// Copyright (c) 2015 The Bitcoin Core developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "chain.h"
#include "chainparams.h"
#include "pow.h"
#include "random.h"
#include "util.h"
#include "test/test_dash.h"

#include <boost/test/unit_test.hpp>

using namespace std;

BOOST_FIXTURE_TEST_SUITE(pow_tests, BasicTestingSetup)

/* Test calculation of next difficulty target with DGW */
BOOST_AUTO_TEST_CASE(get_next_work)
{
    SelectParams(CBaseChainParams::MAIN);
    const Consensus::Params& params = Params().GetConsensus();

    CBlockIndex pindexLast;
    pindexLast.nHeight = 123456;
    pindexLast.nTime = 1408732489;  // Block #123456
    pindexLast.nBits = 0x1b1418d4;
    CBlockHeader pblock;
    pblock.nTime = 1408732505; // Block #123457
    BOOST_CHECK_EQUAL(GetNextWorkRequired(&pindexLast, &pblock, params), 0x1b06b2f1); // Block #123457 has 0x1d00d86a
}

/* Test the constraint on the upper bound for next work */
// BOOST_AUTO_TEST_CASE(get_next_work_pow_limit)
// {
//     SelectParams(CBaseChainParams::MAIN);
//     const Consensus::Params& params = Params().GetConsensus();

//     int64_t nLastRetargetTime = 1231006505; // Block #0
//     CBlockIndex pindexLast;
//     pindexLast.nHeight = 2015;
//     pindexLast.nTime = 1233061996;  // Block #2015
//     pindexLast.nBits = 0x1d00ffff;
//     BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params), 0x1d00ffff);
// }

/* Test the constraint on the lower bound for actual time taken */
// BOOST_AUTO_TEST_CASE(get_next_work_lower_limit_actual)
// {
//     SelectParams(CBaseChainParams::MAIN);
//     const Consensus::Params& params = Params().GetConsensus();

//     int64_t nLastRetargetTime = 1279008237; // Block #66528
//     CBlockIndex pindexLast;
//     pindexLast.nHeight = 68543;
//     pindexLast.nTime = 1279297671;  // Block #68543
//     pindexLast.nBits = 0x1c05a3f4;
//     BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params), 0x1c0168fd);
// }

/* Test the constraint on the upper bound for actual time taken */
// BOOST_AUTO_TEST_CASE(get_next_work_upper_limit_actual)
// {
//     SelectParams(CBaseChainParams::MAIN);
//     const Consensus::Params& params = Params().GetConsensus();

//     int64_t nLastRetargetTime = 1263163443; // NOTE: Not an actual block time
//     CBlockIndex pindexLast;
//     pindexLast.nHeight = 46367;
//     pindexLast.nTime = 1269211443;  // Block #46367
//     pindexLast.nBits = 0x1c387f6f;
//     BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params), 0x1d00e1fd);
// }

BOOST_AUTO_TEST_CASE(GetBlockProofEquivalentTime_test)
{
    SelectParams(CBaseChainParams::MAIN);
    const Consensus::Params& params = Params().GetConsensus();

    std::vector<CBlockIndex> blocks(10000);
    for (int i = 0; i < 10000; i++) {
        blocks[i].pprev = i ? &blocks[i - 1] : NULL;
        blocks[i].nHeight = i;
        blocks[i].nTime = 1269211443 + i * params.nPowTargetSpacing;
        blocks[i].nBits = 0x207fffff; /* target 0x7fffff000... */
        blocks[i].nChainWork = i ? blocks[i - 1].nChainWork + GetBlockProof(blocks[i - 1]) : arith_uint256(0);
    }

    for (int j = 0; j < 1000; j++) {
        CBlockIndex *p1 = &blocks[GetRand(10000)];
        CBlockIndex *p2 = &blocks[GetRand(10000)];
        CBlockIndex *p3 = &blocks[GetRand(10000)];

        int64_t tdiff = GetBlockProofEquivalentTime(*p1, *p2, *p3, params);
        BOOST_CHECK_EQUAL(tdiff, p1->GetBlockTime() - p2->GetBlockTime());
    }
}

BOOST_AUTO_TEST_SUITE_END()
