/*
 * Copyright (C) 2008 Collin Jackson  <collinj@webkit.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <optional>
#include <wtf/Forward.h>
#include <wtf/Variant.h>

#if OS(WINDOWS)
#include <winsock2.h>
#include <ws2tcpip.h>
#else
#include <netinet/in.h>
#endif

namespace WebCore {

class IPAddress {
public:
    static std::optional<IPAddress> fromSockAddrIn6(const struct sockaddr_in6&);
    explicit IPAddress(const struct in_addr& address)
        : m_address(address)
    {
    }

    explicit IPAddress(const struct in6_addr& address)
        : m_address(address)
    {
    }

    bool isIPv4() const { return std::holds_alternative<struct in_addr>(m_address); }
    bool isIPv6() const { return std::holds_alternative<struct in6_addr>(m_address); }

    const struct in_addr& ipv4Address() const { return std::get<struct in_addr>(m_address); }
    const struct in6_addr& ipv6Address() const { return std::get<struct in6_addr>(m_address); }

private:
    std::variant<struct in_addr, struct in6_addr> m_address;
};

enum class DNSError { Unknown, CannotResolve, Cancelled };

using DNSAddressesOrError = Expected<Vector<IPAddress>, DNSError>;
using DNSCompletionHandler = CompletionHandler<void(DNSAddressesOrError&&)>;

WEBCORE_EXPORT void prefetchDNS(const String& hostname);
WEBCORE_EXPORT void resolveDNS(const String& hostname, uint64_t identifier, DNSCompletionHandler&&);
WEBCORE_EXPORT void stopResolveDNS(uint64_t identifier);

inline std::optional<IPAddress> IPAddress::fromSockAddrIn6(const struct sockaddr_in6& address)
{
    if (address.sin6_family == AF_INET6)
        return IPAddress { address.sin6_addr };
    if (address.sin6_family == AF_INET)
        return IPAddress {reinterpret_cast<const struct sockaddr_in&>(address).sin_addr };
    return { };
}

}