// Copyright (c) 2024-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.

#ifndef BITCOIN_TEST_FUZZ_UTIL_WALLET_H

#define BITCOIN_TEST_FUZZ_UTIL_WALLET_H

#include <test/fuzz/FuzzedDataProvider.h>

#include <test/fuzz/fuzz.h>

#include <test/fuzz/util.h>

#include <policy/policy.h>

#include <wallet/coincontrol.h>

#include <wallet/fees.h>

#include <wallet/spend.h>

#include <wallet/test/util.h>

#include <wallet/wallet.h>

namespace wallet {

/**

 * Wraps a descriptor wallet for fuzzing.

 */

struct FuzzedWallet {

    std::shared_ptr<CWallet> wallet;

    FuzzedWallet(interfaces::Chain& chain, const std::string& name, const std::string& seed_insecure)

    {

        wallet = std::make_shared<CWallet>(&chain, name, CreateMockableWalletDatabase());

        {

            LOCK(wallet->cs_wallet);

            wallet->SetWalletFlag(WALLET_FLAG_DESCRIPTORS);

            auto height{*Assert(chain.getHeight())};

            wallet->SetLastBlockProcessed(height, chain.getBlockHash(height));

        }

        wallet->m_keypool_size = 1; // Avoid timeout in TopUp()

        assert(wallet->IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS));

        ImportDescriptors(seed_insecure);

    }

    void ImportDescriptors(const std::string& seed_insecure)

    {

        const std::vector<std::string> DESCS{

            "pkh(%s/%s/*)",

            "sh(wpkh(%s/%s/*))",

            "tr(%s/%s/*)",

            "wpkh(%s/%s/*)",

        };

        for (const std::string& desc_fmt : DESCS) {

            for (bool internal : {true, false}) {

                const auto descriptor{strprintf(tfm::RuntimeFormat{desc_fmt}, "[5aa9973a/66h/4h/2h]" + seed_insecure, int{internal})};

                FlatSigningProvider keys;

                std::string error;

                auto parsed_desc = std::move(Parse(descriptor, keys, error, /*require_checksum=*/false).at(0));

                assert(parsed_desc);

                assert(error.empty());

                assert(parsed_desc->IsRange());

                assert(parsed_desc->IsSingleType());

                assert(!keys.keys.empty());

                WalletDescriptor w_desc{std::move(parsed_desc), /*creation_time=*/0, /*range_start=*/0, /*range_end=*/1, /*next_index=*/0};

                assert(!wallet->GetDescriptorScriptPubKeyMan(w_desc));

                LOCK(wallet->cs_wallet);

                auto spk_manager{wallet->AddWalletDescriptor(w_desc, keys, /*label=*/"", internal)};

                assert(spk_manager);

                wallet->AddActiveScriptPubKeyMan(spk_manager->GetID(), *Assert(w_desc.descriptor->GetOutputType()), internal);

            }

        }

    }

    CTxDestination GetDestination(FuzzedDataProvider& fuzzed_data_provider)

    {

        auto type{fuzzed_data_provider.PickValueInArray(OUTPUT_TYPES)};

        if (fuzzed_data_provider.ConsumeBool()) {

            return *Assert(wallet->GetNewDestination(type, ""));

        } else {

            return *Assert(wallet->GetNewChangeDestination(type));

        }

    }

    CScript GetScriptPubKey(FuzzedDataProvider& fuzzed_data_provider) { return GetScriptForDestination(GetDestination(fuzzed_data_provider)); }

    void FundTx(FuzzedDataProvider& fuzzed_data_provider, CMutableTransaction tx)

    {

        // The fee of "tx" is 0, so this is the total input and output amount

        const CAmount total_amt{

            std::accumulate(tx.vout.begin(), tx.vout.end(), CAmount{}, [](CAmount t, const CTxOut& out) { return t + out.nValue; })};

        const uint32_t tx_size(GetVirtualTransactionSize(CTransaction{tx}));

        std::set<int> subtract_fee_from_outputs;

        if (fuzzed_data_provider.ConsumeBool()) {

            for (size_t i{}; i < tx.vout.size(); ++i) {

                if (fuzzed_data_provider.ConsumeBool()) {

                    subtract_fee_from_outputs.insert(i);

                }

            }

        }

        std::vector<CRecipient> recipients;

        for (size_t idx = 0; idx < tx.vout.size(); idx++) {

            const CTxOut& tx_out = tx.vout[idx];

            CTxDestination dest;

            ExtractDestination(tx_out.scriptPubKey, dest);

            CRecipient recipient = {dest, tx_out.nValue, subtract_fee_from_outputs.count(idx) == 1};

            recipients.push_back(recipient);

        }

        CCoinControl coin_control;

        coin_control.m_allow_other_inputs = fuzzed_data_provider.ConsumeBool();

        CallOneOf(

            fuzzed_data_provider, [&] { coin_control.destChange = GetDestination(fuzzed_data_provider); },

            [&] { coin_control.m_change_type.emplace(fuzzed_data_provider.PickValueInArray(OUTPUT_TYPES)); },

            [&] { /* no op (leave uninitialized) */ });

        coin_control.fAllowWatchOnly = fuzzed_data_provider.ConsumeBool();

        coin_control.m_include_unsafe_inputs = fuzzed_data_provider.ConsumeBool();

        {

            auto& r{coin_control.m_signal_bip125_rbf};

            CallOneOf(

                fuzzed_data_provider, [&] { r = true; }, [&] { r = false; }, [&] { r = std::nullopt; });

        }

        coin_control.m_feerate = CFeeRate{

            // A fee of this range should cover all cases

            fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(0, 2 * total_amt),

            tx_size,

        };

        if (fuzzed_data_provider.ConsumeBool()) {

            *coin_control.m_feerate += GetMinimumFeeRate(*wallet, coin_control, nullptr);

        }

        coin_control.fOverrideFeeRate = fuzzed_data_provider.ConsumeBool();

        // Add solving data (m_external_provider and SelectExternal)?

        int change_position{fuzzed_data_provider.ConsumeIntegralInRange<int>(-1, tx.vout.size() - 1)};

        bilingual_str error;

        // Clear tx.vout since it is not meant to be used now that we are passing outputs directly.

        // This sets us up for a future PR to completely remove tx from the function signature in favor of passing inputs directly

        tx.vout.clear();

        (void)FundTransaction(*wallet, tx, recipients, change_position, /*lockUnspents=*/false, coin_control);

    }

};

}

#endif // BITCOIN_TEST_FUZZ_UTIL_WALLET_H