// 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 <netgroup.h>

#include <test/fuzz/fuzz.h>

#include <util/asmap.h>

#include <util/strencodings.h>

#include <cstdint>

#include <vector>

using namespace util::hex_literals;

//! asmap code that consumes nothing

static const std::vector<std::byte> IPV6_PREFIX_ASMAP = {};

//! asmap code that consumes the 96 prefix bits of ::ffff:0/96 (IPv4-in-IPv6 map)

static const auto IPV4_PREFIX_ASMAP = "fb03ec0fb03fc0fe00fb03ec0fb03fc0fe00fb03ec0fb0fffffeff"_hex_v;

FUZZ_TARGET(asmap)

{

    // Encoding: [7 bits: asmap size] [1 bit: ipv6?] [3-130 bytes: asmap] [4 or 16 bytes: addr]

    if (buffer.size() < 1 + 3 + 4) return;

  Branch (25:9): [True: 0, False: 0]

    int asmap_size = 3 + (buffer[0] & 127);

    bool ipv6 = buffer[0] & 128;

    const size_t addr_size = ipv6 ? ADDR_IPV6_SIZE : ADDR_IPV4_SIZE;

  Branch (28:30): [True: 0, False: 0]

    if (buffer.size() < size_t(1 + asmap_size + addr_size)) return;

  Branch (29:9): [True: 0, False: 0]

    std::vector<std::byte> asmap = ipv6 ? IPV6_PREFIX_ASMAP : IPV4_PREFIX_ASMAP;

  Branch (30:36): [True: 0, False: 0]

    std::ranges::copy(std::as_bytes(buffer.subspan(1, asmap_size)), std::back_inserter(asmap));

    if (!CheckStandardAsmap(asmap)) return;

  Branch (32:9): [True: 0, False: 0]

    const uint8_t* addr_data = buffer.data() + 1 + asmap_size;

    CNetAddr net_addr;

    if (ipv6) {

  Branch (36:9): [True: 0, False: 0]

        assert(addr_size == ADDR_IPV6_SIZE);

  Branch (37:9): [True: 0, False: 0]

        net_addr.SetLegacyIPv6({addr_data, addr_size});

    } else {

        assert(addr_size == ADDR_IPV4_SIZE);

  Branch (40:9): [True: 0, False: 0]

        in_addr ipv4;

        memcpy(&ipv4, addr_data, addr_size);

        net_addr.SetIP(CNetAddr{ipv4});

    }

    auto netgroupman{NetGroupManager::WithEmbeddedAsmap(asmap)};

    (void)netgroupman.GetMappedAS(net_addr);

}