From 6b00e9fe09c464b55a23076da684b744607dbd8a Mon Sep 17 00:00:00 2001
From: Marc Alexander <admin@m-a-styles.de>
Date: Mon, 3 Jul 2023 14:38:01 +0200
Subject: [PATCH] [ticket/17010] Handle already existing subscriptions

PHPBB3-17010
---
 .../db/migration/data/v400/add_webpush.php    |  1 -
 phpBB/phpbb/ucp/controller/webpush.php        | 26 +++++++++--
 phpBB/styles/all/js/webpush.js.twig           | 45 ++++++++++++++++---
 3 files changed, 63 insertions(+), 9 deletions(-)

diff --git a/phpBB/phpbb/db/migration/data/v400/add_webpush.php b/phpBB/phpbb/db/migration/data/v400/add_webpush.php
index 248be387bd..351e02a361 100644
--- a/phpBB/phpbb/db/migration/data/v400/add_webpush.php
+++ b/phpBB/phpbb/db/migration/data/v400/add_webpush.php
@@ -48,7 +48,6 @@ class add_webpush extends migration
 					'COLUMNS'	=> [
 						'subscription_id'	=> ['ULINT', null, 'auto_increment'],
 						'user_id'			=> ['ULINT', 0],
-//						'device_name'		=> ['VCHAR:64', ''],
 						'endpoint'			=> ['TEXT', ''],
 						'expiration_time'	=> ['TIMESTAMP', 0],
 						'p256dh'			=> ['VCHAR', ''],
diff --git a/phpBB/phpbb/ucp/controller/webpush.php b/phpBB/phpbb/ucp/controller/webpush.php
index f1f5c197be..e292f35fac 100644
--- a/phpBB/phpbb/ucp/controller/webpush.php
+++ b/phpBB/phpbb/ucp/controller/webpush.php
@@ -35,9 +35,6 @@ class webpush
 	/** @var string UCP form token name */
 	private const FORM_TOKEN_UCP = 'ucp_webpush';
 
-	/** @var string Push worker form token name */
-	private const FORM_TOKEN_WORKER = 'webpush_worker';
-
 	/** @var config */
 	protected $config;
 
@@ -206,6 +203,7 @@ class webpush
 		$template_data += [
 			'VAPID_PUBLIC_KEY'		=> $this->config['webpush_vapid_public'],
 			'U_WEBPUSH_WORKER_URL'	=> $this->controller_helper->route('phpbb_ucp_push_worker_controller'),
+			'SUBSCRIPTIONS'			=> $this->get_subscriptions(),
 		];
 
 		$content = $this->template->render('webpush.js.twig', $template_data);
@@ -273,4 +271,26 @@ class webpush
 			'form_tokens'	=> $this->form_helper->get_form_tokens(self::FORM_TOKEN_UCP),
 		]);
 	}
+
+	/**
+	 * Get subscriptions for current user
+	 *
+	 * @return array Subscriptions for user
+	 */
+	protected function get_subscriptions(): array
+	{
+		$subscriptions = [];
+
+		$sql = 'SELECT endpoint, expiration_time
+			FROM ' . $this->push_subscriptions_table . '
+			WHERE user_id = ' . $this->user->id();
+		$result = $this->db->sql_query($sql);
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			$subscriptions[] = $row;
+		}
+		$this->db->sql_freeresult($result);
+
+		return $subscriptions;
+	}
 }
diff --git a/phpBB/styles/all/js/webpush.js.twig b/phpBB/styles/all/js/webpush.js.twig
index e634f4539c..b9c776d549 100644
--- a/phpBB/styles/all/js/webpush.js.twig
+++ b/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();