<?php
function bitly_shorten($url, $token) {
  $args = [
    'access_token' => $token,
    'longUrl' => $url
  ];
  $uri = 'https://api-ssl.bitly.com/v3/shorten?' .
      http_build_query($args, '', '&', PHP_QUERY_RFC3986);
  $output = "";
  try {
    $ch = curl_init($uri);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_TIMEOUT, 4);
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 2);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
    $output = curl_exec($ch);
  }
  catch (Exception $e) {
    return $url;
  }
  $res = json_decode($output, true);

  if ($res['status_txt'] == 'OK') {
    return $res['data']['url'];
  }
  return $url;
}