VBH is the companion app now

Got tired of having to reinstall all three apps so i ported the companion apps features to vitalwear, now you only need VBH and Vitalwear.

I've also added emblems to items in icons so user isnt confused.

app/src/main/AndroidManifest.xml

@@ -54,6 +54,7 @@
             android:name=".MainActivity"
             android:exported="true"
             android:label="@string/app_name"
+            android:launchMode="singleTask"
             android:theme="@style/Theme.VBHelper">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

app/src/main/java/com/github/nacabaro/vbhelper/MainActivity.kt

@@ -19,11 +19,14 @@ import com.github.nacabaro.vbhelper.screens.cardScreen.CardScreenControllerImpl
 import com.github.nacabaro.vbhelper.screens.spriteViewer.SpriteViewerControllerImpl
 import com.github.nacabaro.vbhelper.screens.storageScreen.StorageScreenControllerImpl
 import com.github.nacabaro.vbhelper.ui.theme.VBHelperTheme
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.asSharedFlow
 
 
 class MainActivity : ComponentActivity() {
     private val onActivityLifecycleListeners = HashMap<String, ActivityLifecycleListener>()
     private var initialRoute: String? = null
+    private val deepLinkNavigationEvents = MutableSharedFlow<String>(extraBufferCapacity = 1)
 
     private fun registerActivityLifecycleListener(key: String, activityLifecycleListener: ActivityLifecycleListener) {
         if( onActivityLifecycleListeners[key] != null) {
@@ -57,6 +60,7 @@ class MainActivity : ComponentActivity() {
         enableEdgeToEdge()
 
         initialRoute = getInitialRouteFromIntent(intent)
+        initialRoute?.let { deepLinkNavigationEvents.tryEmit(it) }
 
         setContent {
             VBHelperTheme {
@@ -69,7 +73,8 @@ class MainActivity : ComponentActivity() {
                     storageScreenController = storageScreenController,
                     spriteViewerController = spriteViewerController,
                     cardScreenController = cardScreenController,
-                    initialRoute = initialRoute
+                    initialRoute = initialRoute,
+                    deepLinkNavigationEvents = deepLinkNavigationEvents.asSharedFlow(),
                 )
             }
         }
@@ -97,6 +102,7 @@ class MainActivity : ComponentActivity() {
         super.onNewIntent(intent)
         setIntent(intent)
         initialRoute = getInitialRouteFromIntent(intent)
+        initialRoute?.let { deepLinkNavigationEvents.tryEmit(it) }
     }
 
     private fun getInitialRouteFromIntent(intent: Intent?): String? {
@@ -120,7 +126,8 @@ class MainActivity : ComponentActivity() {
         homeScreenController: HomeScreenControllerImpl,
         spriteViewerController: SpriteViewerControllerImpl,
         cardScreenController: CardScreenControllerImpl,
-        initialRoute: String? = null
+        initialRoute: String? = null,
+        deepLinkNavigationEvents: kotlinx.coroutines.flow.Flow<String>,
     ) {
         AppNavigation(
             applicationNavigationHandlers = AppNavigationHandlers(
@@ -133,7 +140,8 @@ class MainActivity : ComponentActivity() {
                 spriteViewerController,
                 cardScreenController
             ),
-            initialRoute = initialRoute
+            initialRoute = initialRoute,
+            navigationEvents = deepLinkNavigationEvents,
         )
     }
 }

app/src/main/java/com/github/nacabaro/vbhelper/daos/CharacterTransferPolicyDao.kt

@@ -0,0 +1,17 @@
+package com.github.nacabaro.vbhelper.daos
+
+import androidx.room.Dao
+import androidx.room.Query
+import androidx.room.Upsert
+import com.github.nacabaro.vbhelper.domain.device_data.CharacterTransferPolicy
+
+@Dao
+interface CharacterTransferPolicyDao {
+    @Query("SELECT * FROM CharacterTransferPolicy WHERE characterId = :characterId")
+    fun getByCharacterId(characterId: Long): CharacterTransferPolicy?
+
+    @Upsert
+    fun upsert(policy: CharacterTransferPolicy)
+}
+
+

app/src/main/java/com/github/nacabaro/vbhelper/database/AppDatabase.kt

@@ -7,6 +7,7 @@ import androidx.sqlite.db.SupportSQLiteDatabase
 import com.github.nacabaro.vbhelper.daos.AdventureDao
 import com.github.nacabaro.vbhelper.daos.CardAdventureDao
 import com.github.nacabaro.vbhelper.daos.CharacterDao
+import com.github.nacabaro.vbhelper.daos.CharacterTransferPolicyDao
 import com.github.nacabaro.vbhelper.daos.DexDao
 import com.github.nacabaro.vbhelper.daos.CardDao
 import com.github.nacabaro.vbhelper.daos.CardFusionsDao
@@ -27,6 +28,7 @@ import com.github.nacabaro.vbhelper.domain.characters.Sprite
 import com.github.nacabaro.vbhelper.domain.characters.Adventure
 import com.github.nacabaro.vbhelper.domain.characters.Dex
 import com.github.nacabaro.vbhelper.domain.device_data.BECharacterData
+import com.github.nacabaro.vbhelper.domain.device_data.CharacterTransferPolicy
 import com.github.nacabaro.vbhelper.domain.device_data.SpecialMissions
 import com.github.nacabaro.vbhelper.domain.device_data.TransformationHistory
 import com.github.nacabaro.vbhelper.domain.device_data.UserCharacter
@@ -36,7 +38,7 @@ import com.github.nacabaro.vbhelper.domain.device_data.VitalWearCharacterSetting
 import com.github.nacabaro.vbhelper.domain.items.Items
 
 @Database(
-    version = 5,
+    version = 6,
     entities = [
         Card::class,
         CardProgress::class,
@@ -50,6 +52,7 @@ import com.github.nacabaro.vbhelper.domain.items.Items
         SpecialMissions::class,
         TransformationHistory::class,
         VitalsHistory::class,
+        CharacterTransferPolicy::class,
         Dex::class,
         Items::class,
         Adventure::class,
@@ -71,6 +74,7 @@ abstract class AppDatabase : RoomDatabase() {
     abstract fun cardAdventureDao(): CardAdventureDao
     abstract fun cardFusionsDao(): CardFusionsDao
     abstract fun vitalWearSettingsDao(): VitalWearSettingsDao
+    abstract fun characterTransferPolicyDao(): CharacterTransferPolicyDao
 
     companion object {
         val MIGRATION_1_2 = object : Migration(1, 2) {
@@ -139,5 +143,27 @@ abstract class AppDatabase : RoomDatabase() {
             }
         }
 
+        val MIGRATION_5_6 = object : Migration(5, 6) {
+            override fun migrate(db: SupportSQLiteDatabase) {
+                db.execSQL(
+                    """
+                    CREATE TABLE IF NOT EXISTS `CharacterTransferPolicy` (
+                        `characterId` INTEGER NOT NULL,
+                        `nativeDeviceType` TEXT NOT NULL,
+                        `preferredHceExportFormat` TEXT NOT NULL,
+                        `preferredNfcaExportFormat` TEXT NOT NULL,
+                        `lastObservedImportFormat` TEXT,
+                        `lastTransferTransport` TEXT,
+                        `lastTransferTarget` TEXT,
+                        `preserveVbRoundTrip` INTEGER NOT NULL,
+                        `preserveBeRoundTrip` INTEGER NOT NULL,
+                        PRIMARY KEY(`characterId`),
+                        FOREIGN KEY(`characterId`) REFERENCES `UserCharacter`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE
+                    )
+                    """.trimIndent()
+                )
+            }
+        }
+
     }
 }

app/src/main/java/com/github/nacabaro/vbhelper/domain/device_data/CharacterTransferPolicy.kt

@@ -0,0 +1,32 @@
+package com.github.nacabaro.vbhelper.domain.device_data
+
+import androidx.room.Entity
+import androidx.room.ForeignKey
+import androidx.room.PrimaryKey
+import com.github.nacabaro.vbhelper.transfer.ExportFormat
+import com.github.nacabaro.vbhelper.transfer.TransferTarget
+import com.github.nacabaro.vbhelper.transfer.TransferTransport
+import com.github.nacabaro.vbhelper.utils.DeviceType
+
+@Entity(
+    foreignKeys = [
+        ForeignKey(
+            entity = UserCharacter::class,
+            parentColumns = ["id"],
+            childColumns = ["characterId"],
+            onDelete = ForeignKey.CASCADE,
+        )
+    ]
+)
+data class CharacterTransferPolicy(
+    @PrimaryKey val characterId: Long,
+    val nativeDeviceType: DeviceType,
+    val preferredHceExportFormat: ExportFormat,
+    val preferredNfcaExportFormat: ExportFormat,
+    val lastObservedImportFormat: ExportFormat?,
+    val lastTransferTransport: TransferTransport?,
+    val lastTransferTarget: TransferTarget?,
+    val preserveVbRoundTrip: Boolean,
+    val preserveBeRoundTrip: Boolean,
+)
+

app/src/main/java/com/github/nacabaro/vbhelper/navigation/AppNavigation.kt

@@ -6,6 +6,7 @@ import androidx.compose.animation.fadeOut
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.Scaffold
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
@@ -39,6 +40,7 @@ import com.github.nacabaro.vbhelper.screens.settingsScreen.CreditsScreen
 import com.github.nacabaro.vbhelper.screens.spriteViewer.SpriteViewerControllerImpl
 import com.github.nacabaro.vbhelper.screens.storageScreen.StorageScreenControllerImpl
 import com.github.nacabaro.vbhelper.source.StorageRepository
+import kotlinx.coroutines.flow.Flow
 
 data class AppNavigationHandlers(
     val settingsScreenController: SettingsScreenControllerImpl,
@@ -54,10 +56,23 @@ data class AppNavigationHandlers(
 @Composable
 fun AppNavigation(
     applicationNavigationHandlers: AppNavigationHandlers,
-    initialRoute: String? = null
+    initialRoute: String? = null,
+    navigationEvents: Flow<String>? = null,
 ) {
     val navController = rememberNavController()
 
+    LaunchedEffect(navController, navigationEvents) {
+        navigationEvents?.collect { route ->
+            navController.navigate(route) {
+                launchSingleTop = true
+                restoreState = true
+                popUpTo(navController.graph.startDestinationId) {
+                    saveState = true
+                }
+            }
+        }
+    }
+
     Scaffold(
         bottomBar = {
             BottomNavigationBar(navController = navController)

app/src/main/java/com/github/nacabaro/vbhelper/navigation/BottomNavigationBar.kt

@@ -31,9 +31,32 @@ fun BottomNavigationBar(navController: NavController) {
                 selected = currentRoute == item.route,
                 onClick = {
                     if (item == NavigationItems.Home) {
+                        // Home should always show the Home root, not a restored nested route
+                        // like Settings that was opened from Home previously.
+                        val poppedToHome = navController.popBackStack(
+                            NavigationItems.Home.route,
+                            inclusive = false,
+                        )
+                        if (!poppedToHome) {
                             navController.navigate(NavigationItems.Home.route) {
-                            popUpTo(0) { inclusive = false }
+                                popUpTo(navController.graph.startDestinationId) { inclusive = false }
                                 launchSingleTop = true
+                                restoreState = false
+                            }
+                        }
+                    } else if (item == NavigationItems.Storage) {
+                        // Adventure is launched from Storage; tapping Storage again should always
+                        // bring the user back to the Storage root instead of appearing stuck.
+                        val poppedToStorage = navController.popBackStack(
+                            NavigationItems.Storage.route,
+                            inclusive = false,
+                        )
+                        if (!poppedToStorage) {
+                            navController.navigate(NavigationItems.Storage.route) {
+                                popUpTo(navController.graph.startDestinationId) { saveState = true }
+                                launchSingleTop = true
+                                restoreState = true
+                            }
                         }
                     } else {
                         navController.navigate(item.route) {

app/src/main/java/com/github/nacabaro/vbhelper/screens/scanScreen/ScanScreenControllerImpl.kt

@@ -22,9 +22,12 @@ import com.github.nacabaro.vbhelper.screens.scanScreen.converters.FromNfcConvert
 import com.github.nacabaro.vbhelper.screens.scanScreen.converters.ToNfcConverter
 import com.github.nacabaro.vbhelper.source.VitalWearCharacterExporter
 import com.github.nacabaro.vbhelper.source.VitalWearCharacterImporter
+import com.github.nacabaro.vbhelper.transfer.ExportFormat
 import com.github.nacabaro.vbhelper.source.getCryptographicTransformerMap
 import com.github.nacabaro.vbhelper.source.isMissingSecrets
 import com.github.nacabaro.vbhelper.source.proto.Secrets
+import com.github.nacabaro.vbhelper.transfer.TransferTarget
+import com.github.nacabaro.vbhelper.transfer.TransferTransport
 import com.github.nacabaro.vbhelper.transfer.hce.VitalWearHceReaderClient
 import com.github.nacabaro.vbhelper.R
 import kotlinx.coroutines.Dispatchers
@@ -213,7 +216,42 @@ class ScanScreenControllerImpl(
                     onComplete.invoke(ScanScreenController.WriteResult.MOVE_CONFIRMED)
                     componentActivity.getString(R.string.scan_sent_character_success)
                 } catch (writeError: Throwable) {
-                    Log.e("NFC_WRITE_A", "NFC-A write failed; attempting opposite direction", writeError)
+                    Log.e("NFC_WRITE_A", "NFC-A write failed; trying alternate payload format", writeError)
+                    val characterId = lastRequestedCharacterId
+                    val alternateFormat = when (nfcCharacter) {
+                        is BENfcCharacter -> ExportFormat.VB
+                        is VBNfcCharacter -> ExportFormat.BE
+                        else -> null
+                    }
+
+                    val alternateSent = if (characterId != null && alternateFormat != null) {
+                        runCatching {
+                            val alternateCharacter = runBlocking {
+                                ToNfcConverter(componentActivity = componentActivity).characterToNfc(
+                                    characterId = characterId,
+                                    target = TransferTarget.REAL_BRACELET,
+                                    transport = TransferTransport.NFCA,
+                                    forcedFormat = alternateFormat,
+                                )
+                            }
+                            when (alternateCharacter) {
+                                is VBNfcCharacter -> tagCommunicator.sendCharacter(alternateCharacter)
+                                is BENfcCharacter -> tagCommunicator.sendCharacter(alternateCharacter)
+                            }
+                            true
+                        }.getOrElse { alternateError ->
+                            Log.e("NFC_WRITE_A", "Alternate payload write failed", alternateError)
+                            false
+                        }
+                    } else {
+                        false
+                    }
+
+                    if (alternateSent) {
+                        onComplete.invoke(ScanScreenController.WriteResult.MOVE_CONFIRMED)
+                        "Sent character after converting payload for the tapped bracelet."
+                    } else {
+                        Log.e("NFC_WRITE_A", "NFC-A write failed; attempting opposite direction fallback", writeError)
                         runCatching {
                             val receivedCharacter = tagCommunicator.receiveCharacter()
                             val fallbackMessage = importCharacterFromNfcAFallback(receivedCharacter)
@@ -224,6 +262,7 @@ class ScanScreenControllerImpl(
                             componentActivity.getString(R.string.scan_error_generic)
                         }
                     }
+                }
             },
             isoDepHandler = { isoDep ->
                 val characterId = lastRequestedCharacterId
@@ -707,7 +746,11 @@ class ScanScreenControllerImpl(
 
     override suspend fun characterToNfc(characterId: Long): NfcCharacter {
         lastRequestedCharacterId = characterId
-        val character = ToNfcConverter(componentActivity = componentActivity).characterToNfc(characterId)
+        val character = ToNfcConverter(componentActivity = componentActivity).characterToNfc(
+            characterId = characterId,
+            target = TransferTarget.REAL_BRACELET,
+            transport = TransferTransport.NFCA,
+        )
         Log.d("CharacterType", character.toString())
         return character
     }

app/src/main/java/com/github/nacabaro/vbhelper/screens/scanScreen/converters/FromNfcConverter.kt

@@ -11,6 +11,8 @@ import com.github.nacabaro.vbhelper.domain.device_data.SpecialMissions
 import com.github.nacabaro.vbhelper.domain.device_data.UserCharacter
 import com.github.nacabaro.vbhelper.domain.device_data.VBCharacterData
 import com.github.nacabaro.vbhelper.domain.device_data.VitalsHistory
+import com.github.nacabaro.vbhelper.transfer.CharacterTransferPolicyResolver
+import com.github.nacabaro.vbhelper.transfer.ExportFormat
 import com.github.nacabaro.vbhelper.utils.DeviceType
 import java.util.GregorianCalendar
 
@@ -20,6 +22,7 @@ class FromNfcConverter (
     private val application = componentActivity.applicationContext as VBHelper
     private val database = application.container.db
     private val transferSeenDao = application.container.transferSeenDao
+    private val transferPolicyResolver = CharacterTransferPolicyResolver(database.characterTransferPolicyDao())
 
     
     fun addCharacterUsingCard(
@@ -134,6 +137,18 @@ class FromNfcConverter (
             )
         }
 
+        database
+            .characterTransferPolicyDao()
+            .upsert(
+                transferPolicyResolver.policyForNfcaImport(
+                    characterId = characterId,
+                    observedFormat = when (nfcCharacter) {
+                        is BENfcCharacter -> ExportFormat.BE
+                        else -> ExportFormat.VB
+                    }
+                )
+            )
+
         addTransformationHistoryToDatabase(
             characterId = characterId,
             nfcCharacter = nfcCharacter,

app/src/main/java/com/github/nacabaro/vbhelper/screens/scanScreen/converters/ToNfcConverter.kt

@@ -15,6 +15,10 @@ import com.github.nacabaro.vbhelper.domain.device_data.BECharacterData
 import com.github.nacabaro.vbhelper.domain.device_data.UserCharacter
 import com.github.nacabaro.vbhelper.domain.device_data.VBCharacterData
 import com.github.nacabaro.vbhelper.dtos.CharacterDtos
+import com.github.nacabaro.vbhelper.transfer.CharacterTransferPolicyResolver
+import com.github.nacabaro.vbhelper.transfer.ExportFormat
+import com.github.nacabaro.vbhelper.transfer.TransferTarget
+import com.github.nacabaro.vbhelper.transfer.TransferTransport
 import com.github.nacabaro.vbhelper.utils.DeviceType
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.firstOrNull
@@ -30,11 +34,15 @@ class ToNfcConverter(
 
     private val application: VBHelper = componentActivity.applicationContext as VBHelper
     private val database: AppDatabase = application.container.db
+    private val transferPolicyResolver = CharacterTransferPolicyResolver(database.characterTransferPolicyDao())
 
 
 
     suspend fun characterToNfc(
-        characterId: Long
+        characterId: Long,
+        target: TransferTarget = TransferTarget.REAL_BRACELET,
+        transport: TransferTransport = TransferTransport.NFCA,
+        forcedFormat: ExportFormat? = null,
     ): NfcCharacter {
         val app = componentActivity.applicationContext as VBHelper
         val database = app.container.db
@@ -46,15 +54,20 @@ class ToNfcConverter(
         val characterInfo = database
             .characterDao()
             .getCharacterInfo(userCharacter.charId)
+        val card = database
+            .cardDao()
+            .getCardByCharacterIdSync(characterId)
+            ?: error("Card not found for character $characterId")
 
-        // Use the character's own type as the authoritative signal for encoding.
+        val exportFormat = forcedFormat ?: transferPolicyResolver.resolveExportFormat(
-        // The card's isBEm flag only indicates the *card* is a BEM card, not that the
+            characterId = characterId,
-        // stored UserCharacter has a BECharacterData row.  Mixing those two signals was
+            characterType = userCharacter.characterType,
-        // the root cause of a NoSuchElementException when a VB-type character was
+            transport = transport,
-        // associated with a BE-type card.
+            target = target,
-        val shouldEncodeAsBem = userCharacter.characterType == DeviceType.BEDevice
+            isBemCard = card.isBEm,
+        )
 
-        return if (shouldEncodeAsBem)
+        return if (exportFormat == ExportFormat.BE)
             nfcToBENfc(characterId, characterInfo, userCharacter)
         else
             nfcToVBNfc(characterId, characterInfo, userCharacter)

app/src/main/java/com/github/nacabaro/vbhelper/source/VitalWearCharacterExporter.kt

@@ -3,6 +3,10 @@ package com.github.nacabaro.vbhelper.source
 import com.github.cfogrady.vitalwear.protos.Character
 import com.github.nacabaro.vbhelper.database.AppDatabase
 import com.github.nacabaro.vbhelper.domain.device_data.BECharacterData
+import com.github.nacabaro.vbhelper.transfer.CharacterTransferPolicyResolver
+import com.github.nacabaro.vbhelper.transfer.TransferTarget
+import com.github.nacabaro.vbhelper.transfer.TransferTransport
+import com.github.nacabaro.vbhelper.transfer.toTransferDeviceType
 import com.github.nacabaro.vbhelper.utils.DeviceType
 import kotlinx.coroutines.flow.firstOrNull
 
@@ -30,6 +34,8 @@ internal fun resolveTrainingSeconds(
 class VitalWearCharacterExporter(
     private val database: AppDatabase
 ) {
+    private val transferPolicyResolver = CharacterTransferPolicyResolver(database.characterTransferPolicyDao())
+
     /**
      * Builds a Character proto from the stored character data.
      * Used by the HCE ISO-DEP transfer path.
@@ -44,6 +50,13 @@ class VitalWearCharacterExporter(
         val cardProgress = database.cardProgressDao().getCardProgressSync(card.id) ?: 0
         val beData = database.userCharacterDao().getBeDataOrNull(characterId)
         val vbData = database.userCharacterDao().getVbDataOrNull(characterId)
+        val exportFormat = transferPolicyResolver.resolveExportFormat(
+            characterId = characterId,
+            characterType = userCharacter.characterType,
+            transport = TransferTransport.HCE,
+            target = TransferTarget.VITAL_WEAR,
+            isBemCard = card.isBEm,
+        )
         val normalizedTransformationCountdownMinutes = normalizeTransformationCountdownMinutes(
             transformationCountdownMinutes = userCharacter.transformationCountdown,
             hasPossibleTransformations = hasPossibleTransformations(userCharacter.charId),
@@ -68,7 +81,7 @@ class VitalWearCharacterExporter(
                     .setTotalWins(characterWithSprites.totalBattlesWon)
                     .setCurrentPhaseWins(characterWithSprites.currentPhaseBattlesWon)
                     .setMood(characterWithSprites.mood)
-                    .setDeviceType(userCharacter.characterType.toTransferDeviceType())
+                    .setDeviceType(exportFormat.toTransferDeviceType())
                     .setAgeInDays(userCharacter.ageInDays.coerceAtLeast(0))
                     .setActivityLevel(userCharacter.activityLevel.coerceAtLeast(0))
                     .setHeartRateCurrent(userCharacter.heartRateCurrent.coerceAtLeast(0))

app/src/main/java/com/github/nacabaro/vbhelper/source/VitalWearCharacterImporter.kt

@@ -9,6 +9,8 @@ import com.github.nacabaro.vbhelper.domain.device_data.BECharacterData
 import com.github.nacabaro.vbhelper.domain.device_data.UserCharacter
 import com.github.nacabaro.vbhelper.domain.device_data.VBCharacterData
 import com.github.nacabaro.vbhelper.domain.device_data.VitalWearCharacterSettings
+import com.github.nacabaro.vbhelper.transfer.CharacterTransferPolicyResolver
+import com.github.nacabaro.vbhelper.transfer.ExportFormat
 import com.github.nacabaro.vbhelper.utils.DeviceType
 import kotlinx.coroutines.flow.firstOrNull
 import kotlinx.coroutines.runBlocking
@@ -18,6 +20,8 @@ class VitalWearCharacterImporter(
     private val database: AppDatabase,
     private val transferSeenDao: SharedTransferSeenDao,
 ) {
+    private val transferPolicyResolver = CharacterTransferPolicyResolver(database.characterTransferPolicyDao())
+
     data class ImportResult(
         val success: Boolean,
         val message: String
@@ -58,6 +62,11 @@ class VitalWearCharacterImporter(
             fallbackIsBeCharacter = fallbackIsBeCharacter,
         )
         val isBeCharacter = deviceType == DeviceType.BEDevice
+        val observedImportFormat = resolveObservedHceImportFormat(
+            transferDeviceType = character.characterStats.deviceType,
+            importedCard = importedCard,
+            hasBePayloadStats = hasBePayloadStats,
+        )
 
         val userCharacterId = database.userCharacterDao().insertCharacterData(
             UserCharacter(
@@ -138,6 +147,17 @@ class VitalWearCharacterImporter(
             )
         }
 
+        runBlocking {
+            database.characterTransferPolicyDao().upsert(
+                transferPolicyResolver.policyForHceImport(
+                    characterId = userCharacterId,
+                    importedCardIsBem = importedCard.isBEm,
+                    resolvedDeviceType = deviceType,
+                    observedFormat = observedImportFormat,
+                )
+            )
+        }
+
         val now = System.currentTimeMillis()
         markSeen(importedCard.name, slotId, importedCard.id, now)
 
@@ -270,6 +290,23 @@ class VitalWearCharacterImporter(
         return rarities.getOrElse(rawValue) { resolveDefaultAbilityRarity() }
     }
 
+    private fun resolveObservedHceImportFormat(
+        transferDeviceType: Character.CharacterStats.TransferDeviceType,
+        importedCard: Card,
+        hasBePayloadStats: Boolean,
+    ): ExportFormat {
+        return when (transferDeviceType) {
+            Character.CharacterStats.TransferDeviceType.TRANSFER_DEVICE_TYPE_BE -> ExportFormat.BE
+            Character.CharacterStats.TransferDeviceType.TRANSFER_DEVICE_TYPE_VB -> ExportFormat.VB
+            Character.CharacterStats.TransferDeviceType.UNRECOGNIZED,
+            Character.CharacterStats.TransferDeviceType.TRANSFER_DEVICE_TYPE_UNSPECIFIED -> if (importedCard.isBEm || hasBePayloadStats) {
+                ExportFormat.BE
+            } else {
+                ExportFormat.VB
+            }
+        }
+    }
+
     private fun markSeen(cardName: String, slotId: Int, cardId: Long, timestamp: Long) {
         database.dexDao().insertCharacter(slotId, cardId, timestamp)
         transferSeenDao.markSeen(cardName, slotId, timestamp)

app/src/main/java/com/github/nacabaro/vbhelper/transfer/CharacterTransferPolicyResolver.kt

@@ -0,0 +1,112 @@
+package com.github.nacabaro.vbhelper.transfer
+
+import com.github.nacabaro.vbhelper.daos.CharacterTransferPolicyDao
+import com.github.nacabaro.vbhelper.domain.device_data.CharacterTransferPolicy
+import com.github.nacabaro.vbhelper.utils.DeviceType
+
+class CharacterTransferPolicyResolver(
+    private val policyDao: CharacterTransferPolicyDao,
+) {
+    fun resolveExportFormat(
+        characterId: Long,
+        characterType: DeviceType,
+        transport: TransferTransport,
+        target: TransferTarget,
+        isBemCard: Boolean,
+    ): ExportFormat {
+        val policy = policyDao.getByCharacterId(characterId)
+        return when (transport) {
+            TransferTransport.HCE -> policy?.preferredHceExportFormat
+                ?: defaultHceExportFormat(characterType, isBemCard, target)
+            TransferTransport.NFCA -> policy?.preferredNfcaExportFormat
+                ?: defaultNfcaExportFormat(characterType, isBemCard, target)
+        }
+    }
+
+    fun policyForNfcaImport(
+        characterId: Long,
+        observedFormat: ExportFormat,
+    ): CharacterTransferPolicy {
+        val nativeDeviceType = observedFormat.toNativeDeviceType()
+        return CharacterTransferPolicy(
+            characterId = characterId,
+            nativeDeviceType = nativeDeviceType,
+            preferredHceExportFormat = defaultHceExportFormat(nativeDeviceType, nativeDeviceType == DeviceType.BEDevice, TransferTarget.VITAL_WEAR),
+            preferredNfcaExportFormat = observedFormat,
+            lastObservedImportFormat = observedFormat,
+            lastTransferTransport = TransferTransport.NFCA,
+            lastTransferTarget = TransferTarget.REAL_BRACELET,
+            preserveVbRoundTrip = observedFormat == ExportFormat.VB,
+            preserveBeRoundTrip = observedFormat == ExportFormat.BE,
+        )
+    }
+
+    fun policyForHceImport(
+        characterId: Long,
+        importedCardIsBem: Boolean,
+        resolvedDeviceType: DeviceType,
+        observedFormat: ExportFormat,
+    ): CharacterTransferPolicy {
+        val nativeDeviceType = when {
+            importedCardIsBem -> DeviceType.BEDevice
+            resolvedDeviceType == DeviceType.BEDevice && observedFormat == ExportFormat.BE -> DeviceType.VBDevice
+            resolvedDeviceType == DeviceType.VitalWear -> DeviceType.VBDevice
+            else -> resolvedDeviceType
+        }
+        val preferredNfcaExportFormat = if (importedCardIsBem || nativeDeviceType == DeviceType.BEDevice) {
+            ExportFormat.BE
+        } else {
+            ExportFormat.VB
+        }
+
+        return CharacterTransferPolicy(
+            characterId = characterId,
+            nativeDeviceType = nativeDeviceType,
+            preferredHceExportFormat = defaultHceExportFormat(nativeDeviceType, importedCardIsBem, TransferTarget.VITAL_WEAR),
+            preferredNfcaExportFormat = preferredNfcaExportFormat,
+            lastObservedImportFormat = observedFormat,
+            lastTransferTransport = TransferTransport.HCE,
+            lastTransferTarget = TransferTarget.VITAL_WEAR,
+            preserveVbRoundTrip = preferredNfcaExportFormat == ExportFormat.VB,
+            preserveBeRoundTrip = importedCardIsBem || observedFormat == ExportFormat.BE,
+        )
+    }
+
+    private fun defaultHceExportFormat(
+        characterType: DeviceType,
+        isBemCard: Boolean,
+        target: TransferTarget,
+    ): ExportFormat {
+        if (target != TransferTarget.VITAL_WEAR) {
+            return defaultNfcaExportFormat(characterType, isBemCard, target)
+        }
+
+        // VitalWear is the HCE endpoint. Default to BE projection so HCE transfers can carry the
+        // richer payload, while NFCA policy still controls what is sent back to real bracelets.
+        return ExportFormat.BE
+    }
+
+    private fun defaultNfcaExportFormat(
+        characterType: DeviceType,
+        isBemCard: Boolean,
+        target: TransferTarget,
+    ): ExportFormat {
+        require(target == TransferTarget.REAL_BRACELET) {
+            "NFCA exports are only supported for real bracelets."
+        }
+        return if (isBemCard || characterType == DeviceType.BEDevice) {
+            ExportFormat.BE
+        } else {
+            ExportFormat.VB
+        }
+    }
+
+    private fun ExportFormat.toNativeDeviceType(): DeviceType {
+        return when (this) {
+            ExportFormat.BE -> DeviceType.BEDevice
+            ExportFormat.VB -> DeviceType.VBDevice
+        }
+    }
+}
+
+

app/src/main/java/com/github/nacabaro/vbhelper/transfer/TransferRoute.kt

@@ -0,0 +1,31 @@
+package com.github.nacabaro.vbhelper.transfer
+
+import com.github.cfogrady.vitalwear.protos.Character
+
+/**
+ * Real bracelets talk over NFC-A while VitalWear uses HCE / ISO-DEP.
+ * Keep transport, target, and payload format separate so one canonical character can be
+ * projected differently depending on where it is being transferred.
+ */
+enum class TransferTransport {
+    NFCA,
+    HCE,
+}
+
+enum class TransferTarget {
+    REAL_BRACELET,
+    VITAL_WEAR,
+}
+
+enum class ExportFormat {
+    VB,
+    BE,
+}
+
+fun ExportFormat.toTransferDeviceType(): Character.CharacterStats.TransferDeviceType {
+    return when (this) {
+        ExportFormat.VB -> Character.CharacterStats.TransferDeviceType.TRANSFER_DEVICE_TYPE_VB
+        ExportFormat.BE -> Character.CharacterStats.TransferDeviceType.TRANSFER_DEVICE_TYPE_BE
+    }
+}
+