feat: added usb transfer support (Android only)

android/app/src/main/AndroidManifest.xml

@@ -1,4 +1,5 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
+<uses-feature android:name="android.hardware.usb.host" />
     <application
         android:label="Badge Magic"
         android:name="${applicationName}"
@@ -15,6 +16,14 @@
                  the Android process has started. This theme is visible to the user
                  while the Flutter UI initializes. After that, this theme continues
                  to determine the Window background behind the Flutter UI. -->
+            <intent-filter>
+                <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
+            </intent-filter>
+
+            <meta-data
+                android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
+                android:resource="@xml/device_filter" />
+
             <meta-data
               android:name="io.flutter.embedding.android.NormalTheme"
               android:resource="@style/NormalTheme"

android/app/src/main/res/xml/device_filter.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <!-- FOSSASIA BadgeMagic - badgemagic firmware (transfer) -->
+    <usb-device vendor-id="4348" product-id="55200" />      <!-- 0x10FC, 0x55E0 -->
+
+    <!-- FOSSASIA BadgeMagic - rust badgemagic (bootloader)-->  
+    <usb-device vendor-id="1046" product-id="20512" />      <!-- 0x0416, 0x5020 -->
+</resources>

lib/bademagic_module/usb/payload_builder.dart

@@ -0,0 +1,27 @@
+import 'package:badgemagic/bademagic_module/bluetooth/datagenerator.dart';
+
+/// Builds USB CDC payloads from Badge data.
+/// Same format as BLE, but split into 64-byte chunks.
+class PayloadBuilder {
+  final DataTransferManager manager;
+
+  PayloadBuilder({required this.manager});
+
+  Future<List<List<int>>> buildPayloads() async {
+    // Generate the raw payload using the existing BLE generator
+    final rawChunks = await manager.generateDataChunk();
+
+    // Flatten because BLE uses 16-byte chunks
+    final flat = rawChunks.expand((c) => c).toList();
+
+    // Split into 64-byte chunks for USB CDC
+    final usbChunks = <List<int>>[];
+    for (int i = 0; i < flat.length; i += 64) {
+      usbChunks.add(
+        flat.sublist(i, i + 64 > flat.length ? flat.length : i + 64),
+      );
+    }
+
+    return usbChunks;
+  }
+}

lib/bademagic_module/usb/usb_cdc.dart

@@ -0,0 +1,110 @@
+import 'dart:typed_data';
+import 'package:logger/logger.dart';
+import 'package:usb_serial/usb_serial.dart';
+
+/// Wrapper around usb_serial for BadgeMagic devices
+class UsbCdc {
+  final logger = Logger();
+  UsbPort? _port;
+
+  // FOSSASIA BadgeMagic Device IDs - BOTH MODES
+  static const int normalVendorId = 4348; // 0x10FC - Normal mode
+  static const int normalProductId = 55200; // 0x55E0 - Normal mode
+  static const int bootloaderVendorId = 1046; // 0x0416 - Bootloader mode
+  static const int bootloaderProductId = 20512; // 0x5020 - Bootloader mode
+
+  /// Open the first available FOSSASIA USB device
+  Future<bool> openDevice() async {
+    final devices = await listDevices();
+
+    // Filter for FOSSASIA badges - BOTH MODES
+    final fossasiaDevices = devices
+        .where((device) =>
+            (device.vid == normalVendorId && device.pid == normalProductId) ||
+            (device.vid == bootloaderVendorId &&
+                device.pid == bootloaderProductId))
+        .toList();
+
+    if (fossasiaDevices.isEmpty) {
+      logger.e("No FOSSASIA badge found. Available devices: $devices");
+      return false;
+    }
+
+    final device = fossasiaDevices.first;
+    logger.d("Found FOSSASIA device: ${device.vid}:${device.pid}");
+
+    // BOOTLOADER DETECTION
+    if (device.vid == bootloaderVendorId && device.pid == bootloaderProductId) {
+      logger.e("Device is in bootloader mode - cannot transfer data");
+      throw Exception(
+          "Device is in bootloader mode. Please disconnect, then connect without holding any buttons.");
+    }
+
+    _port = await device.create();
+    if (_port == null) {
+      logger.e("Failed to create USB port");
+      return false;
+    }
+
+    final opened = await _port!.open();
+    if (!opened) {
+      logger.e("Failed to open USB port");
+      return false;
+    }
+
+    await _port!.setPortParameters(
+      115200,
+      UsbPort.DATABITS_8,
+      UsbPort.STOPBITS_1,
+      UsbPort.PARITY_NONE,
+    );
+
+    logger.d("USB device opened successfully");
+    return true;
+  }
+
+  /// Write data to the USB port
+  Future<void> write(List<int> data) async {
+    if (_port == null) throw Exception("USB port not open");
+
+    try {
+      await _port!.write(Uint8List.fromList(data));
+      logger.d("USB chunk written: ${data.length} bytes");
+    } catch (e) {
+      logger.e("Failed to write USB chunk: $e");
+      rethrow;
+    }
+  }
+
+  /// Close the USB port
+  Future<void> close() async {
+    try {
+      await _port?.close();
+      logger.d("USB port closed");
+    } catch (e) {
+      logger.e("Error closing USB port: $e");
+    }
+  }
+
+  /// List connected USB devices with better logging
+  Future<List<UsbDevice>> listDevices() async {
+    try {
+      final devices = await UsbSerial.listDevices();
+      logger.d(
+          "USB devices found: ${devices.map((d) => 'VID:${d.vid?.toRadixString(16)} PID:${d.pid?.toRadixString(16)}').toList()}");
+      return devices;
+    } catch (e) {
+      logger.e("Error listing USB devices: $e");
+      return [];
+    }
+  }
+
+  /// Helper to check if any FOSSASIA device is connected
+  Future<bool> isFossasiaDeviceConnected() async {
+    final devices = await listDevices();
+    return devices.any((device) =>
+        (device.vid == normalVendorId && device.pid == normalProductId) ||
+        (device.vid == bootloaderVendorId &&
+            device.pid == bootloaderProductId));
+  }
+}

lib/bademagic_module/usb/usb_scan_state.dart

@@ -0,0 +1,45 @@
+// usb_scan_state.dart
+import 'dart:async';
+import 'package:badgemagic/bademagic_module/bluetooth/base_ble_state.dart';
+import 'package:badgemagic/bademagic_module/usb/payload_builder.dart';
+import 'package:badgemagic/bademagic_module/usb/usb_cdc.dart';
+import 'package:badgemagic/bademagic_module/bluetooth/completed_state.dart';
+import 'package:badgemagic/bademagic_module/usb/usb_write_state.dart';
+
+/// USB scan state (mirrors ScanState for BLE)
+class UsbScanState extends NormalBleState {
+  final PayloadBuilder builder;
+
+  UsbScanState({required this.builder});
+
+  @override
+  Future<BleState?> processState() async {
+    final usb = UsbCdc();
+    toast.showToast("Searching for USB device...");
+
+    try {
+      final devices =
+          await usb.listDevices(); // wrapper for UsbSerial.listDevices()
+
+      final fossasiaDevices = devices
+          .where((device) => device.vid == 0x0416 && device.pid == 0x5020)
+          .toList();
+
+      if (fossasiaDevices.isEmpty) {
+        toast.showErrorToast("No FOSSASIA badge found");
+        return CompletedState(
+            isSuccess: false, message: "No FOSSASIA USB device found");
+      }
+
+      toast.showToast("USB device found. Preparing transfer...");
+
+      // Directly pass to UsbWriteState
+      final writeState = UsbWriteState(builder: builder);
+      return await writeState.process();
+    } catch (e) {
+      logger.e("USB scan error: $e");
+      toast.showErrorToast("USB scan failed: $e");
+      return CompletedState(isSuccess: false, message: "USB scan failed: $e");
+    }
+  }
+}

lib/bademagic_module/usb/usb_write_state.dart

@@ -0,0 +1,76 @@
+import 'package:badgemagic/bademagic_module/bluetooth/base_ble_state.dart';
+import 'package:badgemagic/bademagic_module/bluetooth/completed_state.dart';
+import 'package:badgemagic/bademagic_module/usb/payload_builder.dart';
+import 'package:badgemagic/bademagic_module/usb/usb_cdc.dart';
+import 'dart:io' show Platform;
+import 'package:flutter/services.dart'; // for MissingPluginException
+
+class UsbWriteState extends NormalBleState {
+  final PayloadBuilder builder;
+
+  UsbWriteState({required this.builder});
+
+  @override
+  Future<BleState?> processState() async {
+    // Unsupported platforms (macOS, Web, etc.)
+    if (!Platform.isAndroid) {
+      toast.showErrorToast("USB transfer not supported on this platform");
+      return CompletedState(isSuccess: false, message: "Unsupported platform");
+    }
+
+    final usb = UsbCdc();
+    try {
+      bool opened;
+      try {
+        opened = await usb.openDevice();
+      } on MissingPluginException catch (_) {
+        toast.showErrorToast(
+          "USB plugin not available. Please ensure the plugin is installed and platform supports USB.",
+        );
+        throw Exception("USB plugin missing or not registered");
+      }
+
+      if (!opened) {
+        toast.showErrorToast("No BadgeMagic USB device found");
+        throw Exception("No USB device connected");
+      }
+
+      final dataChunks = await builder.buildPayloads();
+      logger.d("USB payload chunks: ${dataChunks.length}");
+
+      for (final chunk in dataChunks) {
+        bool success = false;
+        for (int attempt = 1; attempt <= 3; attempt++) {
+          try {
+            await usb.write(chunk);
+            logger.d("USB chunk written: $chunk");
+            success = true;
+            break;
+          } catch (e) {
+            logger.e("USB write failed (attempt $attempt/3): $e");
+          }
+        }
+        if (!success) {
+          toast.showErrorToast("Failed to transfer data over USB");
+          throw Exception("USB transfer failed");
+        }
+        await Future.delayed(const Duration(milliseconds: 20));
+      }
+
+      toast.showToast("USB transfer completed successfully");
+      return CompletedState(isSuccess: true, message: "USB transfer complete");
+    } catch (e) {
+      logger.e("USB transfer error: $e");
+      if (e.toString().contains("MissingPluginException")) {
+        // Already handled above; no need to show extra toast
+      } else if (e.toString().contains("No USB device connected")) {
+        // Already shown toast above
+      } else {
+        toast.showErrorToast("USB transfer failed: ${e.toString()}");
+      }
+      throw e;
+    } finally {
+      await usb.close();
+    }
+  }
+}

lib/constants.dart

@@ -8,6 +8,11 @@ const drawBadgeScreen = "bm_db_screen";
 const savedClipartScreen = "bm_sc_screen";
 const savedBadgeScreen = "bm_sb_screen";
 
+enum ConnectionType {
+  bluetooth,
+  usb,
+}
+
 //Colors used in the app
 // Primary Colors
 const Color colorPrimary = Color(0xFFD32F2F);

lib/main.dart

@@ -16,6 +16,7 @@ import 'package:flutter_screenutil/flutter_screenutil.dart';
 import 'package:provider/provider.dart';
 import 'globals/globals.dart' as globals;
 import 'services/localization_service.dart';
+import 'package:badgemagic/providers/transfer_provider.dart';
 
 Future<void> main() async {
   setupLocator();
@@ -47,7 +48,9 @@ Future<void> main() async {
       ChangeNotifierProvider<FontProvider>(
           create: (context) => getIt<FontProvider>()),
       ChangeNotifierProvider<BadgeScanProvider>(
-        create: (_) => getIt<BadgeScanProvider>(),
+          create: (_) => getIt<BadgeScanProvider>()),
+      ChangeNotifierProvider<TransferProvider>(
+        create: (context) => TransferProvider(), // Create a new instance
       ),
     ],
     child: const MyApp(),