request for the API's videos.insert method to create and upload the video.
$insertRequest = $youtube->videos->insert("status,snippet", $video);
// Create a MediaFileUpload object for resumable uploads.
$media = new Google_Http_MediaFileUpload(
$client,
$insertRequest,
'video/*',
null,
true,
$chunkSizeBytes
);
$media->setFileSize(filesize($videoPath));
// Read the media file and upload it chunk by chunk.
$status = false;
$handle = fopen($videoPath, "rb");
while (!$status && !feof($handle)) {
$chunk = fread($handle, $chunkSizeBytes);
$status = $media->nextChunk($chunk);
}
fclose($handle);
// If you want to make other calls after the file upload, set setDefer back to false
$client->setDefer(false);
$htmlBody .= "<h3>Video Uploaded</h3><ul>";
$htmlBody .= sprintf('<li>%s (%s)</li>',
$status['snippet']['title'],
$status['id']);
$htmlBody .= '</ul>';
} catch (Google_Service_Exception $e) {
$htmlBody .= sprintf('<p>A service error occurred: <code>%s</code></p>',
htmlspecialchars($e->getMessage()));
} catch (Google_Exception $e) {
$htmlBody .= sprintf('<p>An client error occurred: <code>%s</code></p>',
htmlspecialchars($e->getMessage()));
}
$_SESSION[$tokenSessionKey] = $client->getAccessToken();
} elseif ($OAUTH2_CLIENT_ID == 'REPLACE_ME') {
$htmlBody = <<<END
<h3>Client Credentials Required</h3>
<p>
You need to set <code>\$OAUTH2_CLIENT_ID</code> and
<code>\$OAUTH2_CLIENT_ID</code> before proceeding.
<p>
END;
} else {
// If the user hasn't authorized the app, initiate the OAuth flow
$state = mt_rand();
$client->setState($state);
$_SESSION['state'] = $state;
$authUrl = $client->createAuthUrl();
$htmlBody = <<<END
<h3>Authorization Required</h3>
<p>You need to authorize access before proceeding.<p>
END;
}
echo $videoPath;
?>
<!doctype html>
<html>
<head>
<title>Video Uploaded</title>
</head>
<body>
<?=$htmlBody?>
</body>
</html>
I really appreciate if someone could help.