// Copyright (c) 2019-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 <core_io.h>

#include <primitives/block.h>

#include <primitives/transaction_identifier.h>

#include <pubkey.h>

#include <rpc/util.h>

#include <test/fuzz/fuzz.h>

#include <uint256.h>

#include <univalue.h>

#include <util/strencodings.h>

#include <algorithm>

#include <cassert>

#include <cstdint>

#include <string>

#include <vector>

FUZZ_TARGET(hex)

{

    const std::string random_hex_string(buffer.begin(), buffer.end());

    const std::vector<unsigned char> data = ParseHex(random_hex_string);

    const std::vector<std::byte> bytes{ParseHex<std::byte>(random_hex_string)};

    assert(std::ranges::equal(std::as_bytes(std::span{data}), bytes));

    const std::string hex_data = HexStr(data);

    if (IsHex(random_hex_string)) {

        assert(ToLower(random_hex_string) == hex_data);

    }

    if (uint256::FromHex(random_hex_string)) {

        assert(random_hex_string.length() == 64);

        assert(Txid::FromHex(random_hex_string));

        assert(Wtxid::FromHex(random_hex_string));

        assert(uint256::FromUserHex(random_hex_string));

    }

    if (const auto result{uint256::FromUserHex(random_hex_string)}) {

        const auto result_string{result->ToString()}; // ToString() returns a fixed-length string without "0x" prefix

        assert(result_string.length() == 64);

        assert(IsHex(result_string));

        assert(TryParseHex(result_string));

        assert(Txid::FromHex(result_string));

        assert(Wtxid::FromHex(result_string));

        assert(uint256::FromHex(result_string));

    }

    try {

        (void)HexToPubKey(random_hex_string);

    } catch (const UniValue&) {

    }

    CBlockHeader block_header;

    (void)DecodeHexBlockHeader(block_header, random_hex_string);

    CBlock block;

    (void)DecodeHexBlk(block, random_hex_string);

}