import React, { useEffect, useState } from 'react';
import common from '../src/helpers/common'; // Ensure this path is correct

function PwaManager() {
    const [deferredPrompt, setDeferredPrompt] = useState(null);
    const [isPWAInstalled, setIsPWAInstalled] = useState(false);
    const [isStandAlone, setIsStandAlone] = useState(false);
    const [isSubscribed, setIsSubscribed] = useState(false);
    const [subscription, setSubscription] = useState(null);
    const [registration, setRegistration] = useState(null);
    const [notificationPermission, setNotificationPermission] = useState(Notification.permission);

    // Handle PWA installation
    useEffect(() => {

        setNotificationPermission(Notification.permission);

        // Handle Push Notification Subscription
        if ('serviceWorker' in navigator && 'PushManager' in window) {
            navigator.serviceWorker.ready.then(reg => {
                reg.pushManager.getSubscription().then(sub => {
                    if (sub) {
                        setSubscription(sub);
                        setIsSubscribed(true);
                    }
                });
                setRegistration(reg);
            });
        }



        // Check if the app is running in standalone mode
        if (window.matchMedia('(display-mode: standalone)').matches) {
            setIsStandAlone(true);
        }

        const handleBeforeInstallPrompt = (e) => {
            e.preventDefault();
            setDeferredPrompt(e);
        };

        const handleAppInstalled = () => {
            setIsPWAInstalled(true);
        };

        window.addEventListener('beforeinstallprompt', handleBeforeInstallPrompt);
        window.addEventListener('appinstalled', handleAppInstalled);

        return () => {
            window.removeEventListener('beforeinstallprompt', handleBeforeInstallPrompt);
            window.removeEventListener('appinstalled', handleAppInstalled);
        };
    }, []);

    const installPWA = async (e) => {

        e.preventDefault();
        if (deferredPrompt) {
            deferredPrompt.prompt();
            const { outcome } = await deferredPrompt.userChoice;
            if (outcome === 'accepted') {
                setIsPWAInstalled(true);
            }
            setDeferredPrompt(null);
        }
    };

    // Utility function for converting base64 string to Uint8Array
    const base64ToUint8Array = base64 => {
        const padding = '='.repeat((4 - (base64.length % 4)) % 4);
        const b64 = (base64 + padding).replace(/-/g, '+').replace(/_/g, '/');
        const rawData = window.atob(b64);
        const outputArray = new Uint8Array(rawData.length);
        for (let i = 0; i < rawData.length; ++i) {
            outputArray[i] = rawData.charCodeAt(i);
        }
        return outputArray;
    };

    const subscribeToNotifications = async (e) => {

        try {
            e.preventDefault();
            if (!registration) {
                console.error('Service worker registration not found.');
                registration
                return;
            }
            const sub = await registration.pushManager.subscribe({
                userVisibleOnly: true,
                applicationServerKey: base64ToUint8Array(process.env.NEXT_PUBLIC_VAPID_PUBLIC_KEY)
            });
            // Call your API to save subscription data on server
            setSubscription(sub);
            setIsSubscribed(true);
            console.log('Web push subscribed!');
            console.log(sub);
        } catch (error) {
            console.error('Error subscribing to notifications:', error);
        }
    };

    const unsubscribeFromNotifications = async (e) => {

        try {
            e.preventDefault();
            await subscription.unsubscribe();
            // Call your API to delete or invalidate subscription data on server
            setSubscription(null);
            setIsSubscribed(false);
            console.log('Web push unsubscribed!');
        } catch (error) {
            console.error('Error unsubscribing from notifications:', error);
        }
    };

    // Function to request push notification permission
    const requestNotificationPermission = async (e) => {
        e.preventDefault();
        const permission = await Notification.requestPermission();
        setNotificationPermission(permission);
        if (permission === "granted") {
            // User granted permission
            subscribeToNotifications(null); // Pass the required argument here
        } else {
            // User denied or dismissed permission
            console.log("Push notifications permission denied.");
        }
    };

    // Function to toggle push notifications
    const togglePushNotifications = async (e) => {

        e.preventDefault();
        if (notificationPermission === "granted") {
            // If already subscribed, unsubscribe
            unsubscribeFromNotifications(null); // Pass null as the argument
        } else if (notificationPermission === "default" || notificationPermission === "denied") {
            // Request permission if not already granted
            await requestNotificationPermission(e);
        }
    };


    const sendTestNotification = async (e) => {

        e.preventDefault();
        if (!subscription) {
            console.error('Web push not subscribed');
            return;
        }

        await fetch('/api/notify', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({ subscription })
        });
    };

    return (
        <>
            <div>
                <h1>PWA Manager</h1>
                {!isStandAlone && !isPWAInstalled && (
                    <button
                        onClick={installPWA}
                        className="bg-blue-500 hover:bg-blue-700 text-white text-xs py-1 px-2 rounded-full focus:outline-none focus:shadow-outline transition duration-150 ease-in-out"
                    >
                        Install PWA
                    </button>
                )}
                {isPWAInstalled && <p>App is installed!</p>}
                {isStandAlone && <p>PWA App</p>}
                <button
                    onClick={subscribeToNotifications}
                    disabled={isSubscribed}
                    className={`text-xs py-1 px-2 rounded-full focus:outline-none transition duration-150 ease-in-out ${isSubscribed ? 'cursor-not-allowed bg-gray-300 text-gray-500' : 'bg-green-500 hover:bg-green-700 text-white'
                        }`}
                >
                    Subscribe to Notifications
                </button>
                <button
                    onClick={unsubscribeFromNotifications}
                    disabled={!isSubscribed}
                    className={`text-xs py-1 px-2 rounded-full focus:outline-none transition duration-150 ease-in-out ${!isSubscribed ? 'cursor-not-allowed bg-gray-300 text-gray-500' : 'bg-red-500 hover:bg-red-700 text-white'
                        }`}
                >
                    Unsubscribe from Notifications
                </button>


            </div>
            <div>
                <button
                    onClick={sendTestNotification}
                    disabled={!isSubscribed}
                    className={`text-xs py-1 px-2 rounded-full focus:outline-none transition duration-150 ease-in-out ${!isSubscribed ? 'cursor-not-allowed bg-gray-300 text-gray-500' : 'bg-yellow-500 hover:bg-yellow-600 text-white'
                        }`}
                >
                    Send Test Notification
                </button>

                {notificationPermission !== "granted" && (
                    <button
                        onClick={togglePushNotifications}
                        className={`text-xs py-1 px-2 rounded-full focus:outline-none transition duration-150 ease-in-out ${notificationPermission === "denied" ? 'bg-red-500 hover:bg-red-700 text-white' : 'bg-green-500 hover:bg-green-700 text-white'
                            }`}
                    >
                        {notificationPermission === "denied" ? 'Notifications Denied!' : 'Enable Notifications'}
                    </button>
                )}
            </div>
            <div>
                <a href="https://t.me/mwhitnessing_bot" className="inline-flex items-center ml-4" target="_blank">
                    <img src="/content/icons/telegram-svgrepo-com.svg" alt="Телеграм" width="32" height="32" className="align-middle" />
                    <span className="align-middle">Телеграм</span>
                </a>
            </div>
            <
        </>
    );

}

export default PwaManager;
