bool
BlockAssembler::DbLockLimitOk (const CTxMemPool::setEntries& candidates) const
{
  std::vector<CTransactionRef> vtx;
  for (const auto& iter : inBlock)
    vtx.push_back(MakeTransactionRef(iter->GetTx()));
  for (const auto& iter : candidates)
    vtx.push_back(MakeTransactionRef(iter->GetTx()));

  return CheckDbLockLimit (vtx);
}

//
// Create a new block with just given transactions, coinbase paying to
// scriptPubKey, and try to add it to the current chain.
//
CBlock
TestChain100Setup::CreateAndProcessBlock(const std::vector<CMutableTransaction>& txns, const CScript& scriptPubKey)
{
    const CChainParams& chainparams = Params();
    std::unique_ptr<CBlockTemplate> pblocktemplate = BlockAssembler(chainparams).CreateNewBlock(scriptPubKey);
    CBlock& block = pblocktemplate->block;

    // Replace mempool-selected txns with just coinbase plus passed-in txns:
    block.vtx.resize(1);
    for (const CMutableTransaction& tx : txns)
        block.vtx.push_back(MakeTransactionRef(tx));
    // IncrementExtraNonce creates a valid coinbase and merkleRoot
    {
        LOCK(cs_main);
        unsigned int extraNonce = 0;
        IncrementExtraNonce(&block, chainActive.Tip(), extraNonce);
    }

    while (!CheckProofOfWork(block.GetHash(), block.nBits, chainparams.GetConsensus())) ++block.nNonce;

    std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(block);
    ProcessNewBlock(chainparams, shared_pblock, true, nullptr);

    CBlock result = block;
    return result;
}

static void add_coin(const CAmount& nValue, int nInput, CoinSet& set)
{
    CMutableTransaction tx;
    tx.vout.resize(nInput + 1);
    tx.vout[nInput].nValue = nValue;
    set.emplace(MakeTransactionRef(tx), nInput);
}

static int64_t AddTx(CWallet& wallet, uint32_t lockTime, int64_t mockTime, int64_t blockTime)
{
    CMutableTransaction tx;
    tx.nLockTime = lockTime;
    SetMockTime(mockTime);
    CBlockIndex* block = nullptr;
    if (blockTime > 0) {
        LOCK(cs_main);
        auto inserted = mapBlockIndex.emplace(GetRandHash(), new CBlockIndex);
        assert(inserted.second);
        const uint256& hash = inserted.first->first;
        block = inserted.first->second;
        block->nTime = blockTime;
        block->phashBlock = &hash;
    }

    CWalletTx wtx(&wallet, MakeTransactionRef(tx));
    if (block) {
        wtx.SetMerkleBranch(block, 0);
    }
    {
        LOCK(cs_main);
        wallet.AddToWallet(wtx);
    }
    LOCK(wallet.cs_wallet);
    return wallet.mapWallet.at(wtx.GetHash()).nTimeSmart;
}

static void DuplicateInputs(benchmark::State& state)
{
    const CScript SCRIPT_PUB{CScript(OP_TRUE)};

    const CChainParams& chainparams = Params();

    CBlock block{};
    CMutableTransaction coinbaseTx{};
    CMutableTransaction naughtyTx{};

    CBlockIndex* pindexPrev = ::ChainActive().Tip();
    assert(pindexPrev != nullptr);
    block.nBits = GetNextWorkRequired(pindexPrev, &block, chainparams.GetConsensus());
    block.nNonce = 0;
    auto nHeight = pindexPrev->nHeight + 1;

    // Make a coinbase TX
    coinbaseTx.vin.resize(1);
    coinbaseTx.vin[0].prevout.SetNull();
    coinbaseTx.vout.resize(1);
    coinbaseTx.vout[0].scriptPubKey = SCRIPT_PUB;
    coinbaseTx.vout[0].nValue = GetBlockSubsidy(nHeight, chainparams.GetConsensus());
    coinbaseTx.vin[0].scriptSig = CScript() << nHeight << OP_0;


    naughtyTx.vout.resize(1);
    naughtyTx.vout[0].nValue = 0;
    naughtyTx.vout[0].scriptPubKey = SCRIPT_PUB;

    uint64_t n_inputs = (((MAX_BLOCK_SERIALIZED_SIZE / WITNESS_SCALE_FACTOR) - (CTransaction(coinbaseTx).GetTotalSize() + CTransaction(naughtyTx).GetTotalSize())) / 41) - 100;
    for (uint64_t x = 0; x < (n_inputs - 1); ++x) {
        naughtyTx.vin.emplace_back(GetRandHash(), 0, CScript(), 0);
    }
    naughtyTx.vin.emplace_back(naughtyTx.vin.back());

    block.vtx.push_back(MakeTransactionRef(std::move(coinbaseTx)));
    block.vtx.push_back(MakeTransactionRef(std::move(naughtyTx)));

    block.hashMerkleRoot = BlockMerkleRoot(block);

    while (state.KeepRunning()) {
        CValidationState cvstate{};
        assert(!CheckBlock(block, cvstate, chainparams.GetConsensus(), false, false));
        assert(cvstate.GetRejectReason() == "bad-txns-inputs-duplicate");
    }
}

// Copied from src/wallet/test/coinselector_tests.cpp
static void add_coin(const CAmount& nValue, int nInput, std::vector<OutputGroup>& set)
{
    CMutableTransaction tx;
    tx.vout.resize(nInput + 1);
    tx.vout[nInput].nValue = nValue;
    std::unique_ptr<CWalletTx> wtx = MakeUnique<CWalletTx>(&testWallet, MakeTransactionRef(std::move(tx)));
    set.emplace_back(COutput(wtx.get(), nInput, 0, true, true, true).GetInputCoin(), 0, true, 0, 0);
    wtxn.emplace_back(std::move(wtx));
}

static void addCoin(const CAmount& nValue, const CWallet& wallet, std::vector<std::unique_ptr<CWalletTx>>& wtxs)
{
    static int nextLockTime = 0;
    CMutableTransaction tx;
    tx.nLockTime = nextLockTime++; // so all transactions get different hashes
    tx.vout.resize(1);
    tx.vout[0].nValue = nValue;
    wtxs.push_back(MakeUnique<CWalletTx>(&wallet, MakeTransactionRef(std::move(tx))));
}

static bool
ToMemPool(const CMutableTransaction& tx)
{
    LOCK(cs_main);

    CValidationState state;
    return AcceptToMemoryPool(mempool, state, MakeTransactionRef(tx), nullptr /* pfMissingInputs */,
                              nullptr /* plTxnReplaced */, true /* bypass_limits */, 0 /* nAbsurdFee */);
}

static void AddTx(const CTransaction& tx, const CAmount& nFee, CTxMemPool& pool)
{
    int64_t nTime = 0;
    unsigned int nHeight = 1;
    bool spendsCoinbase = false;
    unsigned int sigOpCost = 4;
    LockPoints lp;
    pool.addUnchecked(tx.GetHash(), CTxMemPoolEntry(
                                        MakeTransactionRef(tx), nFee, nTime, nHeight,
                                        spendsCoinbase, sigOpCost, lp));
}

void
CAuxpowBuilder::setCoinbase(const CScript& scr)
{
	CMutableTransaction mtx;
	mtx.vin.resize(1);
	mtx.vin[0].prevout.SetNull();
	mtx.vin[0].scriptSig = scr;

	parentBlock.vtx.clear();
	parentBlock.vtx.push_back(MakeTransactionRef(std::move(mtx)));
	parentBlock.hashMerkleRoot = BlockMerkleRoot(parentBlock);
}

Result CommitTransaction(CWallet* wallet, const uint256& txid, CMutableTransaction&& mtx, std::vector<std::string>& errors, uint256& bumped_txid)
{
    LOCK2(cs_main, wallet->cs_wallet);
    if (!errors.empty()) {
        return Result::MISC_ERROR;
    }
    auto it = txid.IsNull() ? wallet->mapWallet.end() : wallet->mapWallet.find(txid);
    if (it == wallet->mapWallet.end()) {
        errors.push_back("Invalid or non-wallet transaction id");
        return Result::MISC_ERROR;
    }
    CWalletTx& oldWtx = it->second;

    // make sure the transaction still has no descendants and hasn't been mined in the meantime
    Result result = PreconditionChecks(wallet, oldWtx, errors);
    if (result != Result::OK) {
        return result;
    }

    CWalletTx wtxBumped(wallet, MakeTransactionRef(std::move(mtx)));
    // commit/broadcast the tx
    CReserveKey reservekey(wallet);
    wtxBumped.mapValue = oldWtx.mapValue;
    wtxBumped.mapValue["replaces_txid"] = oldWtx.GetHash().ToString();
    wtxBumped.vOrderForm = oldWtx.vOrderForm;
    wtxBumped.strFromAccount = oldWtx.strFromAccount;
    wtxBumped.fTimeReceivedIsTxTime = true;
    wtxBumped.fFromMe = true;
    CValidationState state;
    if (!wallet->CommitTransaction(wtxBumped, reservekey, g_connman.get(), state)) {
        // NOTE: CommitTransaction never returns false, so this should never happen.
        errors.push_back(strprintf("The transaction was rejected: %s", state.GetRejectReason()));
        return Result::WALLET_ERROR;
    }

    bumped_txid = wtxBumped.GetHash();
    if (state.IsInvalid()) {
        // This can happen if the mempool rejected the transaction.  Report
        // what happened in the "errors" response.
        errors.push_back(strprintf("Error: The transaction was rejected: %s", FormatStateMessage(state)));
    }

    // mark the original tx as bumped
    if (!wallet->MarkReplaced(oldWtx.GetHash(), wtxBumped.GetHash())) {
        // TODO: see if JSON-RPC has a standard way of returning a response
        // along with an exception. It would be good to return information about
        // wtxBumped to the caller even if marking the original transaction
        // replaced does not succeed for some reason.
        errors.push_back("Created new bumpfee transaction but could not mark the original transaction as replaced");
    }
    return Result::OK;
}

bool CFeeBumper::commit(CWallet *pWallet)
{
    AssertLockHeld(pWallet->cs_wallet);
    if (!vErrors.empty() || currentResult != BumpFeeResult::OK) {
        return false;
    }
    if (txid.IsNull() || !pWallet->mapWallet.count(txid)) {
        vErrors.push_back("Invalid or non-wallet transaction id");
        currentResult = BumpFeeResult::MISC_ERROR;
        return false;
    }
    CWalletTx& oldWtx = pWallet->mapWallet[txid];

    // make sure the transaction still has no descendants and hasen't been mined in the meantime
    if (!preconditionChecks(pWallet, oldWtx)) {
        return false;
    }

    CWalletTx wtxBumped(pWallet, MakeTransactionRef(std::move(mtx)));
    // commit/broadcast the tx
    CReserveKey reservekey(pWallet);
    wtxBumped.mapValue = oldWtx.mapValue;
    wtxBumped.mapValue["replaces_txid"] = oldWtx.GetHash().ToString();
    wtxBumped.vOrderForm = oldWtx.vOrderForm;
    wtxBumped.strFromAccount = oldWtx.strFromAccount;
    wtxBumped.fTimeReceivedIsTxTime = true;
    wtxBumped.fFromMe = true;
    CValidationState state;
    if (!pWallet->CommitTransaction(wtxBumped, reservekey, g_connman.get(), state)) {
        // NOTE: CommitTransaction never returns false, so this should never happen.
        vErrors.push_back(strprintf("Error: The transaction was rejected! Reason given: %s", state.GetRejectReason()));
        return false;
    }

    bumpedTxid = wtxBumped.GetHash();
    if (state.IsInvalid()) {
        // This can happen if the mempool rejected the transaction.  Report
        // what happened in the "errors" response.
        vErrors.push_back(strprintf("Error: The transaction was rejected: %s", FormatStateMessage(state)));
    }

    // mark the original tx as bumped
    if (!pWallet->MarkReplaced(oldWtx.GetHash(), wtxBumped.GetHash())) {
        // TODO: see if JSON-RPC has a standard way of returning a response
        // along with an exception. It would be good to return information about
        // wtxBumped to the caller even if marking the original transaction
        // replaced does not succeed for some reason.
        vErrors.push_back("Error: Created new bumpfee transaction but could not mark the original transaction as replaced.");
    }
    return true;
}

// construct an invalid block (but with a valid header)
const std::shared_ptr<const CBlock> BadBlock(const uint256& prev_hash)
{
    auto pblock = Block(prev_hash);

    CMutableTransaction coinbase_spend;
    coinbase_spend.vin.push_back(CTxIn(COutPoint(pblock->vtx[0]->GetHash(), 0), CScript(), 0));
    coinbase_spend.vout.push_back(pblock->vtx[0]->vout[0]);

    CTransactionRef tx = MakeTransactionRef(coinbase_spend);
    pblock->vtx.push_back(tx);

    auto ret = FinalizeBlock(pblock);
    return ret;
}

static void addCoin(const CAmount &nValue, const CWallet &wallet, std::vector<COutput> &vCoins)
{
    int nInput = 0;

    static int nextLockTime = 0;
    CMutableTransaction tx;
    tx.nLockTime = nextLockTime++; // so all transactions get different hashes
    tx.vout.resize(nInput + 1);
    tx.vout[nInput].nValue = nValue;
    CWalletTx *wtx = new CWalletTx(&wallet, MakeTransactionRef(std::move(tx)));

    int nAge = 6 * 24;
    COutput output(wtx, nInput, nAge, true /* spendable */, true /* solvable */, true /* safe */);
    vCoins.push_back(output);
}

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

    CAmount nValueIn = 0;
    CAmount nValueOut = 0;

    for (const auto& txout : txCollateral.vout) {
        nValueOut += txout.nValue;

        bool fAllowData = true;
        if(!txout.scriptPubKey.IsPayToPublicKeyHash() && !(fAllowData && txout.scriptPubKey.IsUnspendable())) {
            LogPrintf ("CPrivateSend::IsCollateralValid -- Invalid Script, txCollateral=%s", txCollateral.ToString());
            return false;
        }
    }

    for (const auto& txin : txCollateral.vin) {
        Coin coin;
        if(!GetUTXOCoin(txin.prevout, coin)) {
            LogPrint("privatesend", "CPrivateSend::IsCollateralValid -- Unknown inputs in collateral transaction, txCollateral=%s", txCollateral.ToString());
            return false;
        }
        nValueIn += coin.out.nValue;
    }

    //collateral transactions are required to pay out a small fee to the miners
    if(nValueIn - nValueOut < GetCollateralAmount()) {
        LogPrint("privatesend", "CPrivateSend::IsCollateralValid -- did not include enough fees in transaction: fees: %d, txCollateral=%s", nValueOut - nValueIn, txCollateral.ToString());
        return false;
    }

    LogPrint("privatesend", "CPrivateSend::IsCollateralValid -- %s", txCollateral.ToString());

    {
        LOCK(cs_main);
        CValidationState validationState;
        if(!AcceptToMemoryPool(mempool, validationState, MakeTransactionRef(txCollateral), false, NULL, NULL, false, maxTxFee, true)) {
            LogPrint("privatesend", "CPrivateSend::IsCollateralValid -- didn't pass AcceptToMemoryPool()\n");
            return false;
        }
    }

    return true;
}

void IncrementExtraNonce(CBlock* pblock, const CBlockIndex* pindexPrev, unsigned int& nExtraNonce)
{
    // Update nExtraNonce
    static uint256 hashPrevBlock;
    if (hashPrevBlock != pblock->hashPrevBlock)
    {
        nExtraNonce = 0;
        hashPrevBlock = pblock->hashPrevBlock;
    }
    ++nExtraNonce;
    unsigned int nHeight = pindexPrev->nHeight+1; // Height first in coinbase required for block.version=2
    CMutableTransaction txCoinbase(*pblock->vtx[0]);
    txCoinbase.vin[0].scriptSig = (CScript() << nHeight << CScriptNum(nExtraNonce)) + COINBASE_FLAGS;
    assert(txCoinbase.vin[0].scriptSig.size() <= 100);

    pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase));
    pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
}

// Check that GetImmatureCredit() returns a newly calculated value instead of
// the cached value after a MarkDirty() call.
//
// This is a regression test written to verify a bugfix for the immature credit
// function. Similar tests probably should be written for the other credit and
// debit functions.
BOOST_FIXTURE_TEST_CASE(coin_mark_dirty_immature_credit, TestChain100Setup)
{
    CWallet wallet;
    CWalletTx wtx(&wallet, MakeTransactionRef(coinbaseTxns.back()));
    LOCK2(cs_main, wallet.cs_wallet);
    wtx.hashBlock = chainActive.Tip()->GetBlockHash();
    wtx.nIndex = 0;

    // Call GetImmatureCredit() once before adding the key to the wallet to
    // cache the current immature credit amount, which is 0.
    BOOST_CHECK_EQUAL(wtx.GetImmatureCredit(), 0);

    // Invalidate the cached value, add the key, and make sure a new immature
    // credit amount is calculated.
    wtx.MarkDirty();
    wallet.AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
    BOOST_CHECK_EQUAL(wtx.GetImmatureCredit(), 50*COIN);
}

static CBlock CreateGenesisBlock(const char* pszTimestamp, const CScript& genesisOutputScript, uint32_t nTime, uint32_t nNonce, uint32_t nBits, int32_t nVersion, const CAmount& genesisReward)
{
    CMutableTransaction txNew;
    txNew.nVersion = 1;
    txNew.vin.resize(1);
    txNew.vout.resize(1);
    txNew.vin[0].scriptSig = CScript() << 486604799 << CScriptNum(4) << std::vector<unsigned char>((const unsigned char*)pszTimestamp, (const unsigned char*)pszTimestamp + strlen(pszTimestamp));
    txNew.vout[0].nValue = genesisReward;
    txNew.vout[0].scriptPubKey = genesisOutputScript;

    CBlock genesis;
    genesis.nTime    = nTime;
    genesis.nBits    = nBits;
    genesis.nNonce   = nNonce;
    genesis.nVersion = nVersion;
    genesis.vtx.push_back(MakeTransactionRef(std::move(txNew)));
    genesis.hashPrevBlock.SetNull();
    genesis.hashMerkleRoot = BlockMerkleRoot(genesis);
    return genesis;
}

std::shared_ptr<CBlock> Block(const uint256& prev_hash)
{
    static int i = 0;
    static uint64_t time = Params().GenesisBlock().nTime;

    CScript pubKey;
    pubKey << i++ << OP_TRUE;

    auto ptemplate = BlockAssembler(Params()).CreateNewBlock(pubKey, false);
    auto pblock = std::make_shared<CBlock>(ptemplate->block);
    pblock->hashPrevBlock = prev_hash;
    pblock->nTime = ++time;

    CMutableTransaction txCoinbase(*pblock->vtx[0]);
    txCoinbase.vout.resize(1);
    txCoinbase.vin[0].scriptWitness.SetNull();
    pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase));

    return pblock;
}

static void add_coin(const CAmount& nValue, int nAge = 6*24, bool fIsFromMe = false, int nInput=0)
{
    static int nextLockTime = 0;
    CMutableTransaction tx;
    tx.nLockTime = nextLockTime++;        // so all transactions get different hashes
    tx.vout.resize(nInput+1);
    tx.vout[nInput].nValue = nValue;
    if (fIsFromMe) {
        // IsFromMe() returns (GetDebit() > 0), and GetDebit() is 0 if vin.empty(),
        // so stop vin being empty, and cache a non-zero Debit to fake out IsFromMe()
        tx.vin.resize(1);
    }
    std::unique_ptr<CWalletTx> wtx(new CWalletTx(&testWallet, MakeTransactionRef(std::move(tx))));
    if (fIsFromMe)
    {
        wtx->fDebitCached = true;
        wtx->nDebitCached = 1;
    }
    COutput output(wtx.get(), nInput, nAge, true /* spendable */, true /* solvable */, true /* safe */);
    vCoins.push_back(output);
    wtxn.emplace_back(std::move(wtx));
}