/*
 * Copyright (c) 2008 University of Washington
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#ifndef IPV4_INTERFACE_ADDRESS_H
#define IPV4_INTERFACE_ADDRESS_H

#include "ns3/ipv4-address.h"

#include <ostream>
#include <stdint.h>

namespace ns3
{

/**
 * \ingroup address
 * \ingroup ipv4
 *
 * \brief a class to store IPv4 address information on an interface
 *
 * Corresponds to Linux struct in_ifaddr.  A list of these addresses
 * is stored in Ipv4Interface.  This class is modelled after how current
 * Linux handles IP aliasing for IPv4.  Notably, aliasing of IPv4
 * interfaces (e.g., "eth0:1") is not used, and instead an interface
 * is assigned possibly multiple addresses, with each address being
 * classified as being primary and secondary.  See the iproute2
 * documentation for this distinction.
 */
class Ipv4InterfaceAddress
{
  public:
    /**
     * \enum InterfaceAddressScope_e
     * \brief Address scope.
     */
    enum InterfaceAddressScope_e
    {
        HOST,
        LINK,
        GLOBAL
    };

    Ipv4InterfaceAddress();

    /**
     * \brief Configure local address, mask and broadcast address
     * \param local the local address
     * \param mask the network mask
     */
    Ipv4InterfaceAddress(Ipv4Address local, Ipv4Mask mask);
    /**
     * Copy constructor
     * \param o the object to copy
     */
    Ipv4InterfaceAddress(const Ipv4InterfaceAddress& o);

    /**
     * \brief Set local address
     * \param local the address
     *
     * \note Functionally identical to `Ipv4InterfaceAddress::SetAddress`.
     *       The method corresponds to the linux variable in_ifaddr.ifa_local
     *       `Ipv4InterfaceAddress::SetAddress` is to be preferred.
     */
    void SetLocal(Ipv4Address local);

    /**
     * \brief Set local address
     * \param address the address
     *
     * \note Functially identical to `Ipv4InterfaceAddress::SetLocal`.
     *       This function is consistent with `Ipv6InterfaceAddress::SetAddress`.
     */
    void SetAddress(Ipv4Address address);

    /**
     * \brief Get the local address
     * \returns the local address
     *
     * \note Functionally identical to `Ipv4InterfaceAddress::GetAddress`.
     *       The method corresponds to the linux variable in_ifaddr.ifa_local
     *       `Ipv4InterfaceAddress::GetAddress` is to be preferred.
     */
    Ipv4Address GetLocal() const;

    /**
     * \brief Get the local address
     * \returns the local address
     *
     * \note Functially identical to `Ipv4InterfaceAddress::GetLocal`.
     *       This function is consistent with `Ipv6InterfaceAddress::GetAddress`.
     */
    Ipv4Address GetAddress() const;

    /**
     * \brief Set the network mask
     * \param mask the network mask
     */
    void SetMask(Ipv4Mask mask);
    /**
     * \brief Get the network mask
     * \returns the network mask
     */
    Ipv4Mask GetMask() const;
    /**
     * \brief Set the broadcast address
     * \param broadcast the broadcast address
     */
    void SetBroadcast(Ipv4Address broadcast);
    /**
     * \brief Get the broadcast address
     * \returns the broadcast address
     */
    Ipv4Address GetBroadcast() const;

    /**
     * \brief Set the scope.
     * \param scope the scope of address
     */
    void SetScope(Ipv4InterfaceAddress::InterfaceAddressScope_e scope);

    /**
     * \brief Get address scope.
     * \return scope
     */
    Ipv4InterfaceAddress::InterfaceAddressScope_e GetScope() const;

    /**
     * \brief Checks if the address is in the same subnet.
     * \param b the address to check
     * \return true if the address is in the same subnet.
     */
    bool IsInSameSubnet(const Ipv4Address b) const;

    /**
     * \brief Check if the address is a secondary address
     *
     * Secondary address is used for multihoming
     * \returns true if the address is secondary
     */
    bool IsSecondary() const;

    /**
     * \brief Make the address secondary (used for multihoming)
     */
    void SetSecondary();
    /**
     * \brief Make the address primary
     */
    void SetPrimary();

  private:
    Ipv4Address m_local; //!< Interface address
    // Note:  m_peer may be added in future when necessary
    // Ipv4Address m_peer;   // Peer destination address (in Linux:  m_address)
    Ipv4Mask m_mask;         //!< Network mask
    Ipv4Address m_broadcast; //!< Broadcast address

    InterfaceAddressScope_e m_scope; //!< Address scope
    bool m_secondary;                //!< For use in multihoming

    /**
     * \brief Equal to operator.
     *
     * \param a the first operand
     * \param b the first operand
     * \returns true if the operands are equal
     */
    friend bool operator==(const Ipv4InterfaceAddress& a, const Ipv4InterfaceAddress& b);

    /**
     * \brief Not equal to operator.
     *
     * \param a the first operand
     * \param b the first operand
     * \returns true if the operands are not equal
     */
    friend bool operator!=(const Ipv4InterfaceAddress& a, const Ipv4InterfaceAddress& b);
};

/**
 * \brief Stream insertion operator.
 *
 * \param os the reference to the output stream
 * \param addr the Ipv4InterfaceAddress
 * \returns the reference to the output stream
 */
std::ostream& operator<<(std::ostream& os, const Ipv4InterfaceAddress& addr);

inline bool
operator==(const Ipv4InterfaceAddress& a, const Ipv4InterfaceAddress& b)
{
    return (a.m_local == b.m_local && a.m_mask == b.m_mask && a.m_broadcast == b.m_broadcast &&
            a.m_scope == b.m_scope && a.m_secondary == b.m_secondary);
}

inline bool
operator!=(const Ipv4InterfaceAddress& a, const Ipv4InterfaceAddress& b)
{
    return (a.m_local != b.m_local || a.m_mask != b.m_mask || a.m_broadcast != b.m_broadcast ||
            a.m_scope != b.m_scope || a.m_secondary != b.m_secondary);
}

} // namespace ns3

#endif /* IPV4_ADDRESS_H */
