/// <summary>
/// Handle the data context changing.
/// </summary>
/// <param name="sender">
/// The event sender.
/// </param>
/// <param name="e">
/// The event arguments.
/// </param>
private void OnDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
TransactionUnlockViewModel oldViewModel = e.OldValue as TransactionUnlockViewModel;
TransactionUnlockViewModel newViewModel = e.NewValue as TransactionUnlockViewModel;
if (oldViewModel != null)
{
oldViewModel.ReadyToClose -= OnViewModelReadyToClose;
}
if (newViewModel != null)
{
newViewModel.ReadyToClose += OnViewModelReadyToClose;
}
}
/// <summary>
/// Purchase SIFT from one of our accounts.
/// </summary>
/// <param name="address">
/// The account to use for purchase.
/// </param>
/// <param name="quantity">
/// The quantity to purchase.
/// </param>
/// <returns>
/// Details of the purchase result indicating whether a success or failure happened.
/// </returns>
public async Task <SiftPurchaseResponse> PurchaseSift(string address, uint quantity)
{
try
{
// Ensure we have the balance
decimal purchaseCostWei = WeiPerSift * quantity;
EthereumAccount account = Accounts.FirstOrDefault(acc => acc.Address == address);
if (account == null)
{
return(new SiftPurchaseResponse(SiftPurchaseFailureType.UnknownAccount, "The specified account address is not known."));
}
if (account.BalanceWei < purchaseCostWei)
{
return(new SiftPurchaseResponse(SiftPurchaseFailureType.InsufficientFunds, "The specified account does not have sufficient funds."));
}
// Determine the gas cost for this
TransactionGasInfo gasInfo = await CalculateGasCostForEtherSend(address, IcoContractAddress, purchaseCostWei);
decimal gasPrice = gasInfo.GasPrice;
decimal gasCost = gasInfo.GasCost;
decimal gas = gasInfo.Gas;
decimal remainingGasMoney = account.BalanceWei - purchaseCostWei;
if (remainingGasMoney < gasCost)
{
return(new SiftPurchaseResponse(SiftPurchaseFailureType.InsufficientGas, "You do not have enough gas for this transaction."));
}
byte gasMultiple = 25;
decimal maximumGasCost;
while ((maximumGasCost = gasCost * gasMultiple) * gasPrice > remainingGasMoney)
{
gasMultiple--;
}
// Prompt to unlock account
Logger.ApplicationInstance.Debug("Asking user confirmation for sending " + purchaseCostWei + " from " + address + " to " + IcoContractAddress);
Func <TransactionUnlockViewModel> fnc = new Func <TransactionUnlockViewModel>(() =>
{
TransactionUnlockViewModel vm = new TransactionUnlockViewModel(gasCost, gasMultiple, gas, address, IcoContractAddress, purchaseCostWei);
TransactionUnlockWindow window = new TransactionUnlockWindow
{
DataContext = vm
};
window.ShowDialog();
return(vm);
});
TransactionUnlockViewModel viewModel = Application.Current.Dispatcher.Invoke(fnc);
if (viewModel.WasCancelled)
{
return(new SiftPurchaseResponse(SiftPurchaseFailureType.UserCancelled, "User cancelled transaction on confirmation screen."));
}
// Unlock the account
SiftDialog dialog = SiftDialog.ShowButtonless("Sending Transaction", "Please wait whilst the transaction to buy SIFT is sent to the Ethereum network, this should only take a few seconds...", true);
Logger.ApplicationInstance.Debug("Attempting to unlock " + address);
if (!await _web3.Personal.UnlockAccount.SendRequestAsync(address, viewModel.Password == null ? string.Empty : viewModel.Password.ToString(), 120))
{
return(new SiftPurchaseResponse(SiftPurchaseFailureType.UnlockError, "Unable to unlock account with the supplied password."));
}
// Send and mine the transaction
Logger.ApplicationInstance.Debug("Account unlocked, sending " + purchaseCostWei + " from " + address + " to " + IcoContractAddress);
TransactionInput transactionInput = new TransactionInput
{
From = address,
To = IcoContractAddress,
Value = new HexBigInteger(new BigInteger(purchaseCostWei)),
GasPrice = new HexBigInteger(new BigInteger(viewModel.SelectedGasMultiplier * gasCost)),
Gas = new HexBigInteger(new BigInteger(viewModel.Gas))
};
Logger.ApplicationInstance.Info("Sending transaction for " + purchaseCostWei + " to " + IcoContractAddress + " from " + address);
string transactionHash = await _web3.Eth.Transactions.SendTransaction.SendRequestAsync(transactionInput);
Action act = dialog.Close;
if (dialog.Dispatcher.CheckAccess())
{
act();
}
else
{
dialog.Dispatcher.Invoke(act);
}
// Return the response of the transaction hash
return(new SiftPurchaseResponse(transactionHash));
}
catch (Exception ex)
{
Logger.ApplicationInstance.Error("Error purchasing SIFT", ex);
if (ex.Message.Contains("personal_unlockAccount method not implemented"))
{
return(new SiftPurchaseResponse(SiftPurchaseFailureType.MissingRpcPersonal, "Your geth installation doesn't have the personal RPC enabled, please enable it to continue."));
}
else if (ex.Message.Contains("could not decrypt key with given passphrase"))
{
return(new SiftPurchaseResponse(SiftPurchaseFailureType.PasswordInvalid, "The password you supplied was incorrect"));
}
return(new SiftPurchaseResponse(SiftPurchaseFailureType.Unknown, ex.ToString()));
}
}
/// <summary>
/// Handle the password being changed.
/// </summary>
/// <param name="sender">
/// The event sender.
/// </param>
/// <param name="e">
/// The event arguments.
/// </param>
private void OnPasswordChanged(object sender, RoutedEventArgs e)
{
TransactionUnlockViewModel vm = (TransactionUnlockViewModel)DataContext;
vm.Password = ((PasswordBox)sender).SecurePassword;
}
