/**
 * Push Notification Helper
 */
import { logError, logWarn } from './logger';

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;
}

export const setupNotifications = async (token: string, orgId: string) => {
    if (!('serviceWorker' in navigator) || !('PushManager' in window)) {
        logWarn('Push notifications are not supported in this browser.');
        return;
    }

    try {
        // 1. Check existing permission — ne pas re-demander si déjà refusé
        if (Notification.permission === 'denied') {
            return; // silencieux : l'utilisateur a déjà dit non
        }

        // 2. Register Service Worker
        const registration = await navigator.serviceWorker.register('/sw.js');

        // 3. Request Permission (seulement si 'default', pas 'denied')
        const permission = Notification.permission === 'granted'
            ? 'granted'
            : await Notification.requestPermission();
        if (permission !== 'granted') {
            return; // silencieux
        }

        // 3. Get VAPID public key from server
        const keyRes = await fetch(`${import.meta.env.VITE_API_URL}/v1/notifications/vapid-key`, {
            headers: { 'Authorization': `Bearer ${token}`, 'x-organization-id': orgId }
        });
        const { publicKey } = await keyRes.json();

        if (!publicKey) {
            logWarn('VAPID public key missing from server');
            return;
        }

        // 4. Subscribe to Push
        const subscription = await registration.pushManager.subscribe({
            userVisibleOnly: true,
            applicationServerKey: urlBase64ToUint8Array(publicKey)
        });

        // 5. Send subscription to server
        await fetch(`${import.meta.env.VITE_API_URL}/v1/notifications/subscribe`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': `Bearer ${token}`,
                'x-organization-id': orgId
            },
            body: JSON.stringify({ subscription })
        });

    } catch (err) {
        logError('Failed to setup push notifications', err);
    }
};