Create peer connection for remote streams

lib/helpers/websocket_helper.dart

@@ -182,7 +182,9 @@ class WebSocketHelper {
             peerID: msg.data["peerID"],
             candidate: signalData.containsKey("candidate")
                 ? RTCIceCandidate(
-                    signalData["candidate"], null, signalData["sdpMLineIndex"])
+                    signalData["candidate"],
+                    "${signalData["sdpMLineIndex"]}" /* fix plugin crash */,
+                    signalData["sdpMLineIndex"])
                 : null,
             sessionDescription: signalData.containsKey("type")
                 ? RTCSessionDescription(signalData["sdp"], signalData["type"])

lib/models/call_config.dart

@@ -10,4 +10,9 @@ class CallConfig {
   const CallConfig({
     @required this.iceServers,
   }) : assert(iceServers != null);
+
+  /// Turn this call configuration into the right for the WebRTC plugin
+  Map<String, dynamic> get pluginConfig => {
+        "iceServers": iceServers.map((f) => {"url": f}).toList()
+      };
 }

lib/ui/screens/call_screen.dart

@@ -13,6 +13,8 @@ import 'package:comunic/utils/account_utils.dart';
 import 'package:comunic/utils/intl_utils.dart';
 import 'package:comunic/utils/ui_utils.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_webrtc/rtc_peerconnection.dart';
+import 'package:flutter_webrtc/webrtc.dart';
 
 /// Call screen
 ///
@@ -41,6 +43,7 @@ class _CallScreenState extends SafeState<CallScreen> {
   var _error = false;
   CallMembersList _membersList;
   UsersList _usersList;
+  final _peersConnections = Map<int, RTCPeerConnection>();
 
   @override
   void initState() {
@@ -141,6 +144,18 @@ class _CallScreenState extends SafeState<CallScreen> {
       _membersList.getUser(memberID).status = MemberStatus.READY;
       setState(() {});
 
+      // Create peer connection
+      final peerConnection = await createPeerConnection(_conf.pluginConfig, {
+        "mandatory": {
+          "OfferToReceiveAudio": true,
+          "OfferToReceiveVideo":
+              _conversation.callCapabilities == CallCapabilities.VIDEO,
+        },
+        "optional": [],
+      });
+
+      _peersConnections[memberID] = peerConnection;
+
       // Request an offer to establish a peer connection
       await CallsHelper.requestOffer(convID, memberID);
     } catch (e, stack) {
@@ -150,9 +165,38 @@ class _CallScreenState extends SafeState<CallScreen> {
   }
 
   /// Call this method each time we get a new signal
-  void _newSignal(NewCallSignalEvent ev) {
-    print(
-        "${ev.peerID} - ${ev.sessionDescription != null ? ev.sessionDescription.toMap() : ev.candidate.toMap()}");
+  void _newSignal(NewCallSignalEvent ev) async {
+    try {
+      // Check if we can process this message
+      if (!_peersConnections.containsKey(ev.peerID)) {
+        print(
+            "Could not process a signal for the connection with peer ${ev.peerID}!");
+        return;
+      }
+
+      // Check the kind of signal
+      // SessionDescription
+      if (ev.sessionDescription != null) {
+        await _peersConnections[ev.peerID]
+            .setRemoteDescription(ev.sessionDescription);
+
+        // Send answer if required
+        if (ev.sessionDescription.type == "offer") {
+          final answer = await _peersConnections[ev.peerID].createAnswer({});
+
+          //TODO : Send answer back to server
+          print("ANSWER TO SEND ${answer.toMap()}");
+        }
+      }
+
+      // Ice Candidate
+      else {
+        await _peersConnections[ev.peerID].addCandidate(ev.candidate);
+      }
+    } catch (e, stack) {
+      print("Error while handling new signal ! $e\n$stack");
+      showSimpleSnack(context, tr("Error while processing new signal!"));
+    }
   }
 
   /// Call this when a user has interrupted streaming