From c8b7934d931255bb20a4040b3007226059f078bd Mon Sep 17 00:00:00 2001
From: Tangem <git@tangem.com>
Date: Sat, 10 Jan 2026 14:08:10 +0300
Subject: [PATCH] Updated on 2026-08-14

---
 .../tap/di/domain/TransactionDomainModule.kt  |  19 ++-
 .../api/gasless/GaslessTxServiceApi.kt        |   2 +-
 .../GaslessTxDataToGaslessRequestConverter.kt |   3 +-
 .../CreateAndSendGaslessTransactionUseCase.kt |   5 -
 .../gasless/EstimateFeeForTokenUseCase.kt     | 131 ++++++++++++++++++
 5 files changed, 152 insertions(+), 8 deletions(-)
 create mode 100644 domain/transaction/src/main/java/com/tangem/domain/transaction/usecase/gasless/EstimateFeeForTokenUseCase.kt

diff --git a/app/src/main/java/com/tangem/tap/di/domain/TransactionDomainModule.kt b/app/src/main/java/com/tangem/tap/di/domain/TransactionDomainModule.kt
index 9f0811eff8..b0b821fffb 100644
--- a/app/src/main/java/com/tangem/tap/di/domain/TransactionDomainModule.kt
+++ b/app/src/main/java/com/tangem/tap/di/domain/TransactionDomainModule.kt
@@ -26,7 +26,7 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.SupervisorJob
 import javax.inject.Singleton
 
-@Suppress("TooManyFunctions")
+@Suppress("TooManyFunctions", "LargeClass")
 @Module
 @InstallIn(SingletonComponent::class)
 internal object TransactionDomainModule {
@@ -346,4 +346,21 @@ internal object TransactionDomainModule {
             getHotWalletSigner = tangemHotWalletSignerFactory::create,
         )
     }
+
+    @Provides
+    @Singleton
+    fun provideEstimateFeeForTokenUseCase(
+        walletManagersFacade: WalletManagersFacade,
+        gaslessTransactionRepository: GaslessTransactionRepository,
+        currenciesRepository: CurrenciesRepository,
+        getMultiCryptoCurrencyStatusUseCase: GetMultiCryptoCurrencyStatusUseCase,
+    ): EstimateFeeForTokenUseCase {
+        return EstimateFeeForTokenUseCase(
+            gaslessTransactionRepository = gaslessTransactionRepository,
+            walletManagersFacade = walletManagersFacade,
+            demoConfig = DemoConfig,
+            currenciesRepository = currenciesRepository,
+            getMultiCryptoCurrencyStatusUseCase = getMultiCryptoCurrencyStatusUseCase,
+        )
+    }
 }
\ No newline at end of file
diff --git a/core/datasource/src/main/java/com/tangem/datasource/api/gasless/GaslessTxServiceApi.kt b/core/datasource/src/main/java/com/tangem/datasource/api/gasless/GaslessTxServiceApi.kt
index 193dc620e8..72b01f4139 100644
--- a/core/datasource/src/main/java/com/tangem/datasource/api/gasless/GaslessTxServiceApi.kt
+++ b/core/datasource/src/main/java/com/tangem/datasource/api/gasless/GaslessTxServiceApi.kt
@@ -14,7 +14,7 @@ interface GaslessTxServiceApi {
     @GET("api/v1/tokens")
     suspend fun getSupportedTokens(): ApiResponse<GaslessServiceResponse<GaslessSupportedTokens>>
 
-    @POST("api/v1/sign")
+    @POST("api/v1/transaction/sign")
     suspend fun signGaslessTransaction(
         @Body transaction: GaslessTransactionRequest,
     ): ApiResponse<GaslessServiceResponse<GaslessSignedTransactionResultDTO>>
diff --git a/data/transaction/src/main/java/com/tangem/data/transaction/convertes/GaslessTxDataToGaslessRequestConverter.kt b/data/transaction/src/main/java/com/tangem/data/transaction/convertes/GaslessTxDataToGaslessRequestConverter.kt
index 44005be4c1..1d20602465 100644
--- a/data/transaction/src/main/java/com/tangem/data/transaction/convertes/GaslessTxDataToGaslessRequestConverter.kt
+++ b/data/transaction/src/main/java/com/tangem/data/transaction/convertes/GaslessTxDataToGaslessRequestConverter.kt
@@ -1,5 +1,6 @@
 package com.tangem.data.transaction.convertes
 
+import com.tangem.blockchain.extensions.formatHex
 import com.tangem.datasource.api.gasless.models.FeeData
 import com.tangem.datasource.api.gasless.models.TransactionData
 import com.tangem.domain.transaction.models.GaslessTransactionData
@@ -27,7 +28,7 @@ class GaslessTxDataToGaslessRequestConverter : Converter<GaslessTransactionData,
         return TransactionData(
             to = transaction.to,
             value = transaction.value.toString(),
-            data = transaction.data.toHexString(),
+            data = transaction.data.toHexString().formatHex(),
         )
     }
 
diff --git a/domain/transaction/src/main/java/com/tangem/domain/transaction/usecase/gasless/CreateAndSendGaslessTransactionUseCase.kt b/domain/transaction/src/main/java/com/tangem/domain/transaction/usecase/gasless/CreateAndSendGaslessTransactionUseCase.kt
index 79a3acff33..c0bc106f89 100644
--- a/domain/transaction/src/main/java/com/tangem/domain/transaction/usecase/gasless/CreateAndSendGaslessTransactionUseCase.kt
+++ b/domain/transaction/src/main/java/com/tangem/domain/transaction/usecase/gasless/CreateAndSendGaslessTransactionUseCase.kt
@@ -266,11 +266,6 @@ class CreateAndSendGaslessTransactionUseCase(
     }
 
     private fun buildTransaction(transactionData: TransactionData.Uncompiled): GaslessTransactionData.Transaction {
-        val amount = transactionData.amount.value
-            ?.movePointRight(transactionData.amount.decimals)
-            ?.toBigInteger()
-            ?: error("Transaction amount value is null")
-
         val callData = (transactionData.extras as? EthereumTransactionExtras)?.callData
             ?: error("Ethereum call data is required")
 
diff --git a/domain/transaction/src/main/java/com/tangem/domain/transaction/usecase/gasless/EstimateFeeForTokenUseCase.kt b/domain/transaction/src/main/java/com/tangem/domain/transaction/usecase/gasless/EstimateFeeForTokenUseCase.kt
new file mode 100644
index 0000000000..de5f21becf
--- /dev/null
+++ b/domain/transaction/src/main/java/com/tangem/domain/transaction/usecase/gasless/EstimateFeeForTokenUseCase.kt
@@ -0,0 +1,131 @@
+package com.tangem.domain.transaction.usecase.gasless
+
+import arrow.core.Either
+import arrow.core.raise.Raise
+import arrow.core.raise.either
+import com.tangem.blockchain.blockchains.ethereum.EthereumWalletManager
+import com.tangem.blockchain.common.transaction.Fee
+import com.tangem.blockchain.extensions.Result
+import com.tangem.domain.demo.DemoTransactionSender
+import com.tangem.domain.demo.models.DemoConfig
+import com.tangem.domain.models.currency.CryptoCurrency
+import com.tangem.domain.models.network.Network
+import com.tangem.domain.models.wallet.UserWallet
+import com.tangem.domain.tokens.GetMultiCryptoCurrencyStatusUseCase
+import com.tangem.domain.tokens.repository.CurrenciesRepository
+import com.tangem.domain.transaction.GaslessTransactionRepository
+import com.tangem.domain.transaction.error.GetFeeError
+import com.tangem.domain.transaction.error.mapToFeeError
+import com.tangem.domain.transaction.models.TransactionFeeExtended
+import com.tangem.domain.transaction.raiseIllegalStateError
+import com.tangem.domain.utils.convertToSdkAmount
+import com.tangem.domain.walletmanager.WalletManagersFacade
+import java.math.BigDecimal
+
+class EstimateFeeForTokenUseCase(
+    private val gaslessTransactionRepository: GaslessTransactionRepository,
+    private val walletManagersFacade: WalletManagersFacade,
+    private val demoConfig: DemoConfig,
+    private val currenciesRepository: CurrenciesRepository,
+    private val getMultiCryptoCurrencyStatusUseCase: GetMultiCryptoCurrencyStatusUseCase,
+) {
+
+    private val tokenFeeCalculator = TokenFeeCalculator(
+        walletManagersFacade = walletManagersFacade,
+        gaslessTransactionRepository = gaslessTransactionRepository,
+        demoConfig = demoConfig,
+    )
+
+    suspend operator fun invoke(
+        userWallet: UserWallet,
+        token: CryptoCurrency,
+        amount: BigDecimal,
+    ): Either<GetFeeError, TransactionFeeExtended> {
+        return either {
+            if (!gaslessTransactionRepository.isNetworkSupported(token.network)) {
+                raise(GetFeeError.GaslessError.NetworkIsNotSupported)
+            }
+
+            val userCurrenciesStatusesByNetwork = getMultiCryptoCurrencyStatusUseCase.invokeMultiWalletSync(
+                userWallet.walletId,
+            ).getOrNull()?.filter {
+                it.currency.network.id == token.network.id
+            } ?: raiseIllegalStateError("currencies list is null for userWalletId=${userWallet.walletId}")
+
+            val tokenCurrencyStatus = userCurrenciesStatusesByNetwork.find {
+                it.currency.id == token.id
+            } ?: raiseIllegalStateError("token currency not found for network ${token.network.id}")
+
+            val amountData = amount.convertToSdkAmount(tokenCurrencyStatus)
+            val result = if (userWallet is UserWallet.Cold &&
+                demoConfig.isDemoCardId(userWallet.scanResponse.card.cardId)
+            ) {
+                demoTransactionSender(userWallet, token).estimateFee(
+                    amount = amountData,
+                    destination = "",
+                )
+            } else {
+                walletManagersFacade.estimateFee(
+                    amount = amountData,
+                    userWalletId = userWallet.walletId,
+                    network = token.network,
+                )
+            }
+
+            val initialTxFee = when (result) {
+                is Result.Success -> result.data
+                is Result.Failure -> raise(result.mapToFeeError())
+                null -> raise(GetFeeError.UnknownError)
+            }
+
+            val initialFeeEth = initialTxFee.normal as? Fee.Ethereum
+                ?: raiseIllegalStateError(
+                    error = "only Fee.Ethereum supported, but was different",
+                )
+
+            val nativeCurrency = currenciesRepository.getNetworkCoin(
+                userWalletId = userWallet.walletId,
+                networkId = token.network.id,
+                derivationPath = token.network.derivationPath,
+            )
+
+            val nativeCurrencyStatus = userCurrenciesStatusesByNetwork.find {
+                it.currency.id == nativeCurrency.id
+            } ?: raiseIllegalStateError("native currency not found for network ${token.network.id}")
+
+            val walletManager = prepareWalletManager(userWallet, token.network)
+
+            tokenFeeCalculator.calculateTokenFee(
+                walletManager = walletManager,
+                tokenForPayFeeStatus = tokenCurrencyStatus,
+                nativeCurrencyStatus = nativeCurrencyStatus,
+                initialFee = initialFeeEth,
+            ).bind()
+        }
+    }
+
+    @Suppress("NullableToStringCall")
+    private suspend fun Raise<GetFeeError>.prepareWalletManager(
+        userWallet: UserWallet,
+        network: Network,
+    ): EthereumWalletManager {
+        val walletManager = walletManagersFacade.getOrCreateWalletManager(
+            userWalletId = userWallet.walletId,
+            network = network,
+        )
+        val ethereumWalletManager = walletManager as? EthereumWalletManager
+            ?: raiseIllegalStateError("WalletManager type ${walletManager?.javaClass?.name} not supported")
+        return ethereumWalletManager
+    }
+
+    private suspend fun demoTransactionSender(
+        userWallet: UserWallet,
+        cryptoCurrency: CryptoCurrency,
+    ): DemoTransactionSender {
+        return DemoTransactionSender(
+            walletManagersFacade
+                .getOrCreateWalletManager(userWallet.walletId, cryptoCurrency.network)
+                ?: error("WalletManager is null"),
+        )
+    }
+}
\ No newline at end of file