/*
 * Copyright (C) 2019-present ScyllaDB
 */

/*
 * SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
 */

#pragma once

#include <seastar/net/ipv4_address.hh>
#include <seastar/net/ipv6_address.hh>
#include "inet_address.hh"
#include "serializer.hh"

namespace ser {

/**
 * Manual definition of inet_address serialization.
 * Because inet_address was initially hardcoded to
 * ipv4, its wire format is not very forward compatible.
 *
 * Since we potentially need to communicate with older
 * version nodes, we manually define the new serial format
 * for inet_address to be:
 *
 * ipv4: 4  bytes address
 * ipv6: 4  bytes marker 0xffffffff (invalid address)
 *       16 bytes data -> address
 *
 * As long as we are restricted to ipv4 (config/user responsibility)
 * we will be able to swap gossip with older nodes. Once the
 * cluster is fully updated, user can enable ipv6 and we will be
 * happy and addressing all the molecules.
 *
 */
template<>
struct serializer<gms::inet_address> {
    template<typename Input>
    static gms::inet_address read(Input& in) {
        auto sz = deserialize(in, std::type_identity<uint32_t>());
        if (sz == std::numeric_limits<uint32_t>::max()) {
            seastar::net::ipv6_address addr(deserialize(in, std::type_identity<net::ipv6_address::ipv6_bytes>()));
            return gms::inet_address(addr);
        }
        return gms::inet_address(sz);
    }
    template<typename Output>
    static void write(Output& out, gms::inet_address v) {
        auto& addr = v.addr();
        if (addr.is_ipv6()) {
            serialize(out, std::numeric_limits<uint32_t>::max());
            auto bv = v.bytes();
            out.write(reinterpret_cast<const char *>(bv.data()), bv.size());
        } else {
            uint32_t ip = addr.as_ipv4_address().ip;
            // must write this little (or rather host) endian
            serialize(out, ip);
        }
    }
    template<typename Input>
    static void skip(Input& v) {
        read(v);
    }
};


}