// Copyright (c) 2020-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 <kernel/mempool_entry.h>

#include <policy/fees.h>

#include <policy/fees_args.h>

#include <primitives/transaction.h>

#include <streams.h>

#include <test/fuzz/FuzzedDataProvider.h>

#include <test/fuzz/fuzz.h>

#include <test/fuzz/util.h>

#include <test/fuzz/util/mempool.h>

#include <test/util/setup_common.h>

#include <memory>

#include <optional>

#include <vector>

namespace {

const BasicTestingSetup* g_setup;

} // namespace

void initialize_policy_estimator()

{

    static const auto testing_setup = MakeNoLogFileContext<>();

    g_setup = testing_setup.get();

}

FUZZ_TARGET(policy_estimator, .init = initialize_policy_estimator)

{

    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());

    bool good_data{true};

    CBlockPolicyEstimator block_policy_estimator{FeeestPath(*g_setup->m_node.args), DEFAULT_ACCEPT_STALE_FEE_ESTIMATES};

    uint32_t current_height{0};

    const auto advance_height{

        [&] { current_height = fuzzed_data_provider.ConsumeIntegralInRange<decltype(current_height)>(current_height, 1 << 30); },

    };

    advance_height();

    LIMITED_WHILE(good_data && fuzzed_data_provider.ConsumeBool(), 10'000)

    {

        CallOneOf(

            fuzzed_data_provider,

            [&] {

                const std::optional<CMutableTransaction> mtx = ConsumeDeserializable<CMutableTransaction>(fuzzed_data_provider, TX_WITH_WITNESS);

                if (!mtx) {

                    good_data = false;

                    return;

                }

                const CTransaction tx{*mtx};

                const auto entry{ConsumeTxMemPoolEntry(fuzzed_data_provider, tx, current_height)};

                const auto tx_submitted_in_package = fuzzed_data_provider.ConsumeBool();

                const auto tx_has_mempool_parents = fuzzed_data_provider.ConsumeBool();

                const auto tx_info = NewMempoolTransactionInfo(entry.GetSharedTx(), entry.GetFee(),

                                                               entry.GetTxSize(), entry.GetHeight(),

                                                               /*mempool_limit_bypassed=*/false,

                                                               tx_submitted_in_package,

                                                               /*chainstate_is_current=*/true,

                                                               tx_has_mempool_parents);

                block_policy_estimator.processTransaction(tx_info);

                if (fuzzed_data_provider.ConsumeBool()) {

                    (void)block_policy_estimator.removeTx(tx.GetHash());

                }

            },

            [&] {

                std::list<CTxMemPoolEntry> mempool_entries;

                LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 10000)

                {

                    const std::optional<CMutableTransaction> mtx = ConsumeDeserializable<CMutableTransaction>(fuzzed_data_provider, TX_WITH_WITNESS);

                    if (!mtx) {

                        good_data = false;

                        break;

                    }

                    const CTransaction tx{*mtx};

                    mempool_entries.emplace_back(CTxMemPoolEntry::ExplicitCopy, ConsumeTxMemPoolEntry(fuzzed_data_provider, tx, current_height));

                }

                std::vector<RemovedMempoolTransactionInfo> txs;

                txs.reserve(mempool_entries.size());

                for (const CTxMemPoolEntry& mempool_entry : mempool_entries) {

                    txs.emplace_back(mempool_entry);

                }

                advance_height();

                block_policy_estimator.processBlock(txs, current_height);

            },

            [&] {

                (void)block_policy_estimator.removeTx(Txid::FromUint256(ConsumeUInt256(fuzzed_data_provider)));

            },

            [&] {

                block_policy_estimator.FlushUnconfirmed();

            });

        (void)block_policy_estimator.estimateFee(fuzzed_data_provider.ConsumeIntegral<int>());

        EstimationResult result;

        auto conf_target = fuzzed_data_provider.ConsumeIntegral<int>();

        auto success_threshold = fuzzed_data_provider.ConsumeFloatingPoint<double>();

        auto horizon = fuzzed_data_provider.PickValueInArray(ALL_FEE_ESTIMATE_HORIZONS);

        auto* result_ptr = fuzzed_data_provider.ConsumeBool() ? &result : nullptr;

        (void)block_policy_estimator.estimateRawFee(conf_target, success_threshold, horizon, result_ptr);

        FeeCalculation fee_calculation;

        conf_target = fuzzed_data_provider.ConsumeIntegral<int>();

        auto* fee_calc_ptr = fuzzed_data_provider.ConsumeBool() ? &fee_calculation : nullptr;

        auto conservative = fuzzed_data_provider.ConsumeBool();

        (void)block_policy_estimator.estimateSmartFee(conf_target, fee_calc_ptr, conservative);

        (void)block_policy_estimator.HighestTargetTracked(fuzzed_data_provider.PickValueInArray(ALL_FEE_ESTIMATE_HORIZONS));

    }

    {

        FuzzedFileProvider fuzzed_file_provider{fuzzed_data_provider};

        AutoFile fuzzed_auto_file{fuzzed_file_provider.open()};

        block_policy_estimator.Write(fuzzed_auto_file);

        block_policy_estimator.Read(fuzzed_auto_file);

        (void)fuzzed_auto_file.fclose();

    }

}