/*
 *  Copyright (c) 2021, The OpenThread Authors.
 *  All rights reserved.
 *
 *  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.
 *  3. Neither the name of the copyright holder nor the
 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT HOLDER 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.
 */

#ifndef OT_POSIX_PLATFORM_IP6_UTILS_HPP_
#define OT_POSIX_PLATFORM_IP6_UTILS_HPP_

#include "openthread-posix-config.h"
#include "platform-posix.h"

#include <arpa/inet.h>
#include <stdlib.h>
#include <string.h>

#include <openthread/ip6.h>

namespace ot {
namespace Posix {
namespace Ip6Utils {

/**
 * Indicates whether or not the IPv6 address scope is Link-Local.
 *
 * @param[in] aAddress   The IPv6 address to check.
 *
 * @retval TRUE   If the IPv6 address scope is Link-Local.
 * @retval FALSE  If the IPv6 address scope is not Link-Local.
 *
 */
inline bool IsIp6AddressLinkLocal(const otIp6Address &aAddress)
{
    return (aAddress.mFields.m8[0] == 0xfe) && ((aAddress.mFields.m8[1] & 0xc0) == 0x80);
}

/**
 * Indicates whether or not the IPv6 address is multicast.
 *
 * @param[in] aAddress   The IPv6 address to check.
 *
 * @retval TRUE   If the IPv6 address scope is multicast.
 * @retval FALSE  If the IPv6 address scope is not multicast.
 *
 */
inline bool IsIp6AddressMulticast(const otIp6Address &aAddress) { return (aAddress.mFields.m8[0] == 0xff); }

/**
 * Indicates whether or not the IPv6 address is unspecified.
 *
 * @param[in] aAddress   The IPv6 address to check.
 *
 * @retval TRUE   If the IPv6 address scope is unspecified.
 * @retval FALSE  If the IPv6 address scope is not unspecified.
 *
 */
inline bool IsIp6AddressUnspecified(const otIp6Address &aAddress) { return otIp6IsAddressUnspecified(&aAddress); }

/**
 * Copies the IPv6 address bytes into a given buffer.
 *
 * @param[in] aAddress  The IPv6 address to copy.
 * @param[in] aBuffer   A pointer to buffer to copy the address to.
 *
 */
inline void CopyIp6AddressTo(const otIp6Address &aAddress, void *aBuffer)
{
    memcpy(aBuffer, &aAddress, sizeof(otIp6Address));
}

/**
 * Reads and set the the IPv6 address bytes from a given buffer.
 *
 * @param[in] aBuffer    A pointer to buffer to read from.
 * @param[out] aAddress  A reference to populate with the read IPv6 address.
 *
 */
inline void ReadIp6AddressFrom(const void *aBuffer, otIp6Address &aAddress)
{
    memcpy(&aAddress, aBuffer, sizeof(otIp6Address));
}

/**
 * This utility class converts binary IPv6 address to text format.
 *
 */
class Ip6AddressString
{
public:
    /**
     * The constructor of this converter.
     *
     * @param[in]   aAddress    A pointer to a buffer holding an IPv6 address.
     *
     */
    Ip6AddressString(const void *aAddress)
    {
        VerifyOrDie(inet_ntop(AF_INET6, aAddress, mBuffer, sizeof(mBuffer)) != nullptr, OT_EXIT_ERROR_ERRNO);
    }

    /**
     * Returns the string as a null-terminated C string.
     *
     * @returns The null-terminated C string.
     *
     */
    const char *AsCString(void) const { return mBuffer; }

private:
    char mBuffer[INET6_ADDRSTRLEN];
};

} // namespace Ip6Utils
} // namespace Posix
} // namespace ot

#endif // OT_POSIX_PLATFORM_IP6_UTILS_HPP_