PoC (DO NOT MERGE) Showcasing delegation of delayed disconnect event

src/livekit/openIDSFU.ts

@@ -10,6 +10,7 @@
 
 import { FailToGetOpenIdToken } from "../utils/errors";
 import { doNetworkOperationWithRetry } from "../utils/matrix";
+import { Config } from "../config/Config.ts";
 
 export interface SFUConfig {
   url: string;
@@ -19,7 +20,7 @@
 // The bits we need from MatrixClient
 export type OpenIDClientParts = Pick<
   MatrixClient,
-  "getOpenIdToken" | "getDeviceId"
+  "getOpenIdToken" | "getDeviceId" | "baseUrl" | "getUserId"
 >;
 /**
  * Gets a bearer token from the homeserver and then use it to authenticate
@@ -35,6 +36,7 @@
   client: OpenIDClientParts,
   serviceUrl: string,
   matrixRoomId: string,
+  delayId: string,
 ): Promise<SFUConfig> {
   let openIdToken: IOpenIDToken;
   try {
@@ -54,6 +56,7 @@
     serviceUrl,
     matrixRoomId,
     openIdToken,
+    delayId,
   );
   logger.info(`Got JWT from call's active focus URL.`);
 
@@ -65,18 +68,46 @@
   livekitServiceURL: string,
   roomName: string,
   openIDToken: IOpenIDToken,
+  delayId: string,
 ): Promise<SFUConfig> {
+  // TODO: rawId is missing a random component
+  // Note This random component needs to be stored/present during the lifetime this MatrixRTC client
+  let rawId = (client.getUserId() ?? "") + client.getDeviceId()
+
+  const utf8 = new TextEncoder().encode(rawId);
+  let idHashed = await crypto.subtle.digest('SHA-256', utf8).then((hashBuffer) => {
+    const hashArray = Array.from(new Uint8Array(hashBuffer));
+    const hashHex = hashArray.map(bytes => bytes.toString(16).padStart(2, '0')).join('');
+    return hashHex;
+  });
+
+  let body = {
+    room_id: roomName,
+    slot_id: "m.call#ROOM",
+    openid_token: openIDToken,
+    member: {
+      id: idHashed,
+      claimed_user_id: client.getUserId(),
+      claimed_device_id: client.getDeviceId(),
+    }
+  };
+
+  if (delayId) {
+    const { features, matrix_rtc_session: matrixRtcSessionConfig } = Config.get();
+    const delay_timeout_ms = matrixRtcSessionConfig?.delayed_leave_event_delay_ms ?? 10000
+    body = {
+      ...body,
+      ...{delay_id: delayId, delay_timeout: delay_timeout_ms, delay_cs_api_url: client.baseUrl}
+    }
+  };
+
   try {
-    const res = await fetch(livekitServiceURL + "/sfu/get", {
+    const res = await fetch(livekitServiceURL + "/get_token", {
       method: "POST",
       headers: {
         "Content-Type": "application/json",
       },
-      body: JSON.stringify({
-        room: roomName,
-        openid_token: openIDToken,
-        device_id: client.getDeviceId(),
-      }),
+      body: JSON.stringify(body),
     });
     if (!res.ok) {
       throw new Error("SFU Config fetch failed with status code " + res.status);

src/state/CallViewModel/CallViewModel.ts

@@ -99,6 +99,7 @@ import { createHomeserverConnected$ } from "./localMember/HomeserverConnected.ts
 import {
   createLocalMembership$,
   enterRTCSession,
+  MatrixState,
   RTCBackendState,
 } from "./localMember/LocalMembership.ts";
 import { createLocalTransport$ } from "./localMember/LocalTransport.ts";

src/state/CallViewModel/localMember/LocalMembership.ts

@@ -53,6 +53,9 @@
 import { Config } from "../../../config/Config.ts";
 import { type Connection } from "../remoteMembers/Connection.ts";
 
+import { getSFUConfigWithOpenID } from "../../../livekit/openIDSFU.ts"
+import { type MatrixClient } from "matrix-js-sdk";
+
 export enum RTCBackendState {
   Error = "error",
   /** Not even a transport is available to the LocalMembership */
@@ -580,6 +583,28 @@
     };
   }
 
+  matrixState$.pipe(scope.bind()).subscribe((matrixState) => {
+    if (matrixState.state !== MatrixState.Connected) return;
+
+    // UNSAVE. Arbitrary change some types to read properties we should not have access to (private)
+    // TODO this is bad and we need a proper solution to expose the delayId (or let the js-sdk take care of delegating the delayed event)
+
+    const sessionWithAccessToPrivateMembers = matrixRTCSession as unknown as {
+      membershipManager: { state: { delayId: string } },
+      room: { client: MatrixClient, roomId: string } ;
+    };
+
+    const delayId = sessionWithAccessToPrivateMembers.membershipManager.state.delayId;
+    const roomId = sessionWithAccessToPrivateMembers.room.roomId
+    const mxClient = sessionWithAccessToPrivateMembers.room.client
+    const serviceUrl = localConnection$?.value?.transport?.livekit_service_url
+
+    //logger.debug("delayId is available", serviceUrl, delayId, roomId, mxClient);
+    if (serviceUrl) {
+        void getJWTTokenWithDelaydEventDelegation(serviceUrl, delayId, mxClient, roomId, logger);
+    }
+  });
+
   return {
     startTracks,
     requestConnect,
@@ -673,3 +698,23 @@
     await widget.api.transport.send(ElementWidgetActions.JoinCall, {});
   }
 }
+
+async function getJWTTokenWithDelaydEventDelegation(
+  serviceUrl: string,
+  delayId: string,
+  client: MatrixClient,
+  matrixRoomId: string,
+  logger: Logger,
+): Promise<void> {
+  try {
+    const sfuConfig = await getSFUConfigWithOpenID(
+      client,
+      serviceUrl,
+      matrixRoomId,
+      delayId,
+    );
+    logger.debug("SFU Config retrieved successfully with delayId:", delayId, sfuConfig);
+  } catch (error) {
+    logger.error("Failed to get SFU config with OpenID:", error);
+  }
+}