From 3b1aa4d4264615166895aabc2a323484ab0c239b Mon Sep 17 00:00:00 2001
From: Robert Ekl <ekl.rob@gmail.com>
Date: Tue, 3 Mar 2026 22:55:14 -0600
Subject: [PATCH] Fix mobile BLE scan stream completion and cleanup

---
 lib/services/bluetooth/mobile_bluetooth.dart | 29 +++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/lib/services/bluetooth/mobile_bluetooth.dart b/lib/services/bluetooth/mobile_bluetooth.dart
index 6131f83..d279477 100644
--- a/lib/services/bluetooth/mobile_bluetooth.dart
+++ b/lib/services/bluetooth/mobile_bluetooth.dart
@@ -46,6 +46,7 @@ class MobileBluetoothService implements BluetoothService {
   StreamSubscription? _connectionStateSubscription;
   StreamSubscription? _notificationSubscription;
   StreamSubscription? _scanSubscription;
+  StreamController<DiscoveredDevice>? _scanController;
 
   // Store scanned device info for use in connect()
   // This preserves the device name from scan results
@@ -183,10 +184,15 @@ class MobileBluetoothService implements BluetoothService {
   @override
   Stream<DiscoveredDevice> scanForDevices({Duration? timeout}) async* {
     final controller = StreamController<DiscoveredDevice>();
+    _scanController = controller;
     
     _updateStatus(ConnectionStatus.scanning);
 
     try {
+      // Ensure any previous scan stream is closed before starting a new one
+      await _scanSubscription?.cancel();
+      _scanSubscription = null;
+
       // Start scanning with filter for MeshCore service UUID
       await fbp.FlutterBluePlus.startScan(
         withServices: [fbp.Guid(BleUuids.serviceUuid)],
@@ -208,14 +214,30 @@ class MobileBluetoothService implements BluetoothService {
           );
           // Store device info for use in connect() - preserves name from scan
           _scannedDevices[device.id] = device;
-          controller.add(device);
+          if (!controller.isClosed) {
+            controller.add(device);
+          }
         }
       });
 
+      // Complete stream when scan naturally stops (timeout or platform stop)
+      unawaited(() async {
+        await fbp.FlutterBluePlus.isScanning.where((isScanning) => !isScanning).first;
+        if (!controller.isClosed) {
+          await controller.close();
+        }
+      }());
+
       yield* controller.stream;
     } finally {
       await _scanSubscription?.cancel();
       _scanSubscription = null;
+      if (!controller.isClosed) {
+        await controller.close();
+      }
+      if (identical(_scanController, controller)) {
+        _scanController = null;
+      }
     }
   }
 
@@ -224,6 +246,11 @@ class MobileBluetoothService implements BluetoothService {
     await fbp.FlutterBluePlus.stopScan();
     await _scanSubscription?.cancel();
     _scanSubscription = null;
+    final scanController = _scanController;
+    if (scanController != null && !scanController.isClosed) {
+      await scanController.close();
+    }
+    _scanController = null;
     // NOTE: Do NOT fire 'disconnected' here. Stopping a scan is not a disconnection.
     // The status will be updated by connect() when a connection starts.
     // Firing 'disconnected' here causes a race condition where the queued event