/*
 * Copyright (c) 2009 IITP RAS
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Kirill Andreev <andreev@iitp.ru>
 */

#ifndef PEER_MANAGEMENT_PROTOCOL_MAC_H
#define PEER_MANAGEMENT_PROTOCOL_MAC_H

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

namespace ns3
{
class MeshWifiInterfaceMac;
class WifiMpdu;
enum WifiMacDropReason : uint8_t; // opaque enum declaration

namespace dot11s
{
class PeerManagementProtocol;
class IeConfiguration;
class IePeerManagement;
class PeerManagementProtocol;

/**
 * @ingroup dot11s
 *
 * @brief This is plugin to Mesh WiFi MAC, which implements the
 * interface to dot11s peer management protocol: it takes proper
 * frames from MAC-layer, extracts peer link management information
 * element and mesh configuration element and passes it to main part
 * of protocol
 */
class PeerManagementProtocolMac : public MeshWifiInterfaceMacPlugin
{
  public:
    /**
     * Constructor
     *
     * @param interface interface index
     * @param protocol peer management protocol
     */
    PeerManagementProtocolMac(uint32_t interface, Ptr<PeerManagementProtocol> protocol);
    ~PeerManagementProtocolMac() override;

    // Inherited from plugin abstract class
    /**
     * Set pointer to parent
     * @param parent Ptr<MeshWifiInterfaceMac>
     */
    void SetParent(Ptr<MeshWifiInterfaceMac> parent) override;
    /**
     * Receive and process a packet
     * @param packet the packet received
     * @param header the header
     * @returns true if received
     */
    bool Receive(Ptr<Packet> packet, const WifiMacHeader& header) override;
    /**
     * This method appears to test a few conditions.  If an action frame,
     * it returns true if SELF_PROTECTED.  It then checks if it is either
     * a broadcast or sent on an active link, and returns true if so.
     * Otherwise, it returns false (indicating it is to be dropped)
     * @param packet the packet
     * @param header the header
     * @param from the MAC address of the sender
     * @param to the MAC address of the receiver
     * @returns true if successful, false if to be dropped
     */
    bool UpdateOutcomingFrame(Ptr<Packet> packet,
                              WifiMacHeader& header,
                              Mac48Address from,
                              Mac48Address to) override;
    /**
     * Add beacon timing and mesh ID information elements, and notify beacon sent
     * @param beacon the beacon
     */
    void UpdateBeacon(MeshWifiBeacon& beacon) const override;
    /**
     * Assign the streams
     * @param stream the stream to assign
     * @return the assigned stream
     */
    int64_t AssignStreams(int64_t stream) override;

    /// @name Statistics
    ///@{
    /**
     * @brief Report statistics
     * @param os the output stream
     */
    void Report(std::ostream&) const;
    /// Reset stats
    void ResetStats();
    /**
     * Get the link metric
     * @param peerAddress the peer address
     * @return The metric
     */
    uint32_t GetLinkMetric(Mac48Address peerAddress);
    ///@}

  private:
    /**
     * assignment operator
     *
     * @param peer the object to assign
     * @returns the assigned value
     */
    PeerManagementProtocolMac& operator=(const PeerManagementProtocolMac& peer);
    /// type conversion operator
    PeerManagementProtocolMac(const PeerManagementProtocolMac&);

    /// allow PeerManagementProtocol class access friend access
    friend class PeerManagementProtocol;
    /// allow PeerLink class access friend access
    friend class PeerLink;

    /// @name Create peer link management frames
    // \{
    /**
     * @brief This structure keeps all fields in peer link management frame,
     * which are not subclasses of WifiInformationElement
     */
    struct PlinkFrameStart
    {
        uint8_t subtype;      ///< subtype
        uint16_t aid;         ///< aid
        SupportedRates rates; ///< rates
        uint16_t qos;         ///< QOS
    };

    /**
     * Create peer link open frame function
     * @returns the packet
     */
    Ptr<Packet> CreatePeerLinkOpenFrame();
    /**
     * Create peer link confirm frame function
     * @returns the packet
     */
    Ptr<Packet> CreatePeerLinkConfirmFrame();
    /**
     * Create peer link clode frame function
     * @returns the packet
     */
    Ptr<Packet> CreatePeerLinkCloseFrame();
    /**
     * Parses the start of the frame, where no WifiInformationElements exist
     * @param packet the packet
     * @returns PlinkFrameStart
     */
    PlinkFrameStart ParsePlinkFrame(Ptr<const Packet> packet);
    // \}
    /**
     *  Closes link when a proper number of successive transmissions have failed
     * @param reason the reason why the MPDU was dropped
     * @param mpdu the dropped MPDU
     */
    void TxError(WifiMacDropReason reason, Ptr<const WifiMpdu> mpdu);
    /**
     * Transmit OK function
     * @param mpdu the MPDU
     */
    void TxOk(Ptr<const WifiMpdu> mpdu);
    // BCA functionality
    /**
     * Set beacon shift function
     * @param shift the beacon time shift
     */
    void SetBeaconShift(Time shift);
    /**
     * Set peer manager protocol function
     * @param protocol the peer manager protocol
     */
    void SetPeerManagerProtocol(Ptr<PeerManagementProtocol> protocol);
    /**
     * Send peer link management frame function
     * @param peerAddress the peer MAC address
     * @param peerMpAddress the peer MP address
     * @param aid the AID
     * @param peerElement IePeerManagement
     * @param meshConfig IeConfiguration
     */
    void SendPeerLinkManagementFrame(Mac48Address peerAddress,
                                     Mac48Address peerMpAddress,
                                     uint16_t aid,
                                     IePeerManagement peerElement,
                                     IeConfiguration meshConfig);
    /**
     * @brief debug only, used to print established links
     * @returns the MAC address
     */
    Mac48Address GetAddress() const;

    /// Statistics structure
    struct Statistics
    {
        uint16_t txOpen;      ///< transmit open
        uint16_t txConfirm;   ///< transmit confirm
        uint16_t txClose;     ///< transmit close
        uint16_t rxOpen;      ///< receive open
        uint16_t rxConfirm;   ///< receive confirm
        uint16_t rxClose;     ///< receive close
        uint16_t dropped;     ///< dropped
        uint16_t brokenMgt;   ///< broken management
        uint16_t txMgt;       ///< transmit management
        uint32_t txMgtBytes;  ///< transmit management bytes
        uint16_t rxMgt;       ///< receive management
        uint32_t rxMgtBytes;  ///< receive management bytes
        uint16_t beaconShift; ///< beacon shift

        /// constructor
        Statistics();
        /**
         * Print function
         * @param os the output stream
         */
        void Print(std::ostream& os) const;
    };

  private:
    Statistics m_stats; ///< statistics
    /// @name Information about MAC and protocol:
    Ptr<MeshWifiInterfaceMac> m_parent;     ///< parent
    uint32_t m_ifIndex;                     ///< IF index
    Ptr<PeerManagementProtocol> m_protocol; ///< protocol
};

} // namespace dot11s
} // namespace ns3

#endif /* PEER_MANAGEMENT_PROTOCOL_MAC_H */
