put pusher bits in separate class to enable and disable on the HS

src/matrix/net/HomeServerApi.js

@@ -254,6 +254,10 @@ export class HomeServerApi {
     uploadAttachment(blob, filename, options = null) {
         return this._authedRequest("POST", `${this._homeserver}/_matrix/media/r0/upload`, {filename}, blob, options);
     }
+
+    setPusher(pusher, options = null) {
+        return this._post("/pushers/set", null, pusher, options);
+    }
 }
 
 export function tests() {

src/matrix/push/Pusher.js

@@ -0,0 +1,35 @@
+export class Pusher {
+    constructor(description) {
+        this._description = description;
+    }
+
+    static httpPusher(host, appId, pushkey, data) {
+        return new Pusher({
+            kind: "http",
+            append: true,   // as pushkeys are shared between multiple users on one origin
+            data: Object.assign({}, data, {url: host + "/_matrix/push/v1/notify"}),
+            pushkey,
+            app_id: appId,
+            app_display_name: "Hydrogen",
+            device_display_name: "Hydrogen",
+            lang: "en"
+        });
+    }
+
+    static createDefaultPayload(sessionId) {
+        return {session_id: sessionId};
+    }
+
+    async enable(hsApi, log) {
+        await hsApi.setPusher(this._description, {log}).response();
+    }
+
+    async disable(hsApi, log) {
+        const deleteDescription = Object.assign({}, this._description, {kind: null});
+        await hsApi.setPusher(deleteDescription, {log}).response();
+    }
+
+    serialize() {
+        return this._description;
+    }
+}