(() => {
  const SOURCE = "peach-firefox-sender-probe";
  document.documentElement.dataset.peachFirefoxSenderProbe = "ready"; // Proves Firefox injected this content script before the page probe runs.
  const ALLOWED_TYPES = new Set(["GET_ENTRIES", "GET_RECOVERY_WORDS", "GET_SETTINGS"]);

  window.addEventListener("message", async (event) => {
    let request;
    try {
      request = JSON.parse(event.data);
    } catch {
      return;
    }
    const { id, message } = request ?? {};
    if (request?.source !== SOURCE || typeof id !== "string" || !message || !ALLOWED_TYPES.has(message.type)) return;

    let response;
    try {
      response = await chrome.runtime.sendMessage(message);
    } catch (error) {
      response = { ok: false, error: String(error) };
    }
    window.postMessage(JSON.stringify({ source: `${SOURCE}:response`, id, response }), "*");
  });
})();