fix: handle counterparty channel closes

app/src/main/java/to/bitkit/ext/PendingSweepBalance.kt

@@ -0,0 +1,19 @@
+package to.bitkit.ext
+
+import org.lightningdevkit.ldknode.PendingSweepBalance
+
+fun PendingSweepBalance.channelId(): String? {
+    return when (this) {
+        is PendingSweepBalance.PendingBroadcast -> this.channelId
+        is PendingSweepBalance.BroadcastAwaitingConfirmation -> this.channelId
+        is PendingSweepBalance.AwaitingThresholdConfirmations -> this.channelId
+    }
+}
+
+fun PendingSweepBalance.latestSpendingTxid(): String? {
+    return when (this) {
+        is PendingSweepBalance.PendingBroadcast -> null
+        is PendingSweepBalance.BroadcastAwaitingConfirmation -> this.latestSpendingTxid
+        is PendingSweepBalance.AwaitingThresholdConfirmations -> this.latestSpendingTxid
+    }
+}

app/src/main/java/to/bitkit/repositories/TransferRepo.kt

@@ -1,15 +1,21 @@
 package to.bitkit.repositories
 
+import com.synonym.bitkitcore.Activity
+import com.synonym.bitkitcore.ActivityFilter
+import com.synonym.bitkitcore.SortDirection
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.withContext
 import org.lightningdevkit.ldknode.ChannelDetails
+import org.lightningdevkit.ldknode.PendingSweepBalance
 import to.bitkit.data.dao.TransferDao
 import to.bitkit.data.entities.TransferEntity
 import to.bitkit.di.BgDispatcher
 import to.bitkit.ext.channelId
+import to.bitkit.ext.latestSpendingTxid
 import to.bitkit.models.TransferType
+import to.bitkit.services.CoreService
 import to.bitkit.utils.Logger
 import java.util.UUID
 import javax.inject.Inject
@@ -23,6 +29,7 @@ class TransferRepo @Inject constructor(
     @BgDispatcher private val bgDispatcher: CoroutineDispatcher,
     private val lightningRepo: LightningRepo,
     private val blocktankRepo: BlocktankRepo,
+    private val coreService: CoreService,
     private val transferDao: TransferDao,
     private val clock: Clock,
 ) {
@@ -98,8 +105,15 @@ class TransferRepo @Inject constructor(
                 } ?: false
 
                 if (!hasBalance) {
-                    markSettled(transfer.id)
-                    Logger.debug("Channel $channelId balance swept, settled transfer: ${transfer.id}", context = TAG)
+                    if (transfer.type == TransferType.FORCE_CLOSE) {
+                        settleForceClose(transfer, channelId, balances?.pendingBalancesFromChannelClosures)
+                    } else {
+                        markSettled(transfer.id)
+                        Logger.debug(
+                            "Channel $channelId balance swept, settled transfer: ${transfer.id}",
+                            context = TAG
+                        )
+                    }
                 }
             }
         }.onSuccess {
@@ -109,6 +123,72 @@ class TransferRepo @Inject constructor(
         }
     }
 
+    private suspend fun settleForceClose(
+        transfer: TransferEntity,
+        channelId: String?,
+        pendingSweeps: List<PendingSweepBalance>?,
+    ) {
+        if (channelId == null) return
+
+        if (coreService.activity.hasOnchainActivityForChannel(channelId)) {
+            markActivityAsTransferByChannel(channelId)
+            markSettled(transfer.id)
+            Logger.debug("Force close sweep detected, settled transfer: ${transfer.id}", context = TAG)
+            return
+        }
+
+        // When LDK batches sweeps from multiple channels into one transaction,
+        // the on-chain activity may only be linked to one channel. Fall back to
+        // checking if there are no remaining pending sweep balances for this channel.
+        val pendingSweep = pendingSweeps?.find { it.channelId() == channelId }
+
+        if (pendingSweep == null) {
+            markSettled(transfer.id)
+            Logger.debug(
+                "Force close sweep completed (no pending sweeps), settled transfer: ${transfer.id}",
+                context = TAG,
+            )
+            return
+        }
+
+        val sweepTxid = pendingSweep.latestSpendingTxid()
+        if (sweepTxid != null && coreService.activity.hasOnchainActivityForTxid(sweepTxid)) {
+            // The sweep tx was already synced as an on-chain activity (linked to another
+            // channel in the same batched sweep). Safe to settle this transfer.
+            markActivityAsTransfer(sweepTxid, channelId)
+            markSettled(transfer.id)
+            Logger.debug(
+                "Force close batched sweep detected via txid $sweepTxid, settled transfer: ${transfer.id}",
+                context = TAG,
+            )
+            return
+        }
+
+        Logger.debug("Force close awaiting sweep detection for transfer: ${transfer.id}", context = TAG)
+    }
+
+    private suspend fun markActivityAsTransfer(txid: String, channelId: String) {
+        val activity = coreService.activity.getOnchainActivityByTxId(txid) ?: return
+        if (activity.isTransfer) return
+        val updated = activity.copy(isTransfer = true, channelId = channelId)
+        coreService.activity.update(activity.id, Activity.Onchain(updated))
+        Logger.debug("Marked activity ${activity.id} as transfer for channel $channelId", context = TAG)
+    }
+
+    private suspend fun markActivityAsTransferByChannel(channelId: String) {
+        val activities = coreService.activity.get(
+            filter = ActivityFilter.ONCHAIN,
+            limit = 50u,
+            sortDirection = SortDirection.DESC,
+        )
+        val activity = activities.firstOrNull { it is Activity.Onchain && it.v1.channelId == channelId }
+            as? Activity.Onchain ?: return
+        if (activity.v1.isTransfer) return
+        val updated = activity.v1.copy(isTransfer = true, channelId = channelId)
+        coreService.activity.update(activity.v1.id, Activity.Onchain(updated))
+        Logger.debug("Marked activity ${activity.v1.id} as transfer for channel $channelId", context = TAG)
+    }
+
     /** Resolve channelId: for LSP orders: via order->fundingTx match, for manual: directly. */
     suspend fun resolveChannelIdForTransfer(
         transfer: TransferEntity,

app/src/main/java/to/bitkit/services/CoreService.kt

@@ -283,6 +283,14 @@ class ActivityService(
         getActivityByTxId(txId = txId)
     }
 
+    suspend fun hasOnchainActivityForChannel(channelId: String): Boolean {
+        val activities = get(filter = ActivityFilter.ONCHAIN, limit = 50u, sortDirection = SortDirection.DESC)
+        return activities.any { it is Activity.Onchain && it.v1.channelId == channelId }
+    }
+
+    suspend fun hasOnchainActivityForTxid(txid: String): Boolean =
+        getOnchainActivityByTxId(txid) != null
+
     @Suppress("LongParameterList")
     suspend fun get(
         filter: ActivityFilter? = null,

app/src/main/java/to/bitkit/ui/ContentView.kt

@@ -171,6 +171,7 @@ import to.bitkit.ui.settings.transactionSpeed.TransactionSpeedSettingsScreen
 import to.bitkit.ui.sheets.BackgroundPaymentsIntroSheet
 import to.bitkit.ui.sheets.BackupRoute
 import to.bitkit.ui.sheets.BackupSheet
+import to.bitkit.ui.sheets.ConnectionClosedSheet
 import to.bitkit.ui.sheets.ForceTransferSheet
 import to.bitkit.ui.sheets.GiftSheet
 import to.bitkit.ui.sheets.HighBalanceWarningSheet
@@ -413,6 +414,10 @@ fun ContentView(
                             onCancel = { appViewModel.hideSheet() },
                         )
 
+                        Sheet.ConnectionClosed -> ConnectionClosedSheet(
+                            onDismiss = { appViewModel.hideSheet() },
+                        )
+
                         is Sheet.Gift -> GiftSheet(sheet, appViewModel)
                         is Sheet.TimedSheet -> {
                             when (sheet.type) {

app/src/main/java/to/bitkit/ui/components/SheetHost.kt

@@ -46,6 +46,7 @@ sealed interface Sheet {
     data object ForceTransfer : Sheet
     data class Gift(val code: String, val amount: ULong) : Sheet
     data object SweepPrompt : Sheet
+    data object ConnectionClosed : Sheet
 
     data class TimedSheet(val type: TimedSheetType) : Sheet
 }

app/src/main/java/to/bitkit/ui/sheets/ConnectionClosedSheet.kt

@@ -0,0 +1,92 @@
+package to.bitkit.ui.sheets
+
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.navigationBarsPadding
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.testTag
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import to.bitkit.R
+import to.bitkit.ui.components.BodyM
+import to.bitkit.ui.components.BottomSheetPreview
+import to.bitkit.ui.components.PrimaryButton
+import to.bitkit.ui.components.VerticalSpacer
+import to.bitkit.ui.scaffold.SheetTopBar
+import to.bitkit.ui.shared.modifiers.sheetHeight
+import to.bitkit.ui.shared.util.gradientBackground
+import to.bitkit.ui.theme.AppThemeSurface
+import to.bitkit.ui.theme.Colors
+
+@Composable
+fun ConnectionClosedSheet(
+    onDismiss: () -> Unit,
+) {
+    Content(onDismiss = onDismiss)
+}
+
+@Composable
+private fun Content(
+    modifier: Modifier = Modifier,
+    onDismiss: () -> Unit = {},
+) {
+    Column(
+        modifier = modifier
+            .sheetHeight()
+            .gradientBackground()
+            .navigationBarsPadding()
+            .padding(horizontal = 16.dp)
+            .testTag("ConnectionClosedSheet")
+    ) {
+        SheetTopBar(titleText = stringResource(R.string.lightning__connection_closed__title))
+
+        BodyM(
+            text = stringResource(R.string.lightning__connection_closed__description),
+            color = Colors.White64,
+            modifier = Modifier.fillMaxWidth()
+        )
+
+        Box(
+            contentAlignment = Alignment.Center,
+            modifier = Modifier
+                .fillMaxWidth()
+                .weight(1f)
+        ) {
+            Image(
+                painter = painterResource(R.drawable.switch_box),
+                contentDescription = null,
+                contentScale = ContentScale.Fit,
+                modifier = Modifier.size(256.dp)
+            )
+        }
+
+        PrimaryButton(
+            text = stringResource(R.string.common__ok),
+            onClick = onDismiss,
+            modifier = Modifier
+                .fillMaxWidth()
+                .testTag("ConnectionClosedButton")
+        )
+
+        VerticalSpacer(16.dp)
+    }
+}
+
+@Preview(showSystemUi = true)
+@Composable
+private fun Preview() {
+    AppThemeSurface {
+        BottomSheetPreview {
+            Content()
+        }
+    }
+}

app/src/main/java/to/bitkit/viewmodels/AppViewModel.kt

@@ -22,6 +22,7 @@ import com.synonym.bitkitcore.LnurlWithdrawData
 import com.synonym.bitkitcore.OnChainInvoice
 import com.synonym.bitkitcore.PaymentType
 import com.synonym.bitkitcore.Scanner
+import com.synonym.bitkitcore.SortDirection
 import com.synonym.bitkitcore.validateBitcoinAddress
 import dagger.hilt.android.lifecycle.HiltViewModel
 import dagger.hilt.android.qualifiers.ApplicationContext
@@ -47,6 +48,7 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlinx.coroutines.withTimeout
 import org.lightningdevkit.ldknode.ChannelDataMigration
+import org.lightningdevkit.ldknode.ClosureReason
 import org.lightningdevkit.ldknode.Event
 import org.lightningdevkit.ldknode.PaymentFailureReason
 import org.lightningdevkit.ldknode.PaymentId
@@ -65,6 +67,8 @@ import to.bitkit.env.Defaults
 import to.bitkit.env.Env
 import to.bitkit.ext.WatchResult
 import to.bitkit.ext.amountOnClose
+import to.bitkit.ext.amountSats
+import to.bitkit.ext.channelId
 import to.bitkit.ext.getClipboardText
 import to.bitkit.ext.getSatsPerVByteFor
 import to.bitkit.ext.maxSendableSat
@@ -85,6 +89,7 @@ import to.bitkit.models.NewTransactionSheetType
 import to.bitkit.models.Suggestion
 import to.bitkit.models.Toast
 import to.bitkit.models.TransactionSpeed
+import to.bitkit.models.TransferType
 import to.bitkit.models.safe
 import to.bitkit.models.toActivityFilter
 import to.bitkit.models.toLdkNetwork
@@ -319,7 +324,7 @@ class AppViewModel @Inject constructor(
             runCatching {
                 when (event) {
                     is Event.BalanceChanged -> handleBalanceChanged()
-                    is Event.ChannelClosed -> handleChannelClosed()
+                    is Event.ChannelClosed -> handleChannelClosed(event)
                     is Event.ChannelPending -> handleChannelPending()
                     is Event.ChannelReady -> handleChannelReady(event)
                     is Event.OnchainTransactionConfirmed -> handleOnchainTransactionConfirmed(event)
@@ -357,11 +362,54 @@ class AppViewModel @Inject constructor(
 
     private suspend fun handleChannelPending() = transferRepo.syncTransferStates()
 
-    private suspend fun handleChannelClosed() {
+    private suspend fun handleChannelClosed(event: Event.ChannelClosed) {
+        val reason = event.reason
+        if (reason != null) {
+            val (isCounterpartyClose, isForceClose) = classifyClosureReason(reason)
+            if (isCounterpartyClose) {
+                createTransferForCounterpartyClose(event.channelId, isForceClose)
+                showSheet(Sheet.ConnectionClosed)
+            }
+        }
         transferRepo.syncTransferStates()
         walletRepo.syncBalances()
     }
 
+    private suspend fun createTransferForCounterpartyClose(channelId: String, isForceClose: Boolean) {
+        val transferType = if (isForceClose) TransferType.FORCE_CLOSE else TransferType.COOP_CLOSE
+
+        val balances = lightningRepo.getBalancesAsync().getOrNull()
+        val lightningBalance = balances?.lightningBalances?.find { it.channelId() == channelId }
+        var channelBalance = lightningBalance?.amountSats() ?: 0uL
+
+        if (channelBalance == 0uL) {
+            val closedChannels = runCatching {
+                coreService.activity.closedChannels(SortDirection.DESC)
+            }.getOrNull()
+            channelBalance = closedChannels
+                ?.firstOrNull { it.channelId == channelId }
+                ?.channelValueSats ?: 0uL
+        }
+
+        if (channelBalance > 0uL) {
+            transferRepo.createTransfer(
+                type = transferType,
+                amountSats = channelBalance.toLong(),
+                channelId = channelId,
+            )
+        }
+    }
+
+    private fun classifyClosureReason(reason: ClosureReason): Pair<Boolean, Boolean> {
+        return when (reason) {
+            is ClosureReason.CounterpartyForceClosed -> true to true
+            is ClosureReason.CommitmentTxConfirmed -> true to true
+            is ClosureReason.CounterpartyInitiatedCooperativeClosure -> true to false
+            is ClosureReason.CounterpartyCoopClosedUnfundedChannel -> true to false
+            else -> false to false
+        }
+    }
+
     private suspend fun handleSyncCompleted() {
         val isShowingLoading = migrationService.isShowingMigrationLoading.value
         val isRestoringRemote = migrationService.isRestoringFromRNRemoteBackup.value
@@ -2230,7 +2278,6 @@ class AppViewModel @Inject constructor(
     }
 
     // TODO Temporary fix while these schemes can't be decoded https://github.com/synonymdev/bitkit-core/issues/70
-    @Suppress("SpellCheckingInspection")
     private fun String.removeLightningSchemes(): String {
         return this
             .replace(Regex("^lightning:", RegexOption.IGNORE_CASE), "")

app/src/main/res/values/strings.xml

@@ -111,6 +111,8 @@
     <string name="lightning__conn_open">Open connections</string>
     <string name="lightning__conn_pending">Pending connections</string>
     <string name="lightning__connection">Connection</string>
+    <string name="lightning__connection_closed__description">The funds on your spending balance have been transferred to your savings.</string>
+    <string name="lightning__connection_closed__title">Connection Closed</string>
     <string name="lightning__connections">Lightning Connections</string>
     <string name="lightning__created_on">Created on</string>
     <string name="lightning__error_add">Bitkit could not add the Lightning peer.</string>