import { ref } from 'vue';

export function usePushNotifications() {
    const isSubscribed = ref(false);

    async function subscribe() {
        if (!('serviceWorker' in navigator)) {
            return;
        }

        const registration = await navigator.serviceWorker.ready;
        const subscription = await registration.pushManager.subscribe({
            userVisibleOnly: true,
            applicationServerKey: urlBase64ToUint8Array(
                document.querySelector('meta[name="vapid-public-key"]')?.getAttribute('content') || '',
            ),
        });

        await fetch('/subscriptions', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'X-CSRF-TOKEN': document.querySelector('meta[name="csrf-token"]')?.getAttribute('content') || '',
            },
            body: JSON.stringify(subscription),
        });

        isSubscribed.value = true;
    }

    async function unsubscribe() {
        if (!('serviceWorker' in navigator)) {
            return;
        }

        const registration = await navigator.serviceWorker.ready;
        const subscription = await registration.pushManager.getSubscription();

        if (subscription) {
            await fetch('/subscriptions/delete', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                    'X-CSRF-TOKEN': document.querySelector('meta[name="csrf-token"]')?.getAttribute('content') || '',
                },
                body: JSON.stringify({ endpoint: subscription.endpoint }),
            });
            await subscription.unsubscribe();
        }

        isSubscribed.value = false;
    }

    function urlBase64ToUint8Array(base64String: string) {
        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;
    }

    return {
        isSubscribed,
        subscribe,
        unsubscribe,
    };
}