Some fixes

app/src/main/java/com/nextcloud/talk/controllers/CallController.java

@@ -929,7 +929,6 @@ public class CallController extends BaseController {
                                 externalSignalingServer = new ExternalSignalingServer();
                                 externalSignalingServer.setExternalSignalingServer(signalingSettingsOverall.getOcs().getSettings().getExternalSignalingServer());
                                 externalSignalingServer.setExternalSignalingTicket(signalingSettingsOverall.getOcs().getSettings().getExternalSignalingTicket());
-                                setupAndInitiateWebSocketsConnection();
                             }
 
                             if (signalingSettingsOverall.getOcs().getSettings().getStunServers() != null) {
@@ -1008,7 +1007,11 @@ public class CallController extends BaseController {
                                 .getCapabilities().getSpreedCapability()
                                 .getFeatures().contains("no-ping"));
 
+                        if (externalSignalingServer == null) {
                             joinRoomAndCall();
+                        } else {
+                            setupAndInitiateWebSocketsConnection();
+                        }
                     }
 
                     @Override
@@ -1216,6 +1219,9 @@ public class CallController extends BaseController {
             case "signalingMessage":
                 processMessage((NCSignalingMessage) webSocketClient.getJobWithId(Integer.valueOf(webSocketCommunicationEvent.getHashMap().get("jobId"))));
                 break;
+            case "peerConnectionReady":
+                webSocketClient.requestOfferForSessionIdWithType(webSocketCommunicationEvent.getHashMap().get("sessionId"), "video");
+                break;
         }
     }
 
@@ -1277,13 +1283,21 @@ public class CallController extends BaseController {
                     case "offer":
                     case "answer":
                         magicPeerConnectionWrapper.setNick(ncSignalingMessage.getPayload().getNick());
+                        SessionDescription sessionDescriptionWithPreferredCodec;
+
+                        if (magicPeerConnectionWrapper.hasMediaStream() ) {
                             String sessionDescriptionStringWithPreferredCodec = MagicWebRTCUtils.preferCodec
                                     (ncSignalingMessage.getPayload().getSdp(),
                                             "VP8", false);
 
-                        SessionDescription sessionDescriptionWithPreferredCodec = new SessionDescription(
+                            sessionDescriptionWithPreferredCodec = new SessionDescription(
                                     SessionDescription.Type.fromCanonicalForm(type),
                                     sessionDescriptionStringWithPreferredCodec);
+                        } else {
+                            sessionDescriptionWithPreferredCodec = new SessionDescription(
+                                    SessionDescription.Type.fromCanonicalForm(type),
+                                    ncSignalingMessage.getPayload().getSdp());
+                        }
 
                         if (magicPeerConnectionWrapper.getPeerConnection() != null) {
                             magicPeerConnectionWrapper.getPeerConnection().setRemoteDescription(magicPeerConnectionWrapper
@@ -1476,11 +1490,7 @@ public class CallController extends BaseController {
         }
 
         for (String sessionId : newSessions) {
-            if (!hasMCU) {
             alwaysGetPeerConnectionWrapperForSessionId(sessionId, false);
-            } else {
-                webSocketClient.requestOfferForSessionIdWithType(sessionId, "video");
-            }
         }
 
         for (String sessionId : oldSesssions) {
@@ -1532,15 +1542,19 @@ public class CallController extends BaseController {
         } else {
             hasMCU = webSocketClient != null && webSocketClient.hasMCU();
 
+            if (sessionId == null) {
+                Log.d("MARIO", "ISNULL");
+            }
+
             if (hasMCU && publisher) {
                 magicPeerConnectionWrapper = new MagicPeerConnectionWrapper(peerConnectionFactory,
-                        iceServers, sdpConstraintsForMCU, sessionId, callSession, localMediaStream, true);
+                        iceServers, sdpConstraintsForMCU, sessionId, callSession, localMediaStream, true, true);
             } else if (hasMCU) {
                 magicPeerConnectionWrapper = new MagicPeerConnectionWrapper(peerConnectionFactory,
-                        iceServers, sdpConstraints, sessionId, callSession, null, false);
+                        iceServers, sdpConstraints, sessionId, callSession, null, false, true);
             } else {
                 magicPeerConnectionWrapper = new MagicPeerConnectionWrapper(peerConnectionFactory,
-                        iceServers, sdpConstraints, sessionId, callSession, localMediaStream, false);
+                        iceServers, sdpConstraints, sessionId, callSession, localMediaStream, false, false);
             }
 
             magicPeerConnectionWrapperList.add(magicPeerConnectionWrapper);

app/src/main/java/com/nextcloud/talk/models/json/websocket/ActorWebSocketMessage.java

@@ -36,4 +36,7 @@ public class ActorWebSocketMessage {
 
     @JsonField(name = "sessionid")
     String sessionId;
+
+    @JsonField(name = "userid")
+    String userid;
 }

app/src/main/java/com/nextcloud/talk/webrtc/MagicPeerConnectionWrapper.java

@@ -48,7 +48,9 @@ import org.webrtc.SessionDescription;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import androidx.annotation.Nullable;
 
@@ -75,7 +77,7 @@ public class MagicPeerConnectionWrapper {
                                       List<PeerConnection.IceServer> iceServerList,
                                       MediaConstraints mediaConstraints,
                                       String sessionId, String localSession, @Nullable MediaStream mediaStream,
-                                      boolean isMCUPublisher) {
+                                      boolean isMCUPublisher, boolean hasMCU) {
 
         this.localMediaStream = mediaStream;
 
@@ -93,12 +95,19 @@ public class MagicPeerConnectionWrapper {
                 peerConnection.addStream(localMediaStream);
             }
 
-            if (isMCUPublisher || hasInitiated) {
+            if (hasMCU || hasInitiated) {
                 DataChannel.Init init = new DataChannel.Init();
                 init.negotiated = false;
                 magicDataChannel = peerConnection.createDataChannel("status", init);
                 magicDataChannel.registerObserver(new MagicDataChannelObserver());
+                if (isMCUPublisher) {
                     peerConnection.createOffer(magicSdpObserver, mediaConstraints);
+                } else if (hasMCU) {
+                    HashMap<String, String> peerConnectionReadyMap = new HashMap<>();
+                    peerConnectionReadyMap.put("sessionId", sessionId);
+                    EventBus.getDefault().post(new WebSocketCommunicationEvent("peerConnectionReady", peerConnectionReadyMap));
+
+                }
             }
         }
     }
@@ -341,13 +350,18 @@ public class MagicPeerConnectionWrapper {
 
         @Override
         public void onCreateSuccess(SessionDescription sessionDescription) {
+            SessionDescription sessionDescriptionWithPreferredCodec;
+            if (localMediaStream != null) {
                 String sessionDescriptionStringWithPreferredCodec = MagicWebRTCUtils.preferCodec
                         (sessionDescription.description,
                                 "VP8", false);
-
+                sessionDescriptionWithPreferredCodec = new SessionDescription(
-            SessionDescription sessionDescriptionWithPreferredCodec = new SessionDescription(
                         sessionDescription.type,
                         sessionDescriptionStringWithPreferredCodec);
+            } else {
+                sessionDescriptionWithPreferredCodec = sessionDescription;
+            }
+
 
             EventBus.getDefault().post(new SessionDescriptionSendEvent(sessionDescriptionWithPreferredCodec, sessionId,
                     sessionDescription.type.canonicalForm().toLowerCase(), null));
@@ -370,4 +384,8 @@ public class MagicPeerConnectionWrapper {
             }
         }
     }
+
+    public boolean hasMediaStream() {
+        return localMediaStream != null;
+    }
 }