From 0ce4311376754b4cea7fc41dd3a6ae0d8077dd0b Mon Sep 17 00:00:00 2001
From: Owen Zhang <38493437+superboyiii@users.noreply.github.com>
Date: Thu, 21 Mar 2019 16:32:41 +0800
Subject: [PATCH] Make calculation for extra gas on "send*" RPC (#70)

* Make calculation for extra gas on "send*" RPC

* Fix for the calculation when little overstep
---
 RpcWallet/RpcWallet.cs          | 46 ++++++++++++++++++++++++++++++++-
 RpcWallet/RpcWallet.csproj      | 11 ++++++++
 RpcWallet/RpcWallet/config.json |  5 ++++
 RpcWallet/Settings.cs           | 29 +++++++++++++++++++++
 4 files changed, 90 insertions(+), 1 deletion(-)
 create mode 100644 RpcWallet/RpcWallet/config.json
 create mode 100644 RpcWallet/Settings.cs

diff --git a/RpcWallet/RpcWallet.cs b/RpcWallet/RpcWallet.cs
index 6c33f92b1..08365cea0 100644
--- a/RpcWallet/RpcWallet.cs
+++ b/RpcWallet/RpcWallet.cs
@@ -1,4 +1,4 @@
-using Akka.Actor;
+using Akka.Actor;
 using Microsoft.AspNetCore.Http;
 using Neo.IO;
 using Neo.IO.Json;
@@ -21,6 +21,7 @@ public class RpcWallet : Plugin, IRpcPlugin
 
         public override void Configure()
         {
+            Settings.Load(GetConfiguration());
         }
 
         public void PreProcess(HttpContext context, string method, JArray _params)
@@ -307,8 +308,25 @@ private JObject SendFrom(UIntBase assetId, UInt160 from, UInt160 to, string valu
                     ScriptHash = to
                 }
             }, from: from, change_address: change_address, fee: fee);
+            if (tx.Size > 1024)
+            {
+                fee += Fixed8.FromDecimal(tx.Size * 0.00001m + 0.001m);
+                tx = Wallet.MakeTransaction(null, new[]
+                {
+                    new TransferOutput
+                        {
+                            AssetId = assetId,
+                            Value = amount,
+                            ScriptHash = to
+                        }
+                }, from: from, change_address: change_address, fee: fee);
+            }
             if (tx == null)
                 throw new RpcException(-300, "Insufficient funds");
+            if (fee > Settings.Default.MaxFee)
+            {
+                throw new RpcException(-100, "The necessary fee is more than the Max_fee, this transaction is failed. Please increase your Max_fee value.");
+            }
             return SignAndRelay(tx);
         }
 
@@ -334,8 +352,17 @@ private JObject SendMany(UInt160 from, JArray to, Fixed8 fee, UInt160 change_add
             if (fee < Fixed8.Zero)
                 throw new RpcException(-32602, "Invalid params");
             Transaction tx = Wallet.MakeTransaction(null, outputs, from: from, change_address: change_address, fee: fee);
+            if (tx.Size > 1024)
+            {
+                fee += Fixed8.FromDecimal(tx.Size * 0.00001m + 0.001m);
+                tx = Wallet.MakeTransaction(null, outputs, from: from, change_address: change_address, fee: fee);
+            }
             if (tx == null)
                 throw new RpcException(-300, "Insufficient funds");
+            if (fee > Settings.Default.MaxFee)
+            {
+                throw new RpcException(-100, "The necessary fee is more than the Max_fee, this transaction is failed. Please increase your Max_fee value.");
+            }
             return SignAndRelay(tx);
         }
 
@@ -357,8 +384,25 @@ private JObject SendToAddress(UIntBase assetId, UInt160 scriptHash, string value
                     ScriptHash = scriptHash
                 }
             }, change_address: change_address, fee: fee);
+            if (tx.Size > 1024)
+            {
+                fee += Fixed8.FromDecimal(tx.Size * 0.00001m + 0.001m);
+                tx = Wallet.MakeTransaction(null, new[]
+                {
+                    new TransferOutput
+                    {
+                        AssetId = assetId,
+                        Value = amount,
+                        ScriptHash = scriptHash
+                    }
+                }, change_address: change_address, fee: fee);
+            }
             if (tx == null)
                 throw new RpcException(-300, "Insufficient funds");
+            if (fee > Settings.Default.MaxFee)
+            {
+                throw new RpcException(-100, "The necessary fee is more than the Max_fee, this transaction is failed. Please increase your Max_fee value.");
+            }
             return SignAndRelay(tx);
         }
     }
diff --git a/RpcWallet/RpcWallet.csproj b/RpcWallet/RpcWallet.csproj
index a88f11518..a19ce802b 100644
--- a/RpcWallet/RpcWallet.csproj
+++ b/RpcWallet/RpcWallet.csproj
@@ -5,9 +5,20 @@
     <TargetFramework>netstandard2.0</TargetFramework>
     <RootNamespace>Neo.Plugins</RootNamespace>
   </PropertyGroup>
+  
+  <ItemGroup>
+    <None Update="RpcWallet\config.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
+    </None>
+  </ItemGroup>
 
   <ItemGroup>
     <PackageReference Include="Neo" Version="2.10.0" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\..\neo\neo\neo.csproj" />
+  </ItemGroup>
+
 </Project>
diff --git a/RpcWallet/RpcWallet/config.json b/RpcWallet/RpcWallet/config.json
new file mode 100644
index 000000000..752d78ff9
--- /dev/null
+++ b/RpcWallet/RpcWallet/config.json
@@ -0,0 +1,5 @@
+{
+  "PluginConfiguration": {
+    "MaxFee": 0.1
+  }
+}
diff --git a/RpcWallet/Settings.cs b/RpcWallet/Settings.cs
new file mode 100644
index 000000000..ad7ebe412
--- /dev/null
+++ b/RpcWallet/Settings.cs
@@ -0,0 +1,29 @@
+using Microsoft.Extensions.Configuration;
+using System;
+using System.Linq;
+
+namespace Neo.Plugins
+{
+    internal class Settings
+    {
+        public Fixed8 MaxFee { get; }
+
+        public static Settings Default { get; private set; }
+
+        private Settings(IConfigurationSection section)
+        {
+            this.MaxFee = GetValueOrDefault(section.GetSection("MaxFee"), Fixed8.FromDecimal(0.1M), p => Fixed8.Parse(p));
+        }
+
+        public T GetValueOrDefault<T>(IConfigurationSection section, T defaultValue, Func<string, T> selector)
+        {
+            if (section.Value == null) return defaultValue;
+            return selector(section.Value);
+        }
+
+        public static void Load(IConfigurationSection section)
+        {
+            Default = new Settings(section);
+        }
+    }
+}