Queue form submissions and process asynchronously

// Stream form submissions from Hooque over SSE
const HOOQUE_URL = process.env.HOOQUE_URL; // e.g. https://app.hooque.io/queues/cons_form_submissions
const TOKEN = process.env.HOOQUE_TOKEN;
const headers = { Authorization: `Bearer ${TOKEN}` };

// Signature verification is handled by Hooque before messages enter this stream.
const streamResp = await fetch(HOOQUE_URL + "/stream", { headers });

for await (const line of readSseLines(streamResp.body)) {
  if (!line.startsWith("data:")) continue;

  const event = JSON.parse(line.slice(5)); // { payload, meta }
  const payload = event.payload;
  const meta = event.meta;

  try {
    await process_form_payload(payload); // form_response
    await fetch(meta.ackUrl, { method: "POST", headers });
  } catch (err) {
    // Failed message can be inspected in Hooque, and we receive an alert about it.
    await fetch(meta.nackUrl, {
      method: "POST",
      headers: { ...headers, "Content-Type": "application/json" },
      body: JSON.stringify({ reason: String(err) }),
    });
  }
}