php server google drive download file in background - php

Question

I need form PHP level, in background without user interaction login on google drive and get files list. I found similar topic and code for question working, but is required handly login, where I need login from php in background.
In second post with code for possibly login witout user interaction, but I don't know where is bug.
My code PHP:
<?php
require_once 'vendor/autoload.php';
require_once 'src/Google_Client.php';
require_once 'src/contrib/Google_DriveService.php';
require_once 'src/auth/Google_AssertionCredentials.php';
$client_email = 'xxxxxx#xxxxxxxxxxxxx.xxx.gserviceaccount.com';
$private_key = file_get_contents('key.p12');
$user_to_impersonate = 'xxxxxxxxxxxxxxx#gmail.com';
$scopes = array('https://www.googleapis.com/auth/drive');
$credentials = new Google_AssertionCredentials(
$client_email,
$scopes,
$private_key,
'notasecret', // Default P12 password
'http://oauth.net/grant_type/jwt/1.0/bearer', // Default grant type
$user_to_impersonate
);
$client = new Google_Client();
$client->setAssertionCredentials($credentials);
if ($client->getAuth()->isAccessTokenExpired()) {
$client->getAuth()->refreshTokenWithAssertion();
}
$service = new Google_Service_Drive($client);
$files = $service->files->listFiles();
echo "count files=".count($files)."<br>";
foreach( $files as $item ) {
echo "title=".$item['title']."<br>";
}
?>
Vendor directory I get from this instruction, and other files I get from this GitHub
I had problem with function Google_Auth_AssertionCredentials, PHP hasn't file with this function. I found that file src/auth/Google_AssertionCredentials.php has similar function Google_AssertionCredentials. I included Google_AssertionCredentials.php file and changed function name.
In finally I have new error:
PHP Fatal error: Cannot call constructor in
\google_drive\vendor\google\apiclient-services\src\Google\Service\Drive.php
on line 75
I don't know what doing again. I tried many other metod for login on google drive, eg. load file list GET method with API_KEY, or via json file.
As result I want get file list, download them. edit and upload.
Any sugestions?
EDIT:
I have part sucess. I found liblary this, and them work with this code:
<?php
function retrieveAllFiles($service) {
$result = array();
$pageToken = NULL;
do {
try {
$parameters = array();
if ($pageToken) {
$parameters['pageToken'] = $pageToken;
}
$files = $service->files->listFiles($parameters);
$result = array_merge($result, $files->getItems());
$pageToken = $files->getNextPageToken();
} catch (Exception $e) {
print "An error occurred: " . $e->getMessage();
$pageToken = NULL;
}
} while ($pageToken);
return $result;
}
session_start();
require_once '/google-api-php-client/autoload.php';
$client_email = 'xxxx#xxxxx.iam.gserviceaccount.com';
$user_to_impersonate = 'xxxxxx#gmail.com';
$private_key = file_get_contents('key.p12');
$scopes = array('https://www.googleapis.com/auth/drive');
$credentials = new Google_Auth_AssertionCredentials(
$client_email,
$scopes,
$private_key,
'notasecret', // Default P12 password
'http://oauth.net/grant_type/jwt/1.0/bearer',
$user_to_impersonate
);
$client = new Google_Client();
if(isset($_SESSION['service_token'])==false && $_SESSION['service_token']=='') {
$client->setAssertionCredentials($credentials);
if ($client->getAuth()->isAccessTokenExpired()) {
$client->getAuth()->refreshTokenWithAssertion($credentials);
}
$_SESSION['service_token'] = $client->getAccessToken();
}
if(isset($_SESSION['service_token']) && $_SESSION['service_token']) {
$client->setAccessToken($_SESSION['service_token']);
if ($client->isAccessTokenExpired()) {
$client->refreshToken($client->getRefreshToken());
$_SESSION['service_token'] = $client->getAccessToken();
}
$service = new Google_Service_Drive($client);
print_r(retrieveAllFiles($service));
}
?>
And in result I have only one file [originalFilename] => Getting started, this is PDF, but I don't see this file on Gogle dirve. On google drive I uploaded file: README.md.
I'm not sure, but maybe this file is on ` 'xxxx#xxxxx.iam.gserviceaccount.com' and script not logged to 'xxxxxx#gmail.com'?