IOS-7720 Mantle token (Express): error when get fee for permission (#815

)

BlockchainSdk.xcodeproj/project.pbxproj

@@ -535,6 +535,7 @@
 		DA82433F27A2B07800CFC2C0 /* PolkadotNetwork.swift in Sources */ = {isa = PBXBuildFile; fileRef = DA82433E27A2B07800CFC2C0 /* PolkadotNetwork.swift */; };
 		DA82434127A2B0AD00CFC2C0 /* PolkadotTarget.swift in Sources */ = {isa = PBXBuildFile; fileRef = DA82434027A2B0AD00CFC2C0 /* PolkadotTarget.swift */; };
 		DA82434327A2B0C100CFC2C0 /* PolkadotResponse.swift in Sources */ = {isa = PBXBuildFile; fileRef = DA82434227A2B0C100CFC2C0 /* PolkadotResponse.swift */; };
+		DA95AE092C7CB1DE0055740F /* MantleUtils.swift in Sources */ = {isa = PBXBuildFile; fileRef = DA95AE082C7CB1DE0055740F /* MantleUtils.swift */; };
 		DA9EA73F29EE958500CAE6F2 /* CosmosTransactionParams.swift in Sources */ = {isa = PBXBuildFile; fileRef = DA9EA73E29EE958500CAE6F2 /* CosmosTransactionParams.swift */; };
 		DA9F76E927EC8AEB00F0665C /* TronAddressService.swift in Sources */ = {isa = PBXBuildFile; fileRef = DA9F76E827EC8AEB00F0665C /* TronAddressService.swift */; };
 		DA9F76EC27EC9A2900F0665C /* TronWalletManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = DA9F76EB27EC9A2900F0665C /* TronWalletManager.swift */; };
@@ -1461,6 +1462,7 @@
 		DA82433E27A2B07800CFC2C0 /* PolkadotNetwork.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PolkadotNetwork.swift; sourceTree = "<group>"; };
 		DA82434027A2B0AD00CFC2C0 /* PolkadotTarget.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PolkadotTarget.swift; sourceTree = "<group>"; };
 		DA82434227A2B0C100CFC2C0 /* PolkadotResponse.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PolkadotResponse.swift; sourceTree = "<group>"; };
+		DA95AE082C7CB1DE0055740F /* MantleUtils.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MantleUtils.swift; sourceTree = "<group>"; };
 		DA9EA73E29EE958500CAE6F2 /* CosmosTransactionParams.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CosmosTransactionParams.swift; sourceTree = "<group>"; };
 		DA9F76E827EC8AEB00F0665C /* TronAddressService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TronAddressService.swift; sourceTree = "<group>"; };
 		DA9F76EB27EC9A2900F0665C /* TronWalletManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TronWalletManager.swift; sourceTree = "<group>"; };
@@ -3411,6 +3413,7 @@
 			children = (
 				DA1BA9A82C454C53006F6839 /* MantleWalletAssembly.swift */,
 				DA1BA9A62C454AFB006F6839 /* MantleWalletManager.swift */,
+				DA95AE082C7CB1DE0055740F /* MantleUtils.swift */,
 			);
 			path = Mantle;
 			sourceTree = "<group>";
@@ -5187,6 +5190,7 @@
 				B69824812B71A8F800E1333D /* HederaNetworkResult.ExchangeRate.swift in Sources */,
 				B6D346002AD9450D0009D1B2 /* NEARTransactionBuilder.swift in Sources */,
 				B00DF9A02BBEACA2004397CB /* QuickNodeAPIResolver.swift in Sources */,
+				DA95AE092C7CB1DE0055740F /* MantleUtils.swift in Sources */,
 				EF2D9DCF2BC40E280055C485 /* Result+.swift in Sources */,
 				EF5F1B9729C9C0500093307B /* Fee.swift in Sources */,
 				B6A71D982B553E7900039991 /* FeePaidCurrency.swift in Sources */,

BlockchainSdk/Blockchains/Mantle/MantleUtils.swift

@@ -0,0 +1,22 @@
+//
+//  MantleUtils.swift
+//  BlockchainSdk
+//
+//  Created by Aleksei Muraveinik on 26.08.24.
+//  Copyright © 2024 Tangem AG. All rights reserved.
+//
+
+import BigInt
+
+public enum MantleUtils {
+    public static let feeGasLimitMultiplier = 1.6
+    static let signGasLimitMultiplier = 0.7
+
+    public static func multiplyGasLimit(_ gasLimit: Int, with multiplier: Double) -> BigUInt {
+        multiplyGasLimit(BigUInt(gasLimit), with: multiplier)
+    }
+
+    static func multiplyGasLimit(_ gasLimit: BigUInt, with multiplier: Double) -> BigUInt {
+        BigUInt(ceil(Double(gasLimit) * multiplier))
+    }
+}

BlockchainSdk/Blockchains/Mantle/MantleWalletManager.swift

@@ -8,42 +8,30 @@
 
 import BigInt
 import Combine
-import Foundation
 
 // This is a workaround for sending a Mantle transaction.
 // Unfortunately, Mantle's current implementation does not conform to our existing fee calculation rules.
 // https://tangem.slack.com/archives/GMXC6PP71/p1719591856597299?thread_ts=1714215815.690169&cid=GMXC6PP71
 final class MantleWalletManager: EthereumWalletManager {
     override func getFee(destination: String, value: String?, data: Data?) -> AnyPublisher<[Fee], any Error> {
-        let blockchain = wallet.blockchain
-
-        let adjustedValue = value
-            .flatMap { value in
-                EthereumUtils.parseEthereumDecimal(value, decimalsCount: blockchain.decimalCount)
-            }
-            .flatMap { parsedValue in
-                Amount(
-                    with: blockchain,
-                    type: .coin,
-                    value: parsedValue - (1 / blockchain.decimalValue)
-                )
-                .encodedForSend
-            }
-
-        return super.getFee(destination: destination, value: adjustedValue, data: data)
-            .withWeakCaptureOf(self)
-            .tryMap { walletManager, fees in
-                try fees.map { fee in
-                    try walletManager.mapMantleFee(fee, gasLimitMultiplier: 1.6)
-                }
+        super.getFee(
+            destination: destination,
+            value: prepareAdjustedValue(value: value),
+            data: data
+        )
+        .withWeakCaptureOf(self)
+        .tryMap { walletManager, fees in
+            try fees.map { fee in
+                try walletManager.mapMantleFee(fee, gasLimitMultiplier: MantleUtils.feeGasLimitMultiplier)
             }
-            .eraseToAnyPublisher()
+        }
+        .eraseToAnyPublisher()
     }
 
     override func sign(_ transaction: Transaction, signer: any TransactionSigner) -> AnyPublisher<String, any Error> {
         var transaction = transaction
         do {
-            transaction.fee = try mapMantleFee(transaction.fee, gasLimitMultiplier: 0.7)
+            transaction.fee = try mapMantleFee(transaction.fee, gasLimitMultiplier: MantleUtils.signGasLimitMultiplier)
         } catch {
             return Fail(error: error).eraseToAnyPublisher()
         }
@@ -53,7 +41,7 @@ final class MantleWalletManager: EthereumWalletManager {
     override func getGasLimit(to: String, from: String, value: String?, data: String?) -> AnyPublisher<BigUInt, any Error> {
         super.getGasLimit(to: to, from: from, value: value, data: data)
             .map { gasLimit in
-                BigUInt(ceil(Double(gasLimit) * 1.6))
+                MantleUtils.multiplyGasLimit(gasLimit, with: MantleUtils.feeGasLimitMultiplier)
             }
             .eraseToAnyPublisher()
     }
@@ -66,13 +54,13 @@ private extension MantleWalletManager {
         let parameters: any EthereumFeeParameters = switch fee.parameters {
         case let parameters as EthereumEIP1559FeeParameters:
             EthereumEIP1559FeeParameters(
-                gasLimit: BigUInt(ceil(Double(parameters.gasLimit) * gasLimitMultiplier)),
+                gasLimit: MantleUtils.multiplyGasLimit(parameters.gasLimit, with: gasLimitMultiplier),
                 maxFeePerGas: parameters.maxFeePerGas,
                 priorityFee: parameters.priorityFee
             )
         case let parameters as EthereumLegacyFeeParameters:
             EthereumLegacyFeeParameters(
-                gasLimit: BigUInt(ceil(Double(parameters.gasLimit) * gasLimitMultiplier)),
+                gasLimit: MantleUtils.multiplyGasLimit(parameters.gasLimit, with: gasLimitMultiplier),
                 gasPrice: parameters.gasPrice
             )
         default:
@@ -85,4 +73,32 @@ private extension MantleWalletManager {
 
         return Fee(amount, parameters: parameters)
     }
+
+    func prepareAdjustedValue(value: String?) -> String? {
+        guard let value, let currentBalance = wallet.amounts[.coin]?.value else {
+            return nil
+        }
+
+        let parsedValue = EthereumUtils.parseEthereumDecimal(
+            value,
+            decimalsCount: wallet.blockchain.decimalCount
+        )
+
+        guard let parsedValue else {
+            return nil
+        }
+
+        let blockchain = wallet.blockchain
+        let delta = blockchain.minimumValue
+
+        let shouldSubtractPenny = currentBalance.isEqual(to: parsedValue, delta: delta)
+        let valueToSubtract = shouldSubtractPenny ? delta : 0
+
+        return Amount(
+            with: blockchain,
+            type: .coin,
+            value: parsedValue - valueToSubtract
+        )
+        .encodedForSend
+    }
 }

BlockchainSdk/Common/Blockchain.swift

@@ -999,6 +999,10 @@ extension Blockchain {
     public var decimalValue: Decimal {
         return pow(Decimal(10), decimalCount)
     }
+
+    public var minimumValue: Decimal {
+        1 / decimalValue
+    }
 }
 
 // MARK: - Card's factory

BlockchainSdk/Extensions/Decimal+.swift

@@ -83,6 +83,10 @@ extension Decimal {
     var roundedDecimalNumber: NSDecimalNumber {
         rounded(roundingMode: .up) as NSDecimalNumber
     }
+
+    public func isEqual(to value: Decimal, delta: Decimal) -> Bool {
+        abs(self - value) <= delta
+    }
 }
 
 // MARK: - Point moving