Support gas limit estimation for contract deployment transactions

AlphaWallet/EtherClient/Requests/EstimateGasRequest.swift

@@ -7,8 +7,22 @@ import BigInt
 struct EstimateGasRequest: JSONRPCKit.Request {
     typealias Response = String
 
+    enum TransactionType {
+        case normal(to: AlphaWallet.Address)
+        case contractDeployment
+    }
+
+    private var to: AlphaWallet.Address? {
+        switch transactionType {
+        case .normal(let to):
+            return to
+        case .contractDeployment:
+            return nil
+        }
+    }
+
     let from: AlphaWallet.Address
-    let to: AlphaWallet.Address
+    let transactionType: TransactionType
     let value: BigInt
     let data: Data
 
@@ -18,14 +32,16 @@ struct EstimateGasRequest: JSONRPCKit.Request {
 
     var parameters: Any? {
         //Explicit type declaration to speed up build time. 160msec -> <100ms, as of Xcode 11.7
-        let results: [[String: String]] = [
+        var results: [[String: String]] = [
             [
                 "from": from.description,
-                "to": to.eip55String,
                 "value": "0x" + String(value, radix: 16),
                 "data": data.hexEncoded,
             ],
         ]
+        if let to: AlphaWallet.Address = to {
+            results[0]["to"] = to.eip55String
+        }
         return results
     }
 

AlphaWallet/Transfer/Controllers/TransactionConfigurator.swift

@@ -136,10 +136,15 @@ class TransactionConfigurator {
     }
 
     private func estimateGasLimit() {
-        guard let toAddress = toAddress else { return }
+        let transactionType: EstimateGasRequest.TransactionType
+        if let toAddress = toAddress {
+            transactionType = .normal(to: toAddress)
+        } else {
+            transactionType = .contractDeployment
+        }
         let request = EstimateGasRequest(
             from: session.account.address,
-            to: toAddress,
+            transactionType: transactionType,
             value: value,
             data: currentConfiguration.data
         )
@@ -170,9 +175,9 @@ class TransactionConfigurator {
             }
 
             self.delegate?.gasLimitEstimateUpdated(to: gasLimit, in: self)
-        }.catch({ e in
+        }.catch { e in
             error(value: e, rpcServer: self.session.server)
-        })
+        }
     }
 
     private func estimateGasPrice() {

AlphaWallet/Transfer/Types/GasLimitConfiguration.swift

@@ -6,5 +6,6 @@ import BigInt
 public struct GasLimitConfiguration {
     static let defaultGasLimit = BigInt(90_000)
     static let minGasLimit = BigInt(21_000)
-    static let maxGasLimit = BigInt(1_000_000)
-}
+    //TODO make max be 1M unless for contract deployment then bigger, maybe 2M
+    static let maxGasLimit = BigInt(2_000_000)
+}