// 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 <addrman.h>

#include <consensus/consensus.h>

#include <net.h>

#include <net_processing.h>

#include <node/warnings.h>

#include <protocol.h>

#include <script/script.h>

#include <sync.h>

#include <test/fuzz/FuzzedDataProvider.h>

#include <test/fuzz/fuzz.h>

#include <test/fuzz/util.h>

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

#include <test/util/mining.h>

#include <test/util/net.h>

#include <test/util/setup_common.h>

#include <test/util/validation.h>

#include <util/time.h>

#include <validationinterface.h>

#include <ios>

#include <string>

#include <utility>

#include <vector>

namespace {

const TestingSetup* g_setup;

void initialize()

{

    static const auto testing_setup = MakeNoLogFileContext<const TestingSetup>(

        /*chain_type=*/ChainType::REGTEST);

    g_setup = testing_setup.get();

}

} // namespace

FUZZ_TARGET(p2p_handshake, .init = ::initialize)

{

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

    ConnmanTestMsg& connman = static_cast<ConnmanTestMsg&>(*g_setup->m_node.connman);

    auto& chainman = static_cast<TestChainstateManager&>(*g_setup->m_node.chainman);

    SetMockTime(1610000000); // any time to successfully reset ibd

    chainman.ResetIbd();

    node::Warnings warnings{};

    NetGroupManager netgroupman{{}};

    AddrMan addrman{netgroupman, /*deterministic=*/true, 0};

    auto peerman = PeerManager::make(connman, addrman,

                                     /*banman=*/nullptr, chainman,

                                     *g_setup->m_node.mempool, warnings,

                                     PeerManager::Options{

                                         .reconcile_txs = true,

                                         .deterministic_rng = true,

                                     });

    connman.SetMsgProc(peerman.get());

    LOCK(NetEventsInterface::g_msgproc_mutex);

    std::vector<CNode*> peers;

    const auto num_peers_to_add = fuzzed_data_provider.ConsumeIntegralInRange(1, 3);

    for (int i = 0; i < num_peers_to_add; ++i) {

        peers.push_back(ConsumeNodeAsUniquePtr(fuzzed_data_provider, i).release());

        connman.AddTestNode(*peers.back());

        peerman->InitializeNode(

            *peers.back(),

            static_cast<ServiceFlags>(fuzzed_data_provider.ConsumeIntegral<uint64_t>()));

    }

    LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 100)

    {

        CNode& connection = *PickValue(fuzzed_data_provider, peers);

        if (connection.fDisconnect || connection.fSuccessfullyConnected) {

            // Skip if the connection was disconnected or if the version

            // handshake was already completed.

            continue;

        }

        SetMockTime(GetTime() +

                    fuzzed_data_provider.ConsumeIntegralInRange<int64_t>(

                        -std::chrono::seconds{10min}.count(), // Allow mocktime to go backwards slightly

                        std::chrono::seconds{TIMEOUT_INTERVAL}.count()));

        CSerializedNetMsg net_msg;

        net_msg.m_type = PickValue(fuzzed_data_provider, ALL_NET_MESSAGE_TYPES);

        net_msg.data = ConsumeRandomLengthByteVector(fuzzed_data_provider, MAX_PROTOCOL_MESSAGE_LENGTH);

        connman.FlushSendBuffer(connection);

        (void)connman.ReceiveMsgFrom(connection, std::move(net_msg));

        bool more_work{true};

        while (more_work) {

            connection.fPauseSend = false;

            try {

                more_work = connman.ProcessMessagesOnce(connection);

            } catch (const std::ios_base::failure&) {

            }

            peerman->SendMessages(&connection);

        }

    }

    g_setup->m_node.connman->StopNodes();

}