function parseQuery(request, key) {
  var params = request.queryString.split("&");
  for (var j = 0; j < params.length; ++j) {
    var p = params[j];
    if (p == key) {
      return true;
    }
    if (p.indexOf(key + "=") == 0) {
      return p.substring(key.length + 1);
    }
    if (!p.includes("=") && key == "") {
      return p;
    }
  }
  return false;
}

// Return file content for the first request with a given key.
// All subsequent requests return a redirect to a different-origin resource.
function handleRequest(request, response) {
  var domain = parseQuery(request, "domain");
  var file = parseQuery(request, "file");
  var allowed = parseQuery(request, "allowed");

  response.setStatusLine(request.httpVersion, 303, "See Other");
  response.setHeader(
    "Location",
    "http://" +
      domain +
      "/tests/dom/media/test/" +
      (allowed ? "allowed.sjs?" : "") +
      file
  );
  response.setHeader("Content-Type", "text/html");
}