[Glitch] Fix browser notification permission request logic

Port f54ca3d08e to glitch-soc

Signed-off-by: Thibaut Girka <thib@sitedethib.com>

app/javascript/flavours/glitch/util/main.js

@@ -1,4 +1,5 @@
 import * as registerPushNotifications from 'flavours/glitch/actions/push_notifications';
+import { setupBrowserNotifications } from 'flavours/glitch/actions/notifications';
 import { default as Mastodon, store } from 'flavours/glitch/containers/mastodon';
 import React from 'react';
 import ReactDOM from 'react-dom';
@@ -22,6 +23,7 @@ function main() {
     const props = JSON.parse(mountNode.getAttribute('data-props'));
 
     ReactDOM.render(<Mastodon {...props} />, mountNode);
+    store.dispatch(setupBrowserNotifications());
     if (process.env.NODE_ENV === 'production') {
       // avoid offline in dev mode because it's harder to debug
       require('offline-plugin/runtime').install();

app/javascript/flavours/glitch/util/notifications.js

@@ -0,0 +1,29 @@
+// Handles browser quirks, based on
+// https://developer.mozilla.org/en-US/docs/Web/API/Notifications_API/Using_the_Notifications_API
+
+const checkNotificationPromise = () => {
+  try {
+    Notification.requestPermission().then();
+  } catch(e) {
+    return false;
+  }
+
+  return true;
+};
+
+const handlePermission = (permission, callback) => {
+  // Whatever the user answers, we make sure Chrome stores the information
+  if(!('permission' in Notification)) {
+    Notification.permission = permission;
+  }
+
+  callback(Notification.permission);
+};
+
+export const requestNotificationPermission = (callback) => {
+  if (checkNotificationPromise()) {
+    Notification.requestPermission().then((permission) => handlePermission(permission, callback));
+  } else {
+    Notification.requestPermission((permission) => handlePermission(permission, callback));
+  }
+};