Error and Exception

F#

diff --git a/src/GWallet.Backend.Tests/GWallet.Backend.Tests.fsproj b/src/GWallet.Backend.Tests/GWallet.Backend.Tests.fsproj
index c095a47..8317fd1 100644
--- a/src/GWallet.Backend.Tests/GWallet.Backend.Tests.fsproj
+++ b/src/GWallet.Backend.Tests/GWallet.Backend.Tests.fsproj
@@ -72,6 +72,7 @@
     <Reference Include="mscorlib" />
     <Reference Include="nunit.framework">
       <HintPath>..\..\packages\NUnit.2.6.4\lib\nunit.framework.dll</HintPath>
+      <Package>nunit</Package>
     </Reference>
     <Reference Include="System" />
     <Reference Include="System.Core" />
diff --git a/src/GWallet.Backend/Account.fs b/src/GWallet.Backend/Account.fs
index 84e618b..ec303d3 100644
--- a/src/GWallet.Backend/Account.fs
+++ b/src/GWallet.Backend/Account.fs
@@ -139,15 +139,15 @@ module Account =
         }
 
     // TODO: add tests for these (just in case address validation breaks after upgrading our dependencies)
-    let ValidateAddress (currency: Currency) (address: string): Async<unit> = async {
+    let ValidateAddress (currency: Currency) (address: string) = 
         if currency.IsEtherBased() then
             Ether.Account.ValidateAddress currency address
-            do! Ether.Server.CheckIfAddressIsAValidPaymentDestination currency address
+            
         elif currency.IsUtxo() then
             UtxoCoin.Account.ValidateAddress currency address
         else
             failwith (sprintf "Unknown currency %A" currency)
-    }
+    
 
 
     let EstimateFee (account: IAccount) (amount: TransferAmount) destination: Async<IBlockchainFeeInfo> =
@@ -312,9 +312,9 @@ module Account =
             raise DestinationEqualToOrigin
 
         let currency = baseAccount.Currency
+        ValidateAddress currency destination
 
         async {
-            do! ValidateAddress currency destination
 
             let! txId =
                 match txMetadata with
@@ -393,9 +393,9 @@ module Account =
 
         File.WriteAllText(filePath, json)
 
-    let CreateReadOnlyAccounts (watchWalletInfo: WatchWalletInfo): Async<unit> = async {
+    let CreateReadOnlyAccounts (watchWalletInfo: WatchWalletInfo) = 
         for etherCurrency in Currency.GetAll().Where(fun currency -> currency.IsEtherBased()) do
-            do! ValidateAddress etherCurrency watchWalletInfo.EtherPublicAddress
+            ValidateAddress etherCurrency watchWalletInfo.EtherPublicAddress
             let conceptAccountForReadOnlyAccount = {
                 Currency = etherCurrency
                 FileRepresentation = { Name = watchWalletInfo.EtherPublicAddress; Content = fun _ -> String.Empty }
@@ -407,14 +407,14 @@ module Account =
             let address =
                 UtxoCoin.Account.GetPublicAddressFromPublicKey utxoCurrency
                                                                (NBitcoin.PubKey(watchWalletInfo.UtxoCoinPublicKey))
-            do! ValidateAddress utxoCurrency address
+            ValidateAddress utxoCurrency address
             let conceptAccountForReadOnlyAccount = {
                 Currency = utxoCurrency
                 FileRepresentation = { Name = address; Content = fun _ -> watchWalletInfo.UtxoCoinPublicKey }
                 ExtractPublicAddressFromConfigFileFunc = (fun file -> file.Name)
             }
             Config.AddAccount conceptAccountForReadOnlyAccount AccountKind.ReadOnly |> ignore
-    }
+
 
     let Remove (account: ReadOnlyAccount) =
         Config.RemoveReadOnlyAccount account
diff --git a/src/GWallet.Backend/Ether/EtherAccount.fs b/src/GWallet.Backend/Ether/EtherAccount.fs
index d8fede4..2bbd7d9 100644
--- a/src/GWallet.Backend/Ether/EtherAccount.fs
+++ b/src/GWallet.Backend/Ether/EtherAccount.fs
@@ -151,6 +151,27 @@ module internal Account =
         return gasPrice64
     }
 
+    let EstimateGasCostForContractWithDefaultFunction (account: IAccount) (amount: TransferAmount) destination: Async<TransactionMetadata> = async {
+        let! gasPrice64 = GetGasPrice account.Currency
+
+
+        let! estimateGasForContract = Ether.Server.EstimateGasCostForContract account destination amount.ValueToSend
+        if (estimateGasForContract.Value > BigInteger(Int64.MaxValue)) then
+            failwith (sprintf "GWallet serialization doesn't support such a big integer (%s) for the gas cost of the ton transfer, please report this issue."
+                          (estimateGasForContract.Value.ToString()))
+        let gasCost64: Int64 = BigInteger.op_Explicit estimateGasForContract.Value
+
+        let ethMinerFee = MinerFee(gasCost64, gasPrice64, DateTime.Now, account.Currency)
+        let! txCount = GetTransactionCount account.Currency account.PublicAddress
+
+        let feeValue = ethMinerFee.CalculateAbsoluteValue()
+        if (amount.ValueToSend <> amount.BalanceAtTheMomentOfSending &&
+            feeValue > (amount.BalanceAtTheMomentOfSending - amount.ValueToSend)) then
+            raise (InsufficientBalanceForFee feeValue)
+
+        return { Ether.Fee = ethMinerFee; Ether.TransactionCount = txCount }
+    }
+
     let private GAS_COST_FOR_A_NORMAL_ETHER_TRANSACTION:int64 = 21000L
 
     let EstimateEtherTransferFee (account: IAccount) (amount: TransferAmount): Async<TransactionMetadata> = async {
@@ -188,7 +209,12 @@ module internal Account =
 
     let EstimateFee (account: IAccount) (amount: TransferAmount) destination: Async<TransactionMetadata> = async {
         if account.Currency.IsEther() then
-            return! EstimateEtherTransferFee account amount
+            let! isContract = Ether.Server.CheckIfAddressIsAContractAddress account.Currency destination
+            if isContract then
+                return! EstimateGasCostForContractWithDefaultFunction account amount destination
+            else
+                return! EstimateEtherTransferFee account amount
         elif account.Currency.IsEthToken() then
             return! EstimateTokenTransferFee account amount.ValueToSend destination
         else
diff --git a/src/GWallet.Backend/Ether/EtherServer.fs b/src/GWallet.Backend/Ether/EtherServer.fs
index cfa90f1..b76d967 100644
--- a/src/GWallet.Backend/Ether/EtherServer.fs
+++ b/src/GWallet.Backend/Ether/EtherServer.fs
@@ -11,6 +11,7 @@ open Nethereum.Hex.HexTypes
 open Nethereum.Web3
 open Nethereum.RPC.Eth.DTOs
 open Nethereum.StandardTokenEIP20.ContractDefinition
+open Nethereum.RPC.TransactionManagers
 
 open GWallet.Backend
 
@@ -580,15 +581,41 @@ module Server =
                 web3Funcs
         }
 
-    let CheckIfAddressIsAValidPaymentDestination (currency: Currency) (address: string): Async<unit> =
+    let CheckIfAddressIsAContractAddress (currency: Currency) (address: string): Async<bool> =
         async {
             let! contractCode = GetContractCode currency address
             let emptyContract = "0x"
 
             if not (contractCode.StartsWith emptyContract) then
                 failwithf "GetCode API should always return a string starting with %s, but got: %s"
-                          emptyContract contractCode
-            elif contractCode <> emptyContract then
-                return raise <| InvalidDestinationAddress "Sending to contract addresses is not supported yet. Supply a normal address please."
+                                          emptyContract contractCode
+
+            return contractCode <> emptyContract
+               
+        }
+
+
+    let EstimateGasCostForContract (account: IAccount) destination amount: Async<HexBigInteger> = 
+        async {
+
+            let transactionInput = EtherTransferTransactionInputBuilder.CreateTransactionInput(account.PublicAddress, destination, amount)
+                                  //(string fromAddress, string toAddress, decimal etherAmount, decimal? gasPriceGwei = null, BigInteger? gas = null)
+            let web3Funcs =          
+                let web3Func (web3: Web3): Async<HexBigInteger> =
+                    let estimateGasJob =
+                        async {
+                            let task = web3.TransactionManager.EstimateGasAsync(transactionInput)
+                            return! Async.AwaitTask task
+                        }
+                    HandlePossibleEtherFailures estimateGasJob
+                GetWeb3Funcs account.Currency web3Func
+
+            return! faultTolerantEtherClient.Query
+                (FaultTolerantParallelClientDefaultSettings account.Currency Mode.Fast)
+                web3Funcs
+
         }
 
+
+        
\ No newline at end of file
diff --git a/src/GWallet.Backend/Exceptions.fs b/src/GWallet.Backend/Exceptions.fs
index 1edf170..5e60e66 100644
--- a/src/GWallet.Backend/Exceptions.fs
+++ b/src/GWallet.Backend/Exceptions.fs
@@ -12,6 +12,3 @@ exception AddressWithInvalidLength of seq<int>
 
 exception AddressWithInvalidChecksum of Option<string>
 exception AccountAlreadyAdded
-
-exception InvalidDestinationAddress of msg: string
-
diff --git a/src/GWallet.Frontend.Console/Program.fs b/src/GWallet.Frontend.Console/Program.fs
index 39e61f3..4e130ea 100644
--- a/src/GWallet.Frontend.Console/Program.fs
+++ b/src/GWallet.Frontend.Console/Program.fs
@@ -240,7 +240,6 @@ let rec PerformOptions(numAccounts: int) =
         SendPayment()
     | Options.AddReadonlyAccounts ->
         AddReadOnlyAccounts()
-            |> Async.RunSynchronously
     | Options.SignOffPayment ->
         SignOffPayment()
     | Options.BroadcastPayment ->
diff --git a/src/GWallet.Frontend.Console/UserInteraction.fs b/src/GWallet.Frontend.Console/UserInteraction.fs
index 50c9fd5..1f0718a 100644
--- a/src/GWallet.Frontend.Console/UserInteraction.fs
+++ b/src/GWallet.Frontend.Console/UserInteraction.fs
@@ -337,12 +337,8 @@ module UserInteraction =
         let validatedAddress =
             try
                 Account.ValidateAddress currency publicAddress
-                    |> Async.RunSynchronously
                 publicAddress
             with
-            | InvalidDestinationAddress msg ->
-                Presentation.Error msg
-                AskPublicAddress currency askText
             | AddressMissingProperPrefix(possiblePrefixes) ->
                 let possiblePrefixesStr = String.Join(", ", possiblePrefixes)
                 Presentation.Error (sprintf "Address starts with the wrong prefix. Valid prefixes: %s"
(END)
     | Options.AddReadonlyAccounts ->
         AddReadOnlyAccounts()
-            |> Async.RunSynchronously
     | Options.SignOffPayment ->
         SignOffPayment()
     | Options.BroadcastPayment ->
diff --git a/src/GWallet.Frontend.Console/UserInteraction.fs b/src/GWallet.Frontend.Console/UserInteraction.fs
index 50c9fd5..1f0718a 100644
--- a/src/GWallet.Frontend.Console/UserInteraction.fs
+++ b/src/GWallet.Frontend.Console/UserInteraction.fs
@@ -337,12 +337,8 @@ module UserInteraction =
         let validatedAddress =
             try
                 Account.ValidateAddress currency publicAddress
-                    |> Async.RunSynchronously
                 publicAddress
             with
-            | InvalidDestinationAddress msg ->
-                Presentation.Error msg
-                AskPublicAddress currency askText
             | AddressMissingProperPrefix(possiblePrefixes) ->
                 let possiblePrefixesStr = String.Join(", ", possiblePrefixes)
                 Presentation.Error (sprintf "Address starts with the wrong prefix. Valid prefixes: %s"
~
(END)
     | Options.AddReadonlyAccounts ->
         AddReadOnlyAccounts()
-            |> Async.RunSynchronously
     | Options.SignOffPayment ->
         SignOffPayment()
     | Options.BroadcastPayment ->
diff --git a/src/GWallet.Frontend.Console/UserInteraction.fs b/src/GWallet.Frontend.Console/UserInteraction.fs
index 50c9fd5..1f0718a 100644
--- a/src/GWallet.Frontend.Console/UserInteraction.fs
+++ b/src/GWallet.Frontend.Console/UserInteraction.fs
@@ -337,12 +337,8 @@ module UserInteraction =
         let validatedAddress =
             try
                 Account.ValidateAddress currency publicAddress
-                    |> Async.RunSynchronously
                 publicAddress
             with
-            | InvalidDestinationAddress msg ->
-                Presentation.Error msg
-                AskPublicAddress currency askText
             | AddressMissingProperPrefix(possiblePrefixes) ->
                 let possiblePrefixesStr = String.Join(", ", possiblePrefixes)
                 Presentation.Error (sprintf "Address starts with the wrong prefix. Valid prefixes: %s"
~
~
(END)
     | Options.AddReadonlyAccounts ->
         AddReadOnlyAccounts()
-            |> Async.RunSynchronously
     | Options.SignOffPayment ->
         SignOffPayment()
     | Options.BroadcastPayment ->
diff --git a/src/GWallet.Frontend.Console/UserInteraction.fs b/src/GWallet.Frontend.Console/UserInteraction.fs
index 50c9fd5..1f0718a 100644
--- a/src/GWallet.Frontend.Console/UserInteraction.fs
+++ b/src/GWallet.Frontend.Console/UserInteraction.fs
@@ -337,12 +337,8 @@ module UserInteraction =
         let validatedAddress =
             try
                 Account.ValidateAddress currency publicAddress
-                    |> Async.RunSynchronously
                 publicAddress
             with
-            | InvalidDestinationAddress msg ->
-                Presentation.Error msg
-                AskPublicAddress currency askText
             | AddressMissingProperPrefix(possiblePrefixes) ->
                 let possiblePrefixesStr = String.Join(", ", possiblePrefixes)
                 Presentation.Error (sprintf "Address starts with the wrong prefix. Valid prefixes: %s"
~
~
~
(END)
     | Options.AddReadonlyAccounts ->
         AddReadOnlyAccounts()
-            |> Async.RunSynchronously
     | Options.SignOffPayment ->
         SignOffPayment()
     | Options.BroadcastPayment ->
diff --git a/src/GWallet.Frontend.Console/UserInteraction.fs b/src/GWallet.Frontend.Console/UserInteraction.fs
index 50c9fd5..1f0718a 100644
--- a/src/GWallet.Frontend.Console/UserInteraction.fs
+++ b/src/GWallet.Frontend.Console/UserInteraction.fs
@@ -337,12 +337,8 @@ module UserInteraction =
         let validatedAddress =
             try
                 Account.ValidateAddress currency publicAddress
-                    |> Async.RunSynchronously
                 publicAddress
             with
-            | InvalidDestinationAddress msg ->
-                Presentation.Error msg
-                AskPublicAddress currency askText
             | AddressMissingProperPrefix(possiblePrefixes) ->
                 let possiblePrefixesStr = String.Join(", ", possiblePrefixes)
                 Presentation.Error (sprintf "Address starts with the wrong prefix. Valid prefixes: %s"
~
~
~
~
~
(END)
     | Options.AddReadonlyAccounts ->
         AddReadOnlyAccounts()
-            |> Async.RunSynchronously
     | Options.SignOffPayment ->
         SignOffPayment()
     | Options.BroadcastPayment ->
diff --git a/src/GWallet.Frontend.Console/UserInteraction.fs b/src/GWallet.Frontend.Console/UserInteraction.fs
index 50c9fd5..1f0718a 100644
--- a/src/GWallet.Frontend.Console/UserInteraction.fs
+++ b/src/GWallet.Frontend.Console/UserInteraction.fs
@@ -337,12 +337,8 @@ module UserInteraction =
         let validatedAddress =
             try
                 Account.ValidateAddress currency publicAddress
-                    |> Async.RunSynchronously
                 publicAddress
             with
-            | InvalidDestinationAddress msg ->
-                Presentation.Error msg
-                AskPublicAddress currency askText
             | AddressMissingProperPrefix(possiblePrefixes) ->
                 let possiblePrefixesStr = String.Join(", ", possiblePrefixes)
                 Presentation.Error (sprintf "Address starts with the wrong prefix. Valid prefixes: %s"
~
~
~
~
~
~
(END)
     | Options.AddReadonlyAccounts ->
         AddReadOnlyAccounts()
-            |> Async.RunSynchronously
     | Options.SignOffPayment ->
         SignOffPayment()
     | Options.BroadcastPayment ->
diff --git a/src/GWallet.Frontend.Console/UserInteraction.fs b/src/GWallet.Frontend.Console/UserInteraction.fs
index 50c9fd5..1f0718a 100644
--- a/src/GWallet.Frontend.Console/UserInteraction.fs
+++ b/src/GWallet.Frontend.Console/UserInteraction.fs
@@ -337,12 +337,8 @@ module UserInteraction =
         let validatedAddress =
             try
                 Account.ValidateAddress currency publicAddress
-                    |> Async.RunSynchronously
                 publicAddress
             with
-            | InvalidDestinationAddress msg ->
-                Presentation.Error msg
-                AskPublicAddress currency askText
             | AddressMissingProperPrefix(possiblePrefixes) ->
                 let possiblePrefixesStr = String.Join(", ", possiblePrefixes)
                 Presentation.Error (sprintf "Address starts with the wrong prefix. Valid prefixes: %s"
~
~
~
~
~
~
~
~
(END)
     | Options.AddReadonlyAccounts ->
         AddReadOnlyAccounts()
-            |> Async.RunSynchronously
     | Options.SignOffPayment ->
         SignOffPayment()
     | Options.BroadcastPayment ->
diff --git a/src/GWallet.Frontend.Console/UserInteraction.fs b/src/GWallet.Frontend.Console/UserInteraction.fs
index 50c9fd5..1f0718a 100644
--- a/src/GWallet.Frontend.Console/UserInteraction.fs
+++ b/src/GWallet.Frontend.Console/UserInteraction.fs
@@ -337,12 +337,8 @@ module UserInteraction =
         let validatedAddress =
             try
                 Account.ValidateAddress currency publicAddress
-                    |> Async.RunSynchronously
                 publicAddress
             with
-            | InvalidDestinationAddress msg ->
-                Presentation.Error msg
-                AskPublicAddress currency askText
             | AddressMissingProperPrefix(possiblePrefixes) ->
                 let possiblePrefixesStr = String.Join(", ", possiblePrefixes)
                 Presentation.Error (sprintf "Address starts with the wrong prefix. Valid prefixes: %s"