feat: implement remote homeserver handling for LiveKit calls

src/app/features/call/CallService.ts

@@ -22,7 +22,14 @@ import {
   LiveKitJWTResponse,
   CallMemberEventContent,
 } from './types';
-import { fetchLiveKitJWT, fetchWellKnownWithRTC, getLiveKitFocus, requestOpenIdToken } from './useRtcConfig';
+import { 
+  fetchLiveKitJWT, 
+  fetchWellKnownWithRTC, 
+  getLiveKitFocus, 
+  requestOpenIdToken,
+  fetchLiveKitJWTFromServers,
+  getLiveKitHomeserverPriority,
+} from './useRtcConfig';
 import { getAudioSettings, SCREEN_SHARE_RESOLUTIONS, SCREEN_SHARE_BITRATES } from '../settings/audio/Audio';
 import { getCallSounds, CallSoundType } from './CallSounds';
 
@@ -293,23 +300,48 @@ export class CallService {
     });
 
     try {
-      // Step 1: Get an OpenID token from the Matrix homeserver
-      const openIdToken = await requestOpenIdToken(
+      // Step 1: Get room and determine which homeservers to try
+      const room = this.matrixClient.getRoom(roomId);
+      if (!room) {
+        throw new Error(`Room ${roomId} not found`);
+      }
+
+      const homeserverPriority = getLiveKitHomeserverPriority(
+        room,
         this.config.homeserverBaseUrl,
-        this.config.userId,
-        this.config.accessToken
+        this.config.userId
       );
 
-      // Step 2: Exchange OpenID token for LiveKit JWT
-      console.log('Requesting LiveKit JWT for Matrix room:', roomId);
-      this.livekitJwt = await fetchLiveKitJWT(
-        this.config.livekitServiceUrl,
+      console.log('Trying homeservers in order:', homeserverPriority);
+
+      // Step 2: Try fetching LiveKit JWT from homeservers in priority order
+      const result = await fetchLiveKitJWTFromServers(
+        homeserverPriority,
         roomId,
         this.config.userId,
         this.config.deviceId,
-        openIdToken
+        this.config.accessToken
       );
 
+      if (!result) {
+        throw new Error('Failed to get LiveKit JWT from any homeserver');
+      }
+
+      this.livekitJwt = result.jwt;
+      
+      // Track if using remote homeserver
+      const userHomeserverDomain = this.config.homeserverBaseUrl
+        .replace('https://', '')
+        .replace('http://', '');
+      const usedHomeserverDomain = result.homeserver
+        .replace('https://', '')
+        .replace('http://', '');
+      
+      if (usedHomeserverDomain !== userHomeserverDomain) {
+        this.activeCall!.livekitHomeserver = result.homeserver;
+        console.log(`Using remote homeserver for LiveKit: ${result.homeserver}`);
+      }
+
       console.log('Got LiveKit JWT, connecting to:', this.livekitJwt.url);
       console.log('LiveKit JWT response:', JSON.stringify(this.livekitJwt));
 
@@ -918,6 +950,22 @@ export class CallService {
     return this.livekitRoom;
   }
 
+  /**
+   * Checks if the current call is using a remote homeserver for LiveKit
+   * @returns true if using a different homeserver than the user's
+   */
+  isUsingRemoteHomeserver(): boolean {
+    return !!this.activeCall?.livekitHomeserver;
+  }
+
+  /**
+   * Gets the homeserver being used for LiveKit (if remote)
+   * @returns The remote homeserver URL, or undefined if using user's homeserver
+   */
+  getLiveKitHomeserver(): string | undefined {
+    return this.activeCall?.livekitHomeserver;
+  }
+
   /**
    * Starts screen sharing with configurable resolution and bitrate
    * @returns true if screen share started successfully

src/app/features/call/types.ts

@@ -119,6 +119,8 @@ export interface ActiveCall {
   isDeafened: boolean;
   isVideoEnabled: boolean;
   isScreenSharing: boolean;
+  /** The homeserver being used for LiveKit JWT (if different from user's homeserver) */
+  livekitHomeserver?: string;
 }
 
 /**

src/app/features/call/useCall.ts

@@ -2,7 +2,7 @@ import { createContext, useContext, useState, useCallback, useEffect, useMemo }
 import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { CallService } from './CallService';
 import { ActiveCall, CallEvent, CallEventType, CallState, CallType } from './types';
-import { fetchWellKnownWithRTC, getLiveKitFocus } from './useRtcConfig';
+import { fetchWellKnownWithRTC, getLiveKitFocus, getLiveKitHomeserverPriority } from './useRtcConfig';
 
 interface CallContextValue {
   callService: CallService | null;
@@ -245,10 +245,36 @@ export function useCallService(): CallContextValue {
  * Hook to check if a call is active in a specific room
  */
 export function useRoomCall(roomId: string) {
-  const { activeCall, startCall, endCall, callSupported, callSupportLoading } = useCall();
+  const { activeCall, startCall, endCall, callSupported, callSupportLoading, callService } = useCall();
+  const mx = useMatrixClient();
 
   const isInCall = activeCall?.roomId === roomId;
   const callState = isInCall ? activeCall.state : CallState.Idle;
+  const isUsingRemoteHomeserver = isInCall ? callService?.isUsingRemoteHomeserver() ?? false : false;
+
+  // Check if a remote homeserver WOULD be used (pre-call check)
+  const wouldUseRemoteHomeserver = useMemo(() => {
+    if (isInCall) return isUsingRemoteHomeserver;
+    
+    const room = mx.getRoom(roomId);
+    if (!room) return false;
+    
+    const homeserverPriority = getLiveKitHomeserverPriority(
+      room,
+      mx.getHomeserverUrl(),
+      mx.getSafeUserId()
+    );
+    
+    // Check if first priority is different from user's homeserver
+    const userHomeserverDomain = mx.getHomeserverUrl()
+      .replace('https://', '')
+      .replace('http://', '');
+    const firstPriorityDomain = homeserverPriority[0]
+      ?.replace('https://', '')
+      .replace('http://', '');
+    
+    return firstPriorityDomain !== userHomeserverDomain;
+  }, [isInCall, isUsingRemoteHomeserver, mx, roomId]);
 
   const startVoiceCall = useCallback(() => startCall(roomId, CallType.Voice), [roomId, startCall]);
   const startVideoCall = useCallback(() => startCall(roomId, CallType.Video), [roomId, startCall]);
@@ -257,6 +283,7 @@ export function useRoomCall(roomId: string) {
     isInCall,
     callState,
     activeCall: isInCall ? activeCall : null,
+    isUsingRemoteHomeserver: wouldUseRemoteHomeserver,
     startVoiceCall,
     startVideoCall,
     endCall,

src/app/features/call/useRtcConfig.ts

@@ -1,6 +1,59 @@
 import { useCallback } from 'react';
+import { Room } from 'matrix-js-sdk';
 import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { LiveKitFocus, LiveKitJWTResponse, OpenIdToken, WellKnownWithRTC } from './types';
+import { getMxIdServer } from '../../utils/matrix';
+import { guessDmRoomUserId } from '../../utils/matrix';
+
+/**
+ * Get room server from room ID (format: !roomid:server.com)
+ */
+function getRoomServer(roomId: string): string | undefined {
+  return getMxIdServer(roomId);
+}
+
+/**
+ * Determine which homeservers to try for LiveKit JWT, in priority order
+ * @param room - Room to start call in
+ * @param userHomeserver - User's homeserver
+ * @param myUserId - Current user's Matrix ID
+ * @returns Array of homeserver base URLs to try in order
+ */
+export function getLiveKitHomeserverPriority(
+  room: Room,
+  userHomeserver: string,
+  myUserId: string
+): string[] {
+  const servers: string[] = [];
+  const memberCount = room.getMembers().length;
+  const isDM = memberCount <= 2;
+
+  if (isDM) {
+    // For DMs: user's homeserver first, then other member's homeserver
+    servers.push(userHomeserver);
+    
+    const otherUserId = guessDmRoomUserId(room, myUserId);
+    if (otherUserId && otherUserId !== myUserId) {
+      const otherServer = getMxIdServer(otherUserId);
+      if (otherServer && otherServer !== userHomeserver) {
+        servers.push(`https://${otherServer}`);
+      }
+    }
+  } else {
+    // For channels: room's homeserver first, then user's homeserver
+    const roomServer = getRoomServer(room.roomId);
+    if (roomServer) {
+      servers.push(`https://${roomServer}`);
+    }
+    
+    // Fallback to user's homeserver if different
+    if (!roomServer || roomServer !== userHomeserver.replace('https://', '').replace('http://', '')) {
+      servers.push(userHomeserver);
+    }
+  }
+
+  return servers;
+}
 
 /**
  * Fetches the LiveKit focus configuration from well-known data
@@ -113,6 +166,59 @@ export async function fetchLiveKitJWT(
   return response.json();
 }
 
+/**
+ * Try fetching LiveKit JWT from multiple homeservers in priority order
+ * @param homeservers - Array of homeserver base URLs to try
+ * @param roomId - The Matrix room ID
+ * @param userId - The Matrix user ID
+ * @param deviceId - The Matrix device ID
+ * @param accessToken - The Matrix access token
+ * @returns LiveKit JWT response and the homeserver that provided it, or null
+ */
+export async function fetchLiveKitJWTFromServers(
+  homeservers: string[],
+  roomId: string,
+  userId: string,
+  deviceId: string,
+  accessToken: string
+): Promise<{ jwt: LiveKitJWTResponse; homeserver: string } | null> {
+  for (const homeserver of homeservers) {
+    try {
+      console.log(`Trying LiveKit JWT from homeserver: ${homeserver}`);
+      
+      // Fetch well-known from this homeserver
+      const wellKnown = await fetchWellKnownWithRTC(homeserver);
+      const livekitFocus = getLiveKitFocus(wellKnown);
+      
+      if (!livekitFocus) {
+        console.log(`No LiveKit config on ${homeserver}, trying next...`);
+        continue;
+      }
+      
+      // Get OpenID token from this homeserver
+      const openIdToken = await requestOpenIdToken(homeserver, userId, accessToken);
+      
+      // Exchange for LiveKit JWT
+      const jwt = await fetchLiveKitJWT(
+        livekitFocus.livekit_service_url,
+        roomId,
+        userId,
+        deviceId,
+        openIdToken
+      );
+      
+      console.log(`Successfully got LiveKit JWT from ${homeserver}`);
+      return { jwt, homeserver };
+    } catch (error) {
+      console.warn(`Failed to get LiveKit JWT from ${homeserver}:`, error);
+      // Continue to next homeserver
+    }
+  }
+  
+  console.error('Failed to get LiveKit JWT from any homeserver');
+  return null;
+}
+
 /**
  * Hook to get RTC configuration functions
  * Provides utilities for fetching well-known data and LiveKit JWTs

src/app/features/room/RoomViewHeader.tsx

@@ -381,6 +381,7 @@ function RoomCallButtons({ roomId }: RoomCallButtonsProps) {
     isInCall,
     callState,
     activeCall,
+    isUsingRemoteHomeserver,
     startVoiceCall,
     startVideoCall,
     endCall,
@@ -433,7 +434,10 @@ function RoomCallButtons({ roomId }: RoomCallButtonsProps) {
         offset={4}
         tooltip={
           <Tooltip>
-            <Text>{isInCall ? 'End Call' : 'Voice Call'}</Text>
+            <Text>
+              {isInCall ? 'End Call' : 'Voice Call'}
+              {isUsingRemoteHomeserver && !isInCall && ' (Remote Server)'}
+            </Text>
           </Tooltip>
         }
       >
@@ -446,7 +450,12 @@ function RoomCallButtons({ roomId }: RoomCallButtonsProps) {
             {isConnecting ? (
               <Spinner size="100" variant="Secondary" />
             ) : (
-              <Icon size="400" src={Icons.Phone} filled={isActive && activeCall?.callType === CallType.Voice} />
+              <Box direction="Row" gap="100" alignItems="Center">
+                <Icon size="400" src={Icons.Phone} filled={isActive && activeCall?.callType === CallType.Voice} />
+                {isUsingRemoteHomeserver && (
+                  <Icon size="50" src={Icons.HashGlobe} style={{ opacity: 0.7 }} />
+                )}
+              </Box>
             )}
           </IconButton>
         )}
@@ -456,7 +465,10 @@ function RoomCallButtons({ roomId }: RoomCallButtonsProps) {
         offset={4}
         tooltip={
           <Tooltip>
-            <Text>{isInCall ? 'End Call' : 'Video Call'}</Text>
+            <Text>
+              {isInCall ? 'End Call' : 'Video Call'}
+              {isUsingRemoteHomeserver && !isInCall && ' (Remote Server)'}
+            </Text>
           </Tooltip>
         }
       >
@@ -469,7 +481,12 @@ function RoomCallButtons({ roomId }: RoomCallButtonsProps) {
             {isConnecting ? (
               <Spinner size="100" variant="Secondary" />
             ) : (
-              <Icon size="400" src={Icons.VideoCamera} filled={isActive && activeCall?.callType === CallType.Video} />
+              <Box direction="Row" gap="100" alignItems="Center">
+                <Icon size="400" src={Icons.VideoCamera} filled={isActive && activeCall?.callType === CallType.Video} />
+                {isUsingRemoteHomeserver && (
+                  <Icon size="50" src={Icons.HashGlobe} style={{ opacity: 0.7 }} />
+                )}
+              </Box>
             )}
           </IconButton>
         )}