function checkServiceWorkerSupport() {
    if (!("serviceWorker" in navigator) || !("PushManager" in window))
        throw new Error("Your browser does not have Service Worker support")
}

async function isPushRegistered() {
	checkServiceWorkerSupport();

	try {
		const registrations = await navigator.serviceWorker.getRegistrations();
		for (const reg of registrations) {
			if (!reg.pushManager) continue;

			const sub = await reg.pushManager.getSubscription();
			if (sub) return true;
		}

		const reg = await navigator.serviceWorker.getRegistration();
		if (!reg || !reg.pushManager) return false;

		const sub = await reg.pushManager.getSubscription();
		return !!sub;
	} catch {
		return false;
	}
}

async function unregisterPush() {
    checkServiceWorkerSupport();

    const registrations = await navigator.serviceWorker.getRegistrations();
    if (!registrations || registrations.length === 0) return;

    for (const reg of registrations) {
        if (!reg.pushManager) continue;

        const sub = await reg.pushManager.getSubscription();
        if (sub) {
            await sub.unsubscribe();
        }

        if (!window.IS_IOS) {
            await reg.unregister();
        }
    }
}

async function registerPush(publicKey) {
	checkServiceWorkerSupport();

	if (window.IS_IOS && !window.IS_STANDALONE) {
		throw new Error(
			"On iOS, notifications require adding this site to the Home Screen"
		);
	}

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

    const registration = await navigator.serviceWorker.register(
        "/assets/custom/serviceWorker.js"
    );

	let subscription = await registration.pushManager.getSubscription();

	if (!subscription) {
		const applicationServerKey = urlBase64ToUint8Array(publicKey);
		subscription = await registration.pushManager.subscribe({
			userVisibleOnly: true,
			applicationServerKey
		});
	}

	const response = await fetch(
		`${window.GLOBAL_ENV.API_ENDPOINT}/v9/users/@me/devices`,
		{
			method: "POST",
			headers: {
				"Content-Type": "application/json",
				Authorization: window.AUTH_TOKEN
			},
			body: JSON.stringify({
				provider: "webpush",
                subscription
			})
		}
	);

	if (!response.ok) {
		const text = await response.text();
		throw new Error(text);
	}
}