From 9df52a0a89b3ac67f99637af19c11450788da89b Mon Sep 17 00:00:00 2001
From: Ryan Zhao <ryanzhaors@qq.com>
Date: Fri, 25 Mar 2022 13:26:26 +1100
Subject: [PATCH] implement new approach for call reconnection

---
 .../Calls/Call Management/SessionCall.swift   | 23 ++++++++++++++++++-
 SessionMessagingKit/Calls/WebRTCSession.swift | 15 ++++--------
 2 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/Session/Calls/Call Management/SessionCall.swift b/Session/Calls/Call Management/SessionCall.swift
index 71309a16e..9d3e3b94b 100644
--- a/Session/Calls/Call Management/SessionCall.swift	
+++ b/Session/Calls/Call Management/SessionCall.swift	
@@ -149,6 +149,8 @@ public final class SessionCall: NSObject, WebRTCSessionDelegate {
         return Date().timeIntervalSince(connectedDate)
     }
     
+    var reconnectTimer: Timer? = nil
+    
     // MARK: Initialization
     init(for sessionID: String, uuid: String, mode: Mode, outgoing: Bool = false) {
         self.sessionID = sessionID
@@ -205,6 +207,7 @@ public final class SessionCall: NSObject, WebRTCSessionDelegate {
                 Storage.shared.write { transaction in
                     self?.webRTCSession.sendOffer(to: self!.sessionID, using: transaction as! YapDatabaseReadWriteTransaction).retainUntilComplete()
                 }
+                self?.setupTimeoutTimer()
             }
         })
     }
@@ -307,9 +310,27 @@ public final class SessionCall: NSObject, WebRTCSessionDelegate {
         }
     }
     
+    public func reconnectIfNeeded() {
+        guard isOutgoing else { return }
+        tryToReconnect()
+    }
+    
+    private func tryToReconnect() {
+        reconnectTimer?.invalidate()
+        if SSKEnvironment.shared.reachabilityManager.isReachable {
+            Storage.write { transaction in
+                self.webRTCSession.sendOffer(to: self.sessionID, using: transaction, isRestartingICEConnection: true).retainUntilComplete()
+            }
+        } else {
+            reconnectTimer = Timer.scheduledTimerOnMainThread(withTimeInterval: 5, repeats: false) { _ in
+                self.tryToReconnect()
+            }
+        }
+    }
+    
     // MARK: Timeout
     public func setupTimeoutTimer() {
-        timeOutTimer = Timer.scheduledTimer(withTimeInterval: 30, repeats: false) { _ in
+        timeOutTimer = Timer.scheduledTimerOnMainThread(withTimeInterval: 30, repeats: false) { _ in
             self.didTimeout = true
             AppEnvironment.shared.callManager.endCall(self) { error in
                 self.timeOutTimer = nil
diff --git a/SessionMessagingKit/Calls/WebRTCSession.swift b/SessionMessagingKit/Calls/WebRTCSession.swift
index aa5b0239e..190e0061d 100644
--- a/SessionMessagingKit/Calls/WebRTCSession.swift
+++ b/SessionMessagingKit/Calls/WebRTCSession.swift
@@ -8,6 +8,7 @@ public protocol WebRTCSessionDelegate : AnyObject {
     func isRemoteVideoDidChange(isEnabled: Bool)
     func dataChannelDidOpen()
     func didReceiveHangUpSignal()
+    func reconnectIfNeeded()
 }
 
 /// See https://webrtc.org/getting-started/overview for more information.
@@ -103,16 +104,6 @@ public final class WebRTCSession : NSObject, RTCPeerConnectionDelegate {
             dataChannel.delegate = self
             self.dataChannel = dataChannel
         }
-        
-        // Network reachability
-        NotificationCenter.default.addObserver(forName: .reachabilityChanged, object: nil, queue: nil) { _ in
-            print("[Calls] Reachability did change.")
-            if self.peerConnection.signalingState == .stable {
-                Storage.write { transaction in
-                    self.sendOffer(to: self.contactSessionID, using: transaction, isRestartingICEConnection: true).retainUntilComplete()
-                }
-            }
-        }
     }
     
     // MARK: Signaling
@@ -271,6 +262,10 @@ public final class WebRTCSession : NSObject, RTCPeerConnectionDelegate {
         print("[Calls] ICE connection state changed to: \(state).")
         if state == .connected {
             delegate?.webRTCIsConnected()
+        } else if state == .disconnected {
+            if self.peerConnection.signalingState == .stable {
+                delegate?.reconnectIfNeeded()
+            }
         }
     }