// Copyright (c) 2011-2020 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "walletmodel.h"

#include "addresstablemodel.h"
#include "guiconstants.h"
#include "paymentserver.h"
#include "recentrequeststablemodel.h"
#include "transactiontablemodel.h"

#include "base58.h"
#include "wallet/db.h"
#include "keystore.h"
#include "main.h"
#include "sync.h"
#include "ui_interface.h"
#include "wallet/wallet.h"
#include "wallet/walletdb.h" // for BackupWallet

#include <stdint.h>

#include <QDebug>
#include <QSet>
#include <QTimer>

using namespace std;

WalletModel::WalletModel(CWallet *wallet, OptionsModel *optionsModel, QObject *parent) :
    QObject(parent), wallet(wallet), optionsModel(optionsModel), addressTableModel(0),
    transactionTableModel(0),
    recentRequestsTableModel(0),
    cachedBalance(0), cachedUnconfirmedBalance(0), cachedImmatureBalance(0),
    cachedEncryptionStatus(Unencrypted),
    cachedNumBlocks(0)
{
    fHaveWatchOnly = wallet->HaveWatchOnly();
    fForceCheckBalanceChanged = false;

    addressTableModel = new AddressTableModel(wallet, this);
    transactionTableModel = new TransactionTableModel(wallet, this);
    recentRequestsTableModel = new RecentRequestsTableModel(wallet, this);

    // This timer will be fired repeatedly to update the balance
    pollTimer = new QTimer(this);
    connect(pollTimer, SIGNAL(timeout()), this, SLOT(pollBalanceChanged()));
    pollTimer->start(MODEL_UPDATE_DELAY);

    subscribeToCoreSignals();
}

WalletModel::~WalletModel()
{
    unsubscribeFromCoreSignals();
}

CAmount WalletModel::getBalance(const CCoinControl *coinControl) const
{
    if (coinControl)
    {
        CAmount nBalance = 0;
        std::vector<COutput> vCoins;
        wallet->AvailableCoins(vCoins, true, coinControl);
        BOOST_FOREACH(const COutput& out, vCoins)
            if(out.fSpendable)
                nBalance += out.tx->vout[out.i].nValue;

        return nBalance;
    }

    return wallet->GetBalance();
}

CAmount WalletModel::getUnconfirmedBalance() const
{
    return wallet->GetUnconfirmedBalance();
}

CAmount WalletModel::getImmatureBalance() const
{
    return wallet->GetImmatureBalance();
}

bool WalletModel::haveWatchOnly() const
{
    return fHaveWatchOnly;
}

CAmount WalletModel::getWatchBalance() const
{
    return wallet->GetWatchOnlyBalance();
}

CAmount WalletModel::getWatchUnconfirmedBalance() const
{
    return wallet->GetUnconfirmedWatchOnlyBalance();
}

CAmount WalletModel::getWatchImmatureBalance() const
{
    return wallet->GetImmatureWatchOnlyBalance();
}

void WalletModel::updateStatus()
{
    EncryptionStatus newEncryptionStatus = getEncryptionStatus();

    if(cachedEncryptionStatus != newEncryptionStatus)
        emit encryptionStatusChanged(newEncryptionStatus);
}

void WalletModel::pollBalanceChanged()
{
    // Get required locks upfront. This avoids the GUI from getting stuck on
    // periodical polls if the core is holding the locks for a longer time -
    // for example, during a wallet rescan.
    TRY_LOCK(cs_main, lockMain);
    if(!lockMain)
        return;
    TRY_LOCK(wallet->cs_wallet, lockWallet);
    if(!lockWallet)
        return;

    if(fForceCheckBalanceChanged || chainActive.Height() != cachedNumBlocks)
    {
        fForceCheckBalanceChanged = false;

        // Balance and number of transactions might have changed
        cachedNumBlocks = chainActive.Height();

        checkBalanceChanged();
        if(transactionTableModel)
            transactionTableModel->updateConfirmations();
    }
}

void WalletModel::checkBalanceChanged()
{
    CAmount newBalance = getBalance();
    CAmount newUnconfirmedBalance = getUnconfirmedBalance();
    CAmount newImmatureBalance = getImmatureBalance();
    CAmount newWatchOnlyBalance = 0;
    CAmount newWatchUnconfBalance = 0;
    CAmount newWatchImmatureBalance = 0;
    if (haveWatchOnly())
    {
        newWatchOnlyBalance = getWatchBalance();
        newWatchUnconfBalance = getWatchUnconfirmedBalance();
        newWatchImmatureBalance = getWatchImmatureBalance();
    }

    if(cachedBalance != newBalance || cachedUnconfirmedBalance != newUnconfirmedBalance || cachedImmatureBalance != newImmatureBalance ||
        cachedWatchOnlyBalance != newWatchOnlyBalance || cachedWatchUnconfBalance != newWatchUnconfBalance || cachedWatchImmatureBalance != newWatchImmatureBalance)
    {
        cachedBalance = newBalance;
        cachedUnconfirmedBalance = newUnconfirmedBalance;
        cachedImmatureBalance = newImmatureBalance;
        cachedWatchOnlyBalance = newWatchOnlyBalance;
        cachedWatchUnconfBalance = newWatchUnconfBalance;
        cachedWatchImmatureBalance = newWatchImmatureBalance;
        emit balanceChanged(newBalance, newUnconfirmedBalance, newImmatureBalance,
                            newWatchOnlyBalance, newWatchUnconfBalance, newWatchImmatureBalance);
    }
}

void WalletModel::updateTransaction()
{
    // Balance and number of transactions might have changed
    fForceCheckBalanceChanged = true;
}

void WalletModel::updateAddressBook(const QString &address, const QString &label,
        bool isMine, const QString &purpose, int status)
{
    if(addressTableModel)
        addressTableModel->updateEntry(address, label, isMine, purpose, status);
}

void WalletModel::updateWatchOnlyFlag(bool fHaveWatchonly)
{
    fHaveWatchOnly = fHaveWatchonly;
    emit notifyWatchonlyChanged(fHaveWatchonly);
}

bool WalletModel::validateAddress(const QString &address)
{
    CBitcoinAddress addressParsed(address.toStdString());
    return addressParsed.IsValid();
}

WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransaction &transaction, const CCoinControl *coinControl)
{
    CAmount total = 0;
    QList<SendCoinsRecipient> recipients = transaction.getRecipients();
    std::vector<std::pair<CScript, CAmount> > vecSend;

    if(recipients.empty())
    {
        return OK;
    }

    QSet<QString> setAddress; // Used to detect duplicates
    int nAddresses = 0;

    // Pre-check input data for validity
    foreach(const SendCoinsRecipient &rcp, recipients)
    {
        if (rcp.paymentRequest.IsInitialized())
        {   // PaymentRequest...
            CAmount subtotal = 0;
            const payments::PaymentDetails& details = rcp.paymentRequest.getDetails();
            for (int i = 0; i < details.outputs_size(); i++)
            {
                const payments::Output& out = details.outputs(i);
                if (out.amount() <= 0) continue;
                subtotal += out.amount();
                const unsigned char* scriptStr = (const unsigned char*)out.script().data();
                CScript scriptPubKey(scriptStr, scriptStr+out.script().size());
                vecSend.push_back(std::pair<CScript, CAmount>(scriptPubKey, out.amount()));
            }
            if (subtotal <= 0)
            {
                return InvalidAmount;
            }
            total += subtotal;
        }
        else
        {   // User-entered bitcoin address / amount:
            if(!validateAddress(rcp.address))
            {
                return InvalidAddress;
            }
            if(rcp.amount <= 0)
            {
                return InvalidAmount;
            }
            setAddress.insert(rcp.address);
            ++nAddresses;

            CScript scriptPubKey = GetScriptForDestination(CBitcoinAddress(rcp.address.toStdString()).Get());
            vecSend.push_back(std::pair<CScript, CAmount>(scriptPubKey, rcp.amount));

            total += rcp.amount;
        }
    }
    if(setAddress.size() != nAddresses)
    {
        return DuplicateAddress;
    }

    CAmount nBalance = getBalance(coinControl);

    if(total > nBalance)
    {
        return AmountExceedsBalance;
    }

    {
        LOCK2(cs_main, wallet->cs_wallet);

        transaction.newPossibleKeyChange(wallet);
        CAmount nFeeRequired = 0;
        std::string strFailReason;

        CWalletTx *newTx = transaction.getTransaction();
        CReserveKey *keyChange = transaction.getPossibleKeyChange();
        bool fCreated = wallet->CreateTransaction(vecSend, *newTx, *keyChange, nFeeRequired, strFailReason, coinControl);
        transaction.setTransactionFee(nFeeRequired);

        if(!fCreated)
        {
            if((total + nFeeRequired) > nBalance)
            {
                return SendCoinsReturn(AmountWithFeeExceedsBalance);
            }
            emit message(tr("Send Coins"), QString::fromStdString(strFailReason),
                         CClientUIInterface::MSG_ERROR);
            return TransactionCreationFailed;
        }

        // reject absurdly high fee > 0.1 bitcoin
        if (nFeeRequired > 10000000)
            return AbsurdFee;
    }

    return SendCoinsReturn(OK);
}

WalletModel::SendCoinsReturn WalletModel::sendCoins(WalletModelTransaction &transaction)
{
    QByteArray transaction_array; /* store serialized transaction */

    {
        LOCK2(cs_main, wallet->cs_wallet);
        CWalletTx *newTx = transaction.getTransaction();

        foreach(const SendCoinsRecipient &rcp, transaction.getRecipients())
        {
            if (rcp.paymentRequest.IsInitialized())
            {
                // Make sure any payment requests involved are still valid.
                if (PaymentServer::verifyExpired(rcp.paymentRequest.getDetails())) {
                    return PaymentRequestExpired;
                }

                // Store PaymentRequests in wtx.vOrderForm in wallet.
                std::string key("PaymentRequest");
                std::string value;
                rcp.paymentRequest.SerializeToString(&value);
                newTx->vOrderForm.push_back(make_pair(key, value));
            }
            else if (!rcp.message.isEmpty()) // Message from normal bitcoin:URI (bitcoin:123...?message=example)
                newTx->vOrderForm.push_back(make_pair("Message", rcp.message.toStdString()));
        }

        CReserveKey *keyChange = transaction.getPossibleKeyChange();
        if(!wallet->CommitTransaction(*newTx, *keyChange))
            return TransactionCommitFailed;

        CTransaction* t = (CTransaction*)newTx;
        CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
        ssTx << *t;
        transaction_array.append(&(ssTx[0]), ssTx.size());
    }

    // Add addresses / update labels that we've sent to to the address book,
    // and emit coinsSent signal for each recipient
    foreach(const SendCoinsRecipient &rcp, transaction.getRecipients())
    {
        // Don't touch the address book when we have a payment request
        if (!rcp.paymentRequest.IsInitialized())
        {
            std::string strAddress = rcp.address.toStdString();
            CTxDestination dest = CBitcoinAddress(strAddress).Get();
            std::string strLabel = rcp.label.toStdString();
            {
                LOCK(wallet->cs_wallet);

                std::map<CTxDestination, CAddressBookData>::iterator mi = wallet->mapAddressBook.find(dest);

                // Check if we have a new address or an updated label
                if (mi == wallet->mapAddressBook.end())
                {
                    wallet->SetAddressBook(dest, strLabel, "send");
                }
                else if (mi->second.name != strLabel)
                {
                    wallet->SetAddressBook(dest, strLabel, ""); // "" means don't change purpose
                }
            }
        }
        emit coinsSent(wallet, rcp, transaction_array);
    }
    checkBalanceChanged(); // update balance immediately, otherwise there could be a short noticeable delay until pollBalanceChanged hits

    return SendCoinsReturn(OK);
}

OptionsModel *WalletModel::getOptionsModel()
{
    return optionsModel;
}

AddressTableModel *WalletModel::getAddressTableModel()
{
    return addressTableModel;
}

TransactionTableModel *WalletModel::getTransactionTableModel()
{
    return transactionTableModel;
}

RecentRequestsTableModel *WalletModel::getRecentRequestsTableModel()
{
    return recentRequestsTableModel;
}

WalletModel::EncryptionStatus WalletModel::getEncryptionStatus() const
{
    if(!wallet->IsCrypted())
    {
        return Unencrypted;
    }
    else if(wallet->IsLocked())
    {
        return Locked;
    }
    else
    {
        return Unlocked;
    }
}

bool WalletModel::setWalletEncrypted(bool encrypted, const SecureString &passphrase)
{
    if(encrypted)
    {
        // Encrypt
        return wallet->EncryptWallet(passphrase);
    }
    else
    {
        // Decrypt -- TODO; not supported yet
        return false;
    }
}

bool WalletModel::setWalletLocked(bool locked, const SecureString &passPhrase)
{
    if(locked)
    {
        // Lock
        return wallet->Lock();
    }
    else
    {
        // Unlock
        return wallet->Unlock(passPhrase);
    }
}

bool WalletModel::changePassphrase(const SecureString &oldPass, const SecureString &newPass)
{
    bool retval;
    {
        LOCK(wallet->cs_wallet);
        wallet->Lock(); // Make sure wallet is locked before attempting pass change
        retval = wallet->ChangeWalletPassphrase(oldPass, newPass);
    }
    return retval;
}

bool WalletModel::backupWallet(const QString &filename)
{
    return BackupWallet(*wallet, filename.toLocal8Bit().data());
}

// Handlers for core signals
static void NotifyKeyStoreStatusChanged(WalletModel *walletmodel, CCryptoKeyStore *wallet)
{
    qDebug() << "NotifyKeyStoreStatusChanged";
    QMetaObject::invokeMethod(walletmodel, "updateStatus", Qt::QueuedConnection);
}

static void NotifyAddressBookChanged(WalletModel *walletmodel, CWallet *wallet,
        const CTxDestination &address, const std::string &label, bool isMine,
        const std::string &purpose, ChangeType status)
{
    QString strAddress = QString::fromStdString(CBitcoinAddress(address).ToString());
    QString strLabel = QString::fromStdString(label);
    QString strPurpose = QString::fromStdString(purpose);

    qDebug() << "NotifyAddressBookChanged: " + strAddress + " " + strLabel + " isMine=" + QString::number(isMine) + " purpose=" + strPurpose + " status=" + QString::number(status);
    QMetaObject::invokeMethod(walletmodel, "updateAddressBook", Qt::QueuedConnection,
                              Q_ARG(QString, strAddress),
                              Q_ARG(QString, strLabel),
                              Q_ARG(bool, isMine),
                              Q_ARG(QString, strPurpose),
                              Q_ARG(int, status));
}

static void NotifyTransactionChanged(WalletModel *walletmodel, CWallet *wallet, const uint256 &hash, ChangeType status)
{
    Q_UNUSED(wallet);
    Q_UNUSED(hash);
    Q_UNUSED(status);
    QMetaObject::invokeMethod(walletmodel, "updateTransaction", Qt::QueuedConnection);
}

static void ShowProgress(WalletModel *walletmodel, const std::string &title, int nProgress)
{
    // emits signal "showProgress"
    QMetaObject::invokeMethod(walletmodel, "showProgress", Qt::QueuedConnection,
                              Q_ARG(QString, QString::fromStdString(title)),
                              Q_ARG(int, nProgress));
}

static void NotifyWatchonlyChanged(WalletModel *walletmodel, bool fHaveWatchonly)
{
    QMetaObject::invokeMethod(walletmodel, "updateWatchOnlyFlag", Qt::QueuedConnection,
                              Q_ARG(bool, fHaveWatchonly));
}

void WalletModel::subscribeToCoreSignals()
{
    // Connect signals to wallet
    wallet->NotifyStatusChanged.connect(boost::bind(&NotifyKeyStoreStatusChanged, this, _1));
    wallet->NotifyAddressBookChanged.connect(boost::bind(NotifyAddressBookChanged, this, _1, _2, _3, _4, _5, _6));
    wallet->NotifyTransactionChanged.connect(boost::bind(NotifyTransactionChanged, this, _1, _2, _3));
    wallet->ShowProgress.connect(boost::bind(ShowProgress, this, _1, _2));
    wallet->NotifyWatchonlyChanged.connect(boost::bind(NotifyWatchonlyChanged, this, _1));
}

void WalletModel::unsubscribeFromCoreSignals()
{
    // Disconnect signals from wallet
    wallet->NotifyStatusChanged.disconnect(boost::bind(&NotifyKeyStoreStatusChanged, this, _1));
    wallet->NotifyAddressBookChanged.disconnect(boost::bind(NotifyAddressBookChanged, this, _1, _2, _3, _4, _5, _6));
    wallet->NotifyTransactionChanged.disconnect(boost::bind(NotifyTransactionChanged, this, _1, _2, _3));
    wallet->ShowProgress.disconnect(boost::bind(ShowProgress, this, _1, _2));
    wallet->NotifyWatchonlyChanged.disconnect(boost::bind(NotifyWatchonlyChanged, this, _1));
}

// WalletModel::UnlockContext implementation
WalletModel::UnlockContext WalletModel::requestUnlock()
{
    bool was_locked = getEncryptionStatus() == Locked;
    if(was_locked)
    {
        // Request UI to unlock wallet
        emit requireUnlock();
    }
    // If wallet is still locked, unlock was failed or cancelled, mark context as invalid
    bool valid = getEncryptionStatus() != Locked;

    return UnlockContext(this, valid, was_locked);
}

WalletModel::UnlockContext::UnlockContext(WalletModel *wallet, bool valid, bool relock):
        wallet(wallet),
        valid(valid),
        relock(relock)
{
}

WalletModel::UnlockContext::~UnlockContext()
{
    if(valid && relock)
    {
        wallet->setWalletLocked(true);
    }
}

void WalletModel::UnlockContext::CopyFrom(const UnlockContext& rhs)
{
    // Transfer context; old object no longer relocks wallet
    *this = rhs;
    rhs.relock = false;
}

bool WalletModel::getPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const
{
    return wallet->GetPubKey(address, vchPubKeyOut);
}

// returns a list of COutputs from COutPoints
void WalletModel::getOutputs(const std::vector<COutPoint>& vOutpoints, std::vector<COutput>& vOutputs)
{
    LOCK2(cs_main, wallet->cs_wallet);
    BOOST_FOREACH(const COutPoint& outpoint, vOutpoints)
    {
        if (!wallet->mapWallet.count(outpoint.hash)) continue;
        int nDepth = wallet->mapWallet[outpoint.hash].GetDepthInMainChain();
        if (nDepth < 0) continue;
        COutput out(&wallet->mapWallet[outpoint.hash], outpoint.n, nDepth, true);
        vOutputs.push_back(out);
    }
}

bool WalletModel::isSpent(const COutPoint& outpoint) const
{
    LOCK2(cs_main, wallet->cs_wallet);
    return wallet->IsSpent(outpoint.hash, outpoint.n);
}

// AvailableCoins + LockedCoins grouped by wallet address (put change in one group with wallet address)
void WalletModel::listCoins(std::map<QString, std::vector<COutput> >& mapCoins) const
{
    std::vector<COutput> vCoins;
    wallet->AvailableCoins(vCoins);

    LOCK2(cs_main, wallet->cs_wallet); // ListLockedCoins, mapWallet
    std::vector<COutPoint> vLockedCoins;
    wallet->ListLockedCoins(vLockedCoins);

    // add locked coins
    BOOST_FOREACH(const COutPoint& outpoint, vLockedCoins)
    {
        if (!wallet->mapWallet.count(outpoint.hash)) continue;
        int nDepth = wallet->mapWallet[outpoint.hash].GetDepthInMainChain();
        if (nDepth < 0) continue;
        COutput out(&wallet->mapWallet[outpoint.hash], outpoint.n, nDepth, true);
        if (outpoint.n < out.tx->vout.size() && wallet->IsMine(out.tx->vout[outpoint.n]) == ISMINE_SPENDABLE)
            vCoins.push_back(out);
    }

    BOOST_FOREACH(const COutput& out, vCoins)
    {
        COutput cout = out;

        while (wallet->IsChange(cout.tx->vout[cout.i]) && cout.tx->vin.size() > 0 && wallet->IsMine(cout.tx->vin[0]))
        {
            if (!wallet->mapWallet.count(cout.tx->vin[0].prevout.hash)) break;
            cout = COutput(&wallet->mapWallet[cout.tx->vin[0].prevout.hash], cout.tx->vin[0].prevout.n, 0, true);
        }

        CTxDestination address;
        if(!out.fSpendable || !ExtractDestination(cout.tx->vout[cout.i].scriptPubKey, address))
            continue;
        mapCoins[QString::fromStdString(CBitcoinAddress(address).ToString())].push_back(out);
    }
}

bool WalletModel::isLockedCoin(uint256 hash, unsigned int n) const
{
    LOCK2(cs_main, wallet->cs_wallet);
    return wallet->IsLockedCoin(hash, n);
}

void WalletModel::lockCoin(COutPoint& output)
{
    LOCK2(cs_main, wallet->cs_wallet);
    wallet->LockCoin(output);
}

void WalletModel::unlockCoin(COutPoint& output)
{
    LOCK2(cs_main, wallet->cs_wallet);
    wallet->UnlockCoin(output);
}

void WalletModel::listLockedCoins(std::vector<COutPoint>& vOutpts)
{
    LOCK2(cs_main, wallet->cs_wallet);
    wallet->ListLockedCoins(vOutpts);
}

void WalletModel::loadReceiveRequests(std::vector<std::string>& vReceiveRequests)
{
    LOCK(wallet->cs_wallet);
    BOOST_FOREACH(const PAIRTYPE(CTxDestination, CAddressBookData)& item, wallet->mapAddressBook)
        BOOST_FOREACH(const PAIRTYPE(std::string, std::string)& item2, item.second.destdata)
            if (item2.first.size() > 2 && item2.first.substr(0,2) == "rr") // receive request
                vReceiveRequests.push_back(item2.second);
}

bool WalletModel::saveReceiveRequest(const std::string &sAddress, const int64_t nId, const std::string &sRequest)
{
    CTxDestination dest = CBitcoinAddress(sAddress).Get();

    std::stringstream ss;
    ss << nId;
    std::string key = "rr" + ss.str(); // "rr" prefix = "receive request" in destdata

    LOCK(wallet->cs_wallet);
    if (sRequest.empty())
        return wallet->EraseDestData(dest, key);
    else
        return wallet->AddDestData(dest, key, sRequest);
}
