// Copyright (c) 2009-2010 Satoshi Nakamoto

// Copyright (c) 2009-present 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 <policy/feerate.h>

#include <tinyformat.h>

#include <cstdlib>

CFeeRate::CFeeRate(const CAmount& nFeePaid, int32_t virtual_bytes)

{

    if (virtual_bytes > 0) {

        m_feerate = FeePerVSize(nFeePaid, virtual_bytes);

    } else {

        m_feerate = FeePerVSize();

    }

}

CAmount CFeeRate::GetFee(int32_t virtual_bytes) const

{

    Assume(virtual_bytes >= 0);

    if (m_feerate.IsEmpty()) { return CAmount(0);}

    CAmount nFee = CAmount(m_feerate.EvaluateFeeUp(virtual_bytes));

    if (nFee == 0 && virtual_bytes != 0 && m_feerate.fee < 0) return CAmount(-1);

    return nFee;

}

std::string CFeeRate::ToString(FeeRateFormat fee_rate_format) const

{

    const CAmount feerate_per_kvb{GetFeePerK()};

    const auto format_feerate = [](const CAmount fee_rate, const CAmount divisor, const int decimals, const std::string& currency_unit, const std::string& size_unit) {

        Assert(divisor > 0);

        const char* sign{fee_rate < 0 ? "-" : ""};

        const CAmount quotient{std::abs(fee_rate / divisor)};

        const CAmount remainder{std::abs(fee_rate % divisor)};

        return strprintf("%s%d.%0*d %s/%s", sign, quotient, decimals, remainder, currency_unit, size_unit);

    };

    switch (fee_rate_format) {

    case FeeRateFormat::BTC_KVB: return format_feerate(feerate_per_kvb, COIN, /*decimals=*/8, CURRENCY_UNIT, "kvB");

    case FeeRateFormat::SAT_VB: return format_feerate(feerate_per_kvb, 1000, /*decimals=*/3, CURRENCY_ATOM, "vB");

    } // no default case, so the compiler can warn about missing cases

    assert(false);

}