// Copyright (c) 2010 Satoshi Nakamoto
// Copyright (c) 2009-2020 The Bitcoin Core developers
// Copyright (c) 2026 The Vexta Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "arith_uint256.h"
#include <chainparams.h>

#include <chainparamsseeds.h>
#include <consensus/merkle.h>
#include <deploymentinfo.h>
#include <hash.h> // for signet block challenge hash
#include <util/system.h>

#include <assert.h>

#include <boost/algorithm/string/classification.hpp>
#include <boost/algorithm/string/split.hpp>

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 = CScript() << 0x0 << OP_CHECKSIG;

    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;
}

/**
 * Build the genesis block. Note that the output of its generation
 * transaction cannot be spent since it did not originally exist in the
 * database.
 *
 * CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)
 *   CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)
 *     CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)
 *     CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)
 *   vMerkleTree: 4a5e1e
 */
static CBlock CreateGenesisBlock(uint32_t nTime, uint32_t nNonce, uint32_t nBits, int32_t nVersion, const CAmount& genesisReward)
{
    const char* pszTimestamp = "Vexta Genesis Block 29/Jun/2026 - VTX network begins";
    const CScript genesisOutputScript = CScript() << 0x0 << OP_CHECKSIG;
    return CreateGenesisBlock(pszTimestamp, genesisOutputScript, nTime, nNonce, nBits, nVersion, genesisReward);
}

/**
 * Main network on which people trade goods and services.
 */
class CMainParams : public CChainParams {
public:
    CMainParams() {
        strNetworkID = CBaseChainParams::MAIN;
        consensus.signet_blocks = false;
        consensus.signet_challenge.clear();
        consensus.BIP16Exception = uint256S("0x0");

        // BIP34, BIP65 and BIP66, CSV and Segwit were activated simultaneously
        // DEPLOYMENT_NVERSIONBIPS, DEPLOYMENT_CSV, DEPLOYMENT_SEGWIT        
        consensus.BIP34Hash = uint256S("0xadd8ca420f557f62377ec2be6e6f47b96cf2e68160d58aeb7b73433de834cca0");
        consensus.BIP34Height = consensus.BIP65Height = consensus.BIP66Height = 1; // Vexta: active from block 1
        consensus.CSVHeight = consensus.SegwitHeight = 1; // Vexta: active from block 1

        
        consensus.powLimit = ArithToUint256(~arith_uint256(0) >> 20);
        consensus.nPowTargetSpacing = 10 * 60;
        consensus.nSubsidyHalvingInterval = 210000; // ~4 years at 10 minute blocks
        consensus.fPowAllowMinDifficultyBlocks = false;
        consensus.fEasyPow = false;
        consensus.fPowNoRetargeting = false;
        consensus.fRbfEnabled = false;

        // Vexta consensus parameters
        consensus.nRuleChangeActivationThreshold = 28224; // 28224 - 70% of 40320 blocks
        consensus.nMinerConfirmationWindow = 40320; // 1 week of blocks

        // Suppress unknown activation warnings before the configured warning height
        consensus.MinBIP9WarningHeight = 1; // Vexta: deployments are active from launch

        // Vexta protocol activation heights
        
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 27;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 1199145601; // January 1, 2008
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = 1230767999; // December 31, 2008
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay

        // Deployment of Taproot (BIPs 340-342)
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay

        // VEXTA quantum-resistant witness v2/v3.
        // Activates at the configured min_activation_height.
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].bit = 3;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].min_activation_height = 6000;

        // The best chain should have at least this much work.
        consensus.nMinimumChainWork = uint256{};

        // By default assume that the signatures in ancestors of this block are valid.
        consensus.defaultAssumeValid = uint256{};

        /**
         * The message start string is designed to be unlikely to occur in normal data.
         * The characters are rarely used upper ASCII, not valid as UTF-8, and produce
         * a large 32-bit integer with any alignment.
         */
        pchMessageStart[0] = 0x56; // V
        pchMessageStart[1] = 0x54; // T
        pchMessageStart[2] = 0x58; // X
        pchMessageStart[3] = 0x31; // 1
        nDefaultPort = 19333;
        nPruneAfterHeight = 100000;
        m_assumed_blockchain_size = 0;
        m_assumed_chain_state_size = 0;

        genesis = CreateGenesisBlock(1782770400, 1605828, 0x1e0ffff0, BLOCK_VERSION_SHA256D, 50 * COIN);
        consensus.hashGenesisBlock = genesis.GetHash();
        assert(consensus.hashGenesisBlock == uint256S("0x0000027626959d894ae1c8a6f9050cdcbdf58eb0037ab06345cb5502955370f1"));
        assert(genesis.hashMerkleRoot == uint256S("0x3c1f602428f06c9baf0961930a5f711a2b5fd6157a9922365e7f1eca1970ff16"));

        // Public Vexta mainnet seed nodes.
        vSeeds.emplace_back("87.106.99.23");  // UK seed
        vSeeds.emplace_back("74.208.53.160"); // US seed

        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,70);
        base58Prefixes[SCRIPT_ADDRESS_OLD] = std::vector<unsigned char>(1,85);
        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,85);
        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,198);
        base58Prefixes[SECRET_KEY_OLD] = std::vector<unsigned char>(1,199);
        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x88, 0xB2, 0x1E};
        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x88, 0xAD, 0xE4};

        bech32_hrp = "vtx";

        vFixedSeeds.clear(); // Vexta: no hardcoded seeds yet

        fDefaultConsistencyChecks = false;
        fRequireStandard = true;
        m_is_test_chain = false;
        m_is_mockable_chain = false;

        checkpointData = {
            {
                {0, consensus.hashGenesisBlock},
            }
        };

        chainTxData = ChainTxData{
            0,
            0,
            0,
        };

        // Vexta difficulty parameters.
        //
        // Vexta uses a single SHA256D proof-of-work algorithm with a moving
        // averaging window for difficulty adjustment.


        consensus.difficultyAveragingWindow = 10; // 10 blocks
        consensus.difficultyTargetTimespan = consensus.difficultyAveragingWindow * consensus.nPowTargetSpacing;


        consensus.difficultyMinActualTimespan = consensus.difficultyTargetTimespan * 92 / 100;
        consensus.difficultyMaxActualTimespan = consensus.difficultyTargetTimespan * 116 / 100;
        consensus.asertActivationHeight = 6500;
        consensus.asertHalfLife = 2 * 24 * 60 * 60;

       

    }
};

/**
 * Testnet (v3): public test network which is reset from time to time.
 */
class CTestNetParams : public CChainParams {
public:
    CTestNetParams() {
        strNetworkID = "test";
        consensus.powLimit = ArithToUint256(~arith_uint256(0) >> 20);
        consensus.nPowTargetSpacing = 10 * 60;
        consensus.nSubsidyHalvingInterval = 210000; // ~4 years at 10 minute blocks

        consensus.BIP16Exception = uint256();
        consensus.BIP34Height = 500; // BIP34 activated on regtest (Used in functional tests)
        consensus.BIP34Hash = uint256();
        consensus.BIP65Height = 1351; // BIP65 activated on regtest (Used in functional tests)
        consensus.BIP66Height = 1251; // BIP66 activated on regtest (Used in functional tests)
        consensus.CSVHeight = 1; // CSV activated on regtest (Used in rpc activation tests)
        consensus.SegwitHeight = 0; // SEGWIT is always activated on regtest unless overridden

        consensus.MinBIP9WarningHeight = 0;

        // Vexta difficulty parameters.
        //
        // Vexta uses a single SHA256D proof-of-work algorithm with a moving
        // averaging window for difficulty adjustment.


        consensus.difficultyAveragingWindow = 10; // 10 blocks
        consensus.difficultyTargetTimespan = consensus.difficultyAveragingWindow * consensus.nPowTargetSpacing;


        consensus.difficultyMinActualTimespan = consensus.difficultyTargetTimespan * 92 / 100;
        consensus.difficultyMaxActualTimespan = consensus.difficultyTargetTimespan * 116 / 100;
        consensus.asertActivationHeight = 6500;
        consensus.asertHalfLife = 2 * 24 * 60 * 60;



        // Vexta protocol activation heights

        consensus.fPowAllowMinDifficultyBlocks = true;
        consensus.fEasyPow = false;
        consensus.fPowNoRetargeting = true;
        consensus.nRuleChangeActivationThreshold = 4032; // 4032 - 70% of 5760
        consensus.nMinerConfirmationWindow = 5760; // 1 day of blocks on testnet
        consensus.fRbfEnabled = false;

        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 27;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 1619222400; // April 24th, 2021
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = 1628640000; // August 11th, 2021
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay

        // Deployment of Taproot (BIPs 340-342)
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = 1718921304; // 20th June 2024 Testnet
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = 1750457304; // 20th June 2025 Testnet
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay

        // VEXTA quantum-resistant witness v2/v3.
        // Activates at the configured min_activation_height.
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].bit = 3;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].min_activation_height = 6000;

        // The best chain should have at least this much work.
        consensus.nMinimumChainWork = uint256{};

        // By default assume that the signatures in ancestors of this block are valid.
        consensus.defaultAssumeValid = uint256{};

        pchMessageStart[0] = 0x56; // V
        pchMessageStart[1] = 0x54; // T
        pchMessageStart[2] = 0x58; // X
        pchMessageStart[3] = 0x54; // T
        nDefaultPort = 12026;
        nPruneAfterHeight = 1000;
        m_assumed_blockchain_size = 0;
        m_assumed_chain_state_size = 0;

        genesis = CreateGenesisBlock("Vexta Testnet Genesis Block 09/Jul/2026 - VTX test network begins", CScript() << 0x0 << OP_CHECKSIG, 1783555200, 2228323, 0x1e0ffff0, 1, 50 * COIN);
        consensus.hashGenesisBlock = genesis.GetHash();
        assert(consensus.hashGenesisBlock == uint256S("0x00000dc74b41d5ebb73e55098e160534f34ec418becf4a3aa5bb218e6055cca5"));
        assert(genesis.hashMerkleRoot == uint256S("0x0fba2f6943df4ab9ffd13b5cf1233a825e364d2228a4683a72866b47d6a767c7"));

        vFixedSeeds.clear();
        vSeeds.clear();

        // DNS seeds will be added after public Vexta testnet seed nodes are deployed.

        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,126);
        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,140);
        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,254);
        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};

        bech32_hrp = "vtxt";

        vFixedSeeds.clear(); // Vexta: no hardcoded testnet seeds yet

        fDefaultConsistencyChecks = false;
        fRequireStandard = false;
        m_is_test_chain = true;
        m_is_mockable_chain = false;

        checkpointData = {
            {
                {0, consensus.hashGenesisBlock},
            }
        };

        m_assumeutxo_data = MapAssumeutxo{};

        chainTxData = ChainTxData{
            0,
            0,
            0,
        };
    }
};

/**
 * Signet: test network with an additional consensus parameter (see BIP325).
 */
class SigNetParams : public CChainParams {
public:
    explicit SigNetParams(const ArgsManager& args) {
        std::vector<uint8_t> bin;
        vSeeds.clear();

        if (!args.IsArgSet("-signetchallenge")) {
            bin = ParseHex("512103ad5e0edad18cb1f0fc0d28a3d4f1f3e445640337489abb10404f2d1e086be430210359ef5021964fe22d6f8e05b2463c9540ce96883fe3b278760f048f5189f2e6c452ae");
            // DNS seeds will be added after first public Vexta signet seed nodes are online.

            consensus.nMinimumChainWork = uint256{};
            consensus.defaultAssumeValid = uint256{};
            m_assumed_blockchain_size = 0;
            m_assumed_chain_state_size = 0;
            chainTxData = ChainTxData{
                0,
                0,
                0,
            };
        } else {
            const auto signet_challenge = args.GetArgs("-signetchallenge");
            if (signet_challenge.size() != 1) {
                throw std::runtime_error(strprintf("%s: -signetchallenge cannot be multiple values.", __func__));
            }
            bin = ParseHex(signet_challenge[0]);

            consensus.nMinimumChainWork = uint256{};
            consensus.defaultAssumeValid = uint256{};
            m_assumed_blockchain_size = 0;
            m_assumed_chain_state_size = 0;
            chainTxData = ChainTxData{
                0,
                0,
                0,
            };
            LogPrintf("Signet with challenge %s\n", signet_challenge[0]);
        }

        if (args.IsArgSet("-signetseednode")) {
            vSeeds = args.GetArgs("-signetseednode");
        }

        strNetworkID = CBaseChainParams::SIGNET;
        consensus.signet_blocks = true;
        consensus.signet_challenge.assign(bin.begin(), bin.end());
        consensus.BIP16Exception = uint256{};
        consensus.BIP34Height = 1;
        consensus.BIP34Hash = uint256{};
        consensus.BIP65Height = 1;
        consensus.BIP66Height = 1;
        consensus.CSVHeight = 1;
        consensus.SegwitHeight = 1;
        consensus.nPowTargetSpacing = 10 * 60;
        consensus.nSubsidyHalvingInterval = 210000; // ~4 years at 10 minute blocks
        consensus.fPowAllowMinDifficultyBlocks = false;
        consensus.fEasyPow = false;
        consensus.fPowNoRetargeting = false;
        consensus.nRuleChangeActivationThreshold = 1815; // 90% of 2016
        consensus.nMinerConfirmationWindow = 2016; // legacy Bitcoin confirmation window
        consensus.fRbfEnabled = false;

        consensus.MinBIP9WarningHeight = 0;
        consensus.powLimit = uint256S("00000377ae000000000000000000000000000000000000000000000000000000");
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 27;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay

        // Activation of Taproot (BIPs 340-342)
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay

        // VEXTA quantum-resistant witness v2/v3.
        // Activates at the configured min_activation_height.
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].bit = 3;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].min_activation_height = 6000;

        // message start is defined as the first 4 bytes of the sha256d of the block script
        CHashWriter h(SER_DISK, 0);
        h << consensus.signet_challenge;
        uint256 hash = h.GetHash();
        memcpy(pchMessageStart, hash.begin(), 4);

        nDefaultPort = 38443;
        nPruneAfterHeight = 1000;

        genesis = CreateGenesisBlock("Vexta Signet Genesis Block 09/Jul/2026 - VTX signet network begins", CScript() << 0x0 << OP_CHECKSIG, 1783555202, 4047966, 0x1e0377ae, 1, 50 * COIN);
        consensus.hashGenesisBlock = genesis.GetHash();

        assert(consensus.hashGenesisBlock == uint256S("0x00000297613fa90675b13ac95d0590e95f787b15410ee3e568d7bc9df796c3c4"));
        assert(genesis.hashMerkleRoot == uint256S("0xd4764aaa54047c0408946a09f43c28b167988604619d055854bc89d51bcb736e"));

        vFixedSeeds.clear();

        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,126);
        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,140);
        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,254);
        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};

        bech32_hrp = "vtxt";

        fDefaultConsistencyChecks = false;
        fRequireStandard = true;
        m_is_test_chain = true;
        m_is_mockable_chain = false;
    }
};

/**
 * Regression test: intended for private networks only. Has minimal difficulty to ensure that
 * blocks can be found instantly.
 */
class CRegTestParams : public CChainParams {
public:
    explicit CRegTestParams(const ArgsManager& args) {
        strNetworkID =  CBaseChainParams::REGTEST;
        consensus.signet_blocks = false;
        consensus.signet_challenge.clear();
        consensus.BIP16Exception = uint256();
        consensus.BIP34Height = 500; // BIP34 activated on regtest (Used in functional tests)
        consensus.BIP34Hash = uint256();
        consensus.BIP65Height = 1351; // BIP65 activated on regtest (Used in functional tests)
        consensus.BIP66Height = 1251; // BIP66 activated on regtest (Used in functional tests)
        consensus.CSVHeight = 432; // CSV activated on regtest (Used in rpc activation tests)
        consensus.SegwitHeight = 0; // SEGWIT is always activated on regtest unless overridden
        consensus.MinBIP9WarningHeight = 0;
        consensus.powLimit = uint256S("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
        consensus.fPowAllowMinDifficultyBlocks = true;
        consensus.fEasyPow = false; // allow easy blocks on regtest (can be set with -easypow)
        consensus.nPowTargetSpacing = 10 * 60;
        consensus.nSubsidyHalvingInterval = 210000; // ~4 years at 10 minute blocks

        consensus.difficultyAveragingWindow = 10; // 10 blocks
        consensus.difficultyTargetTimespan = consensus.difficultyAveragingWindow * consensus.nPowTargetSpacing;


        consensus.difficultyMinActualTimespan = consensus.difficultyTargetTimespan * 92 / 100;
        consensus.difficultyMaxActualTimespan = consensus.difficultyTargetTimespan * 116 / 100;
        consensus.asertActivationHeight = 6500;
        consensus.asertHalfLife = 2 * 24 * 60 * 60;


        consensus.BIP65Height = 1351;
        consensus.BIP66Height = 1251;

        // Vexta protocol activation heights
        consensus.nRuleChangeActivationThreshold = 168; // 70% of 240
        consensus.nMinerConfirmationWindow = 240; // 1 hour in RegTest
        consensus.fRbfEnabled = false;

        consensus.fPowNoRetargeting = true;

        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 27;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 0;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay

        // Activation of Taproot (BIPs 340-342)
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay

        // VEXTA quantum-resistant witness v2/v3.
        // Always active on regtest for development and testing.
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].bit = 3;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_PQR].min_activation_height = 0;

        consensus.nMinimumChainWork = uint256{};
        consensus.defaultAssumeValid = uint256{};


        pchMessageStart[0] = 0x56; // V
        pchMessageStart[1] = 0x54; // T
        pchMessageStart[2] = 0x58; // X
        pchMessageStart[3] = 0x52; // R
        nDefaultPort = 18444;
        nPruneAfterHeight = args.GetBoolArg("-fastprune", false) ? 100 : 1000;
        m_assumed_blockchain_size = 0;
        m_assumed_chain_state_size = 0;

        bech32_hrp = "vtxrt";

        UpdateActivationParametersFromArgs(args);

        genesis = CreateGenesisBlock("Vexta Regtest Genesis Block 09/Jul/2026 - VTX regression test network begins", CScript() << 0x0 << OP_CHECKSIG, 1783555201, 5, 0x207fffff, 1, 50 * COIN);      
        consensus.hashGenesisBlock = genesis.GetHash();

        assert(consensus.hashGenesisBlock == uint256S("0x3b5c0230bafd65f3dabcda2a30f33cdef0c3cda635e7440bda6909bb581462b7"));
        assert(genesis.hashMerkleRoot == uint256S("0x1d7df76c2482ecb39a9347895f012dd0d03696f064feb4b484d5bdb4f33cd924"));

        vFixedSeeds.clear(); //!< Regtest mode doesn't have any fixed seeds.
        vSeeds.clear();      //!< Regtest mode doesn't have any DNS seeds.

        fDefaultConsistencyChecks = true;
        fRequireStandard = true;
        m_is_test_chain = true;
        m_is_mockable_chain = true;

        checkpointData = {
            {
                {0, consensus.hashGenesisBlock},
            }
        };

        m_assumeutxo_data = MapAssumeutxo{};

        chainTxData = ChainTxData{
            0,
            0,
            0
        };

        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,126);
        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,140);
        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,254);
        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};
    }
    /**
     * Allows modifying the Version Bits regtest parameters.
     */
    void UpdateVersionBitsParameters(Consensus::DeploymentPos d, int64_t nStartTime, int64_t nTimeout, int min_activation_height)
    {
        consensus.vDeployments[d].nStartTime = nStartTime;
        consensus.vDeployments[d].nTimeout = nTimeout;
        consensus.vDeployments[d].min_activation_height = min_activation_height;
    }
    void UpdateActivationParametersFromArgs(const ArgsManager& args);
};

static void MaybeUpdateHeights(const ArgsManager& args, Consensus::Params& consensus)
{
    for (const std::string& arg : args.GetArgs("-testactivationheight")) {
        const auto found{arg.find('@')};
        if (found == std::string::npos) {
            throw std::runtime_error(strprintf("Invalid format (%s) for -testactivationheight=name@height.", arg));
        }
        const auto name{arg.substr(0, found)};
        const auto value{arg.substr(found + 1)};
        int32_t height;
        if (!ParseInt32(value, &height) || height < 0 || height >= std::numeric_limits<int>::max()) {
            throw std::runtime_error(strprintf("Invalid height value (%s) for -testactivationheight=name@height.", arg));
        }
        if (name == "segwit") {
            consensus.SegwitHeight = int{height};
        } else if (name == "bip34") {
            consensus.BIP34Height = int{height};
        } else if (name == "dersig") {
            consensus.BIP66Height = int{height};
        } else if (name == "cltv") {
            consensus.BIP65Height = int{height};
        } else if (name == "csv") {
            consensus.CSVHeight = int{height};
        } else {
            throw std::runtime_error(strprintf("Invalid name (%s) for -testactivationheight=name@height.", arg));
        }
    }
}

// This method was added to enable easy mining on regtest networks only.
// it will be easy to mine blocks in regtest network.
// This method can only be applied to RegTest networks by design and is called from
// `CRegTestParams::UpdateActivationParametersFromArgs`
static void MaybeEnableEasyMining(const ArgsManager& args, Consensus::Params& consensus)
{
    if (!args.IsArgSet("-easypow")) return;

    consensus.fEasyPow = true;
    consensus.fPowAllowMinDifficultyBlocks = true;


    // Delay new difficulty retargeting algorithm.
    // This will also delay have fixed subsidy as follows:
    //  else nSubsidy = 8000 * COIN;

    // Delay softforks 
    consensus.BIP34Height = 1000000;
    consensus.CSVHeight = 1000000;
}

void CRegTestParams::UpdateActivationParametersFromArgs(const ArgsManager& args)
{
    MaybeEnableEasyMining(args, consensus);
    MaybeUpdateHeights(args, consensus);

    if (!args.IsArgSet("-vbparams")) return;

    for (const std::string& strDeployment : args.GetArgs("-vbparams")) {
        std::vector<std::string> vDeploymentParams;
        boost::split(vDeploymentParams, strDeployment, boost::is_any_of(":"));
        if (vDeploymentParams.size() < 3 || 4 < vDeploymentParams.size()) {
            throw std::runtime_error("Version bits parameters malformed, expecting deployment:start:end[:min_activation_height]");
        }
        int64_t nStartTime, nTimeout;
        int min_activation_height = 0;
        if (!ParseInt64(vDeploymentParams[1], &nStartTime)) {
            throw std::runtime_error(strprintf("Invalid nStartTime (%s)", vDeploymentParams[1]));
        }
        if (!ParseInt64(vDeploymentParams[2], &nTimeout)) {
            throw std::runtime_error(strprintf("Invalid nTimeout (%s)", vDeploymentParams[2]));
        }
        if (vDeploymentParams.size() >= 4 && !ParseInt32(vDeploymentParams[3], &min_activation_height)) {
            throw std::runtime_error(strprintf("Invalid min_activation_height (%s)", vDeploymentParams[3]));
        }
        bool found = false;
        for (int j=0; j < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++j) {
            if (vDeploymentParams[0] == VersionBitsDeploymentInfo[j].name) {
                UpdateVersionBitsParameters(Consensus::DeploymentPos(j), nStartTime, nTimeout, min_activation_height);
                found = true;
                LogPrintf("Setting version bits activation parameters for %s to start=%ld, timeout=%ld, min_activation_height=%d\n", vDeploymentParams[0], nStartTime, nTimeout, min_activation_height);
                break;
            }
        }
        if (!found) {
            throw std::runtime_error(strprintf("Invalid deployment (%s)", vDeploymentParams[0]));
        }
    }
}

static std::unique_ptr<const CChainParams> globalChainParams;

const CChainParams &Params() {
    assert(globalChainParams);
    return *globalChainParams;
}

std::unique_ptr<const CChainParams> CreateChainParams(const ArgsManager& args, const std::string& chain)
{
    if (chain == CBaseChainParams::MAIN) {
        return std::unique_ptr<CChainParams>(new CMainParams());
    } else if (chain == CBaseChainParams::TESTNET) {
        return std::unique_ptr<CChainParams>(new CTestNetParams());
    } else if (chain == CBaseChainParams::SIGNET) {
        return std::unique_ptr<CChainParams>(new SigNetParams(args));
    } else if (chain == CBaseChainParams::REGTEST) {
        return std::unique_ptr<CChainParams>(new CRegTestParams(args));
    }
    throw std::runtime_error(strprintf("%s: Unknown chain %s.", __func__, chain));
}

void SelectParams(const std::string& network)
{
    SelectBaseParams(network);
    globalChainParams = CreateChainParams(gArgs, network);
}