Add TransactionCost

Trust/EtherClient/EtherKeystore.swift

@@ -115,14 +115,13 @@ class EtherKeystore: Keystore {
         account: Account,
         address: Address,
         nonce: Int64,
-        gasPrice: GethBigInt = GethNewBigInt(50000000000),
-        gasLimit: GethBigInt = GethNewBigInt(90000),
+        cost: TransactionCost,
         data: Data = Data(),
         chainID: GethBigInt = GethNewBigInt(1)
     ) -> Result<Data, KeyStoreError> {
 
         let gethAddress = GethNewAddressFromHex(address.address, nil)
-        let transaction = GethNewTransaction(nonce, gethAddress, amount, gasLimit, gasPrice, data)
+        let transaction = GethNewTransaction(nonce, gethAddress, amount, cost.gasLimit, cost.gasPrice, data)
         let password = getPassword(for: account)
 
         let gethAccount = getGethAccount(for: account.address)

Trust/Transactions/Types/TransactionCost.swift

@@ -0,0 +1,25 @@
+// Copyright SIX DAY LLC. All rights reserved.
+
+import Foundation
+import Geth
+
+enum TransactionCost {
+    case fast
+    case cheap
+    case custom(gasPrice: GethBigInt, gasLimit: GethBigInt)
+
+    var gasPrice: GethBigInt {
+        switch self {
+        case .fast: return GethNewBigInt(40000000000)
+        case .cheap: return GethNewBigInt(15000000000)
+        case .custom(let gasPrice, _): return gasPrice
+        }
+    }
+
+    var gasLimit: GethBigInt {
+        switch self {
+        case .cheap, .fast: return GethNewBigInt(90000)
+        case .custom(_, let gasLimit): return gasLimit
+        }
+    }
+}