From 7c9b72483a66e113db6fee8c23d3b8616c76c41f Mon Sep 17 00:00:00 2001
From: Matthew Fosse <matt@fosse.co>
Date: Sat, 17 Aug 2024 19:28:45 -0400
Subject: [PATCH] Socket null handling (#1610)

* return null if in connection failure state

* reconnect on connection failure

* better connection handling

* probably not necessary but just incase

* connection handling updates

* add cancelOnError: true
---
 cw_bitcoin/lib/electrum.dart        | 54 +++++++++++++++++------------
 cw_bitcoin/lib/electrum_wallet.dart | 22 +++++-------
 2 files changed, 40 insertions(+), 36 deletions(-)

diff --git a/cw_bitcoin/lib/electrum.dart b/cw_bitcoin/lib/electrum.dart
index 69b07d7c1c..28043d0c08 100644
--- a/cw_bitcoin/lib/electrum.dart
+++ b/cw_bitcoin/lib/electrum.dart
@@ -66,6 +66,7 @@ class ElectrumClient {
 
     try {
       await socket?.close();
+      socket = null;
     } catch (_) {}
 
     try {
@@ -90,33 +91,40 @@ class ElectrumClient {
     }
     _setConnectionStatus(ConnectionStatus.connected);
 
-    socket!.listen((Uint8List event) {
-      try {
-        final msg = utf8.decode(event.toList());
-        final messagesList = msg.split("\n");
-        for (var message in messagesList) {
-          if (message.isEmpty) {
-            continue;
+    socket!.listen(
+      (Uint8List event) {
+        try {
+          final msg = utf8.decode(event.toList());
+          final messagesList = msg.split("\n");
+          for (var message in messagesList) {
+            if (message.isEmpty) {
+              continue;
+            }
+            _parseResponse(message);
           }
-          _parseResponse(message);
+        } catch (e) {
+          print(e.toString());
         }
-      } catch (e) {
-        print(e.toString());
-      }
-    }, onError: (Object error) {
-      final errorMsg = error.toString();
-      print(errorMsg);
-      unterminatedString = '';
+      },
+      onError: (Object error) {
+        socket = null;
+        final errorMsg = error.toString();
+        print(errorMsg);
+        unterminatedString = '';
 
-      final currentHost = socket?.address.host;
-      final isErrorForCurrentHost = errorMsg.contains(" ${currentHost} ");
+        final currentHost = socket?.address.host;
+        final isErrorForCurrentHost = errorMsg.contains(" ${currentHost} ");
 
-      if (currentHost != null && isErrorForCurrentHost)
-        _setConnectionStatus(ConnectionStatus.failed);
-    }, onDone: () {
-      unterminatedString = '';
-      if (host == socket?.address.host) _setConnectionStatus(ConnectionStatus.disconnected);
-    });
+        if (currentHost != null && isErrorForCurrentHost)
+          _setConnectionStatus(ConnectionStatus.failed);
+      },
+      onDone: () {
+        socket = null;
+        unterminatedString = '';
+        if (host == socket?.address.host) _setConnectionStatus(ConnectionStatus.disconnected);
+      },
+      cancelOnError: true,
+    );
 
     keepAlive();
   }
diff --git a/cw_bitcoin/lib/electrum_wallet.dart b/cw_bitcoin/lib/electrum_wallet.dart
index 8f2360f262..b8d9adb144 100644
--- a/cw_bitcoin/lib/electrum_wallet.dart
+++ b/cw_bitcoin/lib/electrum_wallet.dart
@@ -218,10 +218,7 @@ abstract class ElectrumWalletBase
       if (electrumClient.isConnected) {
         syncStatus = SyncedSyncStatus();
       } else {
-        if (electrumClient.uri != null) {
-          await electrumClient.connectToUri(electrumClient.uri!, useSSL: electrumClient.useSSL);
-          startSync();
-        }
+        syncStatus = NotConnectedSyncStatus();
       }
     }
   }
@@ -265,6 +262,7 @@ abstract class ElectrumWalletBase
   Future<Isolate>? _isolate;
 
   void Function(FlutterErrorDetails)? _onError;
+  Timer? _reconnectTimer;
   Timer? _autoSaveTimer;
   static const int _autoSaveInterval = 30;
 
@@ -1980,13 +1978,6 @@ abstract class ElectrumWalletBase
         break;
       case ConnectionStatus.failed:
         syncStatus = LostConnectionSyncStatus();
-        // wait for 5 seconds and then try to reconnect:
-        Future.delayed(Duration(seconds: 5), () {
-          electrumClient.connectToUri(
-            node!.uri,
-            useSSL: node!.useSSL ?? false,
-          );
-        });
         break;
       case ConnectionStatus.connecting:
         syncStatus = ConnectingSyncStatus();
@@ -1996,7 +1987,11 @@ abstract class ElectrumWalletBase
   }
 
   void _syncStatusReaction(SyncStatus syncStatus) async {
-    if (syncStatus is NotConnectedSyncStatus) {
+    if (syncStatus is SyncingSyncStatus) {
+      return;
+    }
+
+    if (syncStatus is NotConnectedSyncStatus || syncStatus is LostConnectionSyncStatus) {
       // Needs to re-subscribe to all scripthashes when reconnected
       _scripthashesUpdateSubject = {};
 
@@ -2004,7 +1999,8 @@ abstract class ElectrumWalletBase
 
       _isTryingToConnect = true;
 
-      Future.delayed(Duration(seconds: 10), () {
+      _reconnectTimer?.cancel();
+      _reconnectTimer = Timer(Duration(seconds: 10), () {
         if (this.syncStatus is! SyncedSyncStatus && this.syncStatus is! SyncedTipSyncStatus) {
           this.electrumClient.connectToUri(
                 node!.uri,