fix: use fast fee for savings transfer

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

@@ -46,6 +46,7 @@ import org.lightningdevkit.ldknode.ChannelConfig
 import org.lightningdevkit.ldknode.ChannelDataMigration
 import org.lightningdevkit.ldknode.ChannelDetails
 import org.lightningdevkit.ldknode.ClosureReason
+import org.lightningdevkit.ldknode.CoinSelectionAlgorithm
 import org.lightningdevkit.ldknode.Event
 import org.lightningdevkit.ldknode.NodeStatus
 import org.lightningdevkit.ldknode.PaymentDetails
@@ -1262,6 +1263,20 @@ class LightningRepo @Inject constructor(
         lightningService.listSpendableOutputs()
     }
 
+    suspend fun selectUtxosWithAlgorithm(
+        targetAmountSats: ULong,
+        satsPerVByte: ULong,
+        algorithm: CoinSelectionAlgorithm = CoinSelectionAlgorithm.LARGEST_FIRST,
+        utxos: List<SpendableUtxo>? = null,
+    ): Result<List<SpendableUtxo>> = executeWhenNodeRunning("selectUtxosWithAlgorithm") {
+        lightningService.selectUtxosWithAlgorithm(
+            targetAmountSats = targetAmountSats,
+            satsPerVByte = satsPerVByte,
+            algorithm = algorithm,
+            utxos = utxos,
+        )
+    }
+
     suspend fun calculateTotalFee(
         amountSats: ULong,
         address: Address? = null,

app/src/main/java/to/bitkit/ui/screens/transfer/SpendingConfirmScreen.kt

@@ -17,6 +17,7 @@ import androidx.compose.foundation.layout.statusBarsPadding
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -44,9 +45,9 @@ import com.synonym.bitkitcore.IBtOnchainTransactions
 import com.synonym.bitkitcore.IBtOrder
 import com.synonym.bitkitcore.IBtPayment
 import com.synonym.bitkitcore.ILspNode
-import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import to.bitkit.R
+import to.bitkit.models.safe
 import to.bitkit.ui.components.ButtonSize
 import to.bitkit.ui.components.ChannelStatusUi
 import to.bitkit.ui.components.ConnectionIssuesView
@@ -91,6 +92,12 @@ fun SpendingConfirmScreen(
         return
     }
     val isAdvanced = state.isAdvanced
+    val miningFeeSats = state.miningFeeSats
+    val isConfirmFeeReady = state.isConfirmFeeReady
+
+    LaunchedEffect(order.id, order.feeSat) {
+        viewModel.prepareSpendingConfirmFunding(order)
+    }
 
     val notificationsGranted by settingsViewModel.notificationsGranted.collectAsStateWithLifecycle()
 
@@ -116,6 +123,8 @@ fun SpendingConfirmScreen(
             onUseDefaultLspBalanceClick = viewModel::onUseDefaultLspBalanceClick,
             onTransferToSpendingConfirm = viewModel::onTransferToSpendingConfirm,
             order = order,
+            miningFeeSats = miningFeeSats,
+            isConfirmFeeReady = isConfirmFeeReady,
             hasNotificationPermission = notificationsGranted,
             onSwitchClick = onNotificationSwitchClick,
             isAdvanced = isAdvanced,
@@ -133,7 +142,7 @@ fun SpendingConfirmScreen(
     }
 }
 
-@Suppress("MagicNumber")
+@Suppress("MagicNumber", "LongMethod")
 @Composable
 private fun Content(
     onBackClick: () -> Unit,
@@ -143,8 +152,10 @@ private fun Content(
     onUseDefaultLspBalanceClick: () -> Unit,
     onSwitchClick: () -> Unit,
     hasNotificationPermission: Boolean,
-    onTransferToSpendingConfirm: (IBtOrder) -> Unit,
+    onTransferToSpendingConfirm: suspend (IBtOrder) -> Boolean,
     order: IBtOrder,
+    miningFeeSats: ULong,
+    isConfirmFeeReady: Boolean,
     isAdvanced: Boolean,
 ) {
     val scope = rememberCoroutineScope()
@@ -175,10 +186,10 @@ private fun Content(
                     .fillMaxSize()
                     .verticalScroll(rememberScrollState())
             ) {
+                // Match iOS SpendingConfirm: network fee = mining fee, lsp fee = order fee - client.
                 val clientBalance = order.clientBalanceSat
-                val networkFee = order.networkFeeSat
-                val serviceFee = order.serviceFeeSat
-                val totalFee = order.feeSat
+                val lspFee = order.feeSat.safe() - clientBalance.safe()
+                val total = order.feeSat.safe() + miningFeeSats.safe()
                 val lspBalance = order.lspBalanceSat
 
                 VerticalSpacer(32.dp)
@@ -191,11 +202,11 @@ private fun Content(
                 ) {
                     FeeInfo(
                         label = stringResource(R.string.lightning__spending_confirm__network_fee),
-                        amount = networkFee.toLong(),
+                        amount = miningFeeSats.toLong(),
                     )
                     FeeInfo(
                         label = stringResource(R.string.lightning__spending_confirm__lsp_fee),
-                        amount = serviceFee.toLong(),
+                        amount = lspFee.toLong(),
                     )
                 }
                 Row(
@@ -208,7 +219,7 @@ private fun Content(
                     )
                     FeeInfo(
                         label = stringResource(R.string.lightning__spending_confirm__total),
-                        amount = totalFee.toLong(),
+                        amount = total.toLong(),
                     )
                 }
 
@@ -268,16 +279,22 @@ private fun Content(
                 FillHeight()
 
                 var isLoading by remember { mutableStateOf(false) }
+                // Match iOS: keep swipe in loading state until mining fee is ready.
+                val canConfirm = isConfirmFeeReady && miningFeeSats > 0uL && !isLoading
                 SwipeToConfirm(
                     text = stringResource(R.string.lightning__transfer__swipe),
-                    loading = isLoading,
+                    loading = isLoading || !isConfirmFeeReady,
                     color = Colors.Purple,
                     onConfirm = {
+                        if (!canConfirm) return@SwipeToConfirm
                         scope.launch {
                             isLoading = true
-                            delay(300)
-                            onTransferToSpendingConfirm(order)
-                            onConfirm()
+                            val paid = onTransferToSpendingConfirm(order)
+                            if (paid) {
+                                onConfirm()
+                            } else {
+                                isLoading = false
+                            }
                         }
                     },
                 )
@@ -297,7 +314,7 @@ private fun Preview() {
             onAdvancedClick = {},
             onConfirm = {},
             onUseDefaultLspBalanceClick = {},
-            onTransferToSpendingConfirm = {},
+            onTransferToSpendingConfirm = { true },
             order = IBtOrder(
                 id = "order_7e6f3b7c-486a-4f5a-8b1e-2c9d7f0a8b9d",
                 state = BtOrderState.CREATED,
@@ -359,6 +376,8 @@ private fun Preview() {
             ),
             onSwitchClick = {},
             hasNotificationPermission = true,
+            miningFeeSats = 250uL,
+            isConfirmFeeReady = true,
             isAdvanced = false
         )
     }
@@ -374,7 +393,7 @@ private fun Preview2() {
             onAdvancedClick = {},
             onConfirm = {},
             onUseDefaultLspBalanceClick = {},
-            onTransferToSpendingConfirm = {},
+            onTransferToSpendingConfirm = { true },
             order = IBtOrder(
                 id = "order_7e6f3b7c-486a-4f5a-8b1e-2c9d7f0a8b9d",
                 state = BtOrderState.CREATED,
@@ -436,6 +455,8 @@ private fun Preview2() {
             ),
             onSwitchClick = {},
             hasNotificationPermission = true,
+            miningFeeSats = 250uL,
+            isConfirmFeeReady = true,
             isAdvanced = true
         )
     }
@@ -451,7 +472,7 @@ private fun Preview3() {
             onAdvancedClick = {},
             onConfirm = {},
             onUseDefaultLspBalanceClick = {},
-            onTransferToSpendingConfirm = {},
+            onTransferToSpendingConfirm = { true },
             order = IBtOrder(
                 id = "order_7e6f3b7c-486a-4f5a-8b1e-2c9d7f0a8b9d",
                 state = BtOrderState.CREATED,
@@ -513,6 +534,8 @@ private fun Preview3() {
             ),
             onSwitchClick = {},
             hasNotificationPermission = false,
+            miningFeeSats = 250uL,
+            isConfirmFeeReady = true,
             isAdvanced = false
         )
     }
@@ -528,7 +551,7 @@ private fun Preview4() {
             onAdvancedClick = {},
             onConfirm = {},
             onUseDefaultLspBalanceClick = {},
-            onTransferToSpendingConfirm = {},
+            onTransferToSpendingConfirm = { true },
             order = IBtOrder(
                 id = "order_7e6f3b7c-486a-4f5a-8b1e-2c9d7f0a8b9d",
                 state = BtOrderState.CREATED,
@@ -590,6 +613,8 @@ private fun Preview4() {
             ),
             onSwitchClick = {},
             hasNotificationPermission = true,
+            miningFeeSats = 250uL,
+            isConfirmFeeReady = true,
             isAdvanced = true
         )
     }