Modify fee calculations

Splitting fee between miner and DeStream extracted to function.
In consensus, sum of fees of all transactions is split, not each fee.

Sources/NBitcoin/Networks/DeStreamMain.cs

@@ -30,6 +30,18 @@ namespace NBitcoin
         /// </summary>
         public double FeeRate { get; set; }
 
+        /// <summary>
+        /// Splits fee between miner and DeStream
+        /// </summary>
+        /// <param name="fee">Total amount of fees to be split</param>
+        /// <param name="deStreamFee">DeStream fee part</param>
+        /// <param name="minerReward">Miner fee part</param>
+        public void SplitFee(long fee, out long deStreamFee, out long minerReward)
+        {
+            deStreamFee = Convert.ToInt64(fee * this.DeStreamFeePart);
+            minerReward = fee - deStreamFee;
+        }
+
         public bool IsDeStreamAddress(string address)
         {
             return this.DeStreamWallets.Contains(address);

Sources/Stratis.Bitcoin.Features.Consensus/Rules/CommonRules/DeStreamBlockFeeRule.cs

@@ -35,7 +35,9 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
                         $"Rule context must be {nameof(DeStreamPowRuleContext)} or {nameof(DeStreamRuleContext)}");
             }
 
-            if (Math.Abs(actualFee - expectedFee) > 1)
+            this.Parent.Network.SplitFee(expectedFee, out long expectedDeStreamFee, out long _);
+            
+            if (actualFee < expectedDeStreamFee)
                 ConsensusErrors.BadTransactionFeeOutOfRange.Throw();
 
             return Task.CompletedTask;
@@ -67,13 +69,13 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
         private long GetFeeInTransaction(Transaction transaction, Money totalIn,
             IEnumerable<Script> changeScriptPubKeys)
         {
-            double feeInTransaction = transaction.Outputs
+            long feeInTransaction = Convert.ToInt64(transaction.Outputs
                                           .Where(p => !changeScriptPubKeys.Contains(p.ScriptPubKey))
-                                          .Sum(p => p.Value) * this.Parent.Network.FeeRate;
+                                          .Sum(p => p.Value) * this.Parent.Network.FeeRate);
             if (Math.Abs(totalIn.Satoshi - transaction.TotalOut.Satoshi - feeInTransaction) > 1)
                 ConsensusErrors.BadTransactionFeeOutOfRange.Throw();
 
-            return (long) (feeInTransaction * this.Parent.Network.DeStreamFeePart);
+            return feeInTransaction;
         }
     }
 }
\ No newline at end of file

Sources/Stratis.Bitcoin.Features.Miner/DeStreamPosMinting.cs

@@ -157,16 +157,6 @@ namespace Stratis.Bitcoin.Features.Miner
 
             this.logger.LogTrace("Worker #{0} found the kernel.", workersResult.KernelFoundIndex);
 
-            // Get reward for newly created block.
-            long reward = this.GetReward(fees, chainTip.Height);
-            if (reward < 0)
-            {
-                // TODO: This can't happen unless we remove reward for mined block.
-                // If this can happen over time then this check could be done much sooner
-                // to avoid a lot of computation.
-                this.logger.LogTrace("(-)[NO_REWARD]:false");
-                return false;
-            }
 
             // Split stake if above threshold.
             this.SplitStake(nonEmptyUtxos, chainTip, coinstakeContext.CoinstakeTx.Outputs);
@@ -174,11 +164,8 @@ namespace Stratis.Bitcoin.Features.Miner
             // Input to coinstake transaction.
             UtxoStakeDescription coinstakeInput = workersResult.KernelCoin;
 
-            // Total amount of input values in coinstake transaction.
-            long coinstakeInputValue = coinstakeInput.TxOut.Value + reward;
-
             // Set output amount.
-            this.SetOutputAmount(coinstakeContext.CoinstakeTx.Outputs, coinstakeInput.TxOut.Value, fees, reward);
+            this.SetOutputAmount(coinstakeContext.CoinstakeTx.Outputs, coinstakeInput.TxOut.Value, fees);
 
             // Sign.
             if (!this.SignTransactionInput(coinstakeInput, coinstakeContext.CoinstakeTx))
@@ -204,32 +191,27 @@ namespace Stratis.Bitcoin.Features.Miner
             return true;
         }
 
-        private void SetOutputAmount(TxOutList outputs, long totalOut, long fees, long reward)
+        private void SetOutputAmount(TxOutList outputs, long totalOut, long fees)
         {
+            this.network.SplitFee(fees, out long deStreamFee, out long minerReward);
+            
             if (outputs.Count == 4)
             {
-                outputs[1].Value = (totalOut + reward) / 2 / Money.CENT * Money.CENT;
-                outputs[2].Value = totalOut + reward - outputs[1].Value;
-                outputs[3].Value = fees - reward;
+                outputs[1].Value = (totalOut + minerReward) / 2 / Money.CENT * Money.CENT;
+                outputs[2].Value = totalOut + minerReward - outputs[1].Value;
+                outputs[3].Value = deStreamFee;
                 this.logger.LogTrace("Coinstake first output value is {0}, second is {1}, third is {3}.",
                     outputs[1].Value, outputs[2].Value, outputs[3].Value);
             }
             else
             {
-                outputs[1].Value = totalOut + reward;
-                outputs[2].Value = fees - reward;
+                outputs[1].Value = totalOut + minerReward;
+                outputs[2].Value = deStreamFee;
                 this.logger.LogTrace("Coinstake first output value is {0}, second is {1} .", outputs[1].Value,
                     outputs[2].Value);
             }
         }
 
-        private long GetReward(long fees, int chainTipHeight)
-        {
-            return (long) (fees * (1 - this.network.DeStreamFeePart)) +
-                   this.consensusLoop.ConsensusRules.GetRule<PosCoinviewRule>()
-                       .GetProofOfStakeReward(chainTipHeight + 1);
-        }
-
         private void SplitStake(int nonEmptyUtxos, ChainedHeader chainTip, TxOutList outputs)
         {
             if (!this.GetSplitStake(nonEmptyUtxos, chainTip)) return;

Sources/Stratis.Bitcoin.Features.Miner/DeStreamPosPowBlockDefinition.cs

-using System.Linq;
+using System;
+using System.Linq;
 using Microsoft.Extensions.Logging;
 using NBitcoin;
 using NBitcoin.DataEncoders;
@@ -63,9 +64,9 @@ namespace Stratis.Bitcoin.Features.Miner
             // pblocktemplate->CoinbaseCommitment = GenerateCoinbaseCommitment(*pblock, pindexPrev, chainparams.GetConsensus());
 
             var coinviewRule = this.ConsensusLoop.ConsensusRules.GetRule<CoinViewRule>();
-            this.coinbase.Outputs[0].Value = (long) (this.fees.Satoshi * (1 - this.Network.DeStreamFeePart)) +
-                                             coinviewRule.GetProofOfWorkReward(this.height);
-            this.coinbase.Outputs[1].Value = (long) (this.fees.Satoshi * this.Network.DeStreamFeePart);
+            this.Network.SplitFee(this.fees.Satoshi, out long deStreamFee, out long minerReward);
+            this.coinbase.Outputs[0].Value =  minerReward;
+            this.coinbase.Outputs[1].Value = deStreamFee;
             this.BlockTemplate.TotalFee = this.fees;
 
             int nSerializeSize = this.block.GetSerializedSize();

Sources/Stratis.Bitcoin.Features.Miner/DeStreamPowBlockDefinition.cs

-using System.Linq;
+using System;
+using System.Linq;
 using Microsoft.Extensions.Logging;
 using NBitcoin;
 using NBitcoin.DataEncoders;
@@ -63,9 +64,9 @@ namespace Stratis.Bitcoin.Features.Miner
             // pblocktemplate->CoinbaseCommitment = GenerateCoinbaseCommitment(*pblock, pindexPrev, chainparams.GetConsensus());
 
             var coinviewRule = this.ConsensusLoop.ConsensusRules.GetRule<CoinViewRule>();
-            this.coinbase.Outputs[0].Value = (long) (this.fees.Satoshi * (1 - this.Network.DeStreamFeePart)) +
-                                             coinviewRule.GetProofOfWorkReward(this.height);
-            this.coinbase.Outputs[1].Value = (long) (this.fees.Satoshi * this.Network.DeStreamFeePart);
+            this.Network.SplitFee(this.fees.Satoshi, out long deStreamFee, out long minerReward);
+            this.coinbase.Outputs[0].Value =  minerReward;
+            this.coinbase.Outputs[1].Value = deStreamFee;
             this.BlockTemplate.TotalFee = this.fees;
 
             int nSerializeSize = this.block.GetSerializedSize();

Sources/Stratis.Bitcoin.Features.Wallet/DeStreamWalletTransactionHandler.cs

@@ -22,7 +22,7 @@ namespace Stratis.Bitcoin.Features.Wallet
         /// <inheritdoc />
         protected override void AddFee(TransactionBuildContext context)
         {
-            long fee = (long) (context.Recipients.Sum(p => p.Amount) * this.Network.FeeRate);
+            long fee = Convert.ToInt64(context.Recipients.Sum(p => p.Amount) * this.Network.FeeRate);
             context.TransactionFee = fee;
             context.TransactionBuilder.SendFees(fee);
         }