/*
 * This file is open source software, licensed to you under the terms
 * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
 * distributed with this work for additional information regarding copyright
 * ownership.  You may not use this file except in compliance with the License.
 *
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
/*
 * Copyright (C) 2016 ScyllaDB.
 */

#ifdef SEASTAR_MODULE
module;
#endif

#include <algorithm>
#include <ostream>
#include <arpa/inet.h>
#include <boost/functional/hash.hpp>
#include <fmt/ostream.h>

#ifdef SEASTAR_MODULE
module seastar;
#else
#include <seastar/net/inet_address.hh>
#include <seastar/net/socket_defs.hh>
#include <seastar/net/dns.hh>
#include <seastar/net/ip.hh>
#include <seastar/core/reactor.hh>
#include <seastar/core/print.hh>
#endif

static_assert(std::is_nothrow_default_constructible_v<seastar::net::ipv4_address>);
static_assert(std::is_nothrow_copy_constructible_v<seastar::net::ipv4_address>);
static_assert(std::is_nothrow_move_constructible_v<seastar::net::ipv4_address>);

static_assert(std::is_nothrow_default_constructible_v<seastar::net::ipv6_address>);
static_assert(std::is_nothrow_copy_constructible_v<seastar::net::ipv6_address>);
static_assert(std::is_nothrow_move_constructible_v<seastar::net::ipv6_address>);

static_assert(std::is_nothrow_default_constructible_v<seastar::net::inet_address>);
static_assert(std::is_nothrow_copy_constructible_v<seastar::net::inet_address>);
static_assert(std::is_nothrow_move_constructible_v<seastar::net::inet_address>);

seastar::net::inet_address::inet_address() noexcept
                : inet_address(::in6_addr{})
{}

seastar::net::inet_address::inet_address(family f) noexcept
                : _in_family(f)
{
    memset(&_in6, 0, sizeof(_in6));
}

seastar::net::inet_address::inet_address(::in_addr i) noexcept
                : _in_family(family::INET), _in(i) {
}

seastar::net::inet_address::inet_address(::in6_addr i, uint32_t scope) noexcept
                : _in_family(family::INET6), _in6(i), _scope(scope) {
}

std::optional<seastar::net::inet_address> 
seastar::net::inet_address::parse_numerical(const sstring& addr) {
    inet_address in;
    if (::inet_pton(AF_INET, addr.c_str(), &in._in)) {
        in._in_family = family::INET;
        return in;
    }
    auto i = addr.find_last_of('%');
    if (i != sstring::npos) {
        auto ext = addr.substr(i + 1);
        auto src = addr.substr(0, i);
        auto res = parse_numerical(src);

        if (res) {
            uint32_t index = std::numeric_limits<uint32_t>::max();
            try {
                index = std::stoul(ext);
            } catch (...) {
            }
            for (auto& nwif : engine().net().network_interfaces()) {
                if (nwif.index() == index || nwif.name() == ext || nwif.display_name() == ext) {
                    res->_scope = nwif.index();
                    break;
                }
            }
            return *res;
        }
    }
    if (::inet_pton(AF_INET6, addr.c_str(), &in._in6)) {
        in._in_family = family::INET6;
        return in;
    }
    return {};
}

seastar::net::inet_address::inet_address(const sstring& addr)
                : inet_address([&addr] {
    auto res = parse_numerical(addr);                        
    if (res) {
        return std::move(*res);
    }
    throw std::invalid_argument(addr);
}())
{}

seastar::net::inet_address::inet_address(const ipv4_address& in) noexcept
    : inet_address(::in_addr{hton(in.ip)})
{}

seastar::net::inet_address::inet_address(const ipv6_address& in, uint32_t scope) noexcept
    : inet_address([&] {
        ::in6_addr tmp;
        std::copy(in.bytes().begin(), in.bytes().end(), tmp.s6_addr);
        return tmp;
    }(), scope)
{}

seastar::net::ipv4_address seastar::net::inet_address::as_ipv4_address() const {
    in_addr in = *this;
    return ipv4_address(ntoh(in.s_addr));
}

seastar::net::ipv6_address seastar::net::inet_address::as_ipv6_address() const noexcept {
    in6_addr in6 = *this;
    return ipv6_address{in6};
}

bool seastar::net::inet_address::operator==(const inet_address& o) const noexcept {
    if (o._in_family != _in_family) {
        return false;
    }
    switch (_in_family) {
    case family::INET:
        return _in.s_addr == o._in.s_addr;
    case family::INET6:
        return std::equal(std::begin(_in6.s6_addr), std::end(_in6.s6_addr), std::begin(o._in6.s6_addr));
    default:
        return false;
    }
}

seastar::net::inet_address::operator ::in_addr() const {
    if (_in_family != family::INET) {
        if (IN6_IS_ADDR_V4MAPPED(&_in6)) {
            ::in_addr in;
            in.s_addr = _in6.s6_addr32[3];
            return in;
        }
        throw std::invalid_argument("Not an IPv4 address");
    }
    return _in;
}

seastar::net::inet_address::operator ::in6_addr() const noexcept {
    if (_in_family == family::INET) {
        in6_addr in6 = IN6ADDR_ANY_INIT;
        in6.s6_addr32[2] = htonl(0xffff);
        in6.s6_addr32[3] = _in.s_addr;
        return in6;
    }
    return _in6;
}

seastar::net::inet_address::operator seastar::net::ipv6_address() const noexcept {
    return as_ipv6_address();
}

size_t seastar::net::inet_address::size() const noexcept {
    switch (_in_family) {
    case family::INET:
        return sizeof(::in_addr);
    case family::INET6:
        return sizeof(::in6_addr);
    default:
        return 0;
    }
}

const void * seastar::net::inet_address::data() const noexcept {
    return &_in;
}

bool seastar::net::inet_address::is_loopback() const noexcept {
    switch (_in_family) {
    case family::INET:
        return (net::ntoh(_in.s_addr) & 0xff000000) == 0x7f000000;
    case family::INET6:
        return std::equal(std::begin(_in6.s6_addr), std::end(_in6.s6_addr), std::begin(::in6addr_loopback.s6_addr));
    default:
        return false;
    }
}

bool seastar::net::inet_address::is_addr_any() const noexcept {
    switch (_in_family) {
    case family::INET:
        return _in.s_addr == INADDR_ANY;
    case family::INET6:
        return std::equal(std::begin(_in6.s6_addr), std::end(_in6.s6_addr), std::begin(::in6addr_any.s6_addr));
    default:
        return false;
    }
}

seastar::net::ipv6_address::ipv6_address(const ::in6_addr& in) noexcept {
    std::copy(std::begin(in.s6_addr), std::end(in.s6_addr), ip.begin());
}

seastar::net::ipv6_address::ipv6_address(const ipv6_bytes& in) noexcept
    : ip(in)
{}

seastar::net::ipv6_address::ipv6_address(const ipv6_addr& addr) noexcept
    : ipv6_address(addr.ip)
{}

seastar::net::ipv6_address::ipv6_address() noexcept
    : ipv6_address(::in6addr_any)
{}

seastar::net::ipv6_address::ipv6_address(const std::string& addr) {
    if (!::inet_pton(AF_INET6, addr.c_str(), ip.data())) {
        throw std::runtime_error(fmt::format("Wrong format for IPv6 address {}. Please ensure it's in colon-hex format",
                                        addr));
    }
}

seastar::net::ipv6_address seastar::net::ipv6_address::read(const char* s) noexcept {
    auto* b = reinterpret_cast<const uint8_t *>(s);
    ipv6_address in;
    std::copy(b, b + ipv6_address::size(), in.ip.begin());
    return in;
}

seastar::net::ipv6_address seastar::net::ipv6_address::consume(const char*& p) noexcept {
    auto res = read(p);
    p += size();
    return res;
}

void seastar::net::ipv6_address::write(char* p) const noexcept {
    std::copy(ip.begin(), ip.end(), p);
}

void seastar::net::ipv6_address::produce(char*& p) const noexcept {
    write(p);
    p += size();
}

bool seastar::net::ipv6_address::is_unspecified() const noexcept {
    return std::all_of(ip.begin(), ip.end(), [](uint8_t b) { return b == 0; });
}

std::ostream& seastar::net::operator<<(std::ostream& os, const ipv4_address& a) {
    auto ip = a.ip;
    fmt::print(os, "{:d}.{:d}.{:d}.{:d}",
            (ip >> 24) & 0xff,
            (ip >> 16) & 0xff,
            (ip >> 8) & 0xff,
            (ip >> 0) & 0xff);
    return os;
}

std::ostream& seastar::net::operator<<(std::ostream& os, const ipv6_address& a) {
    char buffer[64];
    return os << ::inet_ntop(AF_INET6, a.ip.data(), buffer, sizeof(buffer));
}

seastar::ipv6_addr::ipv6_addr(const ipv6_bytes& b, uint16_t p) noexcept
    : ip(b), port(p)
{}

seastar::ipv6_addr::ipv6_addr(uint16_t p) noexcept
    : ipv6_addr(net::inet_address(), p)
{}

seastar::ipv6_addr::ipv6_addr(const ::in6_addr& in6, uint16_t p) noexcept
    : ipv6_addr(net::ipv6_address(in6).bytes(), p)
{}

seastar::ipv6_addr::ipv6_addr(const std::string& s)
    : ipv6_addr([&] {
        auto lc = s.find_last_of(']');
        auto cp = s.find_first_of(':', lc);
        auto port = cp != std::string::npos ? std::stoul(s.substr(cp + 1)) : 0;
        auto ss = lc != std::string::npos ? s.substr(1, lc - 1) : s;
        return ipv6_addr(net::ipv6_address(ss).bytes(), uint16_t(port));
    }())
{}

seastar::ipv6_addr::ipv6_addr(const std::string& s, uint16_t p)
    : ipv6_addr(net::ipv6_address(s).bytes(), p)
{}

seastar::ipv6_addr::ipv6_addr(const net::inet_address& i, uint16_t p) noexcept
    : ipv6_addr(i.as_ipv6_address().bytes(), p)
{}

seastar::ipv6_addr::ipv6_addr(const ::sockaddr_in6& s) noexcept
    : ipv6_addr(s.sin6_addr, net::ntoh(s.sin6_port))
{}

seastar::ipv6_addr::ipv6_addr(const socket_address& s) noexcept
    : ipv6_addr(s.as_posix_sockaddr_in6())
{}

bool seastar::ipv6_addr::is_ip_unspecified() const noexcept {
    return std::all_of(ip.begin(), ip.end(), [](uint8_t b) { return b == 0; });
}


seastar::net::inet_address seastar::socket_address::addr() const noexcept {
    switch (family()) {
    case AF_INET:
        return net::inet_address(as_posix_sockaddr_in().sin_addr);
    case AF_INET6:
        return net::inet_address(as_posix_sockaddr_in6().sin6_addr, as_posix_sockaddr_in6().sin6_scope_id);
    default:
        return net::inet_address();
    }
}

::in_port_t seastar::socket_address::port() const noexcept {
    return net::ntoh(u.in.sin_port);
}

bool seastar::socket_address::is_wildcard() const noexcept {
    switch (family()) {
    case AF_INET: {
            ipv4_addr addr(*this);
            return addr.is_ip_unspecified() && addr.is_port_unspecified();
        }
    default:
    case AF_INET6: {
            ipv6_addr addr(*this);
            return addr.is_ip_unspecified() && addr.is_port_unspecified();
        }
    case AF_UNIX:
        return length() <= sizeof(::sa_family_t);
    }
}

std::ostream& seastar::net::operator<<(std::ostream& os, const inet_address& addr) {
    char buffer[64];
    os << inet_ntop(int(addr.in_family()), addr.data(), buffer, sizeof(buffer));
    if (addr.scope() != inet_address::invalid_scope) {
        os << "%" << addr.scope();
    }
    return os;
}

std::ostream& seastar::net::operator<<(std::ostream& os, const inet_address::family& f) {
    switch (f) {
    case inet_address::family::INET:
        os << "INET";
        break;
    case inet_address::family::INET6:
        os << "INET6";
        break;
    default:
        break;
    }
    return os;
}

std::ostream& seastar::operator<<(std::ostream& os, const ipv4_addr& a) {
    return os << seastar::socket_address(a);
}

std::ostream& seastar::operator<<(std::ostream& os, const ipv6_addr& a) {
    return os << seastar::socket_address(a);
}

size_t std::hash<seastar::net::inet_address>::operator()(const seastar::net::inet_address& a) const {
    switch (a.in_family()) {
    case seastar::net::inet_address::family::INET:
        return std::hash<seastar::net::ipv4_address>()(a.as_ipv4_address());
    case seastar::net::inet_address::family::INET6:
        return std::hash<seastar::net::ipv6_address>()(a.as_ipv6_address());
    default:
        return 0;
    }
}

size_t std::hash<seastar::net::ipv6_address>::operator()(const seastar::net::ipv6_address& a) const {
    return boost::hash_range(a.ip.begin(), a.ip.end());
}

size_t std::hash<seastar::ipv4_addr>::operator()(const seastar::ipv4_addr& x) const {
    size_t h = x.ip;
    boost::hash_combine(h, x.port);
    return h;
}
