multiple redirects

pantheon redirects - ensure 'www' and ssl are used

// Ensure url has 'www' and uses SSL
if (isset($_SERVER['PANTHEON_ENVIRONMENT']) && ($_SERVER['PANTHEON_ENVIRONMENT'] === 'live') &&
  (php_sapi_name() != "cli")) {
    $do_redirect = FALSE;
    $url_chunks = explode('.', $_SERVER['HTTP_HOST']);
    if ($url_chunks[0] != 'www') {
      array_unshift($url_chunks, 'www');
      $do_redirect = TRUE;
    }
    if (strtolower($_SERVER['HTTPS']) != 'on') {
      $do_redirect = TRUE;
    }
    if ($do_redirect) {
      $new_url = 'https://' . implode('.', $url_chunks) . $base_path . request_path();
      header('Location: ' . $new_url, TRUE, 301);
      exit();
  }
}