Handle exception on ton fee estimation

app/src/main/java/io/horizontalsystems/bankwallet/modules/fee/FeeCell.kt

@@ -64,7 +64,7 @@ fun FeeCell(
 
         Spacer(Modifier.weight(1f))
 
-        Box(contentAlignment = Alignment.Center) {
+        Box(contentAlignment = Alignment.CenterEnd) {
             if (viewState == ViewState.Loading) {
                 CircularProgressIndicator(
                     modifier = Modifier.size(16.dp),

app/src/main/java/io/horizontalsystems/bankwallet/modules/fee/HSFeeInput.kt

@@ -23,7 +23,8 @@ fun HSFee(
     fee: BigDecimal?,
     amountInputType: AmountInputType,
     rate: CurrencyValue?,
-    navController: NavController
+    navController: NavController,
+    viewState: ViewState? = null
 ) {
     CellUniversalLawrenceSection(
         listOf {
@@ -33,7 +34,8 @@ fun HSFee(
                 fee = fee,
                 amountInputType = amountInputType,
                 rate = rate,
-                navController = navController
+                navController = navController,
+                viewState = viewState
             )
         })
 }
@@ -47,7 +49,8 @@ fun HSFeeRaw(
     fee: BigDecimal?,
     amountInputType: AmountInputType,
     rate: CurrencyValue?,
-    navController: NavController
+    navController: NavController,
+    viewState: ViewState? = null
 ) {
 
     var formatted by remember { mutableStateOf<FeeItem?>(null) }
@@ -60,7 +63,7 @@ fun HSFeeRaw(
         title = title,
         info = info,
         value = formatted,
-        viewState = null,
+        viewState = viewState,
         navController = navController
     )
 }

app/src/main/java/io/horizontalsystems/bankwallet/modules/send/ton/SendTonFeeService.kt

@@ -2,67 +2,97 @@ package io.horizontalsystems.bankwallet.modules.send.ton
 
 import io.horizontalsystems.bankwallet.core.ISendTonAdapter
 import io.horizontalsystems.tonkit.FriendlyAddress
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.ensureActive
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
 import java.math.BigDecimal
 
-class SendTonFeeService(private val adapter: ISendTonAdapter) {
+class SendTonFeeService(private val adapter: ISendTonAdapter) : AutoCloseable {
     private var memo: String? = null
     private var address: FriendlyAddress? = null
     private var amount: BigDecimal? = null
 
     private var fee: BigDecimal? = null
+    private var inProgress = false
     private val _stateFlow = MutableStateFlow(
         State(
-            fee = fee
+            fee = fee,
+            inProgress = inProgress
         )
     )
     val stateFlow = _stateFlow.asStateFlow()
+    private val coroutineScope = CoroutineScope(Dispatchers.Default)
+    private var estimateFeeJob: Job? = null
 
-    private suspend fun refreshFee() {
+    private fun refreshFeeAndEmitState() {
         val amount = amount
         val address = address
         val memo = memo
 
-        fee = if (amount != null && address != null) {
-            adapter.estimateFee(amount, address, memo)
-        } else {
-            null
+        estimateFeeJob?.cancel()
+        estimateFeeJob = coroutineScope.launch {
+            if (amount != null && address != null) {
+                inProgress = true
+                emitState()
+
+                delay(1000)
+                ensureActive()
+                try {
+                    fee = adapter.estimateFee(amount, address, memo)
+                } catch (e: Throwable) {
+                    delay(500)
+                    refreshFeeAndEmitState()
+                }
+            } else {
+                fee = null
+            }
+
+            inProgress = false
+            emitState()
         }
     }
 
-    suspend fun setAmount(amount: BigDecimal?) {
+    fun setAmount(amount: BigDecimal?) {
         this.amount = amount
 
-        refreshFee()
-        emitState()
+        refreshFeeAndEmitState()
     }
 
-    suspend fun setTonAddress(address: FriendlyAddress?) {
+    fun setTonAddress(address: FriendlyAddress?) {
         this.address = address
 
-        refreshFee()
-        emitState()
+        refreshFeeAndEmitState()
     }
 
-    suspend fun setMemo(memo: String?) {
+    fun setMemo(memo: String?) {
         this.memo = memo
 
-        refreshFee()
-        emitState()
+        refreshFeeAndEmitState()
     }
 
     private fun emitState() {
         _stateFlow.update {
             State(
-                fee = fee
+                fee = fee,
+                inProgress = inProgress
             )
         }
     }
 
 
     data class State(
-        val fee: BigDecimal?
+        val fee: BigDecimal?,
+        val inProgress: Boolean
     )
+
+    override fun close() {
+        coroutineScope.cancel()
+    }
 }

app/src/main/java/io/horizontalsystems/bankwallet/modules/send/ton/SendTonScreen.kt

@@ -14,6 +14,7 @@ import androidx.navigation.NavController
 import io.horizontalsystems.bankwallet.R
 import io.horizontalsystems.bankwallet.core.slideFromRight
 import io.horizontalsystems.bankwallet.entities.Address
+import io.horizontalsystems.bankwallet.entities.ViewState
 import io.horizontalsystems.bankwallet.modules.address.AddressParserModule
 import io.horizontalsystems.bankwallet.modules.address.AddressParserViewModel
 import io.horizontalsystems.bankwallet.modules.address.HSAddressInput
@@ -47,6 +48,7 @@ fun SendTonScreen(
     val amountCaution = uiState.amountCaution
     val proceedEnabled = uiState.canBeSend
     val fee = uiState.fee
+    val feeInProgress = uiState.feeInProgress
     val amountInputType = amountInputModeViewModel.inputType
 
     val paymentAddressViewModel = viewModel<AddressParserViewModel>(
@@ -122,7 +124,8 @@ fun SendTonScreen(
                 fee = fee,
                 amountInputType = amountInputType,
                 rate = viewModel.feeCoinRate,
-                navController = navController
+                navController = navController,
+                viewState = if (feeInProgress) ViewState.Loading else null
             )
 
             ButtonPrimaryYellow(

app/src/main/java/io/horizontalsystems/bankwallet/modules/send/ton/SendTonViewModel.kt

@@ -57,6 +57,8 @@ class SendTonViewModel(
     private val logger: AppLogger = AppLogger("send-ton")
 
     init {
+        addCloseable(feeService)
+
         viewModelScope.launch(Dispatchers.Default) {
             amountService.stateFlow.collect {
                 handleUpdatedAmountState(it)
@@ -91,6 +93,7 @@ class SendTonViewModel(
         canBeSend = amountState.canBeSend && addressState.canBeSend,
         showAddressInput = showAddressInput,
         fee = feeState.fee,
+        feeInProgress = feeState.inProgress,
     )
 
     fun onEnterAmount(amount: BigDecimal?) {
@@ -154,15 +157,15 @@ class SendTonViewModel(
         else -> HSCaution(TranslatableString.PlainString(error.message ?: ""))
     }
 
-    private suspend fun handleUpdatedAmountState(amountState: SendTonAmountService.State) {
+    private fun handleUpdatedAmountState(amountState: SendTonAmountService.State) {
         this.amountState = amountState
 
         feeService.setAmount(amountState.amount)
 
         emitState()
     }
 
-    private suspend fun handleUpdatedAddressState(addressState: SendTonAddressService.State) {
+    private fun handleUpdatedAddressState(addressState: SendTonAddressService.State) {
         this.addressState = addressState
 
         feeService.setTonAddress(addressState.tonAddress)
@@ -185,4 +188,5 @@ data class SendTonUiState(
     val canBeSend: Boolean,
     val showAddressInput: Boolean,
     val fee: BigDecimal?,
+    val feeInProgress: Boolean,
 )