[ticket/17010] Handle already existing subscriptions

PHPBB3-17010

phpBB/styles/all/js/webpush.js.twig

@@ -18,6 +18,13 @@ function PhpbbWebpush() {
 		formToken: '{{ FORM_TOKENS.form_token }}'
 	};
 
+	/** @type [{endpoint: string, expiration: string}[]] Subscriptions */
+	let subscriptions = [
+		{% for sub in SUBSCRIPTIONS %}
+			{endpoint: '{{ sub.endpoint }}', expiration: '{{ sub.expiration }}' },
+		{% endfor %}
+	];
+
 	/** @type {string} VAPID public key */
 	const VAPID_PUBLIC_KEY = '{{ VAPID_PUBLIC_KEY }}';
 
@@ -70,7 +77,7 @@ function PhpbbWebpush() {
 
 					registration.pushManager.getSubscription()
 						.then((subscribed) => {
-							if (subscribed) {
+							if (isValidSubscription(subscribed)) {
 								setSubscriptionState(true);
 							}
 						})
@@ -78,6 +85,31 @@ function PhpbbWebpush() {
 		}
 	}
 
+	/**
+	 * Check whether subscription is valid
+	 *
+	 * @param {PushSubscription} subscription
+	 * @returns {boolean}
+	 */
+	const isValidSubscription = (subscription) => {
+		if (!subscription) {
+			return false;
+		}
+
+		if (subscription.expirationTime && subscription.expirationTime <= Date.now()) {
+			return false;
+		}
+
+		for (const curSubscription of subscriptions) {
+			if (subscription.endpoint === curSubscription.endpoint) {
+				return true;
+			}
+		}
+
+		// Subscription is not in valid subscription list for user
+		return false;
+	};
+
 	/**
 	 * Set subscription state for buttons
 	 *
@@ -111,16 +143,19 @@ function PhpbbWebpush() {
 		}
 
 		const registration = await navigator.serviceWorker.getRegistration(serviceWorkerUrl);
+
+		// We might already have a subscription that is unknown to this instance of phpBB.
+		// Unsubscribe before trying to subscribe again.
 		if (typeof registration !== 'undefined') {
 			const subscribed = await registration.pushManager.getSubscription();
 			if (subscribed) {
-				setSubscriptionState(true);
-				return;
+				await subscribed.unsubscribe();
 			}
 		}
-		const newSubscription = await registration.pushManager.subscribe({
+
+		let newSubscription = await registration.pushManager.subscribe({
 			userVisibleOnly: true,
-			applicationServerKey: urlB64ToUint8Array(VAPID_PUBLIC_KEY)
+			applicationServerKey: urlB64ToUint8Array(VAPID_PUBLIC_KEY),
 		});
 
 		const loadingIndicator = phpbb.loadingIndicator();