// Copyright (c) 2014-2020 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 <chain.h>
#include <chainparams.h>
#include <consensus/params.h>
#include <test/util/setup_common.h>
#include <validation.h>
#include <versionbits.h>

#include <boost/test/unit_test.hpp>

/* Define a virtual block time, one block per 10 minutes after Nov 14 2014, 0:55:36am */
static int32_t TestTime(int nHeight) { return 1415926536 + 600 * nHeight; }

static const std::string StateName(ThresholdState state)
{
    switch (state) {
    case ThresholdState::DEFINED:   return "DEFINED";
    case ThresholdState::STARTED:   return "STARTED";
    case ThresholdState::LOCKED_IN: return "LOCKED_IN";
    case ThresholdState::ACTIVE:    return "ACTIVE";
    case ThresholdState::FAILED:    return "FAILED";
    } // no default case, so the compiler can warn about missing cases
    return "";
}

static const Consensus::Params paramsDummy = Consensus::Params();

class TestConditionChecker : public AbstractThresholdConditionChecker
{
private:
    mutable ThresholdConditionCache cache;

public:
    int64_t BeginTime(const Consensus::Params& params) const override { return TestTime(10000); }
    int64_t EndTime(const Consensus::Params& params) const override { return TestTime(20000); }
    int Period(const Consensus::Params& params) const override { return 1000; }
    int Threshold(const Consensus::Params& params) const override { return 900; }
    bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const override { return (pindex->nVersion & 0x100); }

    ThresholdState GetStateFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateFor(pindexPrev, paramsDummy, cache); }
    int GetStateSinceHeightFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateSinceHeightFor(pindexPrev, paramsDummy, cache); }
};

class TestDelayedActivationConditionChecker : public TestConditionChecker
{
public:
    int MinActivationHeight(const Consensus::Params& params) const override { return 15000; }
};

class TestAlwaysActiveConditionChecker : public TestConditionChecker
{
public:
    int64_t BeginTime(const Consensus::Params& params) const override { return Consensus::BIP9Deployment::ALWAYS_ACTIVE; }
};

class TestNeverActiveConditionChecker : public TestConditionChecker
{
public:
    int64_t BeginTime(const Consensus::Params& params) const override { return Consensus::BIP9Deployment::NEVER_ACTIVE; }
};

#define CHECKERS 6

class VersionBitsTester
{
    // A fake blockchain
    std::vector<CBlockIndex*> vpblock;

    // 6 independent checkers for the same bit.
    // The first one performs all checks, the second only 50%, the third only 25%, etc...
    // This is to test whether lack of cached information leads to the same results.
    TestConditionChecker checker[CHECKERS];
    // Another 6 that assume delayed activation
    TestDelayedActivationConditionChecker checker_delayed[CHECKERS];
    // Another 6 that assume always active activation
    TestAlwaysActiveConditionChecker checker_always[CHECKERS];
    // Another 6 that assume never active activation
    TestNeverActiveConditionChecker checker_never[CHECKERS];

    // Test counter (to identify failures)
    int num;

public:
    VersionBitsTester() : num(1000) {}

    VersionBitsTester& Reset() {
        // Have each group of tests be counted by the 1000s part, starting at 1000
        num = num - (num % 1000) + 1000;

        for (unsigned int i = 0; i < vpblock.size(); i++) {
            delete vpblock[i];
        }
        for (unsigned int  i = 0; i < CHECKERS; i++) {
            checker[i] = TestConditionChecker();
            checker_delayed[i] = TestDelayedActivationConditionChecker();
            checker_always[i] = TestAlwaysActiveConditionChecker();
            checker_never[i] = TestNeverActiveConditionChecker();
        }
        vpblock.clear();
        return *this;
    }

    ~VersionBitsTester() {
         Reset();
    }

    VersionBitsTester& Mine(unsigned int height, int32_t nTime, int32_t nVersion) {
        while (vpblock.size() < height) {
            CBlockIndex* pindex = new CBlockIndex();
            pindex->nHeight = vpblock.size();
            pindex->pprev = Tip();
            pindex->nTime = nTime;
            pindex->nVersion = nVersion;
            pindex->BuildSkip();
            vpblock.push_back(pindex);
        }
        return *this;
    }

    VersionBitsTester& TestStateSinceHeight(int height)
    {
        return TestStateSinceHeight(height, height);
    }

    VersionBitsTester& TestStateSinceHeight(int height, int height_delayed)
    {
        const CBlockIndex* tip = Tip();
        for (int i = 0; i < CHECKERS; i++) {
            if (InsecureRandBits(i) == 0) {
                BOOST_CHECK_MESSAGE(checker[i].GetStateSinceHeightFor(tip) == height, strprintf("Test %i for StateSinceHeight", num));
                BOOST_CHECK_MESSAGE(checker_delayed[i].GetStateSinceHeightFor(tip) == height_delayed, strprintf("Test %i for StateSinceHeight (delayed)", num));
                BOOST_CHECK_MESSAGE(checker_always[i].GetStateSinceHeightFor(tip) == 0, strprintf("Test %i for StateSinceHeight (always active)", num));
                BOOST_CHECK_MESSAGE(checker_never[i].GetStateSinceHeightFor(tip) == 0, strprintf("Test %i for StateSinceHeight (never active)", num));
            }
        }
        num++;
        return *this;
    }

    VersionBitsTester& TestState(ThresholdState exp)
    {
        return TestState(exp, exp);
    }

    VersionBitsTester& TestState(ThresholdState exp, ThresholdState exp_delayed)
    {
        if (exp != exp_delayed) {
            // only expected differences are that delayed stays in locked_in longer
            BOOST_CHECK_EQUAL(exp, ThresholdState::ACTIVE);
            BOOST_CHECK_EQUAL(exp_delayed, ThresholdState::LOCKED_IN);
        }

        const CBlockIndex* pindex = Tip();
        for (int i = 0; i < CHECKERS; i++) {
            if (InsecureRandBits(i) == 0) {
                ThresholdState got = checker[i].GetStateFor(pindex);
                ThresholdState got_delayed = checker_delayed[i].GetStateFor(pindex);
                ThresholdState got_always = checker_always[i].GetStateFor(pindex);
                ThresholdState got_never = checker_never[i].GetStateFor(pindex);
                // nHeight of the next block. If vpblock is empty, the next (ie first)
                // block should be the genesis block with nHeight == 0.
                int height = pindex == nullptr ? 0 : pindex->nHeight + 1;
                BOOST_CHECK_MESSAGE(got == exp, strprintf("Test %i for %s height %d (got %s)", num, StateName(exp), height, StateName(got)));
                BOOST_CHECK_MESSAGE(got_delayed == exp_delayed, strprintf("Test %i for %s height %d (got %s; delayed case)", num, StateName(exp_delayed), height, StateName(got_delayed)));
                BOOST_CHECK_MESSAGE(got_always == ThresholdState::ACTIVE, strprintf("Test %i for ACTIVE height %d (got %s; always active case)", num, height, StateName(got_always)));
                BOOST_CHECK_MESSAGE(got_never == ThresholdState::FAILED, strprintf("Test %i for FAILED height %d (got %s; never active case)", num, height, StateName(got_never)));
            }
        }
        num++;
        return *this;
    }

    VersionBitsTester& TestDefined() { return TestState(ThresholdState::DEFINED); }
    VersionBitsTester& TestStarted() { return TestState(ThresholdState::STARTED); }
    VersionBitsTester& TestLockedIn() { return TestState(ThresholdState::LOCKED_IN); }
    VersionBitsTester& TestActive() { return TestState(ThresholdState::ACTIVE); }
    VersionBitsTester& TestFailed() { return TestState(ThresholdState::FAILED); }

    // non-delayed should be active; delayed should still be locked in
    VersionBitsTester& TestActiveDelayed() { return TestState(ThresholdState::ACTIVE, ThresholdState::LOCKED_IN); }

    CBlockIndex* Tip() { return vpblock.empty() ? nullptr : vpblock.back(); }
};

BOOST_FIXTURE_TEST_SUITE(versionbits_tests, TestingSetup)

BOOST_AUTO_TEST_CASE(versionbits_test)
{
    for (int i = 0; i < 64; i++) {
        // DEFINED -> FAILED
        VersionBitsTester().TestDefined().TestStateSinceHeight(0)
                           .Mine(1, TestTime(1), 0x100).TestDefined().TestStateSinceHeight(0)
                           .Mine(11, TestTime(11), 0x100).TestDefined().TestStateSinceHeight(0)
                           .Mine(989, TestTime(989), 0x100).TestDefined().TestStateSinceHeight(0)
                           .Mine(999, TestTime(20000), 0x100).TestDefined().TestStateSinceHeight(0)
                           .Mine(1000, TestTime(20000), 0x100).TestFailed().TestStateSinceHeight(1000)
                           .Mine(1999, TestTime(30001), 0x100).TestFailed().TestStateSinceHeight(1000)
                           .Mine(2000, TestTime(30002), 0x100).TestFailed().TestStateSinceHeight(1000)
                           .Mine(2001, TestTime(30003), 0x100).TestFailed().TestStateSinceHeight(1000)
                           .Mine(2999, TestTime(30004), 0x100).TestFailed().TestStateSinceHeight(1000)
                           .Mine(3000, TestTime(30005), 0x100).TestFailed().TestStateSinceHeight(1000)
        // DEFINED -> STARTED -> FAILED
                           .Reset().TestDefined().TestStateSinceHeight(0)
                           .Mine(1, TestTime(1), 0).TestDefined().TestStateSinceHeight(0)
                           .Mine(1000, TestTime(10000) - 1, 0x100).TestDefined().TestStateSinceHeight(0) // One second more and it would be defined
                           .Mine(2000, TestTime(10000), 0x100).TestStarted().TestStateSinceHeight(2000) // So that's what happens the next period
                           .Mine(2051, TestTime(10010), 0).TestStarted().TestStateSinceHeight(2000) // 51 old blocks
                           .Mine(2950, TestTime(10020), 0x100).TestStarted().TestStateSinceHeight(2000) // 899 new blocks
                           .Mine(3000, TestTime(20000), 0).TestFailed().TestStateSinceHeight(3000) // 50 old blocks (so 899 out of the past 1000)
                           .Mine(4000, TestTime(20010), 0x100).TestFailed().TestStateSinceHeight(3000)

        // DEFINED -> STARTED -> FAILED while threshold reached
                           .Reset().TestDefined().TestStateSinceHeight(0)
                           .Mine(1, TestTime(1), 0).TestDefined().TestStateSinceHeight(0)
                           .Mine(1000, TestTime(10000) - 1, 0x101).TestDefined().TestStateSinceHeight(0) // One second more and it would be defined
                           .Mine(2000, TestTime(10000), 0x101).TestStarted().TestStateSinceHeight(2000) // So that's what happens the next period
                           .Mine(2999, TestTime(30000), 0x100).TestStarted().TestStateSinceHeight(2000) // 999 new blocks
                           .Mine(3000, TestTime(30000), 0x100).TestFailed().TestStateSinceHeight(3000) // 1 new block (so 1000 out of the past 1000 are new)
                           .Mine(3999, TestTime(30001), 0).TestFailed().TestStateSinceHeight(3000)
                           .Mine(4000, TestTime(30002), 0).TestFailed().TestStateSinceHeight(3000)
                           .Mine(14333, TestTime(30003), 0).TestFailed().TestStateSinceHeight(3000)
                           .Mine(24000, TestTime(40000), 0).TestFailed().TestStateSinceHeight(3000)

        // DEFINED -> STARTED -> LOCKEDIN at the last minute -> ACTIVE
                           .Reset().TestDefined()
                           .Mine(1, TestTime(1), 0).TestDefined().TestStateSinceHeight(0)
                           .Mine(1000, TestTime(10000) - 1, 0x101).TestDefined().TestStateSinceHeight(0) // One second more and it would be defined
                           .Mine(2000, TestTime(10000), 0x101).TestStarted().TestStateSinceHeight(2000) // So that's what happens the next period
                           .Mine(2050, TestTime(10010), 0x200).TestStarted().TestStateSinceHeight(2000) // 50 old blocks
                           .Mine(2950, TestTime(10020), 0x100).TestStarted().TestStateSinceHeight(2000) // 900 new blocks
                           .Mine(2999, TestTime(19999), 0x200).TestStarted().TestStateSinceHeight(2000) // 49 old blocks
                           .Mine(3000, TestTime(29999), 0x200).TestLockedIn().TestStateSinceHeight(3000) // 1 old block (so 900 out of the past 1000)
                           .Mine(3999, TestTime(30001), 0).TestLockedIn().TestStateSinceHeight(3000)
                           .Mine(4000, TestTime(30002), 0).TestActiveDelayed().TestStateSinceHeight(4000, 3000) // delayed will not become active until height=15000
                           .Mine(14333, TestTime(30003), 0).TestActiveDelayed().TestStateSinceHeight(4000, 3000)
                           .Mine(15000, TestTime(40000), 0).TestActive().TestStateSinceHeight(4000, 15000)
                           .Mine(24000, TestTime(40000), 0).TestActive().TestStateSinceHeight(4000, 15000)

        // DEFINED multiple periods -> STARTED multiple periods -> FAILED
                           .Reset().TestDefined().TestStateSinceHeight(0)
                           .Mine(999, TestTime(999), 0).TestDefined().TestStateSinceHeight(0)
                           .Mine(1000, TestTime(1000), 0).TestDefined().TestStateSinceHeight(0)
                           .Mine(2000, TestTime(2000), 0).TestDefined().TestStateSinceHeight(0)
                           .Mine(3000, TestTime(10000), 0).TestStarted().TestStateSinceHeight(3000)
                           .Mine(4000, TestTime(10000), 0).TestStarted().TestStateSinceHeight(3000)
                           .Mine(5000, TestTime(10000), 0).TestStarted().TestStateSinceHeight(3000)
                           .Mine(6000, TestTime(20000), 0).TestFailed().TestStateSinceHeight(6000)
                           .Mine(7000, TestTime(20000), 0x100).TestFailed().TestStateSinceHeight(6000)
        ;
    }
}

BOOST_AUTO_TEST_CASE(versionbits_sanity)
{
    // Sanity checks of version bit deployments
    const auto chainParams = CreateChainParams(*m_node.args, CBaseChainParams::MAIN);
    const Consensus::Params &mainnetParams = chainParams->GetConsensus();
    for (int i=0; i<(int) Consensus::MAX_VERSION_BITS_DEPLOYMENTS; i++) {
        uint32_t bitmask = VersionBitsMask(mainnetParams, static_cast<Consensus::DeploymentPos>(i));
        // Make sure that no deployment tries to set an invalid bit.
        BOOST_CHECK_EQUAL(bitmask & ~(uint32_t)VERSIONBITS_TOP_MASK, bitmask);

        // Check min_activation_height is on a retarget boundary
        BOOST_CHECK_EQUAL(mainnetParams.vDeployments[i].min_activation_height % mainnetParams.nMinerConfirmationWindow, 0);
        // Check min_activation_height is 0 for ALWAYS_ACTIVE and never active deployments
        if (mainnetParams.vDeployments[i].nStartTime == Consensus::BIP9Deployment::ALWAYS_ACTIVE || mainnetParams.vDeployments[i].nStartTime == Consensus::BIP9Deployment::NEVER_ACTIVE) {
            BOOST_CHECK_EQUAL(mainnetParams.vDeployments[i].min_activation_height, 0);
        }

        // Verify that the deployment windows of different deployment using the
        // same bit are disjoint.
        // This test may need modification at such time as a new deployment
        // is proposed that reuses the bit of an activated soft fork, before the
        // end time of that soft fork.  (Alternatively, the end time of that
        // activated soft fork could be later changed to be earlier to avoid
        // overlap.)
        for (int j=i+1; j<(int) Consensus::MAX_VERSION_BITS_DEPLOYMENTS; j++) {
            if (VersionBitsMask(mainnetParams, static_cast<Consensus::DeploymentPos>(j)) == bitmask) {
                BOOST_CHECK(mainnetParams.vDeployments[j].nStartTime > mainnetParams.vDeployments[i].nTimeout ||
                        mainnetParams.vDeployments[i].nStartTime > mainnetParams.vDeployments[j].nTimeout);
            }
        }
    }
}

/** Check that ComputeBlockVersion will set the appropriate bit correctly */
static void check_computeblockversion(const Consensus::Params& params, Consensus::DeploymentPos dep)
{
    // This implicitly uses versionbitscache, so clear it every time
    versionbitscache.Clear();

    int64_t bit = params.vDeployments[dep].bit;
    int64_t nStartTime = params.vDeployments[dep].nStartTime;
    int64_t nTimeout = params.vDeployments[dep].nTimeout;
    int min_activation_height = params.vDeployments[dep].min_activation_height;

    // should not be any signalling for first block
    BOOST_CHECK_EQUAL(ComputeBlockVersion(nullptr, params), VERSIONBITS_TOP_BITS);

    // always/never active deployments shouldn't need to be tested further
    if (nStartTime == Consensus::BIP9Deployment::ALWAYS_ACTIVE) return;
    if (nStartTime == Consensus::BIP9Deployment::NEVER_ACTIVE) return;

    BOOST_REQUIRE(nStartTime < nTimeout);
    BOOST_REQUIRE(nStartTime >= 0);
    BOOST_REQUIRE(nTimeout <= std::numeric_limits<uint32_t>::max() || nTimeout == Consensus::BIP9Deployment::NO_TIMEOUT);
    BOOST_REQUIRE(0 <= bit && bit < 32);
    BOOST_REQUIRE(((1 << bit) & VERSIONBITS_TOP_MASK) == 0);
    BOOST_REQUIRE(min_activation_height >= 0);
    BOOST_REQUIRE_EQUAL(min_activation_height % params.nMinerConfirmationWindow, 0);

    // In the first chain, test that the bit is set by CBV until it has failed.
    // In the second chain, test the bit is set by CBV while STARTED and
    // LOCKED-IN, and then no longer set while ACTIVE.
    VersionBitsTester firstChain, secondChain;

    int64_t nTime = nStartTime;

    const CBlockIndex *lastBlock = nullptr;

    // Before MedianTimePast of the chain has crossed nStartTime, the bit
    // should not be set.
    if (nTime == 0) {
        // since CBlockIndex::nTime is uint32_t we can't represent any
        // earlier time, so will transition from DEFINED to STARTED at the
        // end of the first period by mining blocks at nTime == 0
        lastBlock = firstChain.Mine(params.nMinerConfirmationWindow - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
        lastBlock = firstChain.Mine(params.nMinerConfirmationWindow, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
        BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
        // then we'll keep mining at nStartTime...
    } else {
        // use a time 1s earlier than start time to check we stay DEFINED
        --nTime;

        // Start generating blocks before nStartTime
        lastBlock = firstChain.Mine(params.nMinerConfirmationWindow, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);

        // Mine more blocks (4 less than the adjustment period) at the old time, and check that CBV isn't setting the bit yet.
        for (uint32_t i = 1; i < params.nMinerConfirmationWindow - 4; i++) {
            lastBlock = firstChain.Mine(params.nMinerConfirmationWindow + i, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
            BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
        }
        // Now mine 5 more blocks at the start time -- MTP should not have passed yet, so
        // CBV should still not yet set the bit.
        nTime = nStartTime;
        for (uint32_t i = params.nMinerConfirmationWindow - 4; i <= params.nMinerConfirmationWindow; i++) {
            lastBlock = firstChain.Mine(params.nMinerConfirmationWindow + i, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
            BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
        }
        // Next we will advance to the next period and transition to STARTED,
    }

    lastBlock = firstChain.Mine(params.nMinerConfirmationWindow * 3, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
    // so ComputeBlockVersion should now set the bit,
    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
    // and should also be using the VERSIONBITS_TOP_BITS.
    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);

    // Check that ComputeBlockVersion will set the bit until nTimeout
    nTime += 600;
    uint32_t blocksToMine = params.nMinerConfirmationWindow * 2; // test blocks for up to 2 time periods
    uint32_t nHeight = params.nMinerConfirmationWindow * 3;
    // These blocks are all before nTimeout is reached.
    while (nTime < nTimeout && blocksToMine > 0) {
        lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
        BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & VERSIONBITS_TOP_MASK, VERSIONBITS_TOP_BITS);
        blocksToMine--;
        nTime += 600;
        nHeight += 1;
    }

    if (nTimeout != Consensus::BIP9Deployment::NO_TIMEOUT) {
        // can reach any nTimeout other than NO_TIMEOUT due to earlier BOOST_REQUIRE

        nTime = nTimeout;

        // finish the last period before we start timing out
        while (nHeight % params.nMinerConfirmationWindow != 0) {
            lastBlock = firstChain.Mine(nHeight+1, nTime - 1, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
            BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
            nHeight += 1;
        }

        // FAILED is only triggered at the end of a period, so CBV should be setting
        // the bit until the period transition.
        for (uint32_t i = 0; i < params.nMinerConfirmationWindow - 1; i++) {
            lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
            BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);
            nHeight += 1;
        }
        // The next block should trigger no longer setting the bit.
        lastBlock = firstChain.Mine(nHeight+1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
        BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
    }

    // On a new chain:
    // verify that the bit will be set after lock-in, and then stop being set
    // after activation.
    nTime = nStartTime;

    // Mine one period worth of blocks, and check that the bit will be on for the
    // next period.
    lastBlock = secondChain.Mine(params.nMinerConfirmationWindow, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);

    // Mine another period worth of blocks, signaling the new bit.
    lastBlock = secondChain.Mine(params.nMinerConfirmationWindow * 2, nTime, VERSIONBITS_TOP_BITS | (1<<bit)).Tip();
    // After one period of setting the bit on each block, it should have locked in.
    // We keep setting the bit for one more period though, until activation.
    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1<<bit)) != 0);

    // Now check that we keep mining the block until the end of this period, and
    // then stop at the beginning of the next period.
    lastBlock = secondChain.Mine((params.nMinerConfirmationWindow * 3) - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
    BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
    lastBlock = secondChain.Mine(params.nMinerConfirmationWindow * 3, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();

    if (lastBlock->nHeight + 1 < min_activation_height) {
        // check signalling continues while min_activation_height is not reached
        lastBlock = secondChain.Mine(min_activation_height - 1, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
        BOOST_CHECK((ComputeBlockVersion(lastBlock, params) & (1 << bit)) != 0);
        // then reach min_activation_height, which was already REQUIRE'd to start a new period
        lastBlock = secondChain.Mine(min_activation_height, nTime, VERSIONBITS_LAST_OLD_BLOCK_VERSION).Tip();
    }

    // Check that we don't signal after activation
    BOOST_CHECK_EQUAL(ComputeBlockVersion(lastBlock, params) & (1<<bit), 0);
}

BOOST_AUTO_TEST_CASE(versionbits_computeblockversion)
{
    // check that any deployment on any chain can conceivably reach both
    // ACTIVE and FAILED states in roughly the way we expect
    for (const auto& chain_name : {CBaseChainParams::MAIN, CBaseChainParams::TESTNET, CBaseChainParams::SIGNET, CBaseChainParams::REGTEST}) {
        const auto chainParams = CreateChainParams(*m_node.args, chain_name);
        for (int i = 0; i < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++i) {
            check_computeblockversion(chainParams->GetConsensus(), static_cast<Consensus::DeploymentPos>(i));
        }
    }

    {
        // Use regtest/testdummy to ensure we always exercise some
        // deployment that's not always/never active
        ArgsManager args;
        args.ForceSetArg("-vbparams", "testdummy:1199145601:1230767999"); // January 1, 2008 - December 31, 2008
        const auto chainParams = CreateChainParams(args, CBaseChainParams::REGTEST);
        check_computeblockversion(chainParams->GetConsensus(), Consensus::DEPLOYMENT_TESTDUMMY);
    }

    {
        // Use regtest/testdummy to ensure we always exercise the
        // min_activation_height test, even if we're not using that in a
        // live deployment
        ArgsManager args;
        args.ForceSetArg("-vbparams", "testdummy:1199145601:1230767999:403200"); // January 1, 2008 - December 31, 2008, min act height 403200
        const auto chainParams = CreateChainParams(args, CBaseChainParams::REGTEST);
        check_computeblockversion(chainParams->GetConsensus(), Consensus::DEPLOYMENT_TESTDUMMY);
    }
}

BOOST_AUTO_TEST_SUITE_END()