Google Cloud - Save Email Attachments (invoices) then Delete - php

Question

I've coded the script below. This code connects to a Gmail account, searches for emails with attachments, and saves the attachments to Google Drive. It also deletes the emails from the Gmail account.
But anytime I run it:
Fatal error: Uncaught Google\Service\Exception: { "error": { "errors": [ { "domain": "global", "reason": "required", "message": "Login Required", "locationType": "header", "location": "Authorization" } ], "code": 401, "message": "Login Required" } }
I tried several changes. Nothing works. Even ChatGPT cannot find the fix/error.
<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
// Include the autoload file
require_once __DIR__ . '/vendor/autoload.php';
// Set your OAuth 2.0 Client IDs
$client_id = '123456789012-abcdefghijklmnopqrstuvwxyz.apps.googleusercontent.com';
$client_secret = 'ABC-XYZ_123';
// Set your redirect URI
$redirect_uri = 'https://example.com/invoices';
// Create a new Google_Client object
$client = new Google_Client();
$client->setClientId($client_id);
$client->setClientSecret($client_secret);
$client->setRedirectUri($redirect_uri);
// Set the scopes for the API services you want to use
$client->addScope(Google_Service_Drive::DRIVE);
// Authorize the client
$client->authorize();
// Create a new Google_Service_Drive object
$driveService = new Google_Service_Drive($client);
// Connect to Gmail
$hostname = '{imap.gmail.com:993/imap/ssl/novalidate-cert}INBOX';
$username = 'email#gmail.com';
$password = 'password';
// Connect to Gmail
$inbox = imap_open($hostname,$username,$password) or die('Cannot connect to Gmail: ' . imap_last_error());
// Get all emails from inbox
$emails = imap_search($inbox,'ALL');
// If emails are returned
if($emails) {
// Sort emails by date
rsort($emails);
// Loop through emails
foreach($emails as $email_number) {
// Get the full header of the email
$header = imap_fetchheader($inbox, $email_number);
// Parse the header into an object
$header_obj = imap_rfc822_parse_headers($header);
// Get the original sender's name
$sender_name = $header_obj->from[0]->personal;
// Get the date the email was sent
$date_sent = strtotime($header_obj->date);
$formatted_date_sent = date("Y-m-d", $date_sent);
// Get the attachments
$attachments = imap_fetchstructure($inbox,$email_number);
// If attachments are found
if(isset($attachments->parts) && count($attachments->parts)) {
// Loop through attachments
for($i = 0; $i < count($attachments->parts); $i++) {
// Check if the attachment is an object
if (is_object($attachments->parts[$i])) {
// Get the attachment data
$attachment_data = imap_fetchbody($inbox,$email_number,$i+1);
// Decode the attachment data
$attachment_data = base64_decode($attachment_data);
// Create the filename
$filename = $formatted_date_sent . ' ' . $sender_name;
// Save the attachment to Google Drive
$file = new Google_Service_Drive_DriveFile();
$file->setName($filename);
$file->setDescription('Invoice attachment');
$file->setMimeType('application/pdf');
$file->setParents(array('1nkfPyEvFYR_DGUGJDiy8WLx_ANUNsAdW'));
$createdFile = $driveService->files->create($file, array(
'data' => $attachment_data,
'mimeType' => 'application/pdf',
'uploadType' => 'multipart'
));
}
}
}
// Delete the email
imap_delete($inbox,$email_number);
}
}
// Close the connection
imap_close($inbox);
?>

Answer 1

From what I can see you are simply creating a drive service object but not acutally calling any authorization on it.
// Create a new Google_Service_Drive object
$driveService = new Google_Service_Drive($client);
You need to request consent of the user who's drive account you want to write to. With out that your service object is not authorized and you will get a "Login Required" error messages becouse your not logged in.
function getOauth2Client() {
try {
$client = buildClient();
// Set the refresh token on the client.
if (isset($_SESSION['refresh_token']) && $_SESSION['refresh_token']) {
$client->refreshToken($_SESSION['refresh_token']);
}
// If the user has already authorized this app then get an access token
// else redirect to ask the user to authorize access to Google Analytics.
if (isset($_SESSION['access_token']) && $_SESSION['access_token']) {
// Set the access token on the client.
$client->setAccessToken($_SESSION['access_token']);
// Refresh the access token if it's expired.
if ($client->isAccessTokenExpired()) {
$client->fetchAccessTokenWithRefreshToken($client->getRefreshToken());
$client->setAccessToken($client->getAccessToken());
$_SESSION['access_token'] = $client->getAccessToken();
}
return $client;
} else {
// We do not have access request access.
header('Location: ' . filter_var( $client->getRedirectUri(), FILTER_SANITIZE_URL));
}
} catch (Exception $e) {
print "An error occurred: " . $e->getMessage();
}
}
Code ripped from Oauth2Authentication.php