// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_WALLET_WALLET_H
#define BITCOIN_WALLET_WALLET_H

#include "amount.h"
#include "policy/feerate.h"
#include "streams.h"
#include "tinyformat.h"
#include "ui_interface.h"
#include "utilstrencodings.h"
#include "validationinterface.h"
#include "script/ismine.h"
#include "script/sign.h"
#include "wallet/crypter.h"
#include "wallet/walletdb.h"
#include "wallet/rpcwallet.h"

#include <algorithm>
#include <atomic>
#include <map>
#include <set>
#include <stdexcept>
#include <stdint.h>
#include <string>
#include <utility>
#include <vector>

typedef CWallet* CWalletRef;
extern std::vector<CWalletRef> vpwallets;

/**
 * Settings
 */
extern CFeeRate payTxFee;
extern unsigned int nTxConfirmTarget;
extern bool bSpendZeroConfChange;
extern bool fWalletRbf;

static const unsigned int DEFAULT_KEYPOOL_SIZE = 100;
//! -paytxfee default
static const CAmount DEFAULT_TRANSACTION_FEE = 0;
//! -fallbackfee default
static const CAmount DEFAULT_FALLBACK_FEE = 20000;
//! -mintxfee default
static const CAmount DEFAULT_TRANSACTION_MINFEE = 1000;
//! minimum recommended increment for BIP 125 replacement txs
static const CAmount WALLET_INCREMENTAL_RELAY_FEE = 5000;
//! target minimum change amount
static const CAmount MIN_CHANGE = CENT;
//! final minimum change amount after paying for fees
static const CAmount MIN_FINAL_CHANGE = MIN_CHANGE/2;
//! Default for -spendzeroconfchange
static const bool DEFAULT_SPEND_ZEROCONF_CHANGE = true;
//! Default for -walletrejectlongchains
static const bool DEFAULT_WALLET_REJECT_LONG_CHAINS = false;
//! -txconfirmtarget default
static const unsigned int DEFAULT_TX_CONFIRM_TARGET = 6;
//! -walletrbf default
static const bool DEFAULT_WALLET_RBF = false;
static const bool DEFAULT_WALLETBROADCAST = true;
static const bool DEFAULT_DISABLE_WALLET = false;
//! if set, all keys will be derived by using BIP32
static const bool DEFAULT_USE_HD_WALLET = true;

extern const char * DEFAULT_WALLET_DAT;

class CBlockIndex;
class CCoinControl;
class COutput;
class CReserveKey;
class CScript;
class CScheduler;
class CTxMemPool;
class CBlockPolicyEstimator;
class CWalletTx;
struct FeeCalculation;

/** (client) version numbers for particular wallet features */
enum WalletFeature
{
    FEATURE_BASE = 10500, // the earliest version new wallets supports (only useful for getinfo's clientversion output)

    FEATURE_WALLETCRYPT = 40000, // wallet encryption
    FEATURE_COMPRPUBKEY = 60000, // compressed public keys

    FEATURE_HD = 130000, // Hierarchical key derivation after BIP32 (HD Wallet)

    FEATURE_HD_SPLIT = 139900, // Wallet with HD chain split (change outputs will use m/0'/1'/k)

    FEATURE_LATEST = FEATURE_COMPRPUBKEY // HD is optional, use FEATURE_COMPRPUBKEY as latest version
};


/** A key pool entry */
class CKeyPool
{
public:
    int64_t nTime;
    CPubKey vchPubKey;
    bool fInternal; // for change outputs

    CKeyPool();
    CKeyPool(const CPubKey& vchPubKeyIn, bool internalIn);

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action) {
        int nVersion = s.GetVersion();
        if (!(s.GetType() & SER_GETHASH))
            READWRITE(nVersion);
        READWRITE(nTime);
        READWRITE(vchPubKey);
        if (ser_action.ForRead()) {
            try {
                READWRITE(fInternal);
            }
            catch (std::ios_base::failure&) {
                /* flag as external address if we can't read the internal boolean
                   (this will be the case for any wallet before the HD chain split version) */
                fInternal = false;
            }
        }
        else {
            READWRITE(fInternal);
        }
    }
};

/** Address book data */
class CAddressBookData
{
public:
    std::string name;
    std::string purpose;

    CAddressBookData() : purpose("unknown") {}

    typedef std::map<std::string, std::string> StringMap;
    StringMap destdata;
};

struct CRecipient
{
    CScript scriptPubKey;
    CAmount nAmount;
    bool fSubtractFeeFromAmount;
};

typedef std::map<std::string, std::string> mapValue_t;


static inline void ReadOrderPos(int64_t& nOrderPos, mapValue_t& mapValue)
{
    if (!mapValue.count("n"))
    {
        nOrderPos = -1; // TODO: calculate elsewhere
        return;
    }
    nOrderPos = atoi64(mapValue["n"].c_str());
}


static inline void WriteOrderPos(const int64_t& nOrderPos, mapValue_t& mapValue)
{
    if (nOrderPos == -1)
        return;
    mapValue["n"] = i64tostr(nOrderPos);
}

struct COutputEntry
{
    CTxDestination destination;
    CAmount amount;
    int vout;
};

/** A transaction with a merkle branch linking it to the block chain. */
class CMerkleTx
{
private:
  /** Constant used in hashBlock to indicate tx has been abandoned */
    static const uint256 ABANDON_HASH;

public:
    CTransactionRef tx;
    uint256 hashBlock;

    /* An nIndex == -1 means that hashBlock (in nonzero) refers to the earliest
     * block in the chain we know this or any in-wallet dependency conflicts
     * with. Older clients interpret nIndex == -1 as unconfirmed for backward
     * compatibility.
     */
    int nIndex;

    CMerkleTx()
    {
        SetTx(MakeTransactionRef());
        Init();
    }

    CMerkleTx(CTransactionRef arg)
    {
        SetTx(std::move(arg));
        Init();
    }

    /** Helper conversion operator to allow passing CMerkleTx where CTransaction is expected.
     *  TODO: adapt callers and remove this operator. */
    operator const CTransaction&() const { return *tx; }

    void Init()
    {
        hashBlock = uint256();
        nIndex = -1;
    }

    void SetTx(CTransactionRef arg)
    {
        tx = std::move(arg);
    }

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action) {
        std::vector<uint256> vMerkleBranch; // For compatibility with older versions.
        READWRITE(tx);
        READWRITE(hashBlock);
        READWRITE(vMerkleBranch);
        READWRITE(nIndex);
    }

    void SetMerkleBranch(const CBlockIndex* pIndex, int posInBlock);

    /**
     * Return depth of transaction in blockchain:
     * <0  : conflicts with a transaction this deep in the blockchain
     *  0  : in memory pool, waiting to be included in a block
     * >=1 : this many blocks deep in the main chain
     */
    int GetDepthInMainChain(const CBlockIndex* &pindexRet) const;
    int GetDepthInMainChain() const { const CBlockIndex *pindexRet; return GetDepthInMainChain(pindexRet); }
    bool IsInMainChain() const { const CBlockIndex *pindexRet; return GetDepthInMainChain(pindexRet) > 0; }
    int GetBlocksToMaturity() const;
    /** Pass this transaction to the mempool. Fails if absolute fee exceeds absurd fee. */
    bool AcceptToMemoryPool(const CAmount& nAbsurdFee, CValidationState& state);
    bool hashUnset() const { return (hashBlock.IsNull() || hashBlock == ABANDON_HASH); }
    bool isAbandoned() const { return (hashBlock == ABANDON_HASH); }
    void setAbandoned() { hashBlock = ABANDON_HASH; }

    const uint256& GetHash() const { return tx->GetHash(); }
    bool IsCoinBase() const { return tx->IsCoinBase(); }
};

/** 
 * A transaction with a bunch of additional info that only the owner cares about.
 * It includes any unrecorded transactions needed to link it back to the block chain.
 */
class CWalletTx : public CMerkleTx
{
private:
    const CWallet* pwallet;

public:
    /**
     * Key/value map with information about the transaction.
     *
     * The following keys can be read and written through the map and are
     * serialized in the wallet database:
     *
     *     "comment", "to"   - comment strings provided to sendtoaddress,
     *                         sendfrom, sendmany wallet RPCs
     *     "replaces_txid"   - txid (as HexStr) of transaction replaced by
     *                         bumpfee on transaction created by bumpfee
     *     "replaced_by_txid" - txid (as HexStr) of transaction created by
     *                         bumpfee on transaction replaced by bumpfee
     *     "from", "message" - obsolete fields that could be set in UI prior to
     *                         2011 (removed in commit 4d9b223)
     *
     * The following keys are serialized in the wallet database, but shouldn't
     * be read or written through the map (they will be temporarily added and
     * removed from the map during serialization):
     *
     *     "fromaccount"     - serialized strFromAccount value
     *     "n"               - serialized nOrderPos value
     *     "timesmart"       - serialized nTimeSmart value
     *     "spent"           - serialized vfSpent value that existed prior to
     *                         2014 (removed in commit 93a18a3)
     */
    mapValue_t mapValue;
    std::vector<std::pair<std::string, std::string> > vOrderForm;
    unsigned int fTimeReceivedIsTxTime;
    unsigned int nTimeReceived; //!< time received by this node
    /**
     * Stable timestamp that never changes, and reflects the order a transaction
     * was added to the wallet. Timestamp is based on the block time for a
     * transaction added as part of a block, or else the time when the
     * transaction was received if it wasn't part of a block, with the timestamp
     * adjusted in both cases so timestamp order matches the order transactions
     * were added to the wallet. More details can be found in
     * CWallet::ComputeTimeSmart().
     */
    unsigned int nTimeSmart;
    /**
     * From me flag is set to 1 for transactions that were created by the wallet
     * on this bitcoin node, and set to 0 for transactions that were created
     * externally and came in through the network or sendrawtransaction RPC.
     */
    char fFromMe;
    std::string strFromAccount;
    int64_t nOrderPos; //!< position in ordered transaction list

    // memory only
    mutable bool fDebitCached;
    mutable bool fCreditCached;
    mutable bool fImmatureCreditCached;
    mutable bool fAvailableCreditCached;
    mutable bool fWatchDebitCached;
    mutable bool fWatchCreditCached;
    mutable bool fImmatureWatchCreditCached;
    mutable bool fAvailableWatchCreditCached;
    mutable bool fChangeCached;
    mutable CAmount nDebitCached;
    mutable CAmount nCreditCached;
    mutable CAmount nImmatureCreditCached;
    mutable CAmount nAvailableCreditCached;
    mutable CAmount nWatchDebitCached;
    mutable CAmount nWatchCreditCached;
    mutable CAmount nImmatureWatchCreditCached;
    mutable CAmount nAvailableWatchCreditCached;
    mutable CAmount nChangeCached;

    CWalletTx()
    {
        Init(NULL);
    }

    CWalletTx(const CWallet* pwalletIn, CTransactionRef arg) : CMerkleTx(std::move(arg))
    {
        Init(pwalletIn);
    }

    void Init(const CWallet* pwalletIn)
    {
        pwallet = pwalletIn;
        mapValue.clear();
        vOrderForm.clear();
        fTimeReceivedIsTxTime = false;
        nTimeReceived = 0;
        nTimeSmart = 0;
        fFromMe = false;
        strFromAccount.clear();
        fDebitCached = false;
        fCreditCached = false;
        fImmatureCreditCached = false;
        fAvailableCreditCached = false;
        fWatchDebitCached = false;
        fWatchCreditCached = false;
        fImmatureWatchCreditCached = false;
        fAvailableWatchCreditCached = false;
        fChangeCached = false;
        nDebitCached = 0;
        nCreditCached = 0;
        nImmatureCreditCached = 0;
        nAvailableCreditCached = 0;
        nWatchDebitCached = 0;
        nWatchCreditCached = 0;
        nAvailableWatchCreditCached = 0;
        nImmatureWatchCreditCached = 0;
        nChangeCached = 0;
        nOrderPos = -1;
    }

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action) {
        if (ser_action.ForRead())
            Init(NULL);
        char fSpent = false;

        if (!ser_action.ForRead())
        {
            mapValue["fromaccount"] = strFromAccount;

            WriteOrderPos(nOrderPos, mapValue);

            if (nTimeSmart)
                mapValue["timesmart"] = strprintf("%u", nTimeSmart);
        }

        READWRITE(*(CMerkleTx*)this);
        std::vector<CMerkleTx> vUnused; //!< Used to be vtxPrev
        READWRITE(vUnused);
        READWRITE(mapValue);
        READWRITE(vOrderForm);
        READWRITE(fTimeReceivedIsTxTime);
        READWRITE(nTimeReceived);
        READWRITE(fFromMe);
        READWRITE(fSpent);

        if (ser_action.ForRead())
        {
            strFromAccount = mapValue["fromaccount"];

            ReadOrderPos(nOrderPos, mapValue);

            nTimeSmart = mapValue.count("timesmart") ? (unsigned int)atoi64(mapValue["timesmart"]) : 0;
        }

        mapValue.erase("fromaccount");
        mapValue.erase("spent");
        mapValue.erase("n");
        mapValue.erase("timesmart");
    }

    //! make sure balances are recalculated
    void MarkDirty()
    {
        fCreditCached = false;
        fAvailableCreditCached = false;
        fImmatureCreditCached = false;
        fWatchDebitCached = false;
        fWatchCreditCached = false;
        fAvailableWatchCreditCached = false;
        fImmatureWatchCreditCached = false;
        fDebitCached = false;
        fChangeCached = false;
    }

    void BindWallet(CWallet *pwalletIn)
    {
        pwallet = pwalletIn;
        MarkDirty();
    }

    //! filter decides which addresses will count towards the debit
    CAmount GetDebit(const isminefilter& filter) const;
    CAmount GetCredit(const isminefilter& filter) const;
    CAmount GetImmatureCredit(bool fUseCache=true) const;
    CAmount GetAvailableCredit(bool fUseCache=true) const;
    CAmount GetImmatureWatchOnlyCredit(const bool& fUseCache=true) const;
    CAmount GetAvailableWatchOnlyCredit(const bool& fUseCache=true) const;
    CAmount GetChange() const;

    void GetAmounts(std::list<COutputEntry>& listReceived,
                    std::list<COutputEntry>& listSent, CAmount& nFee, std::string& strSentAccount, const isminefilter& filter) const;

    bool IsFromMe(const isminefilter& filter) const
    {
        return (GetDebit(filter) > 0);
    }

    // True if only scriptSigs are different
    bool IsEquivalentTo(const CWalletTx& tx) const;

    bool InMempool() const;
    bool IsTrusted() const;

    int64_t GetTxTime() const;
    int GetRequestCount() const;

    bool RelayWalletTransaction(CConnman* connman);

    std::set<uint256> GetConflicts() const;
};


class CInputCoin {
public:
    CInputCoin(const CWalletTx* walletTx, unsigned int i)
    {
        if (!walletTx)
            throw std::invalid_argument("walletTx should not be null");
        if (i >= walletTx->tx->vout.size())
            throw std::out_of_range("The output index is out of range");

        outpoint = COutPoint(walletTx->GetHash(), i);
        txout = walletTx->tx->vout[i];
    }

    COutPoint outpoint;
    CTxOut txout;

    bool operator<(const CInputCoin& rhs) const {
        return outpoint < rhs.outpoint;
    }

    bool operator!=(const CInputCoin& rhs) const {
        return outpoint != rhs.outpoint;
    }

    bool operator==(const CInputCoin& rhs) const {
        return outpoint == rhs.outpoint;
    }
};

class COutput
{
public:
    const CWalletTx *tx;
    int i;
    int nDepth;

    /** Whether we have the private keys to spend this output */
    bool fSpendable;

    /** Whether we know how to spend this output, ignoring the lack of keys */
    bool fSolvable;

    /**
     * Whether this output is considered safe to spend. Unconfirmed transactions
     * from outside keys and unconfirmed replacement transactions are considered
     * unsafe and will not be used to fund new spending transactions.
     */
    bool fSafe;

    COutput(const CWalletTx *txIn, int iIn, int nDepthIn, bool fSpendableIn, bool fSolvableIn, bool fSafeIn)
    {
        tx = txIn; i = iIn; nDepth = nDepthIn; fSpendable = fSpendableIn; fSolvable = fSolvableIn; fSafe = fSafeIn;
    }

    std::string ToString() const;
};




/** Private key that includes an expiration date in case it never gets used. */
class CWalletKey
{
public:
    CPrivKey vchPrivKey;
    int64_t nTimeCreated;
    int64_t nTimeExpires;
    std::string strComment;
    //! todo: add something to note what created it (user, getnewaddress, change)
    //!   maybe should have a map<string, string> property map

    CWalletKey(int64_t nExpires=0);

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action) {
        int nVersion = s.GetVersion();
        if (!(s.GetType() & SER_GETHASH))
            READWRITE(nVersion);
        READWRITE(vchPrivKey);
        READWRITE(nTimeCreated);
        READWRITE(nTimeExpires);
        READWRITE(LIMITED_STRING(strComment, 65536));
    }
};

/**
 * Internal transfers.
 * Database key is acentry<account><counter>.
 */
class CAccountingEntry
{
public:
    std::string strAccount;
    CAmount nCreditDebit;
    int64_t nTime;
    std::string strOtherAccount;
    std::string strComment;
    mapValue_t mapValue;
    int64_t nOrderPos; //!< position in ordered transaction list
    uint64_t nEntryNo;

    CAccountingEntry()
    {
        SetNull();
    }

    void SetNull()
    {
        nCreditDebit = 0;
        nTime = 0;
        strAccount.clear();
        strOtherAccount.clear();
        strComment.clear();
        nOrderPos = -1;
        nEntryNo = 0;
    }

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action) {
        int nVersion = s.GetVersion();
        if (!(s.GetType() & SER_GETHASH))
            READWRITE(nVersion);
        //! Note: strAccount is serialized as part of the key, not here.
        READWRITE(nCreditDebit);
        READWRITE(nTime);
        READWRITE(LIMITED_STRING(strOtherAccount, 65536));

        if (!ser_action.ForRead())
        {
            WriteOrderPos(nOrderPos, mapValue);

            if (!(mapValue.empty() && _ssExtra.empty()))
            {
                CDataStream ss(s.GetType(), s.GetVersion());
                ss.insert(ss.begin(), '\0');
                ss << mapValue;
                ss.insert(ss.end(), _ssExtra.begin(), _ssExtra.end());
                strComment.append(ss.str());
            }
        }

        READWRITE(LIMITED_STRING(strComment, 65536));

        size_t nSepPos = strComment.find("\0", 0, 1);
        if (ser_action.ForRead())
        {
            mapValue.clear();
            if (std::string::npos != nSepPos)
            {
                CDataStream ss(std::vector<char>(strComment.begin() + nSepPos + 1, strComment.end()), s.GetType(), s.GetVersion());
                ss >> mapValue;
                _ssExtra = std::vector<char>(ss.begin(), ss.end());
            }
            ReadOrderPos(nOrderPos, mapValue);
        }
        if (std::string::npos != nSepPos)
            strComment.erase(nSepPos);

        mapValue.erase("n");
    }

private:
    std::vector<char> _ssExtra;
};


/** 
 * A CWallet is an extension of a keystore, which also maintains a set of transactions and balances,
 * and provides the ability to create new transactions.
 */
class CWallet : public CCryptoKeyStore, public CValidationInterface
{
private:
    static std::atomic<bool> fFlushScheduled;
    std::atomic<bool> fAbortRescan;
    std::atomic<bool> fScanningWallet;

    /**
     * Select a set of coins such that nValueRet >= nTargetValue and at least
     * all coins from coinControl are selected; Never select unconfirmed coins
     * if they are not ours
     */
    bool SelectCoins(const std::vector<COutput>& vAvailableCoins, const CAmount& nTargetValue, std::set<CInputCoin>& setCoinsRet, CAmount& nValueRet, const CCoinControl *coinControl = NULL) const;

    CWalletDB *pwalletdbEncryption;

    //! the current wallet version: clients below this version are not able to load the wallet
    int nWalletVersion;

    //! the maximum wallet format version: memory-only variable that specifies to what version this wallet may be upgraded
    int nWalletMaxVersion;

    int64_t nNextResend;
    int64_t nLastResend;
    bool fBroadcastTransactions;

    /**
     * Used to keep track of spent outpoints, and
     * detect and report conflicts (double-spends or
     * mutated transactions where the mutant gets mined).
     */
    typedef std::multimap<COutPoint, uint256> TxSpends;
    TxSpends mapTxSpends;
    void AddToSpends(const COutPoint& outpoint, const uint256& wtxid);
    void AddToSpends(const uint256& wtxid);

    /* Mark a transaction (and its in-wallet descendants) as conflicting with a particular block. */
    void MarkConflicted(const uint256& hashBlock, const uint256& hashTx);

    void SyncMetaData(std::pair<TxSpends::iterator, TxSpends::iterator>);

    /* Used by TransactionAddedToMemorypool/BlockConnected/Disconnected.
     * Should be called with pindexBlock and posInBlock if this is for a transaction that is included in a block. */
    void SyncTransaction(const CTransactionRef& tx, const CBlockIndex *pindex = NULL, int posInBlock = 0);

    /* the HD chain data model (external chain counters) */
    CHDChain hdChain;

    /* HD derive new child key (on internal or external chain) */
    void DeriveNewChildKey(CKeyMetadata& metadata, CKey& secret, bool internal = false);

    std::set<int64_t> setKeyPool;

    int64_t nTimeFirstKey;

    /**
     * Private version of AddWatchOnly method which does not accept a
     * timestamp, and which will reset the wallet's nTimeFirstKey value to 1 if
     * the watch key did not previously have a timestamp associated with it.
     * Because this is an inherited virtual method, it is accessible despite
     * being marked private, but it is marked private anyway to encourage use
     * of the other AddWatchOnly which accepts a timestamp and sets
     * nTimeFirstKey more intelligently for more efficient rescans.
     */
    bool AddWatchOnly(const CScript& dest) override;

    std::unique_ptr<CWalletDBWrapper> dbw;

public:
    /*
     * Main wallet lock.
     * This lock protects all the fields added by CWallet.
     */
    mutable CCriticalSection cs_wallet;

    /** Get database handle used by this wallet. Ideally this function would
     * not be necessary.
     */
    CWalletDBWrapper& GetDBHandle()
    {
        return *dbw;
    }

    /** Get a name for this wallet for logging/debugging purposes.
     */
    std::string GetName() const
    {
        if (dbw) {
            return dbw->GetName();
        } else {
            return "dummy";
        }
    }

    void LoadKeyPool(int nIndex, const CKeyPool &keypool)
    {
        setKeyPool.insert(nIndex);

        // If no metadata exists yet, create a default with the pool key's
        // creation time. Note that this may be overwritten by actually
        // stored metadata for that key later, which is fine.
        CKeyID keyid = keypool.vchPubKey.GetID();
        if (mapKeyMetadata.count(keyid) == 0)
            mapKeyMetadata[keyid] = CKeyMetadata(keypool.nTime);
    }

    // Map from Key ID (for regular keys) or Script ID (for watch-only keys) to
    // key metadata.
    std::map<CTxDestination, CKeyMetadata> mapKeyMetadata;

    typedef std::map<unsigned int, CMasterKey> MasterKeyMap;
    MasterKeyMap mapMasterKeys;
    unsigned int nMasterKeyMaxID;

    // Create wallet with dummy database handle
    CWallet(): dbw(new CWalletDBWrapper())
    {
        SetNull();
    }

    // Create wallet with passed-in database handle
    CWallet(std::unique_ptr<CWalletDBWrapper> dbw_in) : dbw(std::move(dbw_in))
    {
        SetNull();
    }

    ~CWallet()
    {
        delete pwalletdbEncryption;
        pwalletdbEncryption = NULL;
    }

    void SetNull()
    {
        nWalletVersion = FEATURE_BASE;
        nWalletMaxVersion = FEATURE_BASE;
        nMasterKeyMaxID = 0;
        pwalletdbEncryption = NULL;
        nOrderPosNext = 0;
        nAccountingEntryNumber = 0;
        nNextResend = 0;
        nLastResend = 0;
        nTimeFirstKey = 0;
        fBroadcastTransactions = false;
        nRelockTime = 0;
        fAbortRescan = false;
        fScanningWallet = false;
    }

    std::map<uint256, CWalletTx> mapWallet;
    std::list<CAccountingEntry> laccentries;

    typedef std::pair<CWalletTx*, CAccountingEntry*> TxPair;
    typedef std::multimap<int64_t, TxPair > TxItems;
    TxItems wtxOrdered;

    int64_t nOrderPosNext;
    uint64_t nAccountingEntryNumber;
    std::map<uint256, int> mapRequestCount;

    std::map<CTxDestination, CAddressBookData> mapAddressBook;

    CPubKey vchDefaultKey;

    std::set<COutPoint> setLockedCoins;

    const CWalletTx* GetWalletTx(const uint256& hash) const;

    //! check whether we are allowed to upgrade (or already support) to the named feature
    bool CanSupportFeature(enum WalletFeature wf) { AssertLockHeld(cs_wallet); return nWalletMaxVersion >= wf; }

    /**
     * populate vCoins with vector of available COutputs.
     */
    void AvailableCoins(std::vector<COutput>& vCoins, bool fOnlySafe=true, const CCoinControl *coinControl = NULL, const CAmount& nMinimumAmount = 1, const CAmount& nMaximumAmount = MAX_MONEY, const CAmount& nMinimumSumAmount = MAX_MONEY, const uint64_t& nMaximumCount = 0, const int& nMinDepth = 0, const int& nMaxDepth = 9999999) const;

    /**
     * Return list of available coins and locked coins grouped by non-change output address.
     */
    std::map<CTxDestination, std::vector<COutput>> ListCoins() const;

    /**
     * Find non-change parent output.
     */
    const CTxOut& FindNonChangeParentOutput(const CTransaction& tx, int output) const;

    /**
     * Shuffle and select coins until nTargetValue is reached while avoiding
     * small change; This method is stochastic for some inputs and upon
     * completion the coin set and corresponding actual target value is
     * assembled
     */
    bool SelectCoinsMinConf(const CAmount& nTargetValue, int nConfMine, int nConfTheirs, uint64_t nMaxAncestors, std::vector<COutput> vCoins, std::set<CInputCoin>& setCoinsRet, CAmount& nValueRet) const;

    bool IsSpent(const uint256& hash, unsigned int n) const;

    bool IsLockedCoin(uint256 hash, unsigned int n) const;
    void LockCoin(const COutPoint& output);
    void UnlockCoin(const COutPoint& output);
    void UnlockAllCoins();
    void ListLockedCoins(std::vector<COutPoint>& vOutpts) const;

    /*
     * Rescan abort properties
     */
    void AbortRescan() { fAbortRescan = true; }
    bool IsAbortingRescan() { return fAbortRescan; }
    bool IsScanning() { return fScanningWallet; }

    /**
     * keystore implementation
     * Generate a new key
     */
    CPubKey GenerateNewKey(bool internal = false);
    //! Adds a key to the store, and saves it to disk.
    bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey) override;
    //! Adds a key to the store, without saving it to disk (used by LoadWallet)
    bool LoadKey(const CKey& key, const CPubKey &pubkey) { return CCryptoKeyStore::AddKeyPubKey(key, pubkey); }
    //! Load metadata (used by LoadWallet)
    bool LoadKeyMetadata(const CTxDestination& pubKey, const CKeyMetadata &metadata);

    bool LoadMinVersion(int nVersion) { AssertLockHeld(cs_wallet); nWalletVersion = nVersion; nWalletMaxVersion = std::max(nWalletMaxVersion, nVersion); return true; }
    void UpdateTimeFirstKey(int64_t nCreateTime);

    //! Adds an encrypted key to the store, and saves it to disk.
    bool AddCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret) override;
    //! Adds an encrypted key to the store, without saving it to disk (used by LoadWallet)
    bool LoadCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret);
    bool AddCScript(const CScript& redeemScript) override;
    bool LoadCScript(const CScript& redeemScript);

    //! Adds a destination data tuple to the store, and saves it to disk
    bool AddDestData(const CTxDestination &dest, const std::string &key, const std::string &value);
    //! Erases a destination data tuple in the store and on disk
    bool EraseDestData(const CTxDestination &dest, const std::string &key);
    //! Adds a destination data tuple to the store, without saving it to disk
    bool LoadDestData(const CTxDestination &dest, const std::string &key, const std::string &value);
    //! Look up a destination data tuple in the store, return true if found false otherwise
    bool GetDestData(const CTxDestination &dest, const std::string &key, std::string *value) const;
    //! Get all destination values matching a prefix.
    std::vector<std::string> GetDestValues(const std::string& prefix) const;

    //! Adds a watch-only address to the store, and saves it to disk.
    bool AddWatchOnly(const CScript& dest, int64_t nCreateTime);
    bool RemoveWatchOnly(const CScript &dest) override;
    //! Adds a watch-only address to the store, without saving it to disk (used by LoadWallet)
    bool LoadWatchOnly(const CScript &dest);

    //! Holds a timestamp at which point the wallet is scheduled (externally) to be relocked. Caller must arrange for actual relocking to occur via Lock().
    int64_t nRelockTime;

    bool Unlock(const SecureString& strWalletPassphrase);
    bool ChangeWalletPassphrase(const SecureString& strOldWalletPassphrase, const SecureString& strNewWalletPassphrase);
    bool EncryptWallet(const SecureString& strWalletPassphrase);

    void GetKeyBirthTimes(std::map<CTxDestination, int64_t> &mapKeyBirth) const;
    unsigned int ComputeTimeSmart(const CWalletTx& wtx) const;

    /** 
     * Increment the next transaction order id
     * @return next transaction order id
     */
    int64_t IncOrderPosNext(CWalletDB *pwalletdb = NULL);
    DBErrors ReorderTransactions();
    bool AccountMove(std::string strFrom, std::string strTo, CAmount nAmount, std::string strComment = "");
    bool GetAccountPubkey(CPubKey &pubKey, std::string strAccount, bool bForceNew = false);

    void MarkDirty();
    bool AddToWallet(const CWalletTx& wtxIn, bool fFlushOnClose=true);
    bool LoadToWallet(const CWalletTx& wtxIn);
    void TransactionAddedToMempool(const CTransactionRef& tx) override;
    void BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex *pindex, const std::vector<CTransactionRef>& vtxConflicted) override;
    void BlockDisconnected(const std::shared_ptr<const CBlock>& pblock) override;
    bool AddToWalletIfInvolvingMe(const CTransactionRef& tx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate);
    CBlockIndex* ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate = false);
    void ReacceptWalletTransactions();
    void ResendWalletTransactions(int64_t nBestBlockTime, CConnman* connman) override;
    std::vector<uint256> ResendWalletTransactionsBefore(int64_t nTime, CConnman* connman);
    CAmount GetBalance() const;
    CAmount GetUnconfirmedBalance() const;
    CAmount GetImmatureBalance() const;
    CAmount GetWatchOnlyBalance() const;
    CAmount GetUnconfirmedWatchOnlyBalance() const;
    CAmount GetImmatureWatchOnlyBalance() const;
    CAmount GetLegacyBalance(const isminefilter& filter, int minDepth, const std::string* account) const;
    CAmount GetAvailableBalance(const CCoinControl* coinControl = nullptr) const;

    /**
     * Insert additional inputs into the transaction by
     * calling CreateTransaction();
     */
    bool FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nChangePosInOut, std::string& strFailReason, bool lockUnspents, const std::set<int>& setSubtractFeeFromOutputs, CCoinControl, bool keepReserveKey = true);
    bool SignTransaction(CMutableTransaction& tx);

    /**
     * Create a new transaction paying the recipients with a set of coins
     * selected by SelectCoins(); Also create the change output, when needed
     * @note passing nChangePosInOut as -1 will result in setting a random position
     */
    bool CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletTx& wtxNew, CReserveKey& reservekey, CAmount& nFeeRet, int& nChangePosInOut,
                           std::string& strFailReason, const CCoinControl *coinControl = NULL, bool sign = true);
    bool CommitTransaction(CWalletTx& wtxNew, CReserveKey& reservekey, CConnman* connman, CValidationState& state);

    void ListAccountCreditDebit(const std::string& strAccount, std::list<CAccountingEntry>& entries);
    bool AddAccountingEntry(const CAccountingEntry&);
    bool AddAccountingEntry(const CAccountingEntry&, CWalletDB *pwalletdb);
    template <typename ContainerType>
    bool DummySignTx(CMutableTransaction &txNew, const ContainerType &coins) const;

    static CFeeRate minTxFee;
    static CFeeRate fallbackFee;
    /**
     * Estimate the minimum fee considering user set parameters
     * and the required fee
     */
    static CAmount GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarget, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc = nullptr, bool ignoreGlobalPayTxFee = false);
    /**
     * Return the minimum required fee taking into account the
     * floating relay fee and user set minimum transaction fee
     */
    static CAmount GetRequiredFee(unsigned int nTxBytes);

    bool NewKeyPool();
    size_t KeypoolCountExternalKeys();
    bool TopUpKeyPool(unsigned int kpSize = 0);
    void ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool internal);
    void KeepKey(int64_t nIndex);
    void ReturnKey(int64_t nIndex);
    bool GetKeyFromPool(CPubKey &key, bool internal = false);
    int64_t GetOldestKeyPoolTime();
    void GetAllReserveKeys(std::set<CKeyID>& setAddress) const;

    std::set< std::set<CTxDestination> > GetAddressGroupings();
    std::map<CTxDestination, CAmount> GetAddressBalances();

    std::set<CTxDestination> GetAccountAddresses(const std::string& strAccount) const;

    isminetype IsMine(const CTxIn& txin) const;
    /**
     * Returns amount of debit if the input matches the
     * filter, otherwise returns 0
     */
    CAmount GetDebit(const CTxIn& txin, const isminefilter& filter) const;
    isminetype IsMine(const CTxOut& txout) const;
    CAmount GetCredit(const CTxOut& txout, const isminefilter& filter) const;
    bool IsChange(const CTxOut& txout) const;
    CAmount GetChange(const CTxOut& txout) const;
    bool IsMine(const CTransaction& tx) const;
    /** should probably be renamed to IsRelevantToMe */
    bool IsFromMe(const CTransaction& tx) const;
    CAmount GetDebit(const CTransaction& tx, const isminefilter& filter) const;
    /** Returns whether all of the inputs match the filter */
    bool IsAllFromMe(const CTransaction& tx, const isminefilter& filter) const;
    CAmount GetCredit(const CTransaction& tx, const isminefilter& filter) const;
    CAmount GetChange(const CTransaction& tx) const;
    void SetBestChain(const CBlockLocator& loc) override;

    DBErrors LoadWallet(bool& fFirstRunRet);
    DBErrors ZapWalletTx(std::vector<CWalletTx>& vWtx);
    DBErrors ZapSelectTx(std::vector<uint256>& vHashIn, std::vector<uint256>& vHashOut);

    bool SetAddressBook(const CTxDestination& address, const std::string& strName, const std::string& purpose);

    bool DelAddressBook(const CTxDestination& address);

    const std::string& GetAccountName(const CScript& scriptPubKey) const;

    void Inventory(const uint256 &hash) override
    {
        {
            LOCK(cs_wallet);
            std::map<uint256, int>::iterator mi = mapRequestCount.find(hash);
            if (mi != mapRequestCount.end())
                (*mi).second++;
        }
    }

    void GetScriptForMining(std::shared_ptr<CReserveScript> &script) override;
    
    unsigned int GetKeyPoolSize()
    {
        AssertLockHeld(cs_wallet); // setKeyPool
        return setKeyPool.size();
    }

    bool SetDefaultKey(const CPubKey &vchPubKey);

    //! signify that a particular wallet feature is now used. this may change nWalletVersion and nWalletMaxVersion if those are lower
    bool SetMinVersion(enum WalletFeature, CWalletDB* pwalletdbIn = NULL, bool fExplicit = false);

    //! change which version we're allowed to upgrade to (note that this does not immediately imply upgrading to that format)
    bool SetMaxVersion(int nVersion);

    //! get the current wallet format (the oldest client version guaranteed to understand this wallet)
    int GetVersion() { LOCK(cs_wallet); return nWalletVersion; }

    //! Get wallet transactions that conflict with given transaction (spend same outputs)
    std::set<uint256> GetConflicts(const uint256& txid) const;

    //! Check if a given transaction has any of its outputs spent by another transaction in the wallet
    bool HasWalletSpend(const uint256& txid) const;

    //! Flush wallet (bitdb flush)
    void Flush(bool shutdown=false);

    //! Verify the wallet database and perform salvage if required
    static bool Verify();
    
    /** 
     * Address book entry changed.
     * @note called with lock cs_wallet held.
     */
    boost::signals2::signal<void (CWallet *wallet, const CTxDestination
            &address, const std::string &label, bool isMine,
            const std::string &purpose,
            ChangeType status)> NotifyAddressBookChanged;

    /** 
     * Wallet transaction added, removed or updated.
     * @note called with lock cs_wallet held.
     */
    boost::signals2::signal<void (CWallet *wallet, const uint256 &hashTx,
            ChangeType status)> NotifyTransactionChanged;

    /** Show progress e.g. for rescan */
    boost::signals2::signal<void (const std::string &title, int nProgress)> ShowProgress;

    /** Watch-only address added */
    boost::signals2::signal<void (bool fHaveWatchOnly)> NotifyWatchonlyChanged;

    /** Inquire whether this wallet broadcasts transactions. */
    bool GetBroadcastTransactions() const { return fBroadcastTransactions; }
    /** Set whether this wallet broadcasts transactions. */
    void SetBroadcastTransactions(bool broadcast) { fBroadcastTransactions = broadcast; }

    /** Return whether transaction can be abandoned */
    bool TransactionCanBeAbandoned(const uint256& hashTx) const;

    /* Mark a transaction (and it in-wallet descendants) as abandoned so its inputs may be respent. */
    bool AbandonTransaction(const uint256& hashTx);

    /** Mark a transaction as replaced by another transaction (e.g., BIP 125). */
    bool MarkReplaced(const uint256& originalHash, const uint256& newHash);

    /* Returns the wallets help message */
    static std::string GetWalletHelpString(bool showDebug);

    /* Initializes the wallet, returns a new CWallet instance or a null pointer in case of an error */
    static CWallet* CreateWalletFromFile(const std::string walletFile);
    static bool InitLoadWallet();

    /**
     * Wallet post-init setup
     * Gives the wallet a chance to register repetitive tasks and complete post-init tasks
     */
    void postInitProcess(CScheduler& scheduler);

    /* Wallets parameter interaction */
    static bool ParameterInteraction();

    bool BackupWallet(const std::string& strDest);

    /* Set the HD chain model (chain child index counters) */
    bool SetHDChain(const CHDChain& chain, bool memonly);
    const CHDChain& GetHDChain() const { return hdChain; }

    /* Returns true if HD is enabled */
    bool IsHDEnabled() const;

    /* Generates a new HD master key (will not be activated) */
    CPubKey GenerateNewHDMasterKey();
    
    /* Set the current HD master key (will reset the chain child index counters)
       Sets the master key's version based on the current wallet version (so the
       caller must ensure the current wallet version is correct before calling
       this function). */
    bool SetHDMasterKey(const CPubKey& key);
};

/** A key allocated from the key pool. */
class CReserveKey : public CReserveScript
{
protected:
    CWallet* pwallet;
    int64_t nIndex;
    CPubKey vchPubKey;
public:
    CReserveKey(CWallet* pwalletIn)
    {
        nIndex = -1;
        pwallet = pwalletIn;
    }

    CReserveKey() = default;
    CReserveKey(const CReserveKey&) = delete;
    CReserveKey& operator=(const CReserveKey&) = delete;

    ~CReserveKey()
    {
        ReturnKey();
    }

    void ReturnKey();
    bool GetReservedKey(CPubKey &pubkey, bool internal = false);
    void KeepKey();
    void KeepScript() { KeepKey(); }
};


/** 
 * Account information.
 * Stored in wallet with key "acc"+string account name.
 */
class CAccount
{
public:
    CPubKey vchPubKey;

    CAccount()
    {
        SetNull();
    }

    void SetNull()
    {
        vchPubKey = CPubKey();
    }

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action) {
        int nVersion = s.GetVersion();
        if (!(s.GetType() & SER_GETHASH))
            READWRITE(nVersion);
        READWRITE(vchPubKey);
    }
};

// Helper for producing a bunch of max-sized low-S signatures (eg 72 bytes)
// ContainerType is meant to hold pair<CWalletTx *, int>, and be iterable
// so that each entry corresponds to each vIn, in order.
template <typename ContainerType>
bool CWallet::DummySignTx(CMutableTransaction &txNew, const ContainerType &coins) const
{
    // Fill in dummy signatures for fee calculation.
    int nIn = 0;
    for (const auto& coin : coins)
    {
        const CScript& scriptPubKey = coin.txout.scriptPubKey;
        SignatureData sigdata;

        if (!ProduceSignature(DummySignatureCreator(this), scriptPubKey, sigdata))
        {
            return false;
        } else {
            UpdateTransaction(txNew, nIn, sigdata);
        }

        nIn++;
    }
    return true;
}
#endif // BITCOIN_WALLET_WALLET_H