Single file (pusher.com) PHP SDK

pusher.php

<?php 
function push(string $region, string $app_id, string $app_key, string $app_secret, string $channel, string $event, string $data) {
$postData = json_encode(['data'=>$data, 'name'=>$event, 'channel'=>$channel]);
$md5_string = md5($postData);
$timestamp = strtotime('now +5 minutes');
$auth_signature = hash_hmac('sha256', "POST\n/apps/$app_id/events\nauth_key=$app_key&auth_timestamp=$timestamp&auth_version=1.0&body_md5=$md5_string", $app_secret);
$curl = curl_init();
curl_setopt_array($curl, array(
  CURLOPT_URL => "http://api-$region.pusher.com/apps/$app_id/events?body_md5=$md5_string&auth_version=1.0&auth_key=$app_key&auth_timestamp=$timestamp&auth_signature=$auth_signature&",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => $postData,
  CURLOPT_HTTPHEADER => array(
    "Cache-Control: no-cache",
    "Content-Type: application/json",
  ),
));

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  return "cURL Error #:" . $err;
} else {
  return $response;
}
}