Display nonce that will be used when editing transaction settings with actionsheet for transaction confirmation

AlphaWallet/Transfer/Controllers/TransactionConfigurator.swift

@@ -11,6 +11,7 @@ protocol TransactionConfiguratorDelegate: class {
     func configurationChanged(in configurator: TransactionConfigurator)
     func gasLimitEstimateUpdated(to estimate: BigInt, in configurator: TransactionConfigurator)
     func gasPriceEstimateUpdated(to estimate: BigInt, in configurator: TransactionConfigurator)
+    func updateNonce(to nonce: Int, in configurator: TransactionConfigurator)
 }
 
 class TransactionConfigurator {
@@ -295,6 +296,18 @@ class TransactionConfigurator {
         if !isGasLimitSpecifiedByTransaction {
             estimateGasLimit()
         }
+        firstly {
+            GetNextNonce(server: session.server, wallet: session.account.address).promise()
+        }.done {
+            var customConfig = self.configurations.custom
+            if let existingNonce = customConfig.nonce, existingNonce > 0 {
+                //no-op
+            } else {
+                customConfig.set(nonce: $0)
+                self.configurations.custom = customConfig
+                self.delegate?.updateNonce(to: $0, in: self)
+            }
+        }.cauterize()
     }
 
     func formUnsignedTransaction() -> UnsignedTransaction {

AlphaWallet/Transfer/Coordinators/TransactionConfirmationCoordinator.swift

@@ -205,4 +205,8 @@ extension TransactionConfirmationCoordinator: TransactionConfiguratorDelegate {
     func gasPriceEstimateUpdated(to estimate: BigInt, in configurator: TransactionConfigurator) {
         configureTransactionViewController?.configure(withEstimatedGasPrice: estimate, configurator: configurator)
     }
+
+    func updateNonce(to nonce: Int, in configurator: TransactionConfigurator) {
+        configureTransactionViewController?.configure(nonce: nonce, configurator: configurator)
+    }
 }

AlphaWallet/Transfer/Types/TransactionConfiguration.swift

@@ -30,6 +30,10 @@ struct TransactionConfiguration {
         gasLimit = estimate
     }
 
+    mutating func set(nonce: Int) {
+        self.nonce = nonce
+    }
+
     init(transaction: UnconfirmedTransaction) {
         self.init(
             gasPrice: min(max(transaction.gasPrice ?? GasPriceConfiguration.defaultPrice, GasPriceConfiguration.minPrice), GasPriceConfiguration.maxPrice),

AlphaWallet/Transfer/ViewControllers/ConfigureTransactionViewController.swift

@@ -105,6 +105,18 @@ class ConfigureTransactionViewController: UIViewController {
         tableView.reloadData()
     }
 
+    func configure(nonce: Int, configurator: TransactionConfigurator) {
+        var updatedViewModel = viewModel
+        var configuration = makeConfigureSuitableForSaving(from: updatedViewModel.configurationToEdit.configuration)
+        guard configuration.nonce != nonce else { return }
+        configuration.set(nonce: nonce)
+        updatedViewModel.configurationToEdit = EditedTransactionConfiguration(configuration: configuration)
+        updatedViewModel.configurations = configurator.configurations
+        viewModel = updatedViewModel
+        recalculateTotalFee()
+        tableView.reloadData()
+    }
+
     @objc private func keyboardWillShow(_ notification: Notification) {
         guard let info = notification.userInfo else {
             return