feat: use shifter trainer scan flow

lib/pages/device_details_page.dart

@@ -10,8 +10,6 @@ import 'package:abawo_bt_app/util/bluetooth_settings.dart';
 import 'package:abawo_bt_app/widgets/bike_scan_dialog.dart';
 import 'package:abawo_bt_app/widgets/gear_ratio_editor_card.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_reactive_ble/flutter_reactive_ble.dart'
-    show DiscoveredDevice;
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 import 'package:nb_utils/nb_utils.dart';
@@ -438,20 +436,6 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
       return;
     }
 
-    _isAssignTrainerDialogOpen = true;
-    final DiscoveredDevice? selectedBike;
-    try {
-      selectedBike = await BikeScanDialog.show(
-        context,
-        excludedDeviceId: widget.deviceAddress,
-      );
-    } finally {
-      _isAssignTrainerDialogOpen = false;
-    }
-    if (selectedBike == null || !mounted) {
-      return;
-    }
-
     await _startStatusStreamingIfNeeded();
     final shifter = _shifterService;
     if (shifter == null) {
@@ -463,8 +447,26 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
       );
       return;
     }
+    if (!mounted) {
+      return;
+    }
 
-    final result = await shifter.connectButtonToBike(selectedBike.id);
+    _isAssignTrainerDialogOpen = true;
+    final TrainerScanResult? selectedTrainer;
+    try {
+      selectedTrainer = await BikeScanDialog.show(
+        context,
+        shifter: shifter,
+      );
+    } finally {
+      _isAssignTrainerDialogOpen = false;
+    }
+    if (selectedTrainer == null || !mounted) {
+      return;
+    }
+
+    final result =
+        await shifter.connectButtonToTrainer(selectedTrainer.address);
     if (!mounted) {
       return;
     }
@@ -479,7 +481,13 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
     }
 
     ScaffoldMessenger.of(context).showSnackBar(
-      SnackBar(content: Text('Sent connect request for ${selectedBike.id}.')),
+      SnackBar(
+        content: Text(
+          selectedTrainer.name.isEmpty
+              ? 'Sent connect request for trainer.'
+              : 'Sent connect request for ${selectedTrainer.name}.',
+        ),
+      ),
     );
   }
 

lib/widgets/bike_scan_dialog.dart

@@ -1,39 +1,39 @@
 import 'dart:async';
 
-import 'package:abawo_bt_app/controller/bluetooth.dart';
 import 'package:abawo_bt_app/model/shifter_types.dart';
+import 'package:abawo_bt_app/service/shifter_service.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_reactive_ble/flutter_reactive_ble.dart';
-import 'package:flutter_riverpod/flutter_riverpod.dart';
 
-class BikeScanDialog extends ConsumerStatefulWidget {
+class BikeScanDialog extends StatefulWidget {
   const BikeScanDialog({
-    required this.excludedDeviceId,
+    required this.shifter,
     super.key,
   });
 
-  final String excludedDeviceId;
+  final ShifterService shifter;
 
-  static Future<DiscoveredDevice?> show(
+  static Future<TrainerScanResult?> show(
     BuildContext context, {
-    required String excludedDeviceId,
+    required ShifterService shifter,
   }) {
-    return showDialog<DiscoveredDevice>(
+    return showDialog<TrainerScanResult>(
       context: context,
       barrierDismissible: true,
-      builder: (_) => BikeScanDialog(excludedDeviceId: excludedDeviceId),
+      builder: (_) => BikeScanDialog(shifter: shifter),
     );
   }
 
   @override
-  ConsumerState<BikeScanDialog> createState() => _BikeScanDialogState();
+  State<BikeScanDialog> createState() => _BikeScanDialogState();
 }
 
-class _BikeScanDialogState extends ConsumerState<BikeScanDialog> {
+class _BikeScanDialogState extends State<BikeScanDialog> {
-  bool _showAll = false;
+  bool _showOnlyFtms = true;
   bool _isStartingScan = true;
+  bool _isScanning = false;
   String? _scanError;
-  BluetoothController? _controller;
+  final Map<String, TrainerScanResult> _resultsByAddress = {};
+  StreamSubscription<TrainerScanEvent>? _scanSubscription;
 
   @override
   void initState() {
@@ -42,16 +42,39 @@ class _BikeScanDialogState extends ConsumerState<BikeScanDialog> {
   }
 
   Future<void> _startScan() async {
+    await _scanSubscription?.cancel();
+    if (_isScanning) {
+      await widget.shifter.stopTrainerScan();
+    }
+
     setState(() {
       _isStartingScan = true;
+      _isScanning = false;
       _scanError = null;
+      _resultsByAddress.clear();
     });
 
     try {
-      final controller = await ref.read(bluetoothProvider.future);
+      _scanSubscription = widget.shifter.subscribeToTrainerScanResults().listen(
-      _controller = controller;
+        _handleScanEvent,
-      await controller.stopScan();
+        onError: (Object error) {
-      await controller.startScan();
+          if (!mounted) {
+            return;
+          }
+          setState(() {
+            _scanError = error.toString();
+            _isStartingScan = false;
+            _isScanning = false;
+          });
+        },
+      );
+
+      final startResult = await widget.shifter.startTrainerScan();
+      if (startResult.isErr()) {
+        _scanError = startResult.unwrapErr().toString();
+      } else {
+        _isScanning = true;
+      }
     } catch (error) {
       _scanError = error.toString();
     } finally {
@@ -63,15 +86,43 @@ class _BikeScanDialogState extends ConsumerState<BikeScanDialog> {
     }
   }
 
+  void _handleScanEvent(TrainerScanEvent event) {
+    if (!mounted) {
+      return;
+    }
+
+    setState(() {
+      _isStartingScan = false;
+      switch (event.kind) {
+        case TrainerScanEventKind.scanStarted:
+          _isScanning = true;
+          _scanError = null;
+          break;
+        case TrainerScanEventKind.device:
+          final result = event.result;
+          if (result != null) {
+            _resultsByAddress[result.address.key] = result;
+          }
+          break;
+        case TrainerScanEventKind.scanFinished:
+        case TrainerScanEventKind.scanCancelled:
+          _isScanning = false;
+          break;
+      }
+    });
+  }
+
   @override
   void dispose() {
-    _controller?.stopScan();
+    _scanSubscription?.cancel();
+    if (_isScanning) {
+      unawaited(widget.shifter.stopTrainerScan());
+    }
     super.dispose();
   }
 
   @override
   Widget build(BuildContext context) {
-    final btAsync = ref.watch(bluetoothProvider);
     final size = MediaQuery.of(context).size;
     final dialogWidth = size.width < 640 ? size.width - 24 : 560.0;
     final dialogHeight = size.height < 780 ? size.height * 0.78 : 560.0;
@@ -83,216 +134,85 @@ class _BikeScanDialogState extends ConsumerState<BikeScanDialog> {
       child: SizedBox(
         width: dialogWidth,
         height: dialogHeight,
-        child: btAsync.when(
+        child: Column(
-          loading: () => const Center(child: CircularProgressIndicator()),
-          error: (err, _) => Center(child: Text('Bluetooth error: $err')),
-          data: (controller) {
-            _controller ??= controller;
-            return Column(
           children: [
             _DialogHeader(
-                  showAll: _showAll,
+              showOnlyFtms: _showOnlyFtms,
-                  isScanning: _isStartingScan,
+              isScanning: _isStartingScan || _isScanning,
               onChanged: (value) {
                 setState(() {
-                      _showAll = value;
+                  _showOnlyFtms = value;
                 });
               },
               onRescan: _startScan,
             ),
-                Expanded(
+            Expanded(child: _buildBody(context)),
-                  child: _scanError != null
+          ],
-                      ? _ScanMessage(
+        ),
-                          message: 'Could not start trainer scan: $_scanError',
+      ),
+    );
+  }
+
+  Widget _buildBody(BuildContext context) {
+    if (_scanError != null) {
+      return _ScanMessage(
+        message: 'Could not start shifter trainer scan: $_scanError',
         action: TextButton.icon(
           onPressed: _startScan,
           icon: const Icon(Icons.refresh),
           label: const Text('Retry'),
         ),
-                        )
+      );
-                      : StreamBuilder<List<DiscoveredDevice>>(
-                          stream: controller.scanResultsStream,
-                          initialData: controller.scanResults,
-                          builder: (context, snapshot) {
-                            if (_isStartingScan &&
-                                (snapshot.data == null ||
-                                    snapshot.data!.isEmpty)) {
-                              return const Center(
-                                  child: CircularProgressIndicator());
     }
 
-                            final devices =
+    if (_isStartingScan && _resultsByAddress.isEmpty) {
-                                _filteredDevices(snapshot.data ?? const []);
+      return const Center(child: CircularProgressIndicator());
+    }
+
+    final devices = _filteredDevices();
     if (devices.isEmpty) {
-                              return const _ScanMessage(
+      return _ScanMessage(
-                                message:
+        message: _isScanning
-                                    'No matching trainers nearby. Keep scanning or enable Show All to inspect every device in range.',
+            ? 'The shifter is scanning. Nearby trainers will appear here as soon as the shifter reports them.'
+            : 'No matching trainers were reported by the shifter. Rescan with the trainer nearby and awake.',
       );
     }
 
     return ListView.separated(
       padding: const EdgeInsets.fromLTRB(20, 0, 20, 20),
       itemCount: devices.length,
-                              separatorBuilder: (_, __) =>
+      separatorBuilder: (_, __) => const SizedBox(height: 12),
-                                  const SizedBox(height: 12),
+      itemBuilder: (context, index) => _TrainerScanResultTile(
-                              itemBuilder: (context, index) {
+        result: devices[index],
-                                final device = devices[index];
+        onTap: () => Navigator.of(context).pop(devices[index]),
-                                final isFtms = _advertisesFtms(device);
-                                return Material(
-                                  color: Theme.of(context).colorScheme.surface,
-                                  borderRadius: BorderRadius.circular(22),
-                                  child: InkWell(
-                                    borderRadius: BorderRadius.circular(22),
-                                    onTap: () =>
-                                        Navigator.of(context).pop(device),
-                                    child: Container(
-                                      padding: const EdgeInsets.all(16),
-                                      decoration: BoxDecoration(
-                                        borderRadius: BorderRadius.circular(22),
-                                        border: Border.all(
-                                          color: Theme.of(context)
-                                              .colorScheme
-                                              .outlineVariant
-                                              .withValues(alpha: 0.55),
-                                        ),
-                                      ),
-                                      child: Row(
-                                        children: [
-                                          Container(
-                                            width: 50,
-                                            height: 50,
-                                            decoration: BoxDecoration(
-                                              shape: BoxShape.circle,
-                                              color: Theme.of(context)
-                                                  .colorScheme
-                                                  .primary
-                                                  .withValues(alpha: 0.12),
-                                            ),
-                                            child: Icon(
-                                              Icons.pedal_bike_rounded,
-                                              color: Theme.of(context)
-                                                  .colorScheme
-                                                  .primary,
-                                            ),
-                                          ),
-                                          const SizedBox(width: 14),
-                                          Expanded(
-                                            child: Column(
-                                              crossAxisAlignment:
-                                                  CrossAxisAlignment.start,
-                                              children: [
-                                                Text(
-                                                  device.name.isEmpty
-                                                      ? 'Unknown Device'
-                                                      : device.name,
-                                                  maxLines: 1,
-                                                  overflow:
-                                                      TextOverflow.ellipsis,
-                                                  style: Theme.of(context)
-                                                      .textTheme
-                                                      .titleMedium
-                                                      ?.copyWith(
-                                                        fontWeight:
-                                                            FontWeight.w700,
-                                                      ),
-                                                ),
-                                                const SizedBox(height: 4),
-                                                Text(
-                                                  isFtms
-                                                      ? 'FTMS'
-                                                      : 'Nearby trainer',
-                                                  style: Theme.of(context)
-                                                      .textTheme
-                                                      .bodyMedium
-                                                      ?.copyWith(
-                                                        color: Theme.of(context)
-                                                            .colorScheme
-                                                            .primary,
-                                                        fontWeight:
-                                                            FontWeight.w600,
-                                                      ),
-                                                ),
-                                                const SizedBox(height: 4),
-                                                Text(
-                                                  device.id,
-                                                  maxLines: 1,
-                                                  overflow:
-                                                      TextOverflow.ellipsis,
-                                                  style: Theme.of(context)
-                                                      .textTheme
-                                                      .bodySmall
-                                                      ?.copyWith(
-                                                        color: Theme.of(context)
-                                                            .colorScheme
-                                                            .onSurface
-                                                            .withValues(
-                                                                alpha: 0.62),
-                                                      ),
-                                                ),
-                                              ],
-                                            ),
-                                          ),
-                                          const SizedBox(width: 12),
-                                          Column(
-                                            crossAxisAlignment:
-                                                CrossAxisAlignment.end,
-                                            children: [
-                                              _RssiBadge(rssi: device.rssi),
-                                              const SizedBox(height: 12),
-                                              Icon(
-                                                Icons.chevron_right_rounded,
-                                                color: Theme.of(context)
-                                                    .colorScheme
-                                                    .onSurface
-                                                    .withValues(alpha: 0.55),
-                                              ),
-                                            ],
-                                          ),
-                                        ],
-                                      ),
-                                    ),
-                                  ),
-                                );
-                              },
-                            );
-                          },
-                        ),
-                ),
-              ],
-            );
-          },
-        ),
       ),
     );
   }
 
-  List<DiscoveredDevice> _filteredDevices(List<DiscoveredDevice> devices) {
+  List<TrainerScanResult> _filteredDevices() {
-    return devices.where((device) {
+    final devices = _resultsByAddress.values.where((device) {
-      if (device.id == widget.excludedDeviceId) {
+      return !_showOnlyFtms || device.ftmsDetected;
-        return false;
-      }
-      if (_showAll) {
-        return true;
-      }
-      return _advertisesFtms(device);
     }).toList(growable: false);
+    devices.sort((a, b) {
+      final ftmsCompare = (b.ftmsDetected ? 1 : 0) - (a.ftmsDetected ? 1 : 0);
+      if (ftmsCompare != 0) {
+        return ftmsCompare;
       }
-
+      return b.rssi.compareTo(a.rssi);
-  bool _advertisesFtms(DiscoveredDevice device) {
+    });
-    return device.serviceUuids.any(isFtmsUuid) ||
+    return devices;
-        device.serviceData.keys.any(isFtmsUuid);
   }
 }
 
 class _DialogHeader extends StatelessWidget {
   const _DialogHeader({
-    required this.showAll,
+    required this.showOnlyFtms,
     required this.isScanning,
     required this.onChanged,
     required this.onRescan,
   });
 
-  final bool showAll;
+  final bool showOnlyFtms;
   final bool isScanning;
   final ValueChanged<bool> onChanged;
   final VoidCallback onRescan;
@@ -319,7 +239,7 @@ class _DialogHeader extends StatelessWidget {
                     ),
                     const SizedBox(height: 6),
                     Text(
-                      'Tap a nearby trainer to assign it to the connected shifter.',
+                      'The shifter scans nearby trainers. Tap one to assign it.',
                       style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                             color: Theme.of(context)
                                 .colorScheme
@@ -344,13 +264,13 @@ class _DialogHeader extends StatelessWidget {
                 child: Row(
                   children: [
                     Text(
-                      'Show All',
+                      'FTMS only',
                       style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                             fontWeight: FontWeight.w600,
                           ),
                     ),
                     const SizedBox(width: 8),
-                    Switch(value: showAll, onChanged: onChanged),
+                    Switch(value: showOnlyFtms, onChanged: onChanged),
                   ],
                 ),
               ),
@@ -379,6 +299,109 @@ class _DialogHeader extends StatelessWidget {
   }
 }
 
+class _TrainerScanResultTile extends StatelessWidget {
+  const _TrainerScanResultTile({
+    required this.result,
+    required this.onTap,
+  });
+
+  final TrainerScanResult result;
+  final VoidCallback onTap;
+
+  @override
+  Widget build(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
+    final name = result.name.isEmpty ? 'Unknown Trainer' : result.name;
+    final typeLabel = result.ftmsDetected ? 'FTMS trainer' : 'Nearby device';
+    final addressText = _formatTrainerAddress(result.address);
+
+    return Material(
+      color: colorScheme.surface,
+      borderRadius: BorderRadius.circular(22),
+      child: InkWell(
+        borderRadius: BorderRadius.circular(22),
+        onTap: onTap,
+        child: Container(
+          padding: const EdgeInsets.all(16),
+          decoration: BoxDecoration(
+            borderRadius: BorderRadius.circular(22),
+            border: Border.all(
+              color: colorScheme.outlineVariant.withValues(alpha: 0.55),
+            ),
+          ),
+          child: Row(
+            children: [
+              Container(
+                width: 50,
+                height: 50,
+                decoration: BoxDecoration(
+                  shape: BoxShape.circle,
+                  color: colorScheme.primary.withValues(alpha: 0.12),
+                ),
+                child: Icon(
+                  Icons.pedal_bike_rounded,
+                  color: colorScheme.primary,
+                ),
+              ),
+              const SizedBox(width: 14),
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      name,
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                      style: Theme.of(context).textTheme.titleMedium?.copyWith(
+                            fontWeight: FontWeight.w700,
+                          ),
+                    ),
+                    const SizedBox(height: 4),
+                    Text(
+                      typeLabel,
+                      style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                            color: colorScheme.primary,
+                            fontWeight: FontWeight.w600,
+                          ),
+                    ),
+                    const SizedBox(height: 4),
+                    Text(
+                      addressText,
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                      style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                            color:
+                                colorScheme.onSurface.withValues(alpha: 0.62),
+                          ),
+                    ),
+                  ],
+                ),
+              ),
+              const SizedBox(width: 12),
+              Column(
+                crossAxisAlignment: CrossAxisAlignment.end,
+                children: [
+                  _RssiBadge(rssi: result.rssi),
+                  const SizedBox(height: 12),
+                  Icon(
+                    Icons.chevron_right_rounded,
+                    color: colorScheme.onSurface.withValues(alpha: 0.55),
+                  ),
+                ],
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+
+  String _formatTrainerAddress(TrainerAddress address) {
+    final flags = address.flags.toRadixString(16).padLeft(2, '0');
+    return '${formatMacAddressFromLittleEndian(address.bytes)} · flags 0x$flags';
+  }
+}
+
 class _ScanMessage extends StatelessWidget {
   const _ScanMessage({
     required this.message,