/*
 * Copyright (c) 2007-2009 Strasbourg University
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Sebastien Vincent <vincent@clarinet.u-strasbg.fr>
 */

#ifndef IPV6_INTERFACE_H
#define IPV6_INTERFACE_H

#include "ipv6-interface-address.h"

#include "ns3/object.h"
#include "ns3/ptr.h"
#include "ns3/traced-callback.h"

#include <list>

namespace ns3
{

class NetDevice;
class Packet;
class Node;
class NdiscCache;
class Ipv6InterfaceAddress;
class Ipv6Address;
class Ipv6Header;
class TrafficControlLayer;

/**
 * @ingroup ipv6
 *
 * @brief The IPv6 representation of a network interface.
 *
 * By default IPv6 interfaces are created in the "down" state
 * with IP "fe80::1" and a /64 prefix. Before becoming usable,
 * the user must invoke SetUp on them once the final IPv6 address
 * and mask has been set.
 */
class Ipv6Interface : public Object
{
  public:
    /**
     * @brief Get the type ID
     * @return type ID
     */
    static TypeId GetTypeId();

    /**
     * @brief Constructs an Ipv6Interface.
     */
    Ipv6Interface();

    /**
     * @brief Destructor.
     */
    ~Ipv6Interface() override;

    // Delete copy constructor and assignment operator to avoid misuse
    Ipv6Interface(const Ipv6Interface&) = delete;
    Ipv6Interface& operator=(const Ipv6Interface&) = delete;

    /**
     * @brief Set node associated with interface.
     * @param node node
     */
    void SetNode(Ptr<Node> node);

    /**
     * @brief Set the NetDevice.
     * @param device NetDevice
     */
    void SetDevice(Ptr<NetDevice> device);

    /**
     * @brief Set the TrafficControlLayer.
     * @param tc TrafficControlLayer object
     */
    void SetTrafficControl(Ptr<TrafficControlLayer> tc);

    /**
     * @brief Get the NetDevice.
     * @return the NetDevice associated with this interface
     */
    virtual Ptr<NetDevice> GetDevice() const;

    /**
     * @brief Set the metric.
     * @param metric configured routing metric (cost) of this interface
     */
    void SetMetric(uint16_t metric);

    /**
     * @brief Get the metric
     * @return the metric
     */
    uint16_t GetMetric() const;

    /**
     * @brief Is the interface UP ?
     * @return true if interface is enabled, false otherwise.
     */
    bool IsUp() const;

    /**
     * @brief Is the interface DOWN ?
     * @return true if interface is disabled, false otherwise.
     */
    bool IsDown() const;

    /**
     * @brief Enable this interface.
     */
    void SetUp();

    /**
     * @brief Disable this interface.
     */
    void SetDown();

    /**
     * @brief If the interface allows forwarding packets.
     * @return true if forwarding is enabled, false otherwise
     */
    bool IsForwarding() const;

    /**
     * @brief Set forwarding enabled or not.
     * @param forward forwarding state
     */
    void SetForwarding(bool forward);

    /**
     * @brief Set the current hop limit.
     * @param curHopLimit the value to set
     */
    void SetCurHopLimit(uint8_t curHopLimit);

    /**
     * @brief Get the current hop limit value.
     * @return current hop limit
     */
    uint8_t GetCurHopLimit() const;

    /**
     * @brief Set the base reachable time.
     * @param baseReachableTime the value to set
     */
    void SetBaseReachableTime(uint16_t baseReachableTime);

    /**
     * @brief Get the base reachable time.
     * @return base reachable time
     */
    uint16_t GetBaseReachableTime() const;

    /**
     * @brief Set the reachable time.
     * @param reachableTime value to set
     */
    void SetReachableTime(uint16_t reachableTime);

    /**
     * @brief Get the reachable time.
     * @return reachable time
     */
    uint16_t GetReachableTime() const;

    /**
     * @brief Set the retransmission timer.
     * @param retransTimer value to set
     */
    void SetRetransTimer(uint16_t retransTimer);

    /**
     * @brief Get the retransmission timer.
     * @return retransmission timer
     */
    uint16_t GetRetransTimer() const;

    /**
     * @brief Send a packet through this interface.
     * @param p packet to send
     * @param hdr IPv6 header
     * @param dest next hop address of packet.
     *
     * @note This method will eventually call the private SendTo
     * method which must be implemented by subclasses.
     */
    void Send(Ptr<Packet> p, const Ipv6Header& hdr, Ipv6Address dest);

    /**
     * @brief Add an IPv6 address.
     * @param iface address to add
     * @return true if address was added, false otherwise
     */
    bool AddAddress(Ipv6InterfaceAddress iface);

    /**
     * @brief Get link-local address from IPv6 interface.
     * @return link-local Ipv6InterfaceAddress, assert if not found
     */
    Ipv6InterfaceAddress GetLinkLocalAddress() const;

    /**
     * @brief Checks if the address is a Solicited Multicast address for this interface.
     * @param address the address to check.
     * @return true if it is a solicited multicast address.
     */
    bool IsSolicitedMulticastAddress(Ipv6Address address) const;

    /**
     * @brief Get an address from IPv6 interface.
     * @param index index
     * @return Ipv6InterfaceAddress address whose index is i
     */
    Ipv6InterfaceAddress GetAddress(uint32_t index) const;

    /**
     * @brief Get an address which is in the same network prefix as destination.
     * @param dst destination address
     * @return Corresponding Ipv6InterfaceAddress or assert if not found
     */
    Ipv6InterfaceAddress GetAddressMatchingDestination(Ipv6Address dst);

    /**
     * @brief Get number of addresses on this IPv6 interface.
     * @return number of address
     */
    uint32_t GetNAddresses() const;

    /**
     * @brief Remove an address from interface.
     * @param index index to remove
     * @return Ipv6InterfaceAddress address whose index is index
     */
    Ipv6InterfaceAddress RemoveAddress(uint32_t index);

    /**
     * @brief Remove the given Ipv6 address from the interface.
     * @param address The Ipv6 address to remove
     * @returns The removed Ipv6 interface address
     * @returns The null interface address if the interface did not contain the
     * address or if loopback address was passed as argument
     */
    Ipv6InterfaceAddress RemoveAddress(Ipv6Address address);

    /**
     * @brief Update state of an interface address.
     * @param address IPv6 address
     * @param state new state
     */
    void SetState(Ipv6Address address, Ipv6InterfaceAddress::State_e state);

    /**
     * @brief Update NS DAD packet UID of an interface address.
     * @param address IPv6 address
     * @param uid packet UID
     */
    void SetNsDadUid(Ipv6Address address, uint32_t uid);

    /**
     * @return NDISC cache used by this interface
     */
    Ptr<NdiscCache> GetNdiscCache() const;

    /**
     * This callback is set when an address is removed from an interface with
     * auto-generated Ndisc cache and it allow the neighbor cache helper to update
     * neighbor's Ndisc cache
     *
     * @param removeAddressCallback Callback when remove an address.
     */
    void RemoveAddressCallback(
        Callback<void, Ptr<Ipv6Interface>, Ipv6InterfaceAddress> removeAddressCallback);

    /**
     * This callback is set when an address is added from an interface with
     * auto-generated Ndisc cache and it allow the neighbor cache helper to update
     * neighbor's Ndisc cache
     *
     * @param addAddressCallback Callback when remove an address.
     */
    void AddAddressCallback(
        Callback<void, Ptr<Ipv6Interface>, Ipv6InterfaceAddress> addAddressCallback);

  protected:
    /**
     * @brief Dispose this object.
     */
    void DoDispose() override;

  private:
    /**
     * @brief Container for the Ipv6InterfaceAddresses.
     */
    typedef std::list<std::pair<Ipv6InterfaceAddress, Ipv6Address>> Ipv6InterfaceAddressList;

    /**
     * @brief Container Iterator for the Ipv6InterfaceAddresses.
     */
    typedef std::list<std::pair<Ipv6InterfaceAddress, Ipv6Address>>::iterator
        Ipv6InterfaceAddressListI;

    /**
     * @brief Const Container Iterator for the Ipv6InterfaceAddresses.
     */
    typedef std::list<std::pair<Ipv6InterfaceAddress, Ipv6Address>>::const_iterator
        Ipv6InterfaceAddressListCI;

    /**
     * @brief Initialize interface.
     */
    void DoSetup();

    /**
     * @brief The addresses assigned to this interface.
     */
    Ipv6InterfaceAddressList m_addresses;

    /**
     * @brief The link-local addresses assigned to this interface.
     */
    Ipv6InterfaceAddress m_linkLocalAddress;

    /**
     * @brief The state of this interface.
     */
    bool m_ifup;

    /**
     * @brief Forwarding state.
     */
    bool m_forwarding;

    /**
     * @brief The metric.
     */
    uint16_t m_metric;

    /**
     * @brief Node associated with this interface.
     */
    Ptr<Node> m_node;

    /**
     * @brief NetDevice associated with this interface.
     */
    Ptr<NetDevice> m_device;

    /**
     * @brief TrafficControlLayer associated with this interface.
     */
    Ptr<TrafficControlLayer> m_tc;

    /**
     * @brief Neighbor cache.
     */
    Ptr<NdiscCache> m_ndCache;

    /**
     * @brief Current hop limit.
     */
    uint8_t m_curHopLimit;

    /**
     * @brief Base value used for computing the random reachable time value (in millisecond).
     */
    uint16_t m_baseReachableTime;

    /**
     * @brief Reachable time (in millisecond).
     * The time a neighbor is considered reachable after receiving a reachability confirmation.
     */
    uint16_t m_reachableTime;

    /**
     * @brief Retransmission timer (in millisecond).
     * Time between retransmission of NS.
     */
    uint16_t m_retransTimer;

    Callback<void, Ptr<Ipv6Interface>, Ipv6InterfaceAddress>
        m_removeAddressCallback; //!< remove address callback

    Callback<void, Ptr<Ipv6Interface>, Ipv6InterfaceAddress>
        m_addAddressCallback; //!< add address callback

    /**
     * The trace fired when the interface state changes.
     * Includes state (true if interface is up) and the interface index.
     */
    ns3::TracedCallback<bool, int32_t> m_interfaceStatus;
};

} /* namespace ns3 */

#endif /* IPV6_INTERFACE_H */