fpr.worker.js

addEventListener("fetch", (event) => {
  event.respondWith(handleRequest(event.request));
});

function handleOptions(request) {
  // Make sure the necessary headers are present
  // for this to be a valid pre-flight request
  let headers = request.headers;
  if (
    headers.get("Origin") !== null &&
    headers.get("Access-Control-Request-Method") !== null &&
    headers.get("Access-Control-Request-Headers") !== null
  ) {
    // Handle CORS pre-flight request.
    // If you want to check or reject the requested method + headers
    // you can do that here.
    let respHeaders = {
      ...corsHeaders,
      // Allow all future content Request headers to go back to browser
      // such as Authorization (Bearer) or X-Client-Name-Version
      "Access-Control-Allow-Headers": request.headers.get(
        "Access-Control-Request-Headers"
      ),
      "Access-Control-Allow-Origin": request.headers.get("origin"),
    };
    return new Response(null, {
      headers: respHeaders,
    });
  } else {
    // Handle standard OPTIONS request.
    // If you want to allow other HTTP Methods, you can do that here.
    return new Response(null, {
      headers: {
        Allow: "GET, HEAD, POST, OPTIONS",
      },
    });
  }
}

async function proxyJS(request) {
  const originalResponse = await fetch("https://cdn.firstpromoter.com/fpr.js");
  const js = await originalResponse.text();
  const patchedBody = js.replaceAll(
    "t.firstpromoter.com",
    request.headers.get("host")
  );

  return new Response(patchedBody, {
    status: originalResponse.status,
    statusText: originalResponse.statusText,
    headers: originalResponse.headers,
  });
}

async function proxyReq(request) {
  const url = new URL(request.url);
  const newRequest = new Request(
    "https://t.firstpromoter.com" + url.pathname,
    request
  );
  newRequest.headers.set("host", "t.firstpromoter.com");
  newRequest.headers.set("x-country", request.headers.get("cf-ipcountry"));
  newRequest.headers.set("x-real-ip", request.headers.get("x-real-ip"));
  newRequest.headers.set("X-Forwarded-For", request.headers.get("x-real-ip"));
  newRequest.headers.set("X-Forwarded-Host", url.host);

  let response;
  if (request.method === "OPTIONS") {
    response = handleOptions(request);
  } else {
    response = await fetch(newRequest);
    response = new Response(response.body, response);
    response.headers.set("Access-Control-Allow-Credentials", "true");
    response.headers.set("access-control-allow-headers", "X-Requested-With");
    response.headers.set(
      "Access-Control-Allow-Origin",
      request.headers.get("origin")
    );
    response.headers.set("Access-Control-Allow-Methods", "GET, POST, OPTIONS");
  }
  return response;
}

async function handleRequest(request) {
  const url = new URL(request.url);
  if (url.pathname === "/fpr.js") {
    return await proxyJS(request);
  }
  if (url.pathname === "/get_details" || url.pathname === "/tr") {
    return await proxyReq(request);
  }
  return new Response("Not found", { status: 404 });
}