/*
 * Copyright (c) 2008,2009 IITP RAS
 *
 * 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
 *
 * Author: Kirill Andreev <andreev@iitp.ru>
 */

#ifndef HWMP_STATE_H
#define HWMP_STATE_H

#include "hwmp-protocol.h"

#include "ns3/mesh-wifi-interface-mac-plugin.h"

namespace ns3
{

class MeshWifiInterfaceMac;
class WifiActionHeader;

namespace dot11s
{

class IePreq;
class IePrep;
class IePerr;

/**
 * \ingroup dot11s
 *
 * \brief Interface MAC plugin for HWMP -- 802.11s routing protocol
 */
class HwmpProtocolMac : public MeshWifiInterfaceMacPlugin
{
  public:
    /**
     * Constructor
     *
     * \param ifIndex interface index
     * \param protocol pointer to HWMP protocol instance
     */
    HwmpProtocolMac(uint32_t ifIndex, Ptr<HwmpProtocol> protocol);
    ~HwmpProtocolMac() override;

    // Inherited from MAC plugin
    void SetParent(Ptr<MeshWifiInterfaceMac> parent) override;
    bool Receive(Ptr<Packet> packet, const WifiMacHeader& header) override;
    bool UpdateOutcomingFrame(Ptr<Packet> packet,
                              WifiMacHeader& header,
                              Mac48Address from,
                              Mac48Address to) override;
    // Update beacon is empty, because HWMP does not know anything about beacons
    void UpdateBeacon(MeshWifiBeacon& beacon) const override{};
    int64_t AssignStreams(int64_t stream) override;

  private:
    /// allow HwmpProtocol class friend access
    friend class HwmpProtocol;
    /**
     * \returns a path selection action header
     */
    static WifiActionHeader GetWifiActionHeader();
    /// \name Interaction with HWMP:
    ///@{
    /**
     * Send PREQ function
     * \param preq the PREQ
     */
    void SendPreq(IePreq preq);
    /**
     * Send PREQ function for vector of PREQ
     * \param preq vector of PREQ information elements
     */
    void SendPreqVector(std::vector<IePreq> preq);
    /**
     * Send PREP function
     * \param prep the PREP information element
     * \param receiver the MAC address of the receiver
     */
    void SendPrep(IePrep prep, Mac48Address receiver);
    /**
     * Forward a path error
     * \param destinations vector of failed destinations
     * \param receivers vector of receivers
     */
    void ForwardPerr(std::vector<HwmpProtocol::FailedDestination> destinations,
                     std::vector<Mac48Address> receivers);
    /**
     * initiate my own path error
     * \param destinations vector of failed destinations
     * \param receivers vector of receivers
     */
    void InitiatePerr(std::vector<HwmpProtocol::FailedDestination> destinations,
                      std::vector<Mac48Address> receivers);
    /**
     * Request a destination. If cannot send PREQ immediately, add a
     * destination to existing PREQ generated by me and stored in PREQ queue
     * \param dest is the destination to be resolved
     * \param originator_seqno is a sequence number that shall be preq originator sequenece number
     * \param dst_seqno is a sequence number taken from routing table
     */
    void RequestDestination(Mac48Address dest, uint32_t originator_seqno, uint32_t dst_seqno);
    ///@}

    /// Sends one PREQ when PreqMinInterval after last PREQ expires (if any PREQ exists in rhe
    /// queue)
    void SendMyPreq();
    /// Send PERR function
    void SendMyPerr();
    /**
     * \param peerAddress peer address
     * \return metric to HWMP protocol, needed only by metrics to add peer as routing entry
     */
    uint32_t GetLinkMetric(Mac48Address peerAddress) const;
    /**
     * Get the channel ID
     * \returns the channel ID
     */
    uint16_t GetChannelId() const;
    /**
     * Report statistics
     * \param os The output stream on which to report
     */
    void Report(std::ostream& os) const;
    /// Reset statistics
    void ResetStats();

  private:
    Ptr<MeshWifiInterfaceMac> m_parent; ///< parent
    uint32_t m_ifIndex;                 ///< IF index
    Ptr<HwmpProtocol> m_protocol;       ///< protocol

    /// \name my PREQ and PREQ timer:
    ///@{
    EventId m_preqTimer;          //!< Timer for PREQs
    std::vector<IePreq> m_myPreq; //!< container of PREQs
    ///@}

    /// \name PERR timer and stored path error
    ///@{
    EventId m_perrTimer;

    /// MyPerr structure
    struct MyPerr
    {
        std::vector<HwmpProtocol::FailedDestination> destinations; ///< destinations
        std::vector<Mac48Address> receivers;                       ///< receivers
    };

    MyPerr m_myPerr; ///< PERR

    ///@}

    /// \name Statistics
    ///@{

    /**
     * Statistics structure
     */
    struct Statistics
    {
        uint16_t txPreq;      ///< transmit PREQ
        uint16_t rxPreq;      ///< receive PREQ
        uint16_t txPrep;      ///< transmit PREP
        uint16_t rxPrep;      ///< receive PREP
        uint16_t txPerr;      ///< transmit PERR
        uint16_t rxPerr;      ///< receive PERR
        uint16_t txMgt;       ///< transmit management
        uint32_t txMgtBytes;  ///< transmit management bytes
        uint16_t rxMgt;       ///< receive management
        uint32_t rxMgtBytes;  ///< receive management bytes
        uint16_t txData;      ///< transmit data
        uint32_t txDataBytes; ///< transmit data bytes
        uint16_t rxData;      ///< receive data
        uint32_t rxDataBytes; ///< receive data bytes
        /**
         * Print function
         * \param os the output stream
         */
        void Print(std::ostream& os) const;
        Statistics();
    };

    Statistics m_stats; ///< statistics
                        ///@}

  private:
    /**
     * Receive data frame
     *
     * \param packet
     * \param header
     * \returns true if a packet was received
     */
    bool ReceiveData(Ptr<Packet> packet, const WifiMacHeader& header);
    /**
     * Receive action management frame
     *
     * \param packet
     * \param header
     * \returns true if a packet was received
     */
    bool ReceiveAction(Ptr<Packet> packet, const WifiMacHeader& header);
};
} // namespace dot11s
} // namespace ns3
#endif
