Add support for webpush pusher as defined in MSC4174

src/matrix/Session.js

@@ -946,7 +946,7 @@ export class Session {
     async _enablePush() {
         return this._platform.logger.run("enablePush", async log => {
             const defaultPayload = Pusher.createDefaultPayload(this._sessionInfo.id);
-            const pusher = await this._platform.notificationService.enablePush(Pusher, defaultPayload);
+            const pusher = await this._platform.notificationService.enablePush(Pusher, defaultPayload, this._hsApi);
             if (!pusher) {
                 log.set("no_pusher", true);
                 return false;

src/matrix/net/HomeServerApi.ts

@@ -223,6 +223,10 @@ export class HomeServerApi {
         return this._unauthedRequest("GET", `${this._homeserver}/_matrix/client/versions`, undefined, undefined, options);
     }
 
+    capabilities(options?: BaseRequestOptions): IHomeServerRequest {
+        return this._get("/capabilities", undefined, undefined, options);
+    }
+
     uploadKeys(dehydratedDeviceId: string, payload: Record<string, any>, options?: BaseRequestOptions): IHomeServerRequest {
         let path = "/keys/upload";
         if (dehydratedDeviceId) {

src/matrix/push/Pusher.ts

@@ -56,6 +56,19 @@ export class Pusher {
         });
     }
 
+    static webpushPusher(appId: string, pushkey: string, data: IPusherData): Pusher {
+        return new Pusher({
+            kind: "webpush",
+            append: true,   // as pushkeys are shared between multiple users on one origin
+            data,
+            pushkey,
+            app_id: appId,
+            app_display_name: "Hydrogen",
+            device_display_name: "Hydrogen",
+            lang: "en"
+        });
+    }
+
     static createDefaultPayload(sessionId: string): {session_id: string} {
         return {session_id: sessionId};
     }

src/platform/web/dom/NotificationService.js

@@ -20,12 +20,24 @@ export class NotificationService {
         this._pushConfig = pushConfig;
     }
 
-    async enablePush(pusherFactory, defaultPayload) {
+    async enablePush(pusherFactory, defaultPayload, hsApi) {
         const registration = await this._serviceWorkerHandler?.getRegistration();
         if (registration?.pushManager) {
+            const response = await hsApi.capabilities().response();
+            var webPushCapability = response?.capabilities?.["m.webpush"]
+            if (!webPushCapability)
+                webPushCapability = response?.capabilities?.["org.matrix.msc4174.webpush"]
+
+            var supportDirectWebPush = false;
+            var applicationServerKey = this._pushConfig.applicationServerKey
+            if (webPushCapability && webPushCapability?.enabled == true) {
+                supportDirectWebPush = true;
+                applicationServerKey = webPushCapability?.vapid
+            }
+
             const subscription = await registration.pushManager.subscribe({
                 userVisibleOnly: true,
-                applicationServerKey: this._pushConfig.applicationServerKey,
+                applicationServerKey: applicationServerKey,
             });
             const subscriptionData = subscription.toJSON();
             const pushkey = subscriptionData.keys.p256dh;
@@ -37,12 +49,20 @@ export class NotificationService {
                 events_only: true,
                 default_payload: defaultPayload
             };
-            return pusherFactory.httpPusher(
-                this._pushConfig.gatewayUrl,
-                this._pushConfig.appId,
-                pushkey,
-                data
-            );
+            if (supportDirectWebPush) {
+                return pusherFactory.webpushPusher(
+                    this._pushConfig.appId,
+                    pushkey,
+                    data
+                );
+            } else {
+                return pusherFactory.httpPusher(
+                    this._pushConfig.gatewayUrl,
+                    this._pushConfig.appId,
+                    pushkey,
+                    data
+                );
+            }
         }
     }