// async function registerPush() {
//     try {
//         console.log("Registering for push notifications");

//         if (!('serviceWorker' in navigator)) {
//             console.error("ServiceWorker not supported");
//             return;
//         }

//         const permission = await Notification.requestPermission();
//         console.log("Permission:", permission);

//         if (permission !== 'granted') {
//             console.warn("Notification permission denied");
//             return;
//         }

//         const registration = await navigator.serviceWorker.register('/sw.js');
//         console.log("SW registered:", registration);

//         // const subscription = await registration.pushManager.subscribe({
//         //     userVisibleOnly: true,
//         //     applicationServerKey: vapidKey
//         // });
//         const subscription = await registration.pushManager.subscribe({
//             userVisibleOnly: true,
//             applicationServerKey: urlBase64ToUint8Array(vapidKey),
//         });

//         console.log('VAPID key:', vapidKey);

//         console.log("Subscription created:", subscription);

//         const res = await fetch('/push/subscribe', {
//             method: 'POST',
//             headers: {
//                 'Content-Type': 'application/json',
//                 'X-CSRF-TOKEN': csrfToken
//             },
//             body: JSON.stringify(subscription)
//         });

//         console.log("Server response:", await res.text());

//         alert("Push enabled ✅");
//     } catch (e) {
//         console.error("Push registration failed ❌", e);
//     }
// }

async function registerPush() {
    try {
        console.log("Registering for push notifications");

        if (!('serviceWorker' in navigator)) {
            console.error("ServiceWorker not supported");
            return;
        }

        const permission = await Notification.requestPermission();
        if (permission !== 'granted') {
            console.warn("Notification permission denied");
            return;
        }

        const registration = await navigator.serviceWorker.register('/sw.js');

        // ✅ GET first
        let subscription = await registration.pushManager.getSubscription();

        // ✅ CREATE only if not exists
        if (!subscription) {
            subscription = await registration.pushManager.subscribe({
                userVisibleOnly: true,
                applicationServerKey: urlBase64ToUint8Array(vapidKey),
            });
            console.log("New subscription created");
        } else {
            console.log("Existing subscription reused");
        }

        // 🔥 ALWAYS send to backend
        await fetch('/push/subscribe', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'X-CSRF-TOKEN': csrfToken
            },
            body: JSON.stringify(subscription)
        });

        alert("Push enabled ✅");
    } catch (e) {
        console.error("Push registration failed ❌", e);
    }
}


function urlBase64ToUint8Array(base64String) {
    const padding = '='.repeat((4 - base64String.length % 4) % 4);
    const base64 = (base64String + padding)
        .replace(/-/g, '+')
        .replace(/_/g, '/');

    const rawData = window.atob(base64);
    const outputArray = new Uint8Array(rawData.length);

    for (let i = 0; i < rawData.length; ++i) {
        outputArray[i] = rawData.charCodeAt(i);
    }
    return outputArray;
}