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

#include "masternodeman.h"
#include "masternode.h"
#include "activemasternode.h"
#include "darksend.h"
#include "util.h"
#include "addrman.h"
#include <boost/lexical_cast.hpp>
#include <boost/filesystem.hpp>

CCriticalSection cs_process_message;

/** Masternode manager */
CMasternodeMan mnodeman;

// Keep track of all broadcasts I've seen
map<uint256, CMasternodeBroadcast> mapSeenMasternodeBroadcast;

// Keep track of all pings I've seen
map<uint256, CMasternodePing> mapSeenMasternodePing;

struct CompareValueOnly
{
    bool operator()(const pair<int64_t, CTxIn>& t1,
                    const pair<int64_t, CTxIn>& t2) const
    {
        return t1.first < t2.first;
    }
};
struct CompareValueOnlyMN
{
    bool operator()(const pair<int64_t, CMasternode>& t1,
                    const pair<int64_t, CMasternode>& t2) const
    {
        return t1.first < t2.first;
    }
};

//
// CMasternodeDB
//

CMasternodeDB::CMasternodeDB()
{
    pathMN = GetDataDir() / "mncache.dat";
    strMagicMessage = "MasternodeCache";
}

bool CMasternodeDB::Write(const CMasternodeMan& mnodemanToSave)
{
    int64_t nStart = GetTimeMillis();

    // serialize, checksum data up to that point, then append checksum
    CDataStream ssMasternodes(SER_DISK, CLIENT_VERSION);
    ssMasternodes << strMagicMessage; // masternode cache file specific magic message
    ssMasternodes << FLATDATA(Params().MessageStart()); // network specific magic number
    ssMasternodes << mnodemanToSave;
    uint256 hash = Hash(ssMasternodes.begin(), ssMasternodes.end());
    ssMasternodes << hash;

    // open output file, and associate with CAutoFile
    FILE *file = fopen(pathMN.string().c_str(), "wb");
    CAutoFile fileout(file, SER_DISK, CLIENT_VERSION);
    if (fileout.IsNull())
        return error("%s : Failed to open file %s", __func__, pathMN.string());

    // Write and commit header, data
    try {
        fileout << ssMasternodes;
    }
    catch (std::exception &e) {
        return error("%s : Serialize or I/O error - %s", __func__, e.what());
    }
//    FileCommit(fileout);
    fileout.fclose();

    LogPrintf("Written info to mncache.dat  %dms\n", GetTimeMillis() - nStart);
    LogPrintf("  %s\n", mnodemanToSave.ToString());

    return true;
}

CMasternodeDB::ReadResult CMasternodeDB::Read(CMasternodeMan& mnodemanToLoad)
{
    int64_t nStart = GetTimeMillis();
    // open input file, and associate with CAutoFile
    FILE *file = fopen(pathMN.string().c_str(), "rb");
    CAutoFile filein(file, SER_DISK, CLIENT_VERSION);
    if (filein.IsNull())
    {
        error("%s : Failed to open file %s", __func__, pathMN.string());
        return FileError;
    }

    // use file size to size memory buffer
    int fileSize = boost::filesystem::file_size(pathMN);
    int dataSize = fileSize - sizeof(uint256);
    // Don't try to resize to a negative number if file is small
    if (dataSize < 0)
        dataSize = 0;
    vector<unsigned char> vchData;
    vchData.resize(dataSize);
    uint256 hashIn;

    // read data and checksum from file
    try {
        filein.read((char *)&vchData[0], dataSize);
        filein >> hashIn;
    }
    catch (std::exception &e) {
        error("%s : Deserialize or I/O error - %s", __func__, e.what());
        return HashReadError;
    }
    filein.fclose();

    CDataStream ssMasternodes(vchData, SER_DISK, CLIENT_VERSION);

    // verify stored checksum matches input data
    uint256 hashTmp = Hash(ssMasternodes.begin(), ssMasternodes.end());
    if (hashIn != hashTmp)
    {
        error("%s : Checksum mismatch, data corrupted", __func__);
        return IncorrectHash;
    }

    unsigned char pchMsgTmp[4];
    std::string strMagicMessageTmp;
    try {
        // de-serialize file header (masternode cache file specific magic message) and ..

        ssMasternodes >> strMagicMessageTmp;

        // ... verify the message matches predefined one
        if (strMagicMessage != strMagicMessageTmp)
        {
            error("%s : Invalid masternode cache magic message", __func__);
            return IncorrectMagicMessage;
        }

        // de-serialize file header (network specific magic number) and ..
        ssMasternodes >> FLATDATA(pchMsgTmp);

        // ... verify the network matches ours
        if (memcmp(pchMsgTmp, Params().MessageStart(), sizeof(pchMsgTmp)))
        {
            error("%s : Invalid network magic number", __func__);
            return IncorrectMagicNumber;
        }
        // de-serialize data into CMasternodeMan object
        ssMasternodes >> mnodemanToLoad;
    }
    catch (std::exception &e) {
        mnodemanToLoad.Clear();
        error("%s : Deserialize or I/O error - %s", __func__, e.what());
        return IncorrectFormat;
    }

    mnodemanToLoad.CheckAndRemove(); // clean out expired
    LogPrintf("Loaded info from mncache.dat  %dms\n", GetTimeMillis() - nStart);
    LogPrintf("  %s\n", mnodemanToLoad.ToString());

    return Ok;
}

void DumpMasternodes()
{
    int64_t nStart = GetTimeMillis();

    CMasternodeDB mndb;
    CMasternodeMan tempMnodeman;

    LogPrintf("Verifying mncache.dat format...\n");
    CMasternodeDB::ReadResult readResult = mndb.Read(tempMnodeman);
    // there was an error and it was not an error on file openning => do not proceed
    if (readResult == CMasternodeDB::FileError)
        LogPrintf("Missing masternode cache file - mncache.dat, will try to recreate\n");
    else if (readResult != CMasternodeDB::Ok)
    {
        LogPrintf("Error reading mncache.dat: ");
        if(readResult == CMasternodeDB::IncorrectFormat)
            LogPrintf("magic is ok but data has invalid format, will try to recreate\n");
        else
        {
            LogPrintf("file format is unknown or invalid, please fix it manually\n");
            return;
        }
    }
    LogPrintf("Writting info to mncache.dat...\n");
    mndb.Write(mnodeman);

    LogPrintf("Masternode dump finished  %dms\n", GetTimeMillis() - nStart);
}

CMasternodeMan::CMasternodeMan() {
    nDsqCount = 0;
}

bool CMasternodeMan::Add(CMasternode &mn)
{
    LOCK(cs);

    if (!mn.IsEnabled())
        return false;

    CMasternode *pmn = Find(mn.vin);
    if (pmn == NULL)
    {
        if(fDebug) LogPrintf("CMasternodeMan: Adding new Masternode %s - %i now\n", mn.addr.ToString().c_str(), size() + 1);
        vMasternodes.push_back(mn);
        return true;
    }

    return false;
}

void CMasternodeMan::Check()
{
    LOCK(cs);

    BOOST_FOREACH(CMasternode& mn, vMasternodes) {
        mn.Check();
        
        // // if it matches our Masternode privkey, then we've been remotely activated
        // if(mn.pubkey2 == activeMasternode.pubKeyMasternode && mn.protocolVersion == PROTOCOL_VERSION){
        //     activeMasternode.EnableHotColdMasterNode(mn.vin, mn.addr);
        // }
    }
}

void CMasternodeMan::CheckAndRemove()
{
    LOCK(cs);

    Check();

    //remove inactive
    vector<CMasternode>::iterator it = vMasternodes.begin();
    while(it != vMasternodes.end()){
        if((*it).activeState == CMasternode::MASTERNODE_REMOVE || (*it).activeState == CMasternode::MASTERNODE_VIN_SPENT || (*it).protocolVersion < nMasternodeMinProtocol){
            if(fDebug) LogPrintf("CMasternodeMan: Removing inactive Masternode %s - %i now\n", (*it).addr.ToString().c_str(), size() - 1);
            it = vMasternodes.erase(it);
        } else {
            ++it;
        }
    }

    // check who's asked for the Masternode list
    map<CNetAddr, int64_t>::iterator it1 = mAskedUsForMasternodeList.begin();
    while(it1 != mAskedUsForMasternodeList.end()){
        if((*it1).second < GetTime()) {
            mAskedUsForMasternodeList.erase(it1++);
        } else {
            ++it1;
        }
    }

    // check who we asked for the Masternode list
    it1 = mWeAskedForMasternodeList.begin();
    while(it1 != mWeAskedForMasternodeList.end()){
        if((*it1).second < GetTime()){
            mWeAskedForMasternodeList.erase(it1++);
        } else {
            ++it1;
        }
    }

    // check which Masternodes we've asked for
    map<COutPoint, int64_t>::iterator it2 = mWeAskedForMasternodeListEntry.begin();
    while(it2 != mWeAskedForMasternodeListEntry.end()){
        if((*it2).second < GetTime()){
            mWeAskedForMasternodeListEntry.erase(it2++);
        } else {
            ++it2;
        }
    }

}

void CMasternodeMan::Clear()
{
    LOCK(cs);
    vMasternodes.clear();
    mAskedUsForMasternodeList.clear();
    mWeAskedForMasternodeList.clear();
    mWeAskedForMasternodeListEntry.clear();
    nDsqCount = 0;
}

int CMasternodeMan::CountEnabled()
{
    int i = 0;

    BOOST_FOREACH(CMasternode& mn, vMasternodes) {
        mn.Check();
        if(mn.IsEnabled()) i++;
    }

    return i;
}

int CMasternodeMan::CountMasternodesAboveProtocol(int protocolVersion)
{
    int i = 0;

    BOOST_FOREACH(CMasternode& mn, vMasternodes) {
        mn.Check();
        if(mn.protocolVersion < protocolVersion || !mn.IsEnabled()) continue;
        i++;
    }

    return i;
}

void CMasternodeMan::DsegUpdate(CNode* pnode)
{
    LOCK(cs);

    std::map<CNetAddr, int64_t>::iterator it = mWeAskedForMasternodeList.find(pnode->addr);
    if (it != mWeAskedForMasternodeList.end())
    {
        if (GetTime() < (*it).second) {
            LogPrintf("dseg - we already asked %s for the list; skipping...\n", pnode->addr.ToString());
            return;
        }
    }
    pnode->PushMessage("dseg", CTxIn());
    int64_t askAgain = GetTime() + MASTERNODES_DSEG_SECONDS;
    mWeAskedForMasternodeList[pnode->addr] = askAgain;
}

CMasternode *CMasternodeMan::Find(const CScript &payee)
{
    LOCK(cs);
    CScript payee2;

    BOOST_FOREACH(CMasternode& mn, vMasternodes)
    {
        payee2 = GetScriptForDestination(mn.pubkey.GetID());
        if(payee2 == payee)
            return &mn;
    }
    return NULL;
}

CMasternode *CMasternodeMan::Find(const CTxIn &vin)
{
    LOCK(cs);

    BOOST_FOREACH(CMasternode& mn, vMasternodes)
    {
        if(mn.vin.prevout == vin.prevout)
            return &mn;
    }
    return NULL;
}


CMasternode *CMasternodeMan::Find(const CPubKey &pubKeyMasternode)
{
    LOCK(cs);

    BOOST_FOREACH(CMasternode& mn, vMasternodes)
    {
        if(mn.pubkey2 == pubKeyMasternode)
            return &mn;
    }
    return NULL;
}

CMasternode* CMasternodeMan::GetNextMasternodeInQueueForPayment(int nBlockHeight)
{
    LOCK(cs);

    CMasternode *pOldestMasternode = NULL;

    BOOST_FOREACH(CMasternode &mn, vMasternodes)
    {
        mn.Check();
        if(!mn.IsEnabled()) continue;

        //it's in the list -- so let's skip it
        if(masternodePayments.IsScheduled(mn, nBlockHeight)) continue;

        //make sure it has as many confirmations as there are masternodes
        if(mn.GetMasternodeInputAge() < CountEnabled()) continue;

        if(pOldestMasternode == NULL || pOldestMasternode->SecondsSincePayment() < mn.SecondsSincePayment()){
            pOldestMasternode = &mn;
        }
    }

    return pOldestMasternode;
}

CMasternode *CMasternodeMan::FindRandom()
{
    LOCK(cs);

    if(size() == 0) return NULL;

    return &vMasternodes[GetRandInt(vMasternodes.size())];
}

void CMasternodeMan::DecrementVotedTimes()
{
    BOOST_FOREACH(CMasternode& mn, vMasternodes)
        if(--mn.nVotedTimes < 0) mn.nVotedTimes = 0; 
}

CMasternode* CMasternodeMan::GetCurrentMasterNode(int mod, int64_t nBlockHeight, int minProtocol)
{
    unsigned int score = 0;
    CMasternode* winner = NULL;

    // scan for winner
    BOOST_FOREACH(CMasternode& mn, vMasternodes) {
        mn.Check();
        if(mn.protocolVersion < minProtocol || !mn.IsEnabled()) continue;

        // calculate the score for each Masternode
        uint256 n = mn.CalculateScore(mod, nBlockHeight);
        unsigned int n2 = 0;
        memcpy(&n2, &n, sizeof(n2));

        // determine the winner
        if(n2 > score){
            score = n2;
            winner = &mn;
        }
    }

    return winner;
}

int CMasternodeMan::GetMasternodeRank(const CTxIn& vin, int64_t nBlockHeight, int minProtocol, bool fOnlyActive)
{
    std::vector<pair<unsigned int, CTxIn> > vecMasternodeScores;

    //make sure we know about this block
    uint256 hash = 0;
    if(!GetBlockHash(hash, nBlockHeight)) return -1;

    // scan for winner
    BOOST_FOREACH(CMasternode& mn, vMasternodes) {
        if(mn.protocolVersion < minProtocol) continue;
        if(fOnlyActive) {
            mn.Check();
            if(!mn.IsEnabled()) continue;
        }
        uint256 n = mn.CalculateScore(1, nBlockHeight);
        unsigned int n2 = 0;
        memcpy(&n2, &n, sizeof(n2));

        vecMasternodeScores.push_back(make_pair(n2, mn.vin));
    }

    sort(vecMasternodeScores.rbegin(), vecMasternodeScores.rend(), CompareValueOnly());

    int rank = 0;
    BOOST_FOREACH (PAIRTYPE(unsigned int, CTxIn)& s, vecMasternodeScores){
        rank++;
        if(s.second.prevout == vin.prevout) {
            return rank;
        }
    }

    return -1;
}

std::vector<pair<int, CMasternode> > CMasternodeMan::GetMasternodeRanks(int64_t nBlockHeight, int minProtocol)
{
    std::vector<pair<unsigned int, CMasternode> > vecMasternodeScores;
    std::vector<pair<int, CMasternode> > vecMasternodeRanks;

    //make sure we know about this block
    uint256 hash = 0;
    if(!GetBlockHash(hash, nBlockHeight)) return vecMasternodeRanks;

    // scan for winner
    BOOST_FOREACH(CMasternode& mn, vMasternodes) {

        mn.Check();

        if(mn.protocolVersion < minProtocol) continue;
        if(!mn.IsEnabled()) {
            continue;
        }

        uint256 n = mn.CalculateScore(1, nBlockHeight);
        unsigned int n2 = 0;
        memcpy(&n2, &n, sizeof(n2));

        vecMasternodeScores.push_back(make_pair(n2, mn));
    }

    sort(vecMasternodeScores.rbegin(), vecMasternodeScores.rend(), CompareValueOnlyMN());

    int rank = 0;
    BOOST_FOREACH (PAIRTYPE(unsigned int, CMasternode)& s, vecMasternodeScores){
        rank++;
        vecMasternodeRanks.push_back(make_pair(rank, s.second));
    }

    return vecMasternodeRanks;
}

CMasternode* CMasternodeMan::GetMasternodeByRank(int nRank, int64_t nBlockHeight, int minProtocol, bool fOnlyActive)
{
    std::vector<pair<unsigned int, CTxIn> > vecMasternodeScores;

    // scan for winner
    BOOST_FOREACH(CMasternode& mn, vMasternodes) {

        if(mn.protocolVersion < minProtocol) continue;
        if(fOnlyActive) {
            mn.Check();
            if(!mn.IsEnabled()) continue;
        }

        uint256 n = mn.CalculateScore(1, nBlockHeight);
        unsigned int n2 = 0;
        memcpy(&n2, &n, sizeof(n2));

        vecMasternodeScores.push_back(make_pair(n2, mn.vin));
    }

    sort(vecMasternodeScores.rbegin(), vecMasternodeScores.rend(), CompareValueOnly());

    int rank = 0;
    BOOST_FOREACH (PAIRTYPE(unsigned int, CTxIn)& s, vecMasternodeScores){
        rank++;
        if(rank == nRank) {
            return Find(s.second);
        }
    }

    return NULL;
}

void CMasternodeMan::ProcessMasternodeConnections()
{
    //we don't care about this for regtest
    if(Params().NetworkID() == CBaseChainParams::REGTEST) return;

    LOCK(cs_vNodes);

    if(!darkSendPool.pSubmittedToMasternode) return;

    BOOST_FOREACH(CNode* pnode, vNodes)
    {
        if(darkSendPool.pSubmittedToMasternode->addr == pnode->addr) continue;

        if(pnode->fDarkSendMaster){
            LogPrintf("Closing Masternode connection %s \n", pnode->addr.ToString().c_str());
            pnode->CloseSocketDisconnect();
        }
    }
}

void CMasternodeMan::ProcessMessage(CNode* pfrom, std::string& strCommand, CDataStream& vRecv)
{

    if(fLiteMode) return; //disable all Darksend/Masternode related functionality
    if(IsInitialBlockDownload()) return;

    LOCK(cs_process_message);

    if (strCommand == "mnb") { //Masternode Broadcast
        CMasternodeBroadcast mnb;
        bool fRequested; //specifically requested?
        vRecv >> mnb >> fRequested;

        if(mapSeenMasternodeBroadcast.count(mnb.GetHash())) return; //seen
        mapSeenMasternodeBroadcast[mnb.GetHash()] = mnb;

        int nDoS = 0;
        if(!mnb.CheckAndUpdate(nDoS, fRequested)){

            if(nDoS > 0)
                Misbehaving(pfrom->GetId(), nDoS);

            //failed
            return;
        }

        // make sure the vout that was signed is related to the transaction that spawned the Masternode
        //  - this is expensive, so it's only done once per Masternode
        if(!darkSendSigner.IsVinAssociatedWithPubkey(mnb.vin, mnb.pubkey)) {
            LogPrintf("mnb - Got mismatched pubkey and vin\n");
            Misbehaving(pfrom->GetId(), 33);
            return;
        }

        if(fDebug) LogPrintf("mnb - Got NEW Masternode entry %s\n", mnb.addr.ToString().c_str());

        // make sure it's still unspent
        //  - this is checked later by .check() in many places and by ThreadCheckDarkSendPool()
        if(mnb.CheckInputsAndAdd(nDoS, fRequested)) {
            // use this as a peer
            addrman.Add(CAddress(mnb.addr), pfrom->addr, 2*60*60);
        } else {
            LogPrintf("mnb - Rejected Masternode entry %s\n", mnb.addr.ToString().c_str());

            if (nDoS > 0)
                Misbehaving(pfrom->GetId(), nDoS);
        }
    }

    else if (strCommand == "mnp") { //Masternode Ping
        CMasternodePing mnp;
        vRecv >> mnp;

        if(mapSeenMasternodePing.count(mnp.GetHash())) return; //seen
        mapSeenMasternodePing[mnp.GetHash()] = mnp;

        int nDoS = 0;
        if(mnp.CheckAndUpdate(nDoS))
        {
            //successful, we're done
            return;
        } else { 
            //failure
            if(nDoS > 0)
                Misbehaving(pfrom->GetId(), nDoS);
        }

        if(fDebug) LogPrintf("mnp - Couldn't find Masternode entry %s\n", mnp.vin.ToString().c_str());

        std::map<COutPoint, int64_t>::iterator i = mWeAskedForMasternodeListEntry.find(mnp.vin.prevout);
        if (i != mWeAskedForMasternodeListEntry.end())
        {
            int64_t t = (*i).second;
            if (GetTime() < t) return; // we've asked recently
        }

        // ask for the mnb info once from the node that sent mnp

        LogPrintf("mnp - Asking source node for missing entry %s\n", mnp.vin.ToString().c_str());
        pfrom->PushMessage("dseg", mnp.vin);
        int64_t askAgain = GetTime() + MASTERNODE_MIN_MNP_SECONDS;
        mWeAskedForMasternodeListEntry[mnp.vin.prevout] = askAgain;

    } else if (strCommand == "dseg") { //Get Masternode list or specific entry

        CTxIn vin;
        vRecv >> vin;

        if(vin == CTxIn()) { //only should ask for this once
            //local network
            if(!pfrom->addr.IsRFC1918() && Params().NetworkID() == CBaseChainParams::MAIN) {
                std::map<CNetAddr, int64_t>::iterator i = mAskedUsForMasternodeList.find(pfrom->addr);
                if (i != mAskedUsForMasternodeList.end()){
                    int64_t t = (*i).second;
                    if (GetTime() < t) {
                        Misbehaving(pfrom->GetId(), 34);
                        LogPrintf("dseg - peer already asked me for the list\n");
                        return;
                    }
                }
                int64_t askAgain = GetTime() + MASTERNODES_DSEG_SECONDS;
                mAskedUsForMasternodeList[pfrom->addr] = askAgain;
            }
        } //else, asking for a specific node which is ok

        int i = 0;
        BOOST_FOREACH(CMasternode& mn, vMasternodes) {
            if(mn.addr.IsRFC1918()) continue; //local network

            bool fRequested = true;
            if(mn.IsEnabled()) {
                if(fDebug) LogPrintf("dseg - Sending Masternode entry - %s \n", mn.addr.ToString().c_str());
                if(vin == CTxIn()){
                    CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                    ss.reserve(1000);
                    ss << CMasternodeBroadcast(mn);
                    ss << fRequested;
                    pfrom->PushMessage("mnb", ss);
                } else if (vin == mn.vin) {
                    CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                    ss.reserve(1000);
                    ss << CMasternodeBroadcast(mn);
                    ss << fRequested;
                    pfrom->PushMessage("mnb", ss);

                    LogPrintf("dseg - Sent 1 Masternode entries to %s\n", pfrom->addr.ToString().c_str());
                    return;
                }
            }
            i++;
        }

        LogPrintf("dseg - Sent %d Masternode entries to %s\n", i, pfrom->addr.ToString().c_str());
    }

}

void CMasternodeMan::Remove(CTxIn vin)
{
    LOCK(cs);

    vector<CMasternode>::iterator it = vMasternodes.begin();
    while(it != vMasternodes.end()){
        if((*it).vin == vin){
            if(fDebug) LogPrintf("CMasternodeMan: Removing Masternode %s - %i now\n", (*it).addr.ToString().c_str(), size() - 1);
            vMasternodes.erase(it);
            break;
        }
        ++it;
    }
}

std::string CMasternodeMan::ToString() const
{
    std::ostringstream info;

    info << "Masternodes: " << (int)vMasternodes.size() <<
            ", peers who asked us for Masternode list: " << (int)mAskedUsForMasternodeList.size() <<
            ", peers we asked for Masternode list: " << (int)mWeAskedForMasternodeList.size() <<
            ", entries in Masternode list we asked for: " << (int)mWeAskedForMasternodeListEntry.size() <<
            ", nDsqCount: " << (int)nDsqCount;

    return info.str();
}