// Copyright (c) 2021-2022 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 <consensus/amount.h>

#include <consensus/consensus.h>

#include <util/check.h>

#include <wallet/receive.h>

#include <wallet/transaction.h>

#include <wallet/wallet.h>

namespace wallet {

bool InputIsMine(const CWallet& wallet, const CTxIn& txin)

{

    AssertLockHeld(wallet.cs_wallet);

    const CWalletTx* prev = wallet.GetWalletTx(txin.prevout.hash);

    if (prev && txin.prevout.n < prev->tx->vout.size()) {

        return wallet.IsMine(prev->tx->vout[txin.prevout.n]);

    }

    return false;

}

bool AllInputsMine(const CWallet& wallet, const CTransaction& tx)

{

    LOCK(wallet.cs_wallet);

    for (const CTxIn& txin : tx.vin) {

        if (!InputIsMine(wallet, txin)) return false;

    }

    return true;

}

CAmount OutputGetCredit(const CWallet& wallet, const CTxOut& txout)

{

    if (!MoneyRange(txout.nValue))

        throw std::runtime_error(std::string(__func__) + ": value out of range");

    LOCK(wallet.cs_wallet);

    return (wallet.IsMine(txout) ? txout.nValue : 0);

}

CAmount TxGetCredit(const CWallet& wallet, const CTransaction& tx)

{

    CAmount nCredit = 0;

    for (const CTxOut& txout : tx.vout)

    {

        nCredit += OutputGetCredit(wallet, txout);

        if (!MoneyRange(nCredit))

            throw std::runtime_error(std::string(__func__) + ": value out of range");

    }

    return nCredit;

}

bool ScriptIsChange(const CWallet& wallet, const CScript& script)

{

    // TODO: fix handling of 'change' outputs. The assumption is that any

    // payment to a script that is ours, but is not in the address book

    // is change. That assumption is likely to break when we implement multisignature

    // wallets that return change back into a multi-signature-protected address;

    // a better way of identifying which outputs are 'the send' and which are

    // 'the change' will need to be implemented (maybe extend CWalletTx to remember

    // which output, if any, was change).

    AssertLockHeld(wallet.cs_wallet);

    if (wallet.IsMine(script))

    {

        CTxDestination address;

        if (!ExtractDestination(script, address))

            return true;

        if (!wallet.FindAddressBookEntry(address)) {

            return true;

        }

    }

    return false;

}

bool OutputIsChange(const CWallet& wallet, const CTxOut& txout)

{

    return ScriptIsChange(wallet, txout.scriptPubKey);

}

CAmount OutputGetChange(const CWallet& wallet, const CTxOut& txout)

{

    AssertLockHeld(wallet.cs_wallet);

    if (!MoneyRange(txout.nValue))

        throw std::runtime_error(std::string(__func__) + ": value out of range");

    return (OutputIsChange(wallet, txout) ? txout.nValue : 0);

}

CAmount TxGetChange(const CWallet& wallet, const CTransaction& tx)

{

    LOCK(wallet.cs_wallet);

    CAmount nChange = 0;

    for (const CTxOut& txout : tx.vout)

    {

        nChange += OutputGetChange(wallet, txout);

        if (!MoneyRange(nChange))

            throw std::runtime_error(std::string(__func__) + ": value out of range");

    }

    return nChange;

}

static CAmount GetCachableAmount(const CWallet& wallet, const CWalletTx& wtx, CWalletTx::AmountType type, bool avoid_reuse)

{

    auto& amount = wtx.m_amounts[type];

    if (!amount.IsCached(avoid_reuse)) {

        amount.Set(avoid_reuse, type == CWalletTx::DEBIT ? wallet.GetDebit(*wtx.tx) : TxGetCredit(wallet, *wtx.tx));

        wtx.m_is_cache_empty = false;

    }

    return amount.Get(avoid_reuse);

}

CAmount CachedTxGetCredit(const CWallet& wallet, const CWalletTx& wtx, bool avoid_reuse)

{

    AssertLockHeld(wallet.cs_wallet);

    // Must wait until coinbase is safely deep enough in the chain before valuing it

    if (wallet.IsTxImmatureCoinBase(wtx))

        return 0;

    // GetBalance can assume transactions in mapWallet won't change

    return GetCachableAmount(wallet, wtx, CWalletTx::CREDIT, avoid_reuse);

}

CAmount CachedTxGetDebit(const CWallet& wallet, const CWalletTx& wtx, bool avoid_reuse)

{

    if (wtx.tx->vin.empty())

        return 0;

    return GetCachableAmount(wallet, wtx, CWalletTx::DEBIT, avoid_reuse);

}

CAmount CachedTxGetChange(const CWallet& wallet, const CWalletTx& wtx)

{

    if (wtx.fChangeCached)

        return wtx.nChangeCached;

    wtx.nChangeCached = TxGetChange(wallet, *wtx.tx);

    wtx.fChangeCached = true;

    return wtx.nChangeCached;

}

void CachedTxGetAmounts(const CWallet& wallet, const CWalletTx& wtx,

                  std::list<COutputEntry>& listReceived,

                  std::list<COutputEntry>& listSent, CAmount& nFee,

                  bool include_change)

{

    nFee = 0;

    listReceived.clear();

    listSent.clear();

    // Compute fee:

    CAmount nDebit = CachedTxGetDebit(wallet, wtx, /*avoid_reuse=*/false);

    if (nDebit > 0) // debit>0 means we signed/sent this transaction

    {

        CAmount nValueOut = wtx.tx->GetValueOut();

        nFee = nDebit - nValueOut;

    }

    LOCK(wallet.cs_wallet);

    // Sent/received.

    for (unsigned int i = 0; i < wtx.tx->vout.size(); ++i)

    {

        const CTxOut& txout = wtx.tx->vout[i];

        bool ismine = wallet.IsMine(txout);

        // Only need to handle txouts if AT LEAST one of these is true:

        //   1) they debit from us (sent)

        //   2) the output is to us (received)

        if (nDebit > 0)

        {

            if (!include_change && OutputIsChange(wallet, txout))

                continue;

        }

        else if (!ismine)

            continue;

        // In either case, we need to get the destination address

        CTxDestination address;

        if (!ExtractDestination(txout.scriptPubKey, address) && !txout.scriptPubKey.IsUnspendable())

        {

            wallet.WalletLogPrintf("CWalletTx::GetAmounts: Unknown transaction type found, txid %s\n",

                                    wtx.GetHash().ToString());

            address = CNoDestination();

        }

        COutputEntry output = {address, txout.nValue, (int)i};

        // If we are debited by the transaction, add the output as a "sent" entry

        if (nDebit > 0)

            listSent.push_back(output);

        // If we are receiving the output, add it as a "received" entry

        if (ismine)

            listReceived.push_back(output);

    }

}

bool CachedTxIsFromMe(const CWallet& wallet, const CWalletTx& wtx)

{

    if (!wtx.m_cached_from_me.has_value()) {

        wtx.m_cached_from_me = wallet.IsFromMe(*wtx.tx);

    }

    return wtx.m_cached_from_me.value();

}

// NOLINTNEXTLINE(misc-no-recursion)

bool CachedTxIsTrusted(const CWallet& wallet, const CWalletTx& wtx, std::set<Txid>& trusted_parents)

{

    AssertLockHeld(wallet.cs_wallet);

    // This wtx is already trusted

    if (trusted_parents.contains(wtx.GetHash())) return true;

    if (wtx.isConfirmed()) return true;

    if (wtx.isBlockConflicted()) return false;

    // using wtx's cached debit

    if (!wallet.m_spend_zero_conf_change || !CachedTxIsFromMe(wallet, wtx)) return false;

    // Don't trust unconfirmed transactions from us unless they are in the mempool.

    if (!wtx.InMempool()) return false;

    // Trusted if all inputs are from us and are in the mempool:

    for (const CTxIn& txin : wtx.tx->vin)

    {

        // Transactions not sent by us: not trusted

        const CWalletTx* parent = wallet.GetWalletTx(txin.prevout.hash);

        if (parent == nullptr) return false;

        const CTxOut& parentOut = parent->tx->vout[txin.prevout.n];

        // Check that this specific input being spent is trusted

        if (!wallet.IsMine(parentOut)) return false;

        // If we've already trusted this parent, continue

        if (trusted_parents.count(parent->GetHash())) continue;

        // Recurse to check that the parent is also trusted

        if (!CachedTxIsTrusted(wallet, *parent, trusted_parents)) return false;

        trusted_parents.insert(parent->GetHash());

    }

    return true;

}

bool CachedTxIsTrusted(const CWallet& wallet, const CWalletTx& wtx)

{

    std::set<Txid> trusted_parents;

    LOCK(wallet.cs_wallet);

    return CachedTxIsTrusted(wallet, wtx, trusted_parents);

}

Balance GetBalance(const CWallet& wallet, const int min_depth, bool avoid_reuse)

{

    Balance ret;

    bool allow_used_addresses = !avoid_reuse || !wallet.IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);

    {

        LOCK(wallet.cs_wallet);

        std::set<Txid> trusted_parents;

        for (const auto& [outpoint, txo] : wallet.GetTXOs()) {

            const CWalletTx& wtx = txo.GetWalletTx();

            const bool is_trusted{CachedTxIsTrusted(wallet, wtx, trusted_parents)};

            const int tx_depth{wallet.GetTxDepthInMainChain(wtx)};

            if (!wallet.IsSpent(outpoint) && (allow_used_addresses || !wallet.IsSpentKey(txo.GetTxOut().scriptPubKey))) {

                // Get the amounts for mine

                CAmount credit_mine = txo.GetTxOut().nValue;

                // Set the amounts in the return object

                if (wallet.IsTxImmatureCoinBase(wtx) && wtx.isConfirmed()) {

                    ret.m_mine_immature += credit_mine;

                } else if (is_trusted && tx_depth >= min_depth) {

                    ret.m_mine_trusted += credit_mine;

                } else if (!is_trusted && wtx.InMempool()) {

                    ret.m_mine_untrusted_pending += credit_mine;

                }

            }

        }

    }

    return ret;

}

std::map<CTxDestination, CAmount> GetAddressBalances(const CWallet& wallet)

{

    std::map<CTxDestination, CAmount> balances;

    {

        LOCK(wallet.cs_wallet);

        std::set<Txid> trusted_parents;

        for (const auto& [outpoint, txo] : wallet.GetTXOs()) {

            const CWalletTx& wtx = txo.GetWalletTx();

            if (!CachedTxIsTrusted(wallet, wtx, trusted_parents)) continue;

            if (wallet.IsTxImmatureCoinBase(wtx)) continue;

            int nDepth = wallet.GetTxDepthInMainChain(wtx);

            if (nDepth < (CachedTxIsFromMe(wallet, wtx) ? 0 : 1)) continue;

            CTxDestination addr;

            Assume(wallet.IsMine(txo.GetTxOut()));

            if(!ExtractDestination(txo.GetTxOut().scriptPubKey, addr)) continue;

            CAmount n = wallet.IsSpent(outpoint) ? 0 : txo.GetTxOut().nValue;

            balances[addr] += n;

        }

    }

    return balances;

}

std::set< std::set<CTxDestination> > GetAddressGroupings(const CWallet& wallet)

{

    AssertLockHeld(wallet.cs_wallet);

    std::set< std::set<CTxDestination> > groupings;

    std::set<CTxDestination> grouping;

    for (const auto& walletEntry : wallet.mapWallet)

    {

        const CWalletTx& wtx = walletEntry.second;

        if (wtx.tx->vin.size() > 0)

        {

            bool any_mine = false;

            // group all input addresses with each other

            for (const CTxIn& txin : wtx.tx->vin)

            {

                CTxDestination address;

                if(!InputIsMine(wallet, txin)) /* If this input isn't mine, ignore it */

                    continue;

                if(!ExtractDestination(wallet.mapWallet.at(txin.prevout.hash).tx->vout[txin.prevout.n].scriptPubKey, address))

                    continue;

                grouping.insert(address);

                any_mine = true;

            }

            // group change with input addresses

            if (any_mine)

            {

               for (const CTxOut& txout : wtx.tx->vout)

                   if (OutputIsChange(wallet, txout))

                   {

                       CTxDestination txoutAddr;

                       if(!ExtractDestination(txout.scriptPubKey, txoutAddr))

                           continue;

                       grouping.insert(txoutAddr);

                   }

            }

            if (grouping.size() > 0)

            {

                groupings.insert(grouping);

                grouping.clear();

            }

        }

        // group lone addrs by themselves

        for (const auto& txout : wtx.tx->vout)

            if (wallet.IsMine(txout))

            {

                CTxDestination address;

                if(!ExtractDestination(txout.scriptPubKey, address))

                    continue;

                grouping.insert(address);

                groupings.insert(grouping);

                grouping.clear();

            }

    }

    std::set< std::set<CTxDestination>* > uniqueGroupings; // a set of pointers to groups of addresses

    std::map< CTxDestination, std::set<CTxDestination>* > setmap;  // map addresses to the unique group containing it

    for (const std::set<CTxDestination>& _grouping : groupings)

    {

        // make a set of all the groups hit by this new group

        std::set< std::set<CTxDestination>* > hits;

        std::map< CTxDestination, std::set<CTxDestination>* >::iterator it;

        for (const CTxDestination& address : _grouping)

            if ((it = setmap.find(address)) != setmap.end())

                hits.insert((*it).second);

        // merge all hit groups into a new single group and delete old groups

        std::set<CTxDestination>* merged = new std::set<CTxDestination>(_grouping);

        for (std::set<CTxDestination>* hit : hits)

        {

            merged->insert(hit->begin(), hit->end());

            uniqueGroupings.erase(hit);

            delete hit;

        }

        uniqueGroupings.insert(merged);

        // update setmap

        for (const CTxDestination& element : *merged)

            setmap[element] = merged;

    }

    std::set< std::set<CTxDestination> > ret;

    for (const std::set<CTxDestination>* uniqueGrouping : uniqueGroupings)

    {

        ret.insert(*uniqueGrouping);

        delete uniqueGrouping;

    }

    return ret;

}

} // namespace wallet