// 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 <netaddress.h>

#include <util/asmap.h>

#include <test/fuzz/fuzz.h>

#include <cstdint>

#include <optional>

#include <vector>

#include <cassert>

FUZZ_TARGET(asmap_direct)

{

    // Encoding: [asmap using 1 bit / byte] 0xFF [addr using 1 bit / byte]

    std::optional<size_t> sep_pos_opt;

    for (size_t pos = 0; pos < buffer.size(); ++pos) {

        uint8_t x = buffer[pos];

        if ((x & 0xFE) == 0) continue;

        if (x == 0xFF) {

            if (sep_pos_opt) return;

            sep_pos_opt = pos;

        } else {

            return;

        }

    }

    if (!sep_pos_opt) return; // Needs exactly 1 separator

    const size_t sep_pos{sep_pos_opt.value()};

    if (buffer.size() - sep_pos - 1 > 128) return; // At most 128 bits in IP address

    // Checks on asmap

    std::vector<bool> asmap(buffer.begin(), buffer.begin() + sep_pos);

    if (SanityCheckASMap(asmap, buffer.size() - 1 - sep_pos)) {

        // Verify that for valid asmaps, no prefix (except up to 7 zero padding bits) is valid.

        std::vector<bool> asmap_prefix = asmap;

        while (!asmap_prefix.empty() && asmap_prefix.size() + 7 > asmap.size() && asmap_prefix.back() == false) {

            asmap_prefix.pop_back();

        }

        while (!asmap_prefix.empty()) {

            asmap_prefix.pop_back();

            assert(!SanityCheckASMap(asmap_prefix, buffer.size() - 1 - sep_pos));

        }

        // No address input should trigger assertions in interpreter

        std::vector<bool> addr(buffer.begin() + sep_pos + 1, buffer.end());

        (void)Interpret(asmap, addr);

    }

}