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

#ifndef IPV6_STATIC_ROUTING_H
#define IPV6_STATIC_ROUTING_H

#include "ipv6-header.h"
#include "ipv6-routing-protocol.h"
#include "ipv6.h"

#include "ns3/ipv6-address.h"
#include "ns3/ptr.h"

#include <list>
#include <stdint.h>

namespace ns3
{

class Packet;
class NetDevice;
class Ipv6Interface;
class Ipv6Route;
class Node;
class Ipv6RoutingTableEntry;
class Ipv6MulticastRoutingTableEntry;

/**
 * @ingroup ipv6Routing
 *
 * @brief Static routing protocol for IP version 6 stacks.
 *
 * This class provides a basic set of methods for inserting static
 * unicast and multicast routes into the Ipv6 routing system.
 * This particular protocol is designed to be inserted into an
 * Ipv6ListRouting protocol but can be used also as a standalone
 * protocol.
 *
 * The Ipv6StaticRouting class inherits from the abstract base class
 * Ipv6RoutingProtocol that defines the interface methods that a routing
 * protocol must support.
 *
 * @see Ipv6RoutingProtocol
 * @see Ipv6ListRouting
 * @see Ipv6ListRouting::AddRoutingProtocol
 */
class Ipv6StaticRouting : public Ipv6RoutingProtocol
{
  public:
    /**
     * @brief The interface Id associated with this class.
     * @return type identifier
     */
    static TypeId GetTypeId();

    Ipv6StaticRouting();
    ~Ipv6StaticRouting() override;

    /**
     * @brief Add route to host.
     * @param dest destination address
     * @param nextHop next hop address to route the packet.
     * @param interface interface index
     * @param prefixToUse prefix that should be used for source address for this destination
     * @param metric metric of route in case of multiple routes to same destination
     */
    void AddHostRouteTo(Ipv6Address dest,
                        Ipv6Address nextHop,
                        uint32_t interface,
                        Ipv6Address prefixToUse = Ipv6Address("::"),
                        uint32_t metric = 0);

    /**
     * @brief Add route to host.
     * @param dest destination address.
     * @param interface interface index
     * @param metric metric of route in case of multiple routes to same destination
     */
    void AddHostRouteTo(Ipv6Address dest, uint32_t interface, uint32_t metric = 0);

    /**
     * @brief Add route to network.
     * @param network network address
     * @param networkPrefix network prefix*
     * @param nextHop next hop address to route the packet
     * @param interface interface index
     * @param metric metric of route in case of multiple routes to same destination
     */
    void AddNetworkRouteTo(Ipv6Address network,
                           Ipv6Prefix networkPrefix,
                           Ipv6Address nextHop,
                           uint32_t interface,
                           uint32_t metric = 0);

    /**
     * @brief Add route to network.
     * @param network network address
     * @param networkPrefix network prefix*
     * @param nextHop next hop address to route the packet.
     * @param interface interface index
     * @param prefixToUse prefix that should be used for source address for this destination
     * @param metric metric of route in case of multiple routes to same destination
     */
    void AddNetworkRouteTo(Ipv6Address network,
                           Ipv6Prefix networkPrefix,
                           Ipv6Address nextHop,
                           uint32_t interface,
                           Ipv6Address prefixToUse,
                           uint32_t metric = 0);

    /**
     * @brief Add route to network.
     * @param network network address
     * @param networkPrefix network prefix
     * @param interface interface index
     * @param metric metric of route in case of multiple routes to same destination
     */
    void AddNetworkRouteTo(Ipv6Address network,
                           Ipv6Prefix networkPrefix,
                           uint32_t interface,
                           uint32_t metric = 0);

    /**
     * @brief Set the default route.
     * @param nextHop next hop address to route the packet
     * @param interface interface index
     * @param prefixToUse prefix to use (i.e for multihoming)
     * @param metric metric of route in case of multiple routes to same destination
     */
    void SetDefaultRoute(Ipv6Address nextHop,
                         uint32_t interface,
                         Ipv6Address prefixToUse = Ipv6Address("::"),
                         uint32_t metric = 0);

    /**
     * @brief Get the number or entries in the routing table.
     * @return number of entries
     */
    uint32_t GetNRoutes() const;

    /**
     * @brief Get the default route.
     *
     * If multiple default routes exist, the one with lowest metric is returned.
     * @return default Ipv6Route
     */
    Ipv6RoutingTableEntry GetDefaultRoute();

    /**
     * @brief Get a specified route.
     * @param i index
     * @return the route whose index is i
     */
    Ipv6RoutingTableEntry GetRoute(uint32_t i) const;

    /**
     * @brief Get a metric for route from the static unicast routing table.
     * @param index The index (into the routing table) of the route to retrieve.
     * @return If route is set, the metric is returned. If not, an infinity metric (0xffffffff) is
     * returned
     */
    uint32_t GetMetric(uint32_t index) const;

    /**
     * @brief Remove a route from the routing table.
     * @param i index
     */
    void RemoveRoute(uint32_t i);

    /**
     * @brief Remove a route from the routing table.
     * @param network IPv6 network
     * @param prefix IPv6 prefix
     * @param ifIndex interface index
     * @param prefixToUse IPv6 prefix to use with this route (multihoming)
     */
    void RemoveRoute(Ipv6Address network,
                     Ipv6Prefix prefix,
                     uint32_t ifIndex,
                     Ipv6Address prefixToUse);

    /**
     * @brief Add a multicast route for a given multicast source and group.
     * @param origin IPv6 address of the source
     * @param group the multicast group address.
     * @param inputInterface the interface index
     * @param outputInterfaces the list of output interface indices over which the packet
     * should be sent (excluding the inputInterface).
     */
    void AddMulticastRoute(Ipv6Address origin,
                           Ipv6Address group,
                           uint32_t inputInterface,
                           std::vector<uint32_t> outputInterfaces);

    /**
     * @brief Set the default multicast route.
     * @param outputInterface default output interface
     */
    void SetDefaultMulticastRoute(uint32_t outputInterface);

    /**
     * @brief Get the number of entries in the multicast routing table.
     * @return number of entries
     */
    uint32_t GetNMulticastRoutes() const;

    /**
     * @brief Get the specified multicast route.
     * @param i index
     * @return the route whose index is i
     */
    Ipv6MulticastRoutingTableEntry GetMulticastRoute(uint32_t i) const;

    /**
     * @brief Remove a static multicast route.
     * @param origin IPv6 address of the source
     * @param group the multicast group address.
     * @param inputInterface the input interface index
     * @return true on success
     */
    bool RemoveMulticastRoute(Ipv6Address origin, Ipv6Address group, uint32_t inputInterface);

    /**
     * @brief Remove a multicast route.
     * @param i index of route to remove
     */
    void RemoveMulticastRoute(uint32_t i);

    /**
     * @brief If the destination is already present in network destination list.
     * @param dest destination address
     * @param interfaceIndex interface index
     * @return true if dest is already in list, false otherwise
     */
    bool HasNetworkDest(Ipv6Address dest, uint32_t interfaceIndex);

    Ptr<Ipv6Route> RouteOutput(Ptr<Packet> p,
                               const Ipv6Header& header,
                               Ptr<NetDevice> oif,
                               Socket::SocketErrno& sockerr) override;

    bool RouteInput(Ptr<const Packet> p,
                    const Ipv6Header& header,
                    Ptr<const NetDevice> idev,
                    const UnicastForwardCallback& ucb,
                    const MulticastForwardCallback& mcb,
                    const LocalDeliverCallback& lcb,
                    const ErrorCallback& ecb) override;

    void NotifyInterfaceUp(uint32_t interface) override;
    void NotifyInterfaceDown(uint32_t interface) override;
    void NotifyAddAddress(uint32_t interface, Ipv6InterfaceAddress address) override;
    void NotifyRemoveAddress(uint32_t interface, Ipv6InterfaceAddress address) override;
    void NotifyAddRoute(Ipv6Address dst,
                        Ipv6Prefix mask,
                        Ipv6Address nextHop,
                        uint32_t interface,
                        Ipv6Address prefixToUse = Ipv6Address::GetZero()) override;
    void NotifyRemoveRoute(Ipv6Address dst,
                           Ipv6Prefix mask,
                           Ipv6Address nextHop,
                           uint32_t interface,
                           Ipv6Address prefixToUse = Ipv6Address::GetZero()) override;
    void SetIpv6(Ptr<Ipv6> ipv6) override;
    void PrintRoutingTable(Ptr<OutputStreamWrapper> stream,
                           Time::Unit unit = Time::S) const override;

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

  private:
    /// Container for the network routes
    typedef std::list<std::pair<Ipv6RoutingTableEntry*, uint32_t>> NetworkRoutes;

    /// Const Iterator for container for the network routes
    typedef std::list<std::pair<Ipv6RoutingTableEntry*, uint32_t>>::const_iterator NetworkRoutesCI;

    /// Iterator for container for the network routes
    typedef std::list<std::pair<Ipv6RoutingTableEntry*, uint32_t>>::iterator NetworkRoutesI;

    /// Container for the multicast routes
    typedef std::list<Ipv6MulticastRoutingTableEntry*> MulticastRoutes;

    /// Const Iterator for container for the multicast routes
    typedef std::list<Ipv6MulticastRoutingTableEntry*>::const_iterator MulticastRoutesCI;

    /// Iterator for container for the multicast routes
    typedef std::list<Ipv6MulticastRoutingTableEntry*>::iterator MulticastRoutesI;

    /**
     * @brief Checks if a route is already present in the forwarding table.
     * @param route route
     * @param metric metric of route
     * @return true if the route/metric is already in the forwarding table
     */
    bool LookupRoute(const Ipv6RoutingTableEntry& route, uint32_t metric);

    /**
     * @brief Lookup in the forwarding table for destination.
     * @param dest destination address
     * @param interface output interface if any (put 0 otherwise)
     * @return Ipv6Route to route the packet to reach dest address
     */
    Ptr<Ipv6Route> LookupStatic(Ipv6Address dest, Ptr<NetDevice> = nullptr);

    /**
     * @brief Lookup in the multicast forwarding table for destination.
     * @param origin source address
     * @param group group multicast address
     * @param ifIndex interface index
     * @return Ipv6MulticastRoute to route the packet to reach dest address
     */
    Ptr<Ipv6MulticastRoute> LookupStatic(Ipv6Address origin, Ipv6Address group, uint32_t ifIndex);

    /**
     * @brief the forwarding table for network.
     */
    NetworkRoutes m_networkRoutes;

    /**
     * @brief the forwarding table for multicast.
     */
    MulticastRoutes m_multicastRoutes;

    /**
     * @brief Ipv6 reference.
     */
    Ptr<Ipv6> m_ipv6;
};

} /* namespace ns3 */

#endif /* IPV6_STATIC_ROUTING_H */
