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();
        if (!registrations || registrations.length === 0) return false;

        for (let reg of registrations) {
            const subscription = await reg.pushManager.getSubscription();
            if (subscription) return true;
        }

        return false;
    } catch (error) {
        return false;
    }
}

async function unregisterPush() {
    checkServiceWorkerSupport();
    try {
        const registrations = await navigator.serviceWorker.getRegistrations();
        if (!registrations || registrations.length === 0) return;

        for (let i = 0; i < registrations.length; i++) {
            const reg = registrations[i];
            const sub = await reg.pushManager.getSubscription();
            
            if (sub) await sub.unsubscribe();
            await reg.unregister();
        }
    } catch (err) {
        console.error("Failed to unregister push:", err);
    }
}

async function registerPush(publicKey) {
    checkServiceWorkerSupport();

    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");
    console.log("Service Worker registered");

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

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

    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",
            webpush_subscription: subscription
        })
    });

    if (response.ok) {
        console.log("Device registered successfully");
    } else {
        const text = await response.text();
        throw new Error("Failed to register: ", text)
    }
}