1 files changed, 105 insertions, 0 deletions
diff --git a/app/javascript/flavours/glitch/util/web_push_subscription.js b/app/javascript/flavours/glitch/util/web_push_subscription.js
new file mode 100644
index 000000000..de185b6d9
--- /dev/null
+++ b/app/javascript/flavours/glitch/util/web_push_subscription.js
@@ -0,0 +1,105 @@
+import axios from 'axios';
+import { store } from 'flavours/glitch/containers/mastodon';
+import { setBrowserSupport, setSubscription, clearSubscription } from 'flavours/glitch/actions/push_notifications';
+
+// Taken from https://www.npmjs.com/package/web-push
+const urlBase64ToUint8Array = (base64String) => {
+  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;
+};
+
+const getApplicationServerKey = () => document.querySelector('[name="applicationServerKey"]').getAttribute('content');
+
+const getRegistration = () => navigator.serviceWorker.ready;
+
+const getPushSubscription = (registration) =>
+  registration.pushManager.getSubscription()
+    .then(subscription => ({ registration, subscription }));
+
+const subscribe = (registration) =>
+  registration.pushManager.subscribe({
+    userVisibleOnly: true,
+    applicationServerKey: urlBase64ToUint8Array(getApplicationServerKey()),
+  });
+
+const unsubscribe = ({ registration, subscription }) =>
+  subscription ? subscription.unsubscribe().then(() => registration) : registration;
+
+const sendSubscriptionToBackend = (subscription) =>
+  axios.post('/api/web/push_subscriptions', {
+    subscription,
+  }).then(response => response.data);
+
+// Last one checks for payload support: https://web-push-book.gauntface.com/chapter-06/01-non-standards-browsers/#no-payload
+const supportsPushNotifications = ('serviceWorker' in navigator && 'PushManager' in window && 'getKey' in PushSubscription.prototype);
+
+export function register () {
+  store.dispatch(setBrowserSupport(supportsPushNotifications));
+
+  if (supportsPushNotifications) {
+    if (!getApplicationServerKey()) {
+      console.error('The VAPID public key is not set. You will not be able to receive Web Push Notifications.');
+      return;
+    }
+
+    getRegistration()
+      .then(getPushSubscription)
+      .then(({ registration, subscription }) => {
+        if (subscription !== null) {
+          // We have a subscription, check if it is still valid
+          const currentServerKey = (new Uint8Array(subscription.options.applicationServerKey)).toString();
+          const subscriptionServerKey = urlBase64ToUint8Array(getApplicationServerKey()).toString();
+          const serverEndpoint = store.getState().getIn(['push_notifications', 'subscription', 'endpoint']);
+
+          // If the VAPID public key did not change and the endpoint corresponds
+          // to the endpoint saved in the backend, the subscription is valid
+          if (subscriptionServerKey === currentServerKey && subscription.endpoint === serverEndpoint) {
+            return subscription;
+          } else {
+            // Something went wrong, try to subscribe again
+            return unsubscribe({ registration, subscription }).then(subscribe).then(sendSubscriptionToBackend);
+          }
+        }
+
+        // No subscription, try to subscribe
+        return subscribe(registration).then(sendSubscriptionToBackend);
+      })
+      .then(subscription => {
+        // If we got a PushSubscription (and not a subscription object from the backend)
+        // it means that the backend subscription is valid (and was set during hydration)
+        if (!(subscription instanceof PushSubscription)) {
+          store.dispatch(setSubscription(subscription));
+        }
+      })
+      .catch(error => {
+        if (error.code === 20 && error.name === 'AbortError') {
+          console.warn('Your browser supports Web Push Notifications, but does not seem to implement the VAPID protocol.');
+        } else if (error.code === 5 && error.name === 'InvalidCharacterError') {
+          console.error('The VAPID public key seems to be invalid:', getApplicationServerKey());
+        }
+
+        // Clear alerts and hide UI settings
+        store.dispatch(clearSubscription());
+
+        try {
+          getRegistration()
+            .then(getPushSubscription)
+            .then(unsubscribe);
+        } catch (e) {
+
+        }
+      });
+  } else {
+    console.warn('Your browser does not support Web Push Notifications.');
+  }
+}