dash/src/darksend.cpp

// Copyright (c) 2014-2015 The Darkcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "darksend.h"
#include "main.h"
#include "init.h"
#include "util.h"
#include "masternodeman.h"
#include "instantx.h"
#include "ui_interface.h"

#include <boost/algorithm/string/replace.hpp>
#include <boost/filesystem.hpp>
#include <boost/filesystem/fstream.hpp>
#include <boost/lexical_cast.hpp>

#include <algorithm>
#include <boost/assign/list_of.hpp>

using namespace std;
using namespace boost;

CCriticalSection cs_darksend;

// The main object for accessing Darksend 
CDarksendPool darkSendPool;
// A helper object for signing messages from masternodes 
CDarkSendSigner darkSendSigner;
// The current Darksends in progress on the network 
std::vector<CDarksendQueue> vecDarksendQueue;
// Keep track of the used masternodes 
std::vector<CTxIn> vecMasternodesUsed;
// Keep track of the scanning errors I've seen
map<uint256, CDarksendBroadcastTx> mapDarksendBroadcastTxes;
// Keep track of the active masternode
CActiveMasternode activeMasternode;

// Count peers we've requested the list from
int RequestedMasterNodeList = 0;

/* *** BEGIN DARKSEND MAGIC - DARKCOIN **********
    Copyright 2014-2015, Darkcoin Developers
        eduffield - evan@darkcoin.io
        udjinm6   - udjinm6@darkcoin.io
*/

void CDarksendPool::ProcessMessageDarksend(CNode* pfrom, std::string& strCommand, CDataStream& vRecv)
{
    if(fLiteMode) return; //disable all Darksend/masternode related functionality
    if(IsInitialBlockDownload()) return;

    if (strCommand == "dsa") { //Darksend Accept Into Pool

        if (pfrom->nVersion < MIN_POOL_PEER_PROTO_VERSION) {
            std::string strError = _("Incompatible version.");
            LogPrintf("dsa -- incompatible version! \n");
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, strError);

            return;
        }

        if(!fMasterNode){
            std::string strError = _("This is not a masternode.");
            LogPrintf("dsa -- not a masternode! \n");
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, strError);

            return;
        }

        int nDenom;
        CTransaction txCollateral;
        vRecv >> nDenom >> txCollateral;

        std::string error = "";
        CMasternode* pmn = mnodeman.Find(activeMasternode.vin);
        if(pmn == NULL)
        {
            std::string strError = _("Not in the masternode list.");
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, strError);
            return;
        }

        if(sessionUsers == 0) {
            if(pmn->nLastDsq != 0 &&
                pmn->nLastDsq + mnodeman.CountMasternodesAboveProtocol(MIN_POOL_PEER_PROTO_VERSION)/5 > nDsqCount){
                LogPrintf("dsa -- last dsq too recent, must wait. %s \n", pmn->addr.ToString().c_str());
                std::string strError = _("Last Darksend was too recent.");
                pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, strError);
                return;
            }
        }

        if(!IsCompatibleWithSession(nDenom, txCollateral, error))
        {
            LogPrintf("dsa -- not compatible with existing transactions! \n");
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);
            return;
        } else {
            LogPrintf("dsa -- is compatible, please submit! \n");
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_ACCEPTED, error);
            return;
        }

    } else if (strCommand == "dsq") { //Darksend Queue
        LOCK(cs_darksend);

        if (pfrom->nVersion < MIN_POOL_PEER_PROTO_VERSION) {
            return;
        }

        CDarksendQueue dsq;
        vRecv >> dsq;

        CService addr;
        if(!dsq.GetAddress(addr)) return;
        if(!dsq.CheckSignature()) return;

        if(dsq.IsExpired()) return;

        CMasternode* pmn = mnodeman.Find(dsq.vin);
        if(pmn == NULL) return;

        // if the queue is ready, submit if we can
        if(dsq.ready) {
            if(!pSubmittedToMasternode) return;
            if((CNetAddr)pSubmittedToMasternode->addr != (CNetAddr)addr){
                LogPrintf("dsq - message doesn't match current masternode - %s != %s\n", pSubmittedToMasternode->addr.ToString().c_str(), addr.ToString().c_str());
                return;
            }

            if(state == POOL_STATUS_QUEUE){
                //save the relay signature info
                AddRelaySignature(dsq.vchRelaySig, dsq.nBlockHeight, dsq.strSharedKey);

                if (fDebug)  LogPrintf("Darksend queue is ready - %s\n", addr.ToString().c_str());
                PrepareDarksendDenominate();
            }
        } else {
            BOOST_FOREACH(CDarksendQueue q, vecDarksendQueue){
                if(q.vin == dsq.vin) return;
            }

            if(fDebug) LogPrintf("dsq last %d last2 %d count %d\n", pmn->nLastDsq, pmn->nLastDsq + mnodeman.size()/5, nDsqCount);
            //don't allow a few nodes to dominate the queuing process
            if(pmn->nLastDsq != 0 &&
                pmn->nLastDsq + mnodeman.CountMasternodesAboveProtocol(MIN_POOL_PEER_PROTO_VERSION)/5 > nDsqCount){
                if(fDebug) LogPrintf("dsq -- masternode sending too many dsq messages. %s \n", pmn->addr.ToString().c_str());
                return;
            }
            nDsqCount++;
            pmn->nLastDsq = nDsqCount;
            pmn->allowFreeTx = true;

            if(fDebug) LogPrintf("dsq - new Darksend queue object - %s\n", addr.ToString().c_str());
            vecDarksendQueue.push_back(dsq);
            dsq.Relay();
            dsq.time = GetTime();
        }

    } else if (strCommand == "dsr") { //Darksend Relay

        //* Ask a masternode to relay an anonymous output to another masternode *//

        std::string error = "";
        if (pfrom->nVersion < MIN_POOL_PEER_PROTO_VERSION) {
            LogPrintf("dsr -- incompatible version! \n");
            return;
        }

        if(!fMasterNode){
            LogPrintf("dsr -- not a masternode! \n");
            return;
        }

        CDarkSendRelay dsr;
        vRecv >> dsr;

        if(chainActive.Tip()->nHeight - dsr.nBlockHeight > 10) return;

        if(dsr.nRelayType != DARKSEND_RELAY_IN &&
            dsr.nRelayType != DARKSEND_RELAY_OUT &&
            dsr.nRelayType != DARKSEND_RELAY_SIG) return;


        if(dsr.in == CTxIn() && dsr.nRelayType == DARKSEND_RELAY_IN) return;
        if(dsr.out == CTxOut() && dsr.nRelayType == DARKSEND_RELAY_OUT) return;
        if(dsr.in == CTxIn() && dsr.nRelayType == DARKSEND_RELAY_SIG) return;

        CMasternode* pmn = mnodeman.Find(dsr.vinMasternode);
        if(!pmn){
            LogPrintf("dsr -- unknown masternode! %s \n", dsr.vinMasternode.ToString().c_str());
            return;
        }

        int a = mnodeman.GetMasternodeRank(activeMasternode.vin, chainActive.Tip()->nHeight, MIN_POOL_PEER_PROTO_VERSION);

        if(a > 20){
            LogPrintf("dsr -- unknown/invalid masternode! %s \n", activeMasternode.vin.ToString().c_str());
            return;
        }

        //check the signature from the target masternode
        std::string strMessage = boost::lexical_cast<std::string>(dsr.nBlockHeight);
        std::string errorMessage = "";
        if(!darkSendSigner.VerifyMessage(pmn->pubkey2, dsr.vchSig, strMessage, errorMessage)){
            LogPrintf("dsr - Got bad masternode address signature\n");
            Misbehaving(pfrom->GetId(), 100);
            return;
        }

        //connect and deliver the message
        if(ConnectNode((CAddress)pmn->addr, NULL, true)){
            CNode* pNode = FindNode(pmn->addr);
            if(pNode)
            {
                pNode->PushMessage("dsai", dsr);
                return;
            }
        }

    } else if (strCommand == "dsai") { //Darksend Anonymous Item (Input/Output/Sig)

        std::string error = "";
        if (pfrom->nVersion < MIN_POOL_PEER_PROTO_VERSION) {
            LogPrintf("dsai -- incompatible version! \n");
            return;
        }

        if(!fMasterNode){
            LogPrintf("dsai -- not a masternode! \n");
            return;
        }

        CDarkSendRelay dsr;
        vRecv >> dsr;

        if(chainActive.Tip()->nHeight - dsr.nBlockHeight > 10) return;
        if(darkSendPool.strMasternodeSharedKey == "") return;
        if(dsr.nRelayType != DARKSEND_RELAY_IN &&
            dsr.nRelayType != DARKSEND_RELAY_OUT &&
            dsr.nRelayType != DARKSEND_RELAY_SIG) return;
        if(dsr.in == CTxIn() && dsr.nRelayType == DARKSEND_RELAY_IN) return;
        if(dsr.out == CTxOut() && dsr.nRelayType == DARKSEND_RELAY_OUT) return;
        if(dsr.in == CTxIn() && dsr.nRelayType == DARKSEND_RELAY_SIG) return;

        CMasternode* pmn = mnodeman.Find(dsr.vinMasternode);
        if(!pmn){
            LogPrintf("dsr -- unknown masternode! %s \n", dsr.vinMasternode.ToString().c_str());
            return;
        }

        //check the signature from the target masternode
        std::string strMessage = boost::lexical_cast<std::string>(dsr.nBlockHeight);
        std::string errorMessage = "";
        if(!darkSendSigner.VerifyMessage(pmn->pubkey2, dsr.vchSig, strMessage, errorMessage)){
            LogPrintf("dsr - Got bad masternode address signature\n");
            Misbehaving(pfrom->GetId(), 100);
            return;
        }

        if(!dsr.VerifyMessage(darkSendPool.strMasternodeSharedKey)){
            LogPrintf("dsai - Got bad shared key signature\n");
            Misbehaving(pfrom->GetId(), 30);
            return;
        }

        //do we have enough users in the current session?
        if(!IsSessionReady()){
            LogPrintf("dsai -- session not complete! \n");
            return;
        }

        switch(dsr.nRelayType){
        case DARKSEND_RELAY_IN:
            anonTx.AddInput(dsr.in);
            break;
        case DARKSEND_RELAY_OUT:
            anonTx.AddOutput(dsr.out);
            break;
        case DARKSEND_RELAY_SIG:
            anonTx.AddSig(dsr.in);
            break;
        }

        // relay to all peers that an entry was added to the pool successfully.
        RelayStatus(sessionID, GetState(), GetEntriesCount(), MASTERNODE_ACCEPTED);
        Check();

    } else if (strCommand == "dsi") { //Darksend vIn

        std::string error = "";
        if (pfrom->nVersion < MIN_POOL_PEER_PROTO_VERSION) {
            LogPrintf("dsi -- incompatible version! \n");
            error = _("Incompatible version.");
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);

            return;
        }

        if(!fMasterNode){
            LogPrintf("dsi -- not a masternode! \n");
            error = _("This is not a masternode.");
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);

            return;
        }

        std::vector<CTxIn> in;
        int64_t nAmount;
        CTransaction txCollateral;
        std::vector<CTxOut> out;
        vRecv >> in >> nAmount >> txCollateral >> out;

        //do we have enough users in the current session?
        if(!IsSessionReady()){
            LogPrintf("dsi -- session not complete! \n");
            error = _("Session not complete!");
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);
            return;
        }

        //do we have the same denominations as the current session?
        if(!IsCompatibleWithEntries(out))
        {
            LogPrintf("dsi -- not compatible with existing transactions! \n");
            error = _("Not compatible with existing transactions.");
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);
            return;
        }

        //check it like a transaction
        {
            int64_t nValueIn = 0;
            int64_t nValueOut = 0;
            bool missingTx = false;

            CValidationState state;
            CTransaction tx;

            BOOST_FOREACH(const CTxOut o, out){
                nValueOut += o.nValue;
                tx.vout.push_back(o);

                if(o.scriptPubKey.size() != 25){
                    LogPrintf("dsi - non-standard pubkey detected! %s\n", o.scriptPubKey.ToString().c_str());
                    error = _("Non-standard public key detected.");
                    pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);
                    return;
                }
                if(!o.scriptPubKey.IsNormalPaymentScript()){
                    LogPrintf("dsi - invalid script! %s\n", o.scriptPubKey.ToString().c_str());
                    error = _("Invalid script detected.");
                    pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);
                    return;
                }
            }

            BOOST_FOREACH(const CTxIn i, in){
                tx.vin.push_back(i);

                if(fDebug) LogPrintf("dsi -- tx in %s\n", i.ToString().c_str());

                CTransaction tx2;
                uint256 hash;
                if(GetTransaction(i.prevout.hash, tx2, hash, true)){
                    if(tx2.vout.size() > i.prevout.n) {
                        nValueIn += tx2.vout[i.prevout.n].nValue;
                    }
                } else{
                    missingTx = true;
                }
            }

            if (nValueIn > DARKSEND_POOL_MAX) {
                LogPrintf("dsi -- more than Darksend pool max! %s\n", tx.ToString().c_str());
                error = _("Value more than Darksend pool maximum allows.");
                pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);
                return;
            }

            if(!missingTx){
                if (nValueIn-nValueOut > nValueIn*.01) {
                    LogPrintf("dsi -- fees are too high! %s\n", tx.ToString().c_str());
                    error = _("Transaction fees are too high.");
                    pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);
                    return;
                }
            } else {
                LogPrintf("dsi -- missing input tx! %s\n", tx.ToString().c_str());
                error = _("Missing input transaction information.");
                pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);
                return;
            }

            if(!AcceptableInputs(mempool, state, tx)){
                LogPrintf("dsi -- transaction not valid! \n");
                error = _("Transaction not valid.");
                pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);
                return;
            }
        }

        if(AddEntry(in, nAmount, txCollateral, out, error)){
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_ACCEPTED, error);
            Check();

            RelayStatus(sessionID, GetState(), GetEntriesCount(), MASTERNODE_RESET);
        } else {
            pfrom->PushMessage("dssu", sessionID, GetState(), GetEntriesCount(), MASTERNODE_REJECTED, error);
        }

    } else if (strCommand == "dssu") { //Darksend status update

        if (pfrom->nVersion < MIN_POOL_PEER_PROTO_VERSION) {
            return;
        }

        if(!pSubmittedToMasternode) return;
        if((CNetAddr)pSubmittedToMasternode->addr != (CNetAddr)pfrom->addr){
            //LogPrintf("dssu - message doesn't match current masternode - %s != %s\n", pSubmittedToMasternode->addr.ToString().c_str(), pfrom->addr.ToString().c_str());
            return;
        }

        int sessionIDMessage;
        int state;
        int entriesCount;
        int accepted;
        std::string error;
        vRecv >> sessionIDMessage >> state >> entriesCount >> accepted >> error;

        if(fDebug) LogPrintf("dssu - state: %i entriesCount: %i accepted: %i error: %s \n", state, entriesCount, accepted, error.c_str());

        if((accepted != 1 && accepted != 0) && sessionID != sessionIDMessage){
            LogPrintf("dssu - message doesn't match current Darksend session %d %d\n", sessionID, sessionIDMessage);
            return;
        }

        StatusUpdate(state, entriesCount, accepted, error, sessionIDMessage);

    } else if (strCommand == "dss") { //Darksend Sign Final Tx

        if (pfrom->nVersion < MIN_POOL_PEER_PROTO_VERSION) {
            return;
        }

        vector<CTxIn> sigs;
        vRecv >> sigs;

        bool success = false;
        int count = 0;

        LogPrintf(" -- sigs count %d %d\n", (int)sigs.size(), count);

        BOOST_FOREACH(const CTxIn item, sigs)
        {
            if(AddScriptSig(item)) success = true;
            if(fDebug) LogPrintf(" -- sigs count %d %d\n", (int)sigs.size(), count);
            count++;
        }

        if(success){
            CheckFinalTransaction();
            RelayStatus(sessionID, GetState(), GetEntriesCount(), MASTERNODE_RESET);
        }
    } else if (strCommand == "dsf") { //Darksend Final tx
        if (pfrom->nVersion < MIN_POOL_PEER_PROTO_VERSION) {
            return;
        }

        if(!pSubmittedToMasternode) return;
        if((CNetAddr)pSubmittedToMasternode->addr != (CNetAddr)pfrom->addr){
            //LogPrintf("dsc - message doesn't match current masternode - %s != %s\n", pSubmittedToMasternode->addr.ToString().c_str(), pfrom->addr.ToString().c_str());
            return;
        }

        int sessionIDMessage;
        CTransaction txNew;
        vRecv >> sessionIDMessage >> txNew;

        if(sessionID != sessionIDMessage){
            if (fDebug) LogPrintf("dsf - message doesn't match current Darksend session %d %d\n", sessionID, sessionIDMessage);
            return;
        }

        //check to see if input is spent already? (and probably not confirmed)
        SignFinalTransaction(txNew, pfrom);

    } else if (strCommand == "dsc") { //Darksend Complete

        if (pfrom->nVersion < MIN_POOL_PEER_PROTO_VERSION) {
            return;
        }

        if(!pSubmittedToMasternode) return;
        if((CNetAddr)pSubmittedToMasternode->addr != (CNetAddr)pfrom->addr){
            //LogPrintf("dsc - message doesn't match current masternode - %s != %s\n", pSubmittedToMasternode->addr.ToString().c_str(), pfrom->addr.ToString().c_str());
            return;
        }

        int sessionIDMessage;
        bool error;
        std::string lastMessage;
        vRecv >> sessionIDMessage >> error >> lastMessage;

        if(sessionID != sessionIDMessage){
            if (fDebug) LogPrintf("dsc - message doesn't match current Darksend session %d %d\n", darkSendPool.sessionID, sessionIDMessage);
            return;
        }

        darkSendPool.CompletedTransaction(error, lastMessage);
    }

}

int randomizeList (int i) { return std::rand()%i;}

// Recursively determine the rounds of a given input (How deep is the Darksend chain for a given input)
int GetInputDarksendRounds(CTxIn in, int rounds)
{
    static std::map<uint256, CWalletTx> mDenomWtxes;

    if(rounds >= 17) return rounds;

    uint256 hash = in.prevout.hash;
    unsigned int nout = in.prevout.n;

    CWalletTx wtx;
    if(pwalletMain->GetTransaction(hash, wtx))
    {
        std::map<uint256, CWalletTx>::const_iterator mdwi = mDenomWtxes.find(hash);
        // not known yet, let's add it
        if(mdwi == mDenomWtxes.end())
        {
            if(fDebug) LogPrintf("GetInputDarksendRounds INSERTING %s\n", hash.ToString());
            mDenomWtxes[hash] = wtx;
        }
        // found and it's not an initial value, just return it
        else if(mDenomWtxes[hash].vout[nout].nRounds != -10)
        {
            if(fDebug) LogPrintf("GetInputDarksendRounds INFO      %s %3d %d\n", hash.ToString(), nout, mDenomWtxes[hash].vout[nout].nRounds);
            return mDenomWtxes[hash].vout[nout].nRounds;
        }


        // bounds check
        if(nout >= wtx.vout.size())
        {
            mDenomWtxes[hash].vout[nout].nRounds = -4;
            if(fDebug) LogPrintf("GetInputDarksendRounds UPDATED   %s %3d %d\n", hash.ToString(), nout, mDenomWtxes[hash].vout[nout].nRounds);
            return mDenomWtxes[hash].vout[nout].nRounds;
        }

        mDenomWtxes[hash].vout[nout].nRounds = -3;
        if(pwalletMain->IsCollateralAmount(wtx.vout[nout].nValue))
        {
            mDenomWtxes[hash].vout[nout].nRounds = -3;
            if(fDebug) LogPrintf("GetInputDarksendRounds UPDATED   %s %3d %d\n", hash.ToString(), nout, mDenomWtxes[hash].vout[nout].nRounds);
            return mDenomWtxes[hash].vout[nout].nRounds;
        }

        //make sure the final output is non-denominate
        mDenomWtxes[hash].vout[nout].nRounds = -2;
        if(/*rounds == 0 && */!pwalletMain->IsDenominatedAmount(wtx.vout[nout].nValue)) //NOT DENOM
        {
            mDenomWtxes[hash].vout[nout].nRounds = -2;
            if(fDebug) LogPrintf("GetInputDarksendRounds UPDATED   %s %3d %d\n", hash.ToString(), nout, mDenomWtxes[hash].vout[nout].nRounds);
            return mDenomWtxes[hash].vout[nout].nRounds;
        }

        bool fAllDenoms = true;
        BOOST_FOREACH(CTxOut out, wtx.vout)
        {
            fAllDenoms = fAllDenoms && pwalletMain->IsDenominatedAmount(out.nValue);
        }
        // this one is denominated but there is another non-denominated output found in the same tx
        if(!fAllDenoms)
        {
            mDenomWtxes[hash].vout[nout].nRounds = 0;
            if(fDebug) LogPrintf("GetInputDarksendRounds UPDATED   %s %3d %d\n", hash.ToString(), nout, mDenomWtxes[hash].vout[nout].nRounds);
            return mDenomWtxes[hash].vout[nout].nRounds;
        }

        int nShortest = -10; // an initial value, should be no way to get this by calculations
        bool fDenomFound = false;
        // only denoms here so let's look up
        BOOST_FOREACH(CTxIn in2, wtx.vin)
        {
            if(pwalletMain->IsMine(in2))
            {
                int n = GetInputDarksendRounds(in2, rounds+1);
                // denom found, find the shortest chain or initially assign nShortest with the first found value
                if(n >= 0 && (n < nShortest || nShortest == -10))
                {
                    nShortest = n;
                    fDenomFound = true;
                }
            }
        }
        mDenomWtxes[hash].vout[nout].nRounds = fDenomFound
                ? nShortest + 1 // good, we a +1 to the shortest one
                : 0;            // too bad, we are the fist one in that chain
        if(fDebug) LogPrintf("GetInputDarksendRounds UPDATED   %s %3d %d\n", hash.ToString(), nout, mDenomWtxes[hash].vout[nout].nRounds);
        return mDenomWtxes[hash].vout[nout].nRounds;
    }

    return rounds-1;
}

void CDarksendPool::Reset(){
    cachedLastSuccess = 0;
    vecMasternodesUsed.clear();
    UnlockCoins();
    SetNull();
}

void CDarksendPool::SetNull(bool clearEverything){
    finalTransaction.vin.clear();
    finalTransaction.vout.clear();

    entries.clear();
    anonTx.vin.clear();
    anonTx.vout.clear();
    fResentInputsOutputs = false;

    state = POOL_STATUS_IDLE;

    lastTimeChanged = GetTimeMillis();

    entriesCount = 0;
    lastEntryAccepted = 0;
    countEntriesAccepted = 0;
    lastNewBlock = 0;
    fSubmitAnonymousFailed = false;

    sessionUsers = 0;
    sessionDenom = 0;
    sessionFoundMasternode = false;
    vecSessionCollateral.clear();
    txCollateral = CTransaction();

    vchMasternodeRelaySig.clear();
    nMasternodeBlockHeight = 0;

    if(clearEverything){
        myEntries.clear();

        if(fMasterNode){
            sessionID = 1 + (rand() % 999999);
        } else {
            sessionID = 0;
        }
    }

    // -- seed random number generator (used for ordering output lists)
    unsigned int seed = 0;
    RAND_bytes((unsigned char*)&seed, sizeof(seed));
    std::srand(seed);
}

bool CDarksendPool::SetCollateralAddress(std::string strAddress){
    CBitcoinAddress address;
    if (!address.SetString(strAddress))
    {
        LogPrintf("CDarksendPool::SetCollateralAddress - Invalid Darksend collateral address\n");
        return false;
    }
    collateralPubKey.SetDestination(address.Get());
    return true;
}

//
// Unlock coins after Darksend fails or succeeds
//
void CDarksendPool::UnlockCoins(){
    BOOST_FOREACH(CTxIn v, lockedCoins)
        pwalletMain->UnlockCoin(v.prevout);

    lockedCoins.clear();
}

//
// Check the Darksend progress and send client updates if a masternode
//
void CDarksendPool::Check()
{
    if(fDebug) LogPrintf("CDarksendPool::Check()\n");
    if(fDebug) LogPrintf("CDarksendPool::Check() - entries count %lu\n", entries.size());

    //printf("CDarksendPool::Check() %d - %d - %d\n", state, anonTx.CountEntries(), GetTimeMillis()-lastTimeChanged);

    // If entries is full, then move on to the next phase
    if(state == POOL_STATUS_ACCEPTING_ENTRIES && (
        (int)entries.size() >= GetMaxPoolTransactions() ||
        (GetTimeMillis()-lastTimeChanged > 5000 && anonTx.CountEntries() > GetMaxPoolTransactions()*5)
        ))
    {
        if(fDebug) LogPrintf("CDarksendPool::Check() -- TRYING TRANSACTION \n");
        UpdateState(POOL_STATUS_FINALIZE_TRANSACTION);
        nCountAttempts++;
    }

    // create the finalized transaction for distribution to the clients
    if(state == POOL_STATUS_FINALIZE_TRANSACTION) {
        if(fDebug) LogPrintf("CDarksendPool::Check() -- FINALIZE TRANSACTIONS\n");
        UpdateState(POOL_STATUS_SIGNING);

        if (fMasterNode) {
            CTransaction txNew;

            // make our new transaction
            if((int)entries.size() >= GetMaxPoolTransactions()) {
                for(unsigned int i = 0; i < entries.size(); i++){
                    BOOST_FOREACH(const CTxOut& v, entries[i].vout)
                        txNew.vout.push_back(v);

                    BOOST_FOREACH(const CTxDSIn& s, entries[i].sev)
                        txNew.vin.push_back(s);
                }

                // shuffle the outputs for improved anonymity
                std::random_shuffle ( txNew.vout.begin(), txNew.vout.end(), randomizeList);
            } else {
                BOOST_FOREACH(CTxDSIn& v, anonTx.vin)
                    txNew.vin.push_back((CTxIn)v);

                BOOST_FOREACH(CTxOut& v, anonTx.vout)
                    txNew.vout.push_back(v);
            }

            if(fDebug) LogPrintf("Transaction 1: %s\n", txNew.ToString().c_str());
            SignFinalTransaction(txNew, NULL);

            // request signatures from clients
            RelayFinalTransaction(sessionID, finalTransaction);
        }
    }

    //printf("Signing Status %d %d\n", state == POOL_STATUS_SIGNING, SignaturesComplete());

    // If we have all of the signatures, try to compile the transaction
    if(state == POOL_STATUS_SIGNING && SignaturesComplete()) {
        if(fDebug) LogPrintf("CDarksendPool::Check() -- SIGNING\n");
        UpdateState(POOL_STATUS_TRANSMISSION);

        CheckFinalTransaction();
    }

    // reset if we're here for 10 seconds
    if((state == POOL_STATUS_ERROR || state == POOL_STATUS_SUCCESS) && GetTimeMillis()-lastTimeChanged >= 10000) {
        if(fDebug) LogPrintf("CDarksendPool::Check() -- RESETTING MESSAGE \n");
        SetNull(true);
        if(fMasterNode) RelayStatus(darkSendPool.sessionID, darkSendPool.GetState(), darkSendPool.GetEntriesCount(), MASTERNODE_RESET);
        UnlockCoins();
    }
}

void CDarksendPool::CheckFinalTransaction()
{
    CWalletTx txNew = CWalletTx(pwalletMain, finalTransaction);

    LOCK2(cs_main, pwalletMain->cs_wallet);
    {
        if (fMasterNode) { //only the main node is master atm
            if(fDebug) LogPrintf("Transaction 2: %s\n", txNew.ToString().c_str());

            // See if the transaction is valid
            if (!txNew.AcceptToMemoryPool(true))
            {
                if(nCountAttempts > 10) {
                    LogPrintf("CDarksendPool::Check() - CommitTransaction : Error: Transaction not valid\n");
                    SetNull();
                    pwalletMain->Lock();
                }

                // not much we can do in this case]
                UpdateState(POOL_STATUS_ACCEPTING_ENTRIES);
                if(nCountAttempts > 5) RelayCompletedTransaction(sessionID, true, "Transaction not valid, please try again");

                if(!fSubmitAnonymousFailed && nCountAttempts > 5)
                    fSubmitAnonymousFailed = true;
                return;
            }

            LogPrintf("CDarksendPool::Check() -- IS MASTER -- TRANSMITTING DARKSEND\n");

            // sign a message

            int64_t sigTime = GetAdjustedTime();
            std::string strMessage = txNew.GetHash().ToString() + boost::lexical_cast<std::string>(sigTime);
            std::string strError = "";
            std::vector<unsigned char> vchSig;
            CKey key2;
            CPubKey pubkey2;

            if(!darkSendSigner.SetKey(strMasterNodePrivKey, strError, key2, pubkey2))
            {
                LogPrintf("CDarksendPool::Check() - ERROR: Invalid masternodeprivkey: '%s'\n", strError.c_str());
                return;
            }

            if(!darkSendSigner.SignMessage(strMessage, strError, vchSig, key2)) {
                LogPrintf("CDarksendPool::Check() - Sign message failed\n");
                return;
            }

            if(!darkSendSigner.VerifyMessage(pubkey2, vchSig, strMessage, strError)) {
                LogPrintf("CDarksendPool::Check() - Verify message failed\n");
                return;
            }

            if(!mapDarksendBroadcastTxes.count(txNew.GetHash())){
                CDarksendBroadcastTx dstx;
                dstx.tx = txNew;
                dstx.vin = activeMasternode.vin;
                dstx.vchSig = vchSig;
                dstx.sigTime = sigTime;

                mapDarksendBroadcastTxes.insert(make_pair(txNew.GetHash(), dstx));
            }

            // Broadcast the transaction to the network
            txNew.fTimeReceivedIsTxTime = true;
            txNew.RelayWalletTransaction();

            // Tell the clients it was successful
            RelayCompletedTransaction(sessionID, false, _("Transaction created successfully."));

            // Randomly charge clients
            ChargeRandomFees();

            // Reset
            if(fDebug) LogPrintf("CDarksendPool::Check() -- COMPLETED -- RESETTING \n");
            SetNull(true);
            UnlockCoins();
            if(fMasterNode) RelayStatus(darkSendPool.sessionID, darkSendPool.GetState(), darkSendPool.GetEntriesCount(), MASTERNODE_RESET);
            pwalletMain->Lock();
        }
    }
}

//
// Charge clients a fee if they're abusive
//
// Why bother? Darksend uses collateral to ensure abuse to the process is kept to a minimum.
// The submission and signing stages in Darksend are completely separate. In the cases where
// a client submits a transaction then refused to sign, there must be a cost. Otherwise they
// would be able to do this over and over again and bring the mixing to a hault.
//
// How does this work? Messages to masternodes come in via "dsi", these require a valid collateral
// transaction for the client to be able to enter the pool. This transaction is kept by the masternode
// until the transaction is either complete or fails.
//
void CDarksendPool::ChargeFees(){
    if(fMasterNode) {
        //we don't need to charge collateral for every offence.
        int offences = 0;
        int r = rand()%100;
        if(r > 33) return;

        if(state == POOL_STATUS_ACCEPTING_ENTRIES){
            BOOST_FOREACH(const CTransaction& txCollateral, vecSessionCollateral) {
                bool found = false;
                BOOST_FOREACH(const CDarkSendEntry& v, entries) {
                    if(v.collateral == txCollateral) {
                        found = true;
                    }
                }

                // This queue entry didn't send us the promised transaction
                if(!found){
                    LogPrintf("CDarksendPool::ChargeFees -- found uncooperative node (didn't send transaction). Found offence.\n");
                    offences++;
                }
            }
        }

        if(state == POOL_STATUS_SIGNING) {
            // who didn't sign?
            BOOST_FOREACH(const CDarkSendEntry v, entries) {
                BOOST_FOREACH(const CTxDSIn s, v.sev) {
                    if(!s.fHasSig){
                        LogPrintf("CDarksendPool::ChargeFees -- found uncooperative node (didn't sign). Found offence\n");
                        offences++;
                    }
                }
            }
        }

        r = rand()%100;
        int target = 0;

        //mostly offending?
        if(offences >= POOL_MAX_TRANSACTIONS-1 && r > 33) return;

        //everyone is an offender? That's not right
        if(offences >= POOL_MAX_TRANSACTIONS) return;

        //charge one of the offenders randomly
        if(offences > 1) target = 50;

        //pick random client to charge
        r = rand()%100;

        if(state == POOL_STATUS_ACCEPTING_ENTRIES){
            BOOST_FOREACH(const CTransaction& txCollateral, vecSessionCollateral) {
                bool found = false;
                BOOST_FOREACH(const CDarkSendEntry& v, entries) {
                    if(v.collateral == txCollateral) {
                        found = true;
                    }
                }

                // This queue entry didn't send us the promised transaction
                if(!found && r > target){
                    LogPrintf("CDarksendPool::ChargeFees -- found uncooperative node (didn't send transaction). charging fees.\n");

                    CWalletTx wtxCollateral = CWalletTx(pwalletMain, txCollateral);

                    // Broadcast
                    if (!wtxCollateral.AcceptToMemoryPool(true))
                    {
                        // This must not fail. The transaction has already been signed and recorded.
                        LogPrintf("CDarksendPool::ChargeFees() : Error: Transaction not valid");
                    }
                    wtxCollateral.RelayWalletTransaction();
                    return;
                }
            }
        }

        if(state == POOL_STATUS_SIGNING) {
            // who didn't sign?
            BOOST_FOREACH(const CDarkSendEntry v, entries) {
                BOOST_FOREACH(const CTxDSIn s, v.sev) {
                    if(!s.fHasSig && r > target){
                        LogPrintf("CDarksendPool::ChargeFees -- found uncooperative node (didn't sign). charging fees.\n");

                        CWalletTx wtxCollateral = CWalletTx(pwalletMain, v.collateral);

                        // Broadcast
                        if (!wtxCollateral.AcceptToMemoryPool(true))
                        {
                            // This must not fail. The transaction has already been signed and recorded.
                            LogPrintf("CDarksendPool::ChargeFees() : Error: Transaction not valid");
                        }
                        wtxCollateral.RelayWalletTransaction();
                        return;
                    }
                }
            }
        }
    }
}

// charge the collateral randomly
//  - Darksend is completely free, to pay miners we randomly pay the collateral of users.
void CDarksendPool::ChargeRandomFees(){
    if(fMasterNode) {
        int i = 0;

        BOOST_FOREACH(const CTransaction& txCollateral, vecSessionCollateral) {
            int r = rand()%100;

            /*
                Collateral Fee Charges:

                Being that Darksend has "no fees" we need to have some kind of cost associated
                with using it to stop abuse. Otherwise it could serve as an attack vector and
                allow endless transaction that would bloat Darkcoin and make it unusable. To
                stop these kinds of attacks 1 in 10 successful transactions are charged. This
                adds up to a cost of 0.001DRK per transaction on average.
            */
            if(r <= 10)
            {
                LogPrintf("CDarksendPool::ChargeRandomFees -- charging random fees. %u\n", i);

                CWalletTx wtxCollateral = CWalletTx(pwalletMain, txCollateral);

                // Broadcast
                if (!wtxCollateral.AcceptToMemoryPool(true))
                {
                    // This must not fail. The transaction has already been signed and recorded.
                    LogPrintf("CDarksendPool::ChargeRandomFees() : Error: Transaction not valid");
                }
                wtxCollateral.RelayWalletTransaction();
            }
        }
    }
}

//
// Check for various timeouts (queue objects, Darksend, etc)
//
void CDarksendPool::CheckTimeout(){
    if(!fEnableDarksend && !fMasterNode) return;

    // catching hanging sessions
    if(!fMasterNode) {
        if(state == POOL_STATUS_TRANSMISSION) {
            if(fDebug) LogPrintf("CDarksendPool::CheckTimeout() -- Session complete -- Running Check()\n");
            Check();
        }
    }

    // check Darksend queue objects for timeouts
    int c = 0;
    vector<CDarksendQueue>::iterator it;
    for(it=vecDarksendQueue.begin();it<vecDarksendQueue.end();it++){
        if((*it).IsExpired()){
            if(fDebug) LogPrintf("CDarksendPool::CheckTimeout() : Removing expired queue entry - %d\n", c);
            vecDarksendQueue.erase(it);
            break;
        }
        c++;
    }

    int addLagTime = 0;
    if(!fMasterNode) addLagTime = 10000; //if we're the client, give the server a few extra seconds before resetting.

    if(state == POOL_STATUS_ACCEPTING_ENTRIES || state == POOL_STATUS_QUEUE){
        c = 0;

        // if it's a masternode, the entries are stored in "entries", otherwise they're stored in myEntries
        std::vector<CDarkSendEntry> *vec = &myEntries;
        if(fMasterNode) vec = &entries;

        // check for a timeout and reset if needed
        vector<CDarkSendEntry>::iterator it2;
        for(it2=vec->begin();it2<vec->end();it2++){
            if((*it2).IsExpired()){
                if(fDebug) LogPrintf("CDarksendPool::CheckTimeout() : Removing expired entry - %d\n", c);
                vec->erase(it2);
                if(entries.size() == 0 && myEntries.size() == 0){
                    SetNull(true);
                    UnlockCoins();
                }
                if(fMasterNode){
                    RelayStatus(darkSendPool.sessionID, darkSendPool.GetState(), darkSendPool.GetEntriesCount(), MASTERNODE_RESET);
                }
                break;
            }
            c++;
        }

        if(!fSubmitAnonymousFailed && !fMasterNode && state == POOL_STATUS_ACCEPTING_ENTRIES){
            if(GetTimeMillis()-lastTimeChanged >= (DARKSEND_DOWNGRADE_TIMEOUT*1000)+addLagTime){
                lastTimeChanged = GetTimeMillis();
                Downgrade();
            }
        }

        if(GetTimeMillis()-lastTimeChanged >= (DARKSEND_QUEUE_TIMEOUT*1000)+addLagTime){
            lastTimeChanged = GetTimeMillis();

            ChargeFees();
            // reset session information for the queue query stage (before entering a masternode, clients will send a queue request to make sure they're compatible denomination wise)
            sessionUsers = 0;
            sessionDenom = 0;
            sessionFoundMasternode = false;
            vecSessionCollateral.clear();

            UpdateState(POOL_STATUS_ACCEPTING_ENTRIES);
        }
    } else if(GetTimeMillis()-lastTimeChanged >= (DARKSEND_QUEUE_TIMEOUT*1000)+addLagTime){
        if(fDebug) LogPrintf("CDarksendPool::CheckTimeout() -- Session timed out (30s) -- resetting\n");
        SetNull();
        UnlockCoins();

        UpdateState(POOL_STATUS_ERROR);
        lastMessage = _("Session timed out (30 seconds), please resubmit.");
    }

    if(state == POOL_STATUS_SIGNING && GetTimeMillis()-lastTimeChanged >= (DARKSEND_SIGNING_TIMEOUT*1000)+addLagTime ) {
        if(fSubmitAnonymousFailed){
            if(fDebug) LogPrintf("CDarksendPool::CheckTimeout() -- Session timed out -- restting\n");
            ChargeFees();
            SetNull();
            UnlockCoins();
            //add my transactions to the new session

            UpdateState(POOL_STATUS_ERROR);
            lastMessage = _("Signing timed out, please resubmit.");
        } else { //Downgrade and try again
            Downgrade();
            finalTransaction.vin.clear();
            finalTransaction.vout.clear();
            UpdateState(POOL_STATUS_ACCEPTING_ENTRIES);
            lastMessage = _("Downgrading and trying again.");
        }
    }
}

//
// Check for complete queue
//
void CDarksendPool::CheckForCompleteQueue(){
    if(!fEnableDarksend && !fMasterNode) return;

    /* Check to see if we're ready for submissions from clients */
    //
    // After receiving multiple dsa messages, the queue will switch to "accepting entries"
    // which is the active state right before merging the transaction
    //
    if(state == POOL_STATUS_QUEUE && sessionUsers == GetMaxPoolTransactions()) {
        printf("Q ready");
        UpdateState(POOL_STATUS_ACCEPTING_ENTRIES);

        CDarksendQueue dsq;
        dsq.nDenom = sessionDenom;
        dsq.vin = activeMasternode.vin;
        dsq.time = GetTime();
        dsq.ready = true;
        dsq.Sign();
        dsq.Relay();
    }
}

// check to see if the signature is valid
bool CDarksendPool::SignatureValid(const CScript& newSig, const CTxIn& newVin){
    CTransaction txNew;
    txNew.vin.clear();
    txNew.vout.clear();

    int found = -1;
    CScript sigPubKey = CScript();
    unsigned int i = 0;

    BOOST_FOREACH(CDarkSendEntry& e, entries) {
        BOOST_FOREACH(const CTxOut& out, e.vout)
            txNew.vout.push_back(out);

        BOOST_FOREACH(const CTxDSIn& s, e.sev){
            txNew.vin.push_back(s);

            if(s == newVin){
                found = i;
                sigPubKey = s.prevPubKey;
            }
            i++;
        }
    }

    if(found >= 0){ //might have to do this one input at a time?
        int n = found;
        txNew.vin[n].scriptSig = newSig;
        if(fDebug) LogPrintf("CDarksendPool::SignatureValid() - Sign with sig %s\n", newSig.ToString().substr(0,24).c_str());
        if (!VerifyScript(txNew.vin[n].scriptSig, sigPubKey, txNew, n, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_STRICTENC, 0)){
            if(fDebug) LogPrintf("CDarksendPool::SignatureValid() - Signing - Error signing input %u\n", n);
            return false;
        }
    }

    if(fDebug) LogPrintf("CDarksendPool::SignatureValid() - Signing - Successfully validated input\n");
    return true;
}

// check to make sure the collateral provided by the client is valid
bool CDarksendPool::IsCollateralValid(const CTransaction& txCollateral){
    if(txCollateral.vout.size() < 1) return false;
    if(txCollateral.nLockTime != 0) return false;

    int64_t nValueIn = 0;
    int64_t nValueOut = 0;
    bool missingTx = false;

    BOOST_FOREACH(const CTxOut o, txCollateral.vout){
        nValueOut += o.nValue;

        if(!o.scriptPubKey.IsNormalPaymentScript()){
            LogPrintf ("CDarksendPool::IsCollateralValid - Invalid Script %s\n", txCollateral.ToString().c_str());
            return false;
        }
    }

    BOOST_FOREACH(const CTxIn i, txCollateral.vin){
        CTransaction tx2;
        uint256 hash;
        if(GetTransaction(i.prevout.hash, tx2, hash, true)){
            if(tx2.vout.size() > i.prevout.n) {
                nValueIn += tx2.vout[i.prevout.n].nValue;
            }
        } else{
            missingTx = true;
        }
    }

    if(missingTx){
        if(fDebug) LogPrintf ("CDarksendPool::IsCollateralValid - Unknown inputs in collateral transaction - %s\n", txCollateral.ToString().c_str());
        return false;
    }

    //collateral transactions are required to pay out DARKSEND_COLLATERAL as a fee to the miners
    if(nValueIn - nValueOut < DARKSEND_COLLATERAL) {
        if(fDebug) LogPrintf ("CDarksendPool::IsCollateralValid - did not include enough fees in transaction %d\n%s\n", nValueOut-nValueIn, txCollateral.ToString().c_str());
        return false;
    }

    if(fDebug) LogPrintf("CDarksendPool::IsCollateralValid %s\n", txCollateral.ToString().c_str());

    CValidationState state;
    if(!AcceptableInputs(mempool, state, txCollateral)){
        if(fDebug) LogPrintf ("CDarksendPool::IsCollateralValid - didn't pass IsAcceptable\n");
        return false;
    }

    return true;
}


//
// Add a clients transaction to the pool
//
bool CDarksendPool::AddEntry(const std::vector<CTxIn>& newInput, const int64_t& nAmount, const CTransaction& txCollateral, const std::vector<CTxOut>& newOutput, std::string& error){
    if (!fMasterNode) return false;

    BOOST_FOREACH(CTxIn in, newInput) {
        if (in.prevout.IsNull() || nAmount < 0) {
            if(fDebug) LogPrintf ("CDarksendPool::AddEntry - input not valid!\n");
            error = _("Input is not valid.");
            sessionUsers--;
            return false;
        }
    }

    if (!IsCollateralValid(txCollateral)){
        if(fDebug) LogPrintf ("CDarksendPool::AddEntry - collateral not valid!\n");
        error = _("Collateral is not valid.");
        sessionUsers--;
        return false;
    }

    if((int)entries.size() >= GetMaxPoolTransactions()){
        if(fDebug) LogPrintf ("CDarksendPool::AddEntry - entries is full!\n");
        error = _("Entries are full.");
        sessionUsers--;
        return false;
    }

    BOOST_FOREACH(CTxIn in, newInput) {
        if(fDebug) LogPrintf("looking for vin -- %s\n", in.ToString().c_str());
        BOOST_FOREACH(const CDarkSendEntry& v, entries) {
            BOOST_FOREACH(const CTxDSIn& s, v.sev){
                if((CTxIn)s == in) {
                    if(fDebug) LogPrintf ("CDarksendPool::AddEntry - found in vin\n");
                    error = _("Already have that input.");
                    sessionUsers--;
                    return false;
                }
            }
        }
    }

    CDarkSendEntry v;
    v.Add(newInput, nAmount, txCollateral, newOutput);
    entries.push_back(v);

    if(fDebug) LogPrintf("CDarksendPool::AddEntry -- adding %s\n", newInput[0].ToString().c_str());
    error = "";

    return true;
}

bool CDarksendPool::AddScriptSig(const CTxIn& newVin){
    if(fDebug) LogPrintf("CDarksendPool::AddScriptSig -- new sig  %s\n", newVin.scriptSig.ToString().substr(0,24).c_str());


    BOOST_FOREACH(const CDarkSendEntry& v, entries) {
        BOOST_FOREACH(const CTxDSIn& s, v.sev){
            if(s.scriptSig == newVin.scriptSig) {
                LogPrintf("CDarksendPool::AddScriptSig - already exists \n");
                return false;
            }
        }
    }

    if(!SignatureValid(newVin.scriptSig, newVin)){
        if(fDebug) LogPrintf("CDarksendPool::AddScriptSig - Invalid Sig\n");
        return false;
    }

    if(fDebug) LogPrintf("CDarksendPool::AddScriptSig -- sig %s\n", newVin.ToString().c_str());

    BOOST_FOREACH(CTxIn& vin, finalTransaction.vin){
        if(newVin.prevout == vin.prevout && vin.nSequence == newVin.nSequence){
            vin.scriptSig = newVin.scriptSig;
            vin.prevPubKey = newVin.prevPubKey;
            if(fDebug) LogPrintf("CDarksendPool::AddScriptSig -- adding to finalTransaction  %s\n", newVin.scriptSig.ToString().substr(0,24).c_str());
            return true;
        }
    }

    LogPrintf("CDarksendPool::AddScriptSig -- Couldn't set sig!\n" );
    return false;
}

// Check to make sure everything is signed
bool CDarksendPool::SignaturesComplete(){
    bool fFoundIncomplete = false;
    BOOST_FOREACH(CTxDSIn in, anonTx.vin){
        if(!in.fHasSig)
            fFoundIncomplete = true;
    }
    if(fFoundIncomplete == false) return true;

    BOOST_FOREACH(const CDarkSendEntry& v, entries) {
        BOOST_FOREACH(const CTxDSIn& s, v.sev){
            if(!s.fHasSig) return false;
        }
    }
    return true;
}

//
// Execute a Darksend denomination via a masternode.
// This is only ran from clients
//
void CDarksendPool::SendDarksendDenominate(std::vector<CTxIn>& vin, std::vector<CTxOut>& vout, int64_t amount){
    if(darkSendPool.txCollateral == CTransaction()){
        LogPrintf ("CDarksendPool:SendDarksendDenominate() - Darksend collateral not set");
        return;
    }

    // lock the funds we're going to use
    BOOST_FOREACH(CTxIn in, txCollateral.vin)
        lockedCoins.push_back(in);

    BOOST_FOREACH(CTxIn in, vin)
        lockedCoins.push_back(in);

    //BOOST_FOREACH(CTxOut o, vout)
    //    LogPrintf(" vout - %s\n", o.ToString().c_str());


    // we should already be connected to a masternode
    if(!sessionFoundMasternode){
        LogPrintf("CDarksendPool::SendDarksendDenominate() - No masternode has been selected yet.\n");
        UnlockCoins();
        SetNull(true);
        return;
    }

    if (!CheckDiskSpace())
        return;

    if(fMasterNode) {
        LogPrintf("CDarksendPool::SendDarksendDenominate() - Darksend from a masternode is not supported currently.\n");
        return;
    }

    UpdateState(POOL_STATUS_ACCEPTING_ENTRIES);

    LogPrintf("CDarksendPool::SendDarksendDenominate() - Added transaction to pool.\n");

    ClearLastMessage();

    //check it against the memory pool to make sure it's valid
    {
        int64_t nValueOut = 0;

        CValidationState state;
        CTransaction tx;

        BOOST_FOREACH(const CTxOut& o, vout){
            nValueOut += o.nValue;
            tx.vout.push_back(o);
        }

        BOOST_FOREACH(const CTxIn& i, vin){
            tx.vin.push_back(i);

            if(fDebug) LogPrintf("dsi -- tx in %s\n", i.ToString().c_str());
        }

        printf("Submitting tx %s\n", tx.ToString().c_str());

        if(!AcceptableInputs(mempool, state, tx)){
            LogPrintf("dsi -- transaction not valid! %s \n", tx.ToString().c_str());
            return;
        }
    }

    // store our entry for later use
    CDarkSendEntry e;
    e.Add(vin, amount, txCollateral, vout);
    myEntries.push_back(e);

    // submit inputs/outputs through relays
    RelayInAnon(vin, vout);

    Check();
}

// Incoming message from masternode updating the progress of Darksend
//    newAccepted:  -1 mean's it'n not a "transaction accepted/not accepted" message, just a standard update
//                  0 means transaction was not accepted
//                  1 means transaction was accepted

bool CDarksendPool::StatusUpdate(int newState, int newEntriesCount, int newAccepted, std::string& error, int newSessionID){
    if(fMasterNode) return false;
    if(state == POOL_STATUS_ERROR || state == POOL_STATUS_SUCCESS) return false;

    UpdateState(newState);
    entriesCount = newEntriesCount;

    if(error.size() > 0) strAutoDenomResult = _("Masternode:") + " " + error;

    if(newAccepted != -1) {
        lastEntryAccepted = newAccepted;
        countEntriesAccepted += newAccepted;
        if(newAccepted == 0){
            UpdateState(POOL_STATUS_ERROR);
            lastMessage = error;
        }

        if(newAccepted == 1) {
            sessionID = newSessionID;
            LogPrintf("CDarksendPool::StatusUpdate - set sessionID to %d\n", sessionID);
            sessionFoundMasternode = true;
        }
    }

    if(newState == POOL_STATUS_ACCEPTING_ENTRIES){
        if(newAccepted == 1){
            LogPrintf("CDarksendPool::StatusUpdate - entry accepted! \n");
            sessionFoundMasternode = true;
            //wait for other users. Masternode will report when ready
            UpdateState(POOL_STATUS_QUEUE);
            printf("Updated 1\n");
        } else if (newAccepted == 0 && sessionID == 0 && !sessionFoundMasternode) {
            LogPrintf("CDarksendPool::StatusUpdate - entry not accepted by masternode \n");
            UnlockCoins();
            UpdateState(POOL_STATUS_ACCEPTING_ENTRIES);
            DoAutomaticDenominating(); //try another masternode
        }
        if(sessionFoundMasternode) return true;
    }

    return true;
}

//
// After we receive the finalized transaction from the masternode, we must
// check it to make sure it's what we want, then sign it if we agree.
// If we refuse to sign, it's possible we'll be charged collateral
//
bool CDarksendPool::SignFinalTransaction(CTransaction& finalTransactionNew, CNode* node){
    if(fDebug) LogPrintf("CDarksendPool::SignFinalTransaction - Got Finalized Transaction - fSubmitAnonymousFailed %d\n", fSubmitAnonymousFailed);

    finalTransaction = finalTransactionNew;
    LogPrintf("CDarksendPool::SignFinalTransaction %s\n", finalTransaction.ToString().c_str());

    vector<CTxIn> sigs;

    //make sure my inputs/outputs are present, otherwise refuse to sign
    BOOST_FOREACH(const CDarkSendEntry e, myEntries) {
        BOOST_FOREACH(const CTxDSIn s, e.sev) {
            /* Sign my transaction and all outputs */
            int mine = -1;
            CScript prevPubKey = CScript();
            CTxIn vin = CTxIn();

            for(unsigned int i = 0; i < finalTransaction.vin.size(); i++){
                if(finalTransaction.vin[i] == s){
                    mine = i;
                    prevPubKey = s.prevPubKey;
                    vin = s;
                }
            }

            if(mine >= 0){ //might have to do this one input at a time?
                int foundOutputs = 0;
                int64_t nValue1 = 0;
                int64_t nValue2 = 0;

                for(unsigned int i = 0; i < finalTransaction.vout.size(); i++){
                    BOOST_FOREACH(const CTxOut& o, e.vout) {
                        if(finalTransaction.vout[i] == o){
                            foundOutputs++;
                            nValue1 += finalTransaction.vout[i].nValue;
                        }
                    }
                }

                BOOST_FOREACH(const CTxOut o, e.vout)
                    nValue2 += o.nValue;

                int targetOuputs = e.vout.size();
                if(foundOutputs < targetOuputs || nValue1 != nValue2) {
                    // in this case, something went wrong and we'll refuse to sign. It's possible we'll be charged collateral. But that's
                    // better then signing if the transaction doesn't look like what we wanted.
                    LogPrintf("CDarksendPool::Sign - My entries are not correct! Refusing to sign. %d entries %d target. \n", foundOutputs, targetOuputs);
                    ResendMissingInputsOutputs();
                    return false;
                }

                if(fDebug) LogPrintf("CDarksendPool::Sign - Signing my input %i\n", mine);
                if(!SignSignature(*pwalletMain, prevPubKey, finalTransaction, mine, int(SIGHASH_ALL|SIGHASH_ANYONECANPAY))) { // changes scriptSig
                    if(fDebug) LogPrintf("CDarksendPool::Sign - Unable to sign my own transaction! \n");
                    // not sure what to do here, it will timeout...?
                }

                sigs.push_back(finalTransaction.vin[mine]);
                if(fDebug) LogPrintf(" -- dss %d %d %s\n", mine, (int)sigs.size(), finalTransaction.vin[mine].scriptSig.ToString().c_str());
            }

        }

        if(fDebug) LogPrintf("CDarksendPool::Sign - txNew:\n%s", finalTransaction.ToString().c_str());
    }

    if(!fSubmitAnonymousFailed){
        RelaySignaturesAnon(sigs);
    } else {
        // push all of our signatures to the masternode
        if(sigs.size() > 0 && node != NULL)
            node->PushMessage("dss", sigs);
    }

    return true;
}

void CDarksendPool::NewBlock()
{
    if(fDebug) LogPrintf("CDarksendPool::NewBlock \n");

    //we we're processing lots of blocks, we'll just leave
    if(GetTime() - lastNewBlock < 10) return;
    lastNewBlock = GetTime();

    darkSendPool.CheckTimeout();

    if(!fEnableDarksend) return;

    if(!fMasterNode){
        //denominate all non-denominated inputs every 25 minutes.
        if(chainActive.Tip()->nHeight % 10 == 0) UnlockCoins();
    }
}

// Darksend transaction was completed (failed or successful)
void CDarksendPool::CompletedTransaction(bool error, std::string lastMessageNew)
{
    if(fMasterNode) return;

    if(error){
        LogPrintf("CompletedTransaction -- error \n");
        UpdateState(POOL_STATUS_ERROR);

        Check();
        UnlockCoins();
    } else {
        LogPrintf("CompletedTransaction -- success \n");
        UpdateState(POOL_STATUS_SUCCESS);

        myEntries.clear();
        UnlockCoins();
        if(!fMasterNode) SetNull(true);

        // To avoid race conditions, we'll only let DS run once per block
        cachedLastSuccess = chainActive.Tip()->nHeight;
    }
    lastMessage = lastMessageNew;
    completedTransaction = true;
}

void CDarksendPool::ClearLastMessage()
{
    lastMessage = "";
}

//
// Passively run Darksend in the background to anonymize funds based on the given configuration.
//
// This does NOT run by default for daemons, only for QT.
//
bool CDarksendPool::DoAutomaticDenominating(bool fDryRun, bool ready)
{
    LOCK(cs_darksend);

    if(IsInitialBlockDownload()) return false;

    if(fMasterNode) return false;
    if(state == POOL_STATUS_ERROR || state == POOL_STATUS_SUCCESS) return false;

    if(chainActive.Tip()->nHeight - cachedLastSuccess < minBlockSpacing) {
        LogPrintf("CDarksendPool::DoAutomaticDenominating - Last successful Darksend action was too recent\n");
        strAutoDenomResult = _("Last successful Darksend action was too recent.");
        return false;
    }
    if(!fEnableDarksend) {
        if(fDebug) LogPrintf("CDarksendPool::DoAutomaticDenominating - Darksend is disabled\n");
        strAutoDenomResult = _("Darksend is disabled.");
        return false;
    }

    if (!fDryRun && pwalletMain->IsLocked()){
        strAutoDenomResult = _("Wallet is locked.");
        return false;
    }

    if(darkSendPool.GetState() != POOL_STATUS_ERROR && darkSendPool.GetState() != POOL_STATUS_SUCCESS){
        if(darkSendPool.GetMyTransactionCount() > 0){
            return true;
        }
    }

    if(mnodeman.size() == 0){
        if(fDebug) LogPrintf("CDarksendPool::DoAutomaticDenominating - No masternodes detected\n");
        strAutoDenomResult = _("No masternodes detected.");
        return false;
    }

    // ** find the coins we'll use
    std::vector<CTxIn> vCoins;
    std::vector<COutput> vCoins2;
    int64_t nValueMin = CENT;
    int64_t nValueIn = 0;

    // should not be less than fees in DARKSEND_COLLATERAL + few (lets say 5) smallest denoms
    int64_t nLowestDenom = DARKSEND_COLLATERAL + darkSendDenominations[darkSendDenominations.size() - 1]*5;

    // if there are no DS collateral inputs yet
    if(!pwalletMain->HasCollateralInputs())
        // should have some additional amount for them
        nLowestDenom += DARKSEND_COLLATERAL*4;

    int64_t nBalanceNeedsAnonymized = nAnonymizeDarkcoinAmount*COIN - pwalletMain->GetAnonymizedBalance();

    // if balanceNeedsAnonymized is more than pool max, take the pool max
    if(nBalanceNeedsAnonymized > DARKSEND_POOL_MAX) nBalanceNeedsAnonymized = DARKSEND_POOL_MAX;

    // if balanceNeedsAnonymized is more than non-anonymized, take non-anonymized
    int64_t nBalanceNotYetAnonymized = pwalletMain->GetBalance() - pwalletMain->GetAnonymizedBalance();
    if(nBalanceNeedsAnonymized > nBalanceNotYetAnonymized) nBalanceNeedsAnonymized = nBalanceNotYetAnonymized;

    if(nBalanceNeedsAnonymized < nLowestDenom)
    {
        LogPrintf("DoAutomaticDenominating : No funds detected in need of denominating \n");
        strAutoDenomResult = _("No funds detected in need of denominating.");
        return false;
    }

    if (fDebug) LogPrintf("DoAutomaticDenominating : nLowestDenom=%d, nBalanceNeedsAnonymized=%d\n", nLowestDenom, nBalanceNeedsAnonymized);

    // select coins that should be given to the pool
    if (!pwalletMain->SelectCoinsDark(nValueMin, nBalanceNeedsAnonymized, vCoins, nValueIn, 0, nDarksendRounds))
    {
        nValueIn = 0;
        vCoins.clear();

        if (pwalletMain->SelectCoinsDark(nValueMin, 9999999*COIN, vCoins, nValueIn, -2, 0))
        {
            if(!fDryRun) return CreateDenominated(nBalanceNeedsAnonymized);
            return true;
        } else {
            LogPrintf("DoAutomaticDenominating : Can't denominate - no compatible inputs left\n");
            strAutoDenomResult = _("Can't denominate: no compatible inputs left.");
            return false;
        }

    }

    //check to see if we have the collateral sized inputs, it requires these
    if(!pwalletMain->HasCollateralInputs()){
        if(!fDryRun) MakeCollateralAmounts();
        return true;
    }

    if(fDryRun) return true;

    std::vector<CTxOut> vOut;

    // initial phase, find a masternode
    if(!sessionFoundMasternode){
        int nUseQueue = rand()%100;

        sessionTotalValue = pwalletMain->GetTotalValue(vCoins);

        //randomize the amounts we mix
        if(sessionTotalValue > nBalanceNeedsAnonymized) sessionTotalValue = nBalanceNeedsAnonymized;

        double fDarkcoinSubmitted = (sessionTotalValue / CENT);
        LogPrintf("Submitting Darksend for %f DRK CENT - sessionTotalValue %d\n", fDarkcoinSubmitted, sessionTotalValue);

        if(pwalletMain->GetDenominatedBalance(true, true) > 0){ //get denominated unconfirmed inputs
            LogPrintf("DoAutomaticDenominating -- Found unconfirmed denominated outputs, will wait till they confirm to continue.\n");
            strAutoDenomResult = _("Found unconfirmed denominated outputs, will wait till they confirm to continue.");
            return false;
        }

        //don't use the queues all of the time for mixing
        if(nUseQueue > 33){

            // Look through the queues and see if anything matches
            BOOST_FOREACH(CDarksendQueue& dsq, vecDarksendQueue){
                CService addr;
                if(dsq.time == 0) continue;

                if(!dsq.GetAddress(addr)) continue;
                if(dsq.IsExpired()) continue;

                int protocolVersion;
                if(!dsq.GetProtocolVersion(protocolVersion)) continue;
                if(protocolVersion < MIN_POOL_PEER_PROTO_VERSION) continue;

                //non-denom's are incompatible
                if((dsq.nDenom & (1 << 4))) continue;

                //don't reuse masternodes
                BOOST_FOREACH(CTxIn usedVin, vecMasternodesUsed){
                    if(dsq.vin == usedVin) {
                        continue;
                    }
                }

                // Try to match their denominations if possible
                if (!pwalletMain->SelectCoinsByDenominations(dsq.nDenom, nValueMin, nBalanceNeedsAnonymized, vCoins, vCoins2, nValueIn, 0, nDarksendRounds)){
                    LogPrintf("DoAutomaticDenominating - Couldn't match denominations %d\n", dsq.nDenom);
                    continue;
                }

                // connect to masternode and submit the queue request
                if(ConnectNode((CAddress)addr, NULL, true)){
                    CNode* pNode = FindNode(addr);
                    if(pNode)
                    {
                        std::string strReason;
                        if(txCollateral == CTransaction()){
                            if(!pwalletMain->CreateCollateralTransaction(txCollateral, strReason)){
                                LogPrintf("DoAutomaticDenominating -- dsa error:%s\n", strReason.c_str());
                                return false;
                            }
                        }

                        pSubmittedToMasternode = mnodeman.Find(dsq.vin);
                        vecMasternodesUsed.push_back(dsq.vin);
                        sessionDenom = dsq.nDenom;

                        pNode->PushMessage("dsa", sessionDenom, txCollateral);
                        LogPrintf("DoAutomaticDenominating --- connected (from queue), sending dsa for %d %d - %s\n", sessionDenom, GetDenominationsByAmount(sessionTotalValue), pNode->addr.ToString().c_str());
                        strAutoDenomResult = "";
                        return true;
                    }
                } else {
                    LogPrintf("DoAutomaticDenominating --- error connecting \n");
                    strAutoDenomResult = _("Error connecting to masternode.");
                    return DoAutomaticDenominating();
                }

                dsq.time = 0; //remove node
            }
        }

        int i = 0;

        // otherwise, try one randomly
        while(i < 10)
        {
            CMasternode* pmn = mnodeman.FindRandom();
            if(pmn == NULL)
            {
                LogPrintf("DoAutomaticDenominating --- masternode list is empty!\n");
                return false;
            }
            //don't reuse masternodes
            BOOST_FOREACH(CTxIn usedVin, vecMasternodesUsed) {
                if(pmn->vin == usedVin){
                    i++;
                    continue;
                }
            }
            if(pmn->protocolVersion < MIN_POOL_PEER_PROTO_VERSION) {
                i++;
                continue;
            }

            if(pmn->nLastDsq != 0 &&
                pmn->nLastDsq + mnodeman.CountMasternodesAboveProtocol(MIN_POOL_PEER_PROTO_VERSION)/5 > darkSendPool.nDsqCount){
                i++;
                continue;
            }

            lastTimeChanged = GetTimeMillis();
            LogPrintf("DoAutomaticDenominating -- attempt %d connection to masternode %s\n", i, pmn->addr.ToString().c_str());
            if(ConnectNode((CAddress)pmn->addr, NULL, true)){

                LOCK(cs_vNodes);
                BOOST_FOREACH(CNode* pnode, vNodes)
                {
                    if((CNetAddr)pnode->addr != (CNetAddr)pmn->addr) continue;

                    std::string strReason;
                    if(txCollateral == CTransaction()){
                        if(!pwalletMain->CreateCollateralTransaction(txCollateral, strReason)){
                            LogPrintf("DoAutomaticDenominating -- create collateral error:%s\n", strReason.c_str());
                            return false;
                        }
                    }

                    pSubmittedToMasternode = pmn;
                    vecMasternodesUsed.push_back(pmn->vin);

                    std::vector<int64_t> vecAmounts;
                    pwalletMain->ConvertList(vCoins, vecAmounts);
                    sessionDenom = GetDenominationsByAmounts(vecAmounts);

                    pnode->PushMessage("dsa", sessionDenom, txCollateral);
                    LogPrintf("DoAutomaticDenominating --- connected, sending dsa for %d - denom %d\n", sessionDenom, GetDenominationsByAmount(sessionTotalValue));
                    strAutoDenomResult = "";
                    return true;
                }
            } else {
                i++;
                continue;
            }
        }

        strAutoDenomResult = _("No compatible masternode found.");
        return false;
    }

    strAutoDenomResult = "";
    if(!ready) return true;

    if(sessionDenom == 0) return true;

    return false;
}


bool CDarksendPool::PrepareDarksendDenominate()
{
    // Submit transaction to the pool if we get here, use sessionDenom so we use the same amount of money
    std::string strError = pwalletMain->PrepareDarksendDenominate(0, nDarksendRounds);
    LogPrintf("DoAutomaticDenominating : Running Darksend denominate. Return '%s'\n", strError.c_str());

    if(strError == "") return true;

    strAutoDenomResult = strError;
    LogPrintf("DoAutomaticDenominating : Error running denominate, %s\n", strError.c_str());
    return false;
}

bool CDarksendPool::Downgrade()
{
    if(fSubmitAnonymousFailed) return true;
    if(myEntries.size() == 0) return false;

    fSubmitAnonymousFailed = true;
    LogPrintf("CDarksendPool::Downgrade() : Downgrading and submitting directly\n");

    // relay our entry to the master node
    RelayIn(myEntries[0].sev, myEntries[0].amount, txCollateral, myEntries[0].vout);

    return true;
}

bool CDarksendPool::ResendMissingInputsOutputs()
{
    if(fResentInputsOutputs) {
        Downgrade();
        return true;
    }
    if(myEntries.size() == 0) return false;

    LogPrintf("CDarksendPool::Downgrade() : Downgrading and submitting directly\n");
    RelayInAnon(myEntries[0].sev, myEntries[0].vout);
    fResentInputsOutputs = true;
    return true;
}

bool CDarksendPool::SendRandomPaymentToSelf()
{
    int64_t nBalance = pwalletMain->GetBalance();
    int64_t nPayment = (nBalance*0.35) + (rand() % nBalance);

    if(nPayment > nBalance) nPayment = nBalance-(0.1*COIN);

    // make our change address
    CReserveKey reservekey(pwalletMain);

    CScript scriptChange;
    CPubKey vchPubKey;
    assert(reservekey.GetReservedKey(vchPubKey)); // should never fail, as we just unlocked
    scriptChange.SetDestination(vchPubKey.GetID());

    CWalletTx wtx;
    int64_t nFeeRet = 0;
    std::string strFail = "";
    vector< pair<CScript, int64_t> > vecSend;

    // ****** Add fees ************ /
    vecSend.push_back(make_pair(scriptChange, nPayment));

    CCoinControl *coinControl=NULL;
    bool success = pwalletMain->CreateTransaction(vecSend, wtx, reservekey, nFeeRet, strFail, coinControl, ONLY_DENOMINATED);
    if(!success){
        LogPrintf("SendRandomPaymentToSelf: Error - %s\n", strFail.c_str());
        return false;
    }

    pwalletMain->CommitTransaction(wtx, reservekey);

    LogPrintf("SendRandomPaymentToSelf Success: tx %s\n", wtx.GetHash().GetHex().c_str());

    return true;
}

// Split up large inputs or create fee sized inputs
bool CDarksendPool::MakeCollateralAmounts()
{
    // make our change address
    CReserveKey reservekey(pwalletMain);

    CScript scriptChange;
    CPubKey vchPubKey;
    assert(reservekey.GetReservedKey(vchPubKey)); // should never fail, as we just unlocked
    scriptChange.SetDestination(vchPubKey.GetID());

    CWalletTx wtx;
    int64_t nFeeRet = 0;
    std::string strFail = "";
    vector< pair<CScript, int64_t> > vecSend;

    vecSend.push_back(make_pair(scriptChange, DARKSEND_COLLATERAL*4));

    CCoinControl *coinControl=NULL;
    // try to use non-denominated and not mn-like funds
    bool success = pwalletMain->CreateTransaction(vecSend, wtx, reservekey,
            nFeeRet, strFail, coinControl, ONLY_NONDENOMINATED_NOTMN);
    if(!success){
        // if we failed (most likeky not enough funds), try to use denominated instead -
        // MN-like funds should not be touched in any case and we can't mix denominated without collaterals anyway
        success = pwalletMain->CreateTransaction(vecSend, wtx, reservekey,
                nFeeRet, strFail, coinControl, ONLY_DENOMINATED);
        if(!success){
            LogPrintf("MakeCollateralAmounts: Error - %s\n", strFail.c_str());
            return false;
        }
    }

    // use the same cachedLastSuccess as for DS mixinx to prevent race
    if(pwalletMain->CommitTransaction(wtx, reservekey))
        cachedLastSuccess = chainActive.Tip()->nHeight;

    LogPrintf("MakeCollateralAmounts Success: tx %s\n", wtx.GetHash().GetHex().c_str());

    return true;
}

// Create denominations
bool CDarksendPool::CreateDenominated(int64_t nTotalValue)
{
    // make our change address
    CReserveKey reservekey(pwalletMain);

    CScript scriptChange;
    CPubKey vchPubKey;
    assert(reservekey.GetReservedKey(vchPubKey)); // should never fail, as we just unlocked
    scriptChange.SetDestination(vchPubKey.GetID());

    CWalletTx wtx;
    int64_t nFeeRet = 0;
    std::string strFail = "";
    vector< pair<CScript, int64_t> > vecSend;
    int64_t nValueLeft = nTotalValue;

    // ****** Add collateral outputs ************ /
    if(!pwalletMain->HasCollateralInputs()) {
        vecSend.push_back(make_pair(scriptChange, DARKSEND_COLLATERAL*4));
        nValueLeft -= DARKSEND_COLLATERAL*4;
    }

    // ****** Add denoms ************ /
    BOOST_REVERSE_FOREACH(int64_t v, darkSendDenominations){
        int nOutputs = 0;

        // add each output up to 10 times until it can't be added again
        while(nValueLeft - v >= DARKSEND_COLLATERAL && nOutputs <= 10) {
            CScript scriptChange;
            CPubKey vchPubKey;
            //use a unique change address
            assert(reservekey.GetReservedKey(vchPubKey)); // should never fail, as we just unlocked
            scriptChange.SetDestination(vchPubKey.GetID());
            reservekey.KeepKey();

            vecSend.push_back(make_pair(scriptChange, v));

            //increment outputs and subtract denomination amount
            nOutputs++;
            nValueLeft -= v;
            LogPrintf("CreateDenominated1 %d\n", nValueLeft);
        }

        if(nValueLeft == 0) break;
    }
    LogPrintf("CreateDenominated2 %d\n", nValueLeft);

    // if we have anything left over, it will be automatically send back as change - there is no need to send it manually

    CCoinControl *coinControl=NULL;
    bool success = pwalletMain->CreateTransaction(vecSend, wtx, reservekey,
            nFeeRet, strFail, coinControl, ONLY_NONDENOMINATED_NOTMN);
    if(!success){
        LogPrintf("CreateDenominated: Error - %s\n", strFail.c_str());
        return false;
    }

    // use the same cachedLastSuccess as for DS mixinx to prevent race
    if(pwalletMain->CommitTransaction(wtx, reservekey))
        cachedLastSuccess = chainActive.Tip()->nHeight;

    LogPrintf("CreateDenominated Success: tx %s\n", wtx.GetHash().GetHex().c_str());

    return true;
}

bool CDarksendPool::IsCompatibleWithEntries(std::vector<CTxOut>& vout)
{
    BOOST_FOREACH(const CDarkSendEntry v, entries) {
        LogPrintf(" IsCompatibleWithEntries %d %d\n", GetDenominations(vout), GetDenominations(v.vout));
/*
        BOOST_FOREACH(CTxOut o1, vout)
            LogPrintf(" vout 1 - %s\n", o1.ToString().c_str());

        BOOST_FOREACH(CTxOut o2, v.vout)
            LogPrintf(" vout 2 - %s\n", o2.ToString().c_str());
*/
        if(GetDenominations(vout) != GetDenominations(v.vout)) return false;
    }

    return true;
}

bool CDarksendPool::IsCompatibleWithSession(int64_t nDenom, CTransaction txCollateral, std::string& strReason)
{
    LogPrintf("CDarksendPool::IsCompatibleWithSession - sessionDenom %d sessionUsers %d\n", sessionDenom, sessionUsers);

    if (!unitTest && !IsCollateralValid(txCollateral)){
        if(fDebug) LogPrintf ("CDarksendPool::IsCompatibleWithSession - collateral not valid!\n");
        strReason = _("Collateral not valid.");
        return false;
    }

    if(sessionUsers < 0) sessionUsers = 0;

    if(sessionUsers == 0) {
        sessionDenom = nDenom;
        sessionUsers++;
        lastTimeChanged = GetTimeMillis();
        entries.clear();

        if(!unitTest){
            //broadcast that I'm accepting entries, only if it's the first entry through
            CDarksendQueue dsq;
            dsq.nDenom = nDenom;
            dsq.vin = activeMasternode.vin;
            dsq.time = GetTime();
            dsq.Sign();
            dsq.Relay();
        }

        UpdateState(POOL_STATUS_QUEUE);
        printf("Updated 2\n");
        vecSessionCollateral.push_back(txCollateral);
        return true;
    }

    if((state != POOL_STATUS_IDLE && state != POOL_STATUS_QUEUE) || sessionUsers >= GetMaxPoolTransactions()){
        if((state != POOL_STATUS_IDLE && state != POOL_STATUS_QUEUE)) strReason = _("Incompatible mode.");
        if(sessionUsers >= GetMaxPoolTransactions()) strReason = _("Masternode queue is full.");
        LogPrintf("CDarksendPool::IsCompatibleWithSession - incompatible mode, return false %d %d\n", state != POOL_STATUS_ACCEPTING_ENTRIES, sessionUsers >= GetMaxPoolTransactions());
        return false;
    }

    if(nDenom != sessionDenom) {
        strReason = _("No matching denominations found for mixing.");
        return false;
    }

    if(state == POOL_STATUS_IDLE){
        LogPrintf("CDarksendPool::IsCompatibleWithSession - Pool is open to new entries\n");
        UpdateState(POOL_STATUS_ACCEPTING_ENTRIES);
    }

    LogPrintf("CDarksendPool::IsCompatibleWithSession - compatible\n");

    sessionUsers++;
    lastTimeChanged = GetTimeMillis();
    vecSessionCollateral.push_back(txCollateral);

    return true;
}

//create a nice string to show the denominations
void CDarksendPool::GetDenominationsToString(int nDenom, std::string& strDenom){
    // Function returns as follows:
    //
    // bit 0 - 100DRK+1 ( bit on if present )
    // bit 1 - 10DRK+1
    // bit 2 - 1DRK+1
    // bit 3 - .1DRK+1
    // bit 3 - non-denom


    strDenom = "";

    if(nDenom & (1 << 0)) {
        if(strDenom.size() > 0) strDenom += "+";
        strDenom += "100";
    }

    if(nDenom & (1 << 1)) {
        if(strDenom.size() > 0) strDenom += "+";
        strDenom += "10";
    }

    if(nDenom & (1 << 2)) {
        if(strDenom.size() > 0) strDenom += "+";
        strDenom += "1";
    }

    if(nDenom & (1 << 3)) {
        if(strDenom.size() > 0) strDenom += "+";
        strDenom += "0.1";
    }
}

// return a bitshifted integer representing the denominations in this list
int CDarksendPool::GetDenominations(const std::vector<CTxOut>& vout){
    std::vector<pair<int64_t, int> > denomUsed;

    // make a list of denominations, with zero uses
    BOOST_FOREACH(int64_t d, darkSendDenominations)
        denomUsed.push_back(make_pair(d, 0));

    // look for denominations and update uses to 1
    BOOST_FOREACH(CTxOut out, vout){
        bool found = false;
        BOOST_FOREACH (PAIRTYPE(int64_t, int)& s, denomUsed){
            if (out.nValue == s.first){
                s.second = 1;
                found = true;
            }
        }
        if(!found) return 0;
    }

    int denom = 0;
    int c = 0;
    // if the denomination is used, shift the bit on.
    // then move to the next
    BOOST_FOREACH (PAIRTYPE(int64_t, int)& s, denomUsed)
        denom |= s.second << c++;

    // Function returns as follows:
    //
    // bit 0 - 100DRK+1 ( bit on if present )
    // bit 1 - 10DRK+1
    // bit 2 - 1DRK+1
    // bit 3 - .1DRK+1

    return denom;
}


int CDarksendPool::GetDenominationsByAmounts(std::vector<int64_t>& vecAmount){
    CScript e = CScript();
    std::vector<CTxOut> vout1;

    // Make outputs by looping through denominations, from small to large
    BOOST_REVERSE_FOREACH(int64_t v, vecAmount){
        int nOutputs = 0;

        CTxOut o(v, e);
        vout1.push_back(o);
        nOutputs++;
    }

    return GetDenominations(vout1);
}

int CDarksendPool::GetDenominationsByAmount(int64_t nAmount, int nDenomTarget){
    CScript e = CScript();
    int64_t nValueLeft = nAmount;

    std::vector<CTxOut> vout1;

    // Make outputs by looping through denominations, from small to large
    BOOST_REVERSE_FOREACH(int64_t v, darkSendDenominations){
        if(nDenomTarget != 0){
            bool fAccepted = false;
            if((nDenomTarget & (1 << 0)) &&      v == ((100*COIN)+100000)) {fAccepted = true;}
            else if((nDenomTarget & (1 << 1)) && v == ((10*COIN) +10000)) {fAccepted = true;}
            else if((nDenomTarget & (1 << 2)) && v == ((1*COIN)  +1000)) {fAccepted = true;}
            else if((nDenomTarget & (1 << 3)) && v == ((.1*COIN) +100)) {fAccepted = true;}
            if(!fAccepted) continue;
        }

        int nOutputs = 0;

        // add each output up to 10 times until it can't be added again
        while(nValueLeft - v >= 0 && nOutputs <= 10) {
            CTxOut o(v, e);
            vout1.push_back(o);
            nValueLeft -= v;
            nOutputs++;
        }
        LogPrintf("GetDenominationsByAmount --- %d nOutputs %d\n", v, nOutputs);
    }

    //add non-denom left overs as change
    if(nValueLeft > 0){
        CTxOut o(nValueLeft, e);
        vout1.push_back(o);
    }

    return GetDenominations(vout1);
}

bool CDarkSendSigner::IsVinAssociatedWithPubkey(CTxIn& vin, CPubKey& pubkey){
    CScript payee2;
    payee2.SetDestination(pubkey.GetID());

    CTransaction txVin;
    uint256 hash;
    if(GetTransaction(vin.prevout.hash, txVin, hash, true)){
        BOOST_FOREACH(CTxOut out, txVin.vout){
            if(out.nValue == 1000*COIN){
                if(out.scriptPubKey == payee2) return true;
            }
        }
    }

    return false;
}

bool CDarkSendSigner::SetKey(std::string strSecret, std::string& errorMessage, CKey& key, CPubKey& pubkey){
    CBitcoinSecret vchSecret;
    bool fGood = vchSecret.SetString(strSecret);

    if (!fGood) {
        errorMessage = _("Invalid private key.");
        return false;
    }

    key = vchSecret.GetKey();
    pubkey = key.GetPubKey();

    return true;
}

bool CDarkSendSigner::SignMessage(std::string strMessage, std::string& errorMessage, vector<unsigned char>& vchSig, CKey key)
{
    CHashWriter ss(SER_GETHASH, 0);
    ss << strMessageMagic;
    ss << strMessage;

    if (!key.SignCompact(ss.GetHash(), vchSig)) {
        errorMessage = _("Signing failed.");
        return false;
    }

    return true;
}

bool CDarkSendSigner::VerifyMessage(CPubKey pubkey, vector<unsigned char>& vchSig, std::string strMessage, std::string& errorMessage)
{
    CHashWriter ss(SER_GETHASH, 0);
    ss << strMessageMagic;
    ss << strMessage;

    CPubKey pubkey2;
    if (!pubkey2.RecoverCompact(ss.GetHash(), vchSig)) {
        errorMessage = _("Error recovering public key.");
        return false;
    }

    if (fDebug && pubkey2.GetID() != pubkey.GetID())
        LogPrintf("CDarkSendSigner::VerifyMessage -- keys don't match: %s %s", pubkey2.GetID().ToString(), pubkey.GetID().ToString());

    return (pubkey2.GetID() == pubkey.GetID());
}

bool CDarksendQueue::Sign()
{
    if(!fMasterNode) return false;

    std::string strMessage = vin.ToString() + boost::lexical_cast<std::string>(nDenom) + boost::lexical_cast<std::string>(time) + boost::lexical_cast<std::string>(ready);

    CKey key2;
    CPubKey pubkey2;
    std::string errorMessage = "";

    if(!darkSendSigner.SetKey(strMasterNodePrivKey, errorMessage, key2, pubkey2))
    {
        LogPrintf("CDarksendQueue():Relay - ERROR: Invalid masternodeprivkey: '%s'\n", errorMessage.c_str());
        return false;
    }

    if(!darkSendSigner.SignMessage(strMessage, errorMessage, vchSig, key2)) {
        LogPrintf("CDarksendQueue():Relay - Sign message failed");
        return false;
    }

    if(!darkSendSigner.VerifyMessage(pubkey2, vchSig, strMessage, errorMessage)) {
        LogPrintf("CDarksendQueue():Relay - Verify message failed");
        return false;
    }

    // -- second signature, for proving access to the anonymous relay system

    nBlockHeight = chainActive.Tip()->nHeight; //sign with our current blockheight
    strMessage = boost::lexical_cast<std::string>(nBlockHeight);

    CKey secret;
    secret.MakeNewKey(false);
    strSharedKey = CBitcoinSecret(secret).ToString();

    if(!darkSendSigner.SignMessage(strMessage, errorMessage, vchRelaySig, key2)) {
        LogPrintf("CDarksendQueue():Relay - Sign message failed");
        return false;
    }

    if(!darkSendSigner.VerifyMessage(pubkey2, vchRelaySig, strMessage, errorMessage)) {
        LogPrintf("CDarksendQueue():Relay - Verify message failed");
        return false;
    }


    return true;
}

bool CDarksendQueue::Relay()
{

    LOCK(cs_vNodes);
    BOOST_FOREACH(CNode* pnode, vNodes){
        // always relay to everyone
        pnode->PushMessage("dsq", (*this));
    }

    return true;
}

bool CDarksendQueue::CheckSignature()
{
    CMasternode* pmn = mnodeman.Find(vin);

    if(pmn != NULL)
    {
        std::string strMessage = vin.ToString() + boost::lexical_cast<std::string>(nDenom) + boost::lexical_cast<std::string>(time) + boost::lexical_cast<std::string>(ready);

        std::string errorMessage = "";
        if(!darkSendSigner.VerifyMessage(pmn->pubkey2, vchSig, strMessage, errorMessage)){
            return error("CDarksendQueue::CheckSignature() - Got bad masternode address signature %s \n", vin.ToString().c_str());
        }

        // -- second signature, for proving access to the anonymous relay system

        if(ready)
        {
            strMessage = boost::lexical_cast<std::string>(nBlockHeight);

            if(!darkSendSigner.VerifyMessage(pmn->pubkey2, vchRelaySig, strMessage, errorMessage)) {
                LogPrintf("CDarksendQueue():CheckSignature - Verify message failed");
                return false;
            }
        }

        return true;
    }

    return false;
}


void CDarksendPool::RelayFinalTransaction(const int sessionID, const CTransaction& txNew)
{
    LOCK(cs_vNodes);
    BOOST_FOREACH(CNode* pnode, vNodes)
    {
        pnode->PushMessage("dsf", sessionID, txNew);
    }
}

void CDarksendPool::RelaySignaturesAnon(std::vector<CTxIn>& vin)
{
    //empty
    CTxOut out;

    BOOST_FOREACH(CTxIn& in, vin){
        LogPrintf("RelaySignaturesAnon - sig %s\n", in.ToString().c_str());
        CDarkSendRelay dsr(pSubmittedToMasternode->vin, vchMasternodeRelaySig, nMasternodeBlockHeight, DARKSEND_RELAY_SIG, in, out, strMasternodeSharedKey);
        dsr.Relay();
    }
}

void CDarksendPool::RelayInAnon(std::vector<CTxIn>& vin, std::vector<CTxOut>& vout)
{
    //empty in/out
    CTxOut out;
    CTxIn in;

    BOOST_FOREACH(CTxIn& in, vin){
        LogPrintf("RelayInAnon - in %s\n", in.ToString().c_str());
        CDarkSendRelay dsr(pSubmittedToMasternode->vin, vchMasternodeRelaySig, nMasternodeBlockHeight, DARKSEND_RELAY_IN, in, out, strMasternodeSharedKey);
        dsr.Relay();
    }

    BOOST_FOREACH(CTxOut& out, vout){
        LogPrintf("RelayInAnon - out %s\n", out.ToString().c_str());
        CDarkSendRelay dsr(pSubmittedToMasternode->vin, vchMasternodeRelaySig, nMasternodeBlockHeight, DARKSEND_RELAY_OUT, in, out, strMasternodeSharedKey);
        dsr.Relay();
    }
}

void CDarksendPool::RelayIn(const std::vector<CTxIn>& vin, const int64_t& nAmount, const CTransaction& txCollateral, const std::vector<CTxOut>& vout)
{
    LOCK(cs_vNodes);

    BOOST_FOREACH(CNode* pnode, vNodes)
    {
        if(!pSubmittedToMasternode) return;
        if((CNetAddr)darkSendPool.pSubmittedToMasternode->addr != (CNetAddr)pnode->addr) continue;
        LogPrintf("RelayIn - found master, relaying message - %s \n", pnode->addr.ToString().c_str());
        pnode->PushMessage("dsi", vin, nAmount, txCollateral, vout);
    }
}

void CDarksendPool::RelayStatus(const int sessionID, const int newState, const int newEntriesCount, const int newAccepted, const std::string error)
{
    LOCK(cs_vNodes);
    BOOST_FOREACH(CNode* pnode, vNodes)
        pnode->PushMessage("dssu", sessionID, newState, newEntriesCount, newAccepted, error);
}

void CDarksendPool::RelayCompletedTransaction(const int sessionID, const bool error, const std::string errorMessage)
{
    LOCK(cs_vNodes);
    BOOST_FOREACH(CNode* pnode, vNodes)
        pnode->PushMessage("dsc", sessionID, error, errorMessage);
}

bool CDSAnonTx::AddOutput(const CTxOut out){
    if(fDebug) LogPrintf("CDSAnonTx::AddOutput -- new  %s\n", out.ToString().substr(0,24).c_str());

    //already have this output
    if(std::find(vout.begin(), vout.end(), out) != vout.end()) return false;

    vout.push_back(out);
    std::random_shuffle ( vout.begin(), vout.end(), randomizeList);

    return true;
}

bool CDSAnonTx::AddInput(const CTxIn in){
    if(fDebug) LogPrintf("CDSAnonTx::AddInput -- new  %s\n", in.ToString().substr(0,24).c_str());

    //already have this input
    if(std::find(vin.begin(), vin.end(), in) != vin.end()) return false;

    vin.push_back(in);

    return true;
}

bool CDSAnonTx::AddSig(const CTxIn newIn){
    if(fDebug) LogPrintf("CDSAnonTx::AddSig -- new  %s\n", newIn.ToString().substr(0,24).c_str());

    BOOST_FOREACH(CTxDSIn& in, vin){
        if(newIn.prevout == in.prevout && in.nSequence == newIn.nSequence){
            in.scriptSig = newIn.scriptSig;
            in.prevPubKey = newIn.prevPubKey;
            in.fHasSig = true;
            return true;
        }
    }

    return false;
}

//TODO: Rename/move to core
void ThreadCheckDarkSendPool()
{
    if(fLiteMode) return; //disable all Darksend/masternode related functionality

    // Make this thread recognisable as the wallet flushing thread
    RenameThread("darkcoin-darksend");

    unsigned int c = 0;
    std::string errorMessage;

    while (true)
    {
        c++;

        MilliSleep(1000);
        //LogPrintf("ThreadCheckDarkSendPool::check timeout\n");

        if(c % 10 == 0) darkSendPool.Check();
        darkSendPool.CheckTimeout();
        darkSendPool.CheckForCompleteQueue();

        if(c % 60 == 0)
        {
            LOCK(cs_main);
            /*
                cs_main is required for doing CMasternode.Check because something
                is modifying the coins view without a mempool lock. It causes
                segfaults from this code without the cs_main lock.
            */
            mnodeman.CheckAndRemove();
            mnodeman.ProcessMasternodeConnections();
            masternodePayments.CleanPaymentList();
            CleanTransactionLocksList();
        }

        if(c % MASTERNODE_PING_SECONDS == 0) activeMasternode.ManageStatus();

        if(c % MASTERNODES_DUMP_SECONDS == 0) DumpMasternodes();

        //try to sync the masternode list and payment list every 5 seconds from at least 3 nodes
        if(c % 5 == 0 && RequestedMasterNodeList < 3){
            bool fIsInitialDownload = IsInitialBlockDownload();
            if(!fIsInitialDownload) {
                LOCK(cs_vNodes);
                BOOST_FOREACH(CNode* pnode, vNodes)
                {
                    if (pnode->nVersion >= MIN_POOL_PEER_PROTO_VERSION) {

                        //keep track of who we've asked for the list
                        if(pnode->HasFulfilledRequest("mnsync")) continue;
                        pnode->FulfilledRequest("mnsync");

                        LogPrintf("Successfully synced, asking for Masternode list and payment list\n");

                        //request full mn list only if masternodes.dat was updated quite a long time ago
                        mnodeman.DsegUpdate(pnode);

                        pnode->PushMessage("mnget"); //sync payees
                        pnode->PushMessage("getsporks"); //get current network sporks
                        RequestedMasterNodeList++;
                    }
                }
            }
        }

        if(c % 60 == 0){
            //if we've used 1/5 of the masternode list, then clear the list.
            if((int)vecMasternodesUsed.size() > (int)mnodeman.size() / 5)
                vecMasternodesUsed.clear();
        }

        //auto denom every 2.5 minutes (liquidity provides try less often)
        if(c % 60*(nLiquidityProvider+1) == 0){
            if(nLiquidityProvider!=0){
                int nRand = rand() % (101+nLiquidityProvider);
                //about 1/100 chance of starting over after 4 rounds.
                if(nRand == 50+nLiquidityProvider && pwalletMain->GetAverageAnonymizedRounds() > 8){
                    darkSendPool.SendRandomPaymentToSelf();
                    int nLeftToAnon = ((pwalletMain->GetBalance() - pwalletMain->GetAnonymizedBalance())/COIN)-3;
                    if(nLeftToAnon > 999) nLeftToAnon = 999;
                    nAnonymizeDarkcoinAmount = (rand() % nLeftToAnon)+3;
                } else {
                    darkSendPool.DoAutomaticDenominating();
                }
            } else {
                darkSendPool.DoAutomaticDenominating();
            }
        }
    }
}