(function () {
  if (window.Bliss) return;

  function pageStructureId() {
    return (
      document.body?.dataset?.blissStructureId ||
      document.querySelector("[data-bliss-structure-id]")?.dataset
        ?.blissStructureId ||
      null
    );
  }

  function clientId() {
    const key = "bliss:client_id";
    let id = localStorage.getItem(key);
    if (!id) {
      id =
        crypto.randomUUID?.() ||
        String(Date.now()) + "-" + Math.random().toString(36).slice(2);
      localStorage.setItem(key, id);
    }
    return id;
  }

  function b64ToU8(s) {
    const pad = "=".repeat((4 - (s.length % 4)) % 4);
    const raw = atob((s + pad).replace(/-/g, "+").replace(/_/g, "/"));
    const a = new Uint8Array(raw.length);
    for (let i = 0; i < raw.length; i++) a[i] = raw.charCodeAt(i);
    return a;
  }

  async function registration() {
    if (!("serviceWorker" in navigator)) {
      throw new Error("Service workers are not supported here.");
    }
    return navigator.serviceWorker.register("/_bliss/notification-sw.js");
  }

  async function postVisibility(state) {
    if (!("serviceWorker" in navigator)) return;
    const reg = await registration().catch(() => null);
    reg?.active?.postMessage({
      type: "bliss:visibility",
      state,
      structureId: pageStructureId(),
    });
  }

  document.addEventListener("visibilitychange", () => {
    postVisibility(document.visibilityState === "visible" ? "open" : "closed");
  });
  if (document.readyState === "loading") {
    document.addEventListener(
      "DOMContentLoaded",
      () => postVisibility("open"),
      {
        once: true,
      },
    );
  } else {
    postVisibility("open");
  }

  window.Bliss = {
    structureId: pageStructureId,
    clientId,
    notifications: {
      supported() {
        return (
          "serviceWorker" in navigator &&
          "PushManager" in window &&
          "Notification" in window
        );
      },
      permission() {
        return "Notification" in window ? Notification.permission : "denied";
      },
      async register(options = {}) {
        const structureId = options.structureId || pageStructureId();
        if (!structureId) throw new Error("No Bliss structure is active.");
        if (!this.supported()) {
          throw new Error("Push notifications are not supported here.");
        }

        const reg = await registration();
        if (Notification.permission !== "granted") {
          const permission = await Notification.requestPermission();
          if (permission !== "granted") {
            throw new Error("Notification permission was not granted.");
          }
        }

        const vapidResponse = await fetch("/_bliss/notifications/key");
        if (!vapidResponse.ok) {
          throw new Error("Could not load notification key.");
        }
        const { publicKey } = await vapidResponse.json();
        const sub =
          (await reg.pushManager.getSubscription()) ||
          (await reg.pushManager.subscribe({
            userVisibleOnly: true,
            applicationServerKey: b64ToU8(publicKey),
          }));

        const ua =
          String(navigator.userAgent || "") +
          " " +
          String(navigator.platform || "");
        const isKaiOS = /kaios/i.test(ua) || !!navigator.b2g;
        const response = await fetch("/_bliss/notifications/subscribe", {
          method: "POST",
          headers: { "Content-Type": "application/json" },
          body: JSON.stringify({
            structure_id: structureId,
            client_id: clientId(),
            subscription: sub,
            content_encoding: isKaiOS ? "aesgcm" : "aes128gcm",
          }),
        });
        if (!response.ok) {
          const detail = await response.text().catch(() => "");
          throw new Error(detail || "Could not register notifications.");
        }
        await postVisibility("open");
        return true;
      },
    },
  };
})();