/*
 * Copyright (c) 2009 MIRKO BANCHI
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Mirko Banchi <mk.banchi@gmail.com>
 */

#ifndef CTRL_HEADERS_H
#define CTRL_HEADERS_H

#include "block-ack-type.h"
#include "wifi-phy-common.h"
#include "wifi-ru.h"

#include "ns3/header.h"
#include "ns3/mac48-address.h"

#include <list>
#include <optional>
#include <vector>

namespace ns3
{

class WifiTxVector;
enum AcIndex : uint8_t;

/**
 * @ingroup wifi
 * @brief Headers for BlockAckRequest.
 *
 *  802.11 standard includes multiple BlockAckReq variants:
 *    - Basic BlockAckReq (unique type in 802.11e)
 *    - Compressed BlockAckReq
 *    - Multi-TID BlockAckReq
 *    - GCR BlockAckReq
 *  For now only basic BlockAckReq, compressed BlockAckReq and GCR BlockAckReq are supported.
 *  Basic BlockAckReq is the default variant.
 */
class CtrlBAckRequestHeader : public Header
{
  public:
    CtrlBAckRequestHeader();
    ~CtrlBAckRequestHeader() override;
    /**
     * @brief Get the type ID.
     * @return the object TypeId
     */
    static TypeId GetTypeId();

    TypeId GetInstanceTypeId() const override;
    void Print(std::ostream& os) const override;
    uint32_t GetSerializedSize() const override;
    void Serialize(Buffer::Iterator start) const override;
    uint32_t Deserialize(Buffer::Iterator start) override;

    /**
     * Enable or disable HT immediate Ack.
     *
     * @param immediateAck enable or disable HT immediate Ack
     */
    void SetHtImmediateAck(bool immediateAck);
    /**
     * Set the BlockAckRequest type.
     *
     * @param type the BlockAckRequest type
     */
    void SetType(BlockAckReqType type);
    /**
     * Set Traffic ID (TID).
     *
     * @param tid the TID
     */
    void SetTidInfo(uint8_t tid);
    /**
     * Set the starting sequence number from the given
     * raw sequence control field.
     *
     * @param seq the raw sequence control
     */
    void SetStartingSequence(uint16_t seq);
    /**
     * Set the GCR Group address (GCR variant only).
     *
     * @param address the GCR Group Address
     */
    void SetGcrGroupAddress(const Mac48Address& address);

    /**
     * Check if the current Ack Policy is immediate.
     *
     * @return true if the current Ack Policy is immediate,
     *         false otherwise
     */
    bool MustSendHtImmediateAck() const;
    /**
     * Return the BlockAckRequest type.
     *
     * @return the type of the BlockAckRequest
     */
    BlockAckReqType GetType() const;
    /**
     * Return the Traffic ID (TID).
     *
     * @return TID
     */
    uint8_t GetTidInfo() const;
    /**
     * Return the starting sequence number.
     *
     * @return the starting sequence number
     */
    uint16_t GetStartingSequence() const;
    /**
     * @return the GCR Group Address (GCR variant only)
     */
    Mac48Address GetGcrGroupAddress() const;
    /**
     * @return whether the variant of this BlockAckReq is Basic
     */
    bool IsBasic() const;
    /**
     * @return whether the variant of this BlockAckReq is Compressed
     */
    bool IsCompressed() const;
    /**
     * @return whether the variant of this BlockAckReq is Extended Compressed
     */
    bool IsExtendedCompressed() const;
    /**
     * @return whether the variant of this BlockAckReq is Multi-TID
     */
    bool IsMultiTid() const;
    /**
     * @return whether the variant of this BlockAckReq is GCR
     */
    bool IsGcr() const;

    /**
     * Return the starting sequence control.
     *
     * @return the starting sequence control
     */
    uint16_t GetStartingSequenceControl() const;

  private:
    /**
     * Set the starting sequence control with the given
     * sequence control value
     *
     * @param seqControl the sequence control value
     */
    void SetStartingSequenceControl(uint16_t seqControl);
    /**
     * Return the Block Ack control.
     *
     * @return the Block Ack control
     */
    uint16_t GetBarControl() const;
    /**
     * Set the Block Ack control.
     *
     * @param bar the BAR control value
     */
    void SetBarControl(uint16_t bar);

    /**
     * The LSB bit of the BAR control field is used only for the
     * HT (High Throughput) delayed block ack configuration.
     * For now only non HT immediate BlockAck is implemented so this field
     * is here only for a future implementation of HT delayed variant.
     */
    bool m_barAckPolicy;       ///< bar ack policy
    BlockAckReqType m_barType; ///< BAR type
    uint16_t m_tidInfo;        ///< TID info
    uint16_t m_startingSeq;    ///< starting seq
    Mac48Address m_gcrAddress; ///< GCR Group Address (GCR variant only)
};

/**
 * @ingroup wifi
 * @brief Headers for BlockAck response.
 *
 *  802.11 standard includes multiple BlockAck variants:
 *    - Basic BlockAck (unique type in 802.11e)
 *    - Compressed BlockAck
 *    - Multi-TID BlockAck
 *    - GCR BlockAck
 *    - Multi-STA BlockAck
 *  For now only basic BlockAck, compressed BlockAck, GCR BlockAck and Multi-STA BlockAck
 *  are supported.
 *  Basic BlockAck is also default variant.
 */
class CtrlBAckResponseHeader : public Header
{
  public:
    CtrlBAckResponseHeader();
    ~CtrlBAckResponseHeader() override;
    /**
     * @brief Get the type ID.
     * @return the object TypeId
     */
    static TypeId GetTypeId();
    TypeId GetInstanceTypeId() const override;
    void Print(std::ostream& os) const override;
    uint32_t GetSerializedSize() const override;
    void Serialize(Buffer::Iterator start) const override;
    uint32_t Deserialize(Buffer::Iterator start) override;

    /**
     * Enable or disable HT immediate Ack.
     *
     * @param immediateAck enable or disable HT immediate Ack
     */
    void SetHtImmediateAck(bool immediateAck);
    /**
     * Set the block ack type.
     *
     * @param type the BA type
     */
    void SetType(BlockAckType type);
    /**
     * For Block Ack variants other than Multi-STA Block Ack, set the TID_INFO subfield
     * of the BA Control field. For Multi-STA Block Acks, set the TID subfield of the
     * AID TID Info subfield of the Per AID TID Info subfield identified by the given
     * index.
     *
     * @param tid the traffic ID
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     */
    void SetTidInfo(uint8_t tid, std::size_t index = 0);
    /**
     * For Block Ack variants other than Multi-STA Block Ack, set the starting sequence
     * number to the given value. For Multi-STA Block Acks, set the starting sequence
     * number in the Per AID TID Info subfield identified by the given index to the
     * given value.
     *
     * @param seq the starting sequence number
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     */
    void SetStartingSequence(uint16_t seq, std::size_t index = 0);
    /**
     * Set the GCR Group address (GCR variant only).
     *
     * @param address the GCR Group Address
     */
    void SetGcrGroupAddress(const Mac48Address& address);

    /**
     * Check if the current Ack Policy is immediate.
     *
     * @return true if the current Ack Policy is immediate,
     *         false otherwise
     */
    bool MustSendHtImmediateAck() const;
    /**
     * Return the block ack type ID.
     *
     * @return type
     */
    BlockAckType GetType() const;
    /**
     * For Block Ack variants other than Multi-STA Block Ack, get the TID_INFO subfield
     * of the BA Control field. For Multi-STA Block Acks, get the TID subfield of the
     * AID TID Info subfield of the Per AID TID Info subfield identified by the given
     * index.
     *
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     * @return the Traffic ID
     */
    uint8_t GetTidInfo(std::size_t index = 0) const;
    /**
     * For Block Ack variants other than Multi-STA Block Ack, get the starting sequence
     * number. For Multi-STA Block Acks, get the starting sequence number in the
     * Per AID TID Info subfield identified by the given index.
     *
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     * @return the starting sequence number
     */
    uint16_t GetStartingSequence(std::size_t index = 0) const;
    /**
     * @return the GCR Group Address (GCR variant only)
     */
    Mac48Address GetGcrGroupAddress() const;
    /**
     * @return whether the variant of this BlockAckReq is Basic
     */
    bool IsBasic() const;
    /**
     * @return whether the variant of this BlockAckReq is Compressed
     */
    bool IsCompressed() const;
    /**
     * @return whether the variant of this BlockAckReq is Extended Compressed
     */
    bool IsExtendedCompressed() const;
    /**
     * @return whether the variant of this BlockAckReq is Multi-TID
     */
    bool IsMultiTid() const;
    /**
     * @return whether the variant of this BlockAckReq is GCR
     */
    bool IsGcr() const;
    /**
     * @return whether the variant of this BlockAckReq is Multi-STA
     */
    bool IsMultiSta() const;

    /**
     * For Multi-STA Block Acks, set the AID11 subfield of the Per AID TID Info
     * subfield identified by the given index to the given value
     *
     * @param aid the AID11 value
     * @param index the index of the Per AID TID Info subfield
     */
    void SetAid11(uint16_t aid, std::size_t index);
    /**
     * For Multi-STA Block Acks, get the AID11 subfield of the Per AID TID Info
     * subfield identified by the given index.
     *
     * @param index the index of the Per AID TID Info subfield
     * @return the AID11 subfield
     */
    uint16_t GetAid11(std::size_t index) const;
    /**
     * For Multi-STA Block Acks, set the Ack Type subfield of the Per AID TID Info
     * subfield identified by the given index to the given value
     *
     * @param type the ack type value
     * @param index the index of the Per AID TID Info subfield
     */
    void SetAckType(bool type, std::size_t index);
    /**
     * For Multi-STA Block Acks, get the Ack Type subfield of the Per AID TID Info
     * subfield identified by the given index.
     *
     * @param index the index of the Per AID TID Info subfield
     * @return the Ack Type
     */
    bool GetAckType(std::size_t index) const;
    /**
     * For Multi-STA Block Acks, set the RA subfield of the Per AID TID Info
     * subfield (with AID11 subfield equal to 2045) identified by the given index
     * to the given MAC address.
     *
     * @param ra the MAC address
     * @param index the index of the Per AID TID Info subfield
     */
    void SetUnassociatedStaAddress(const Mac48Address& ra, std::size_t index);
    /**
     * For Multi-STA Block Acks, get the RA subfield of the Per AID TID Info
     * subfield (with AID11 subfield equal to 2045) identified by the given index
     * to the given MAC address.
     *
     * @param index the index of the Per AID TID Info subfield
     * @return the MAC address stored in the RA subfield
     */
    Mac48Address GetUnassociatedStaAddress(std::size_t index) const;
    /**
     * For Multi-STA Block Acks, get the number of Per AID TID Info subfields
     * included in this Block Ack.
     *
     * @return the number of Per AID TID Info subfields included in this Multi-STA Block Ack
     */
    std::size_t GetNPerAidTidInfoSubfields() const;
    /**
     * For Multi-STA Block Acks, get the indices of the Per AID TID Info subfields
     * carrying the given AID in the AID11 subfield.
     *
     * @param aid the given AID
     * @return a vector containing the indices of the Per AID TID Info subfields
     *         carrying the given AID in the AID11 subfield
     */
    std::vector<uint32_t> FindPerAidTidInfoWithAid(uint16_t aid) const;

    /**
     * Record in the bitmap that the packet with the given sequence number was
     * received. For Multi-STA Block Acks, <i>index</i> identifies the Per AID
     * TID Info subfield whose bitmap has to be updated.
     *
     * @param seq the sequence number of the received packet
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     */
    void SetReceivedPacket(uint16_t seq, std::size_t index = 0);
    /**
     * Set the bitmap that the packet with the given sequence
     * number and fragment number was received.
     *
     * @param seq the sequence number
     * @param frag the fragment number
     */
    void SetReceivedFragment(uint16_t seq, uint8_t frag);
    /**
     * Check if the packet with the given sequence number was acknowledged in this
     * BlockAck response. For Multi-STA Block Acks, <i>index</i> identifies the
     * Per AID TID Info subfield whose bitmap has to be checked.
     *
     * @param seq the sequence number to be checked
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     * @return true if the packet with the given sequence number
     *         was ACKed in this BlockAck response, false otherwise
     */
    bool IsPacketReceived(uint16_t seq, std::size_t index = 0) const;
    /**
     * Check if the packet with the given sequence number
     * and fragment number was acknowledged in this BlockAck response.
     *
     * @param seq the sequence number
     * @param frag the fragment number
     * @return true if the packet with the given sequence number
     *         and sequence number was acknowledged in this BlockAck response,
     *         false otherwise
     */
    bool IsFragmentReceived(uint16_t seq, uint8_t frag) const;

    /**
     * Return the value of the Starting Sequence Control subfield. For Multi-STA
     * Block Acks, <i>index</i> identifies the Per AID TID Info subfield whose
     * Starting Sequence Control subfield has to be returned.
     *
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     * @return the value of the Starting Sequence Control subfield
     */
    uint16_t GetStartingSequenceControl(std::size_t index = 0) const;
    /**
     * Set the Starting Sequence Control subfield with the given sequence control
     * value. For Multi-STA Block Acks, <i>index</i> identifies the Per AID TID Info
     * subfield whose Starting Sequence Control subfield has to be set.
     *
     * @param seqControl the raw sequence control value
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     */
    void SetStartingSequenceControl(uint16_t seqControl, std::size_t index = 0);
    /**
     * Return a const reference to the bitmap from the BlockAck response header.
     * For Multi-STA Block Acks, return a const reference to the bitmap included
     * in the Per AID TID Info subfield identified by <i>index</i>.
     *
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     * @return a const reference to the bitmap from the BlockAck response header
     */
    const std::vector<uint8_t>& GetBitmap(std::size_t index = 0) const;

    /**
     * Reset the bitmap to 0. For Multi-STA Block Acks, reset the bitmap included
     * in the Per AID TID Info subfield identified by <i>index</i>.
     *
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     */
    void ResetBitmap(std::size_t index = 0);

  private:
    /**
     * Return the Block Ack control.
     *
     * @return the Block Ack control
     */
    uint16_t GetBaControl() const;
    /**
     * Set the Block Ack control.
     *
     * @param ba the BA control to set
     */
    void SetBaControl(uint16_t ba);

    /**
     * Serialize bitmap to the given buffer. For Multi-STA Block Acks, <i>index</i>
     * identifies the Per AID TID Info subfield whose bitmap has to be serialized.
     *
     * @param start iterator pointing to the beginning of the buffer to write into.
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     * @return Buffer::Iterator to the next available buffer
     */
    Buffer::Iterator SerializeBitmap(Buffer::Iterator start, std::size_t index = 0) const;
    /**
     * Deserialize bitmap from the given buffer. For Multi-STA Block Acks, <i>index</i>
     * identifies the Per AID TID Info subfield whose bitmap has to be deserialized.
     *
     * @param start iterator pointing to the beginning of the buffer to read from.
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     * @return Buffer::Iterator to the next available buffer
     */
    Buffer::Iterator DeserializeBitmap(Buffer::Iterator start, std::size_t index = 0);

    /**
     * This function is used to correctly index in both bitmap
     * and compressed bitmap, one bit or one block of 16 bits respectively.
     *
     * for more details see 7.2.1.8 in IEEE 802.11n/D4.00
     *
     * @param seq the sequence number
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     *
     * @return If we are using basic block ack, return value represents index of
     * block of 16 bits for packet having sequence number equals to <i>seq</i>.
     * If we are using compressed block ack, return value represents bit
     * to set to 1 in the compressed bitmap to indicate that packet having
     * sequence number equals to <i>seq</i> was correctly received.
     */
    uint16_t IndexInBitmap(uint16_t seq, std::size_t index = 0) const;

    /**
     * Check if sequence number <i>seq</i> can be acknowledged in the bitmap. For
     * Multi-STA Block Acks, check if sequence number <i>seq</i> can be acknowledged
     * in the bitmap included in the Per AID TID Info subfield identified by <i>index</i>.
     *
     * @param seq the sequence number
     * @param index the index of the Per AID TID Info subfield (Multi-STA Block Ack only)
     * @return true if the sequence number is concerned by the bitmap
     */
    bool IsInBitmap(uint16_t seq, std::size_t index = 0) const;

    /**
     * The LSB bit of the BA control field is used only for the
     * HT (High Throughput) delayed block ack configuration.
     * For now only non HT immediate block ack is implemented so this field
     * is here only for a future implementation of HT delayed variant.
     */
    bool m_baAckPolicy;    ///< BA Ack Policy
    BlockAckType m_baType; ///< BA type
    uint16_t m_tidInfo;    ///< TID info (reserved if Multi-STA Block Ack)

    /**
     * The following structure can hold the BA Information field for the Basic and
     * Compressed variants, one instance of the {Per TID Info, Block Ack Starting
     * Sequence Control, Block Ack Bitmap} subfields for the Multi-TID variant or
     * one instance of the Per AID TID Info subfield for the Multi-STA variant
     * (which includes the AID TID Info, Block Ack Starting Sequence Control and
     * Block Ack Bitmap subfields).
     */
    struct BaInfoInstance
    {
        uint16_t m_aidTidInfo;         //!< Reserved for Basic and Compressed
                                       //!< Per TID Info subfield for Multi-TID
                                       //!< AID TID Info subfield for Multi-STA
        uint16_t m_startingSeq;        //!< Block Ack Starting Sequence Control subfield
        std::vector<uint8_t> m_bitmap; //!< block ack bitmap
        Mac48Address m_address;        //!< RA subfield (address of an unassociated station) for
                                       //!< Multi-STA variant; GCR Group Address subfield for GCR
                                       //!< variant; reserved for other variants
    };

    std::vector<BaInfoInstance> m_baInfo; //!< BA Information field
};

/**
 * @ingroup wifi
 * The different Trigger frame types.
 */
enum class TriggerFrameType : uint8_t
{
    BASIC_TRIGGER = 0,      // Basic
    BFRP_TRIGGER = 1,       // Beamforming Report Poll
    MU_BAR_TRIGGER = 2,     // Multi-User Block Ack Request
    MU_RTS_TRIGGER = 3,     // Multi-User Request To Send
    BSRP_TRIGGER = 4,       // Buffer Status Report Poll
    GCR_MU_BAR_TRIGGER = 5, // Groupcast with Retries MU-BAR
    BQRP_TRIGGER = 6,       // Bandwidth Query Report Poll
    NFRP_TRIGGER = 7        // NDP Feedback Report Poll
};

/**
 * @ingroup wifi
 * The different variants for Common Info field and User Info field of Trigger Frames.
 */
enum class TriggerFrameVariant : uint8_t
{
    HE = 0,
    EHT
};

/**
 * @ingroup wifi
 * @brief User Info field of Trigger frames.
 *
 * Trigger frames, introduced by 802.11ax amendment (see Section 9.3.1.23 of D3.0),
 * include one or more User Info fields, each of which carries information about the
 * HE TB PPDU that the addressed station sends in response to the Trigger frame.
 */
class CtrlTriggerUserInfoField
{
  public:
    /**
     * Constructor
     *
     * @param triggerType the Trigger frame type
     * @param variant the Trigger Frame variant
     */
    CtrlTriggerUserInfoField(TriggerFrameType triggerType, TriggerFrameVariant variant);
    /**
     * Copy assignment operator.
     *
     * @param userInfo the User Info field to copy
     * @return a reference to the copied object
     *
     * Checks that the given User Info fields is included in the same type
     * of Trigger Frame.
     */
    CtrlTriggerUserInfoField& operator=(const CtrlTriggerUserInfoField& userInfo);
    /**
     * Destructor
     */
    ~CtrlTriggerUserInfoField();
    /**
     * Print the content of this User Info field
     *
     * @param os output stream
     */
    void Print(std::ostream& os) const;
    /**
     * Get the expected size of this User Info field
     *
     * @return the expected size of this User Info field.
     */
    uint32_t GetSerializedSize() const;
    /**
     * Serialize the User Info field to the given buffer.
     *
     * @param start an iterator which points to where the header should
     *        be written
     * @return Buffer::Iterator to the next available buffer
     */
    Buffer::Iterator Serialize(Buffer::Iterator start) const;
    /**
     * Deserialize the User Info field from the given buffer.
     *
     * @param start an iterator which points to where the header should
     *        read from
     * @return Buffer::Iterator to the next available buffer
     */
    Buffer::Iterator Deserialize(Buffer::Iterator start);
    /**
     * Get the type of the Trigger Frame this User Info field belongs to.
     *
     * @return the type of the Trigger Frame this User Info field belongs to
     */
    TriggerFrameType GetType() const;
    /**
     * @return the preamble type of the TB PPDU solicited by this User Info field.
     */
    WifiPreamble GetPreambleType() const;
    /**
     * Set the AID12 subfield, which carries the 12 LSBs of the AID of the
     * station for which this User Info field is intended. The whole AID can
     * be passed, since the passed value is properly masked.
     *
     * @param aid the value for the AID12 subfield
     */
    void SetAid12(uint16_t aid);
    /**
     * Get the value of the AID12 subfield.
     *
     * @return the AID12 subfield
     */
    uint16_t GetAid12() const;
    /**
     * Check if this User Info field allocates a Random Access RU for stations
     * associated with the AP that transmitted the Trigger frame.
     *
     * @return true if a Random Access RU for associated stations is allocated
     */
    bool HasRaRuForAssociatedSta() const;
    /**
     * Check if this User Info field allocates a Random Access RU for stations
     * not associated with the AP that transmitted the Trigger frame.
     *
     * @return true if a Random Access RU for unassociated stations is allocated
     */
    bool HasRaRuForUnassociatedSta() const;
    /**
     * Set the RU Allocation subfield according to the specified RU.
     * This method cannot be called on MU-RTS Trigger Frames (call SetMuRtsRuAllocation instead).
     *
     * @param ru the RU this User Info field is allocating
     */
    void SetRuAllocation(WifiRu::RuSpec ru);
    /**
     * Get the RU specified by the RU Allocation subfield.
     * This method cannot be called on MU-RTS Trigger Frames (call GetMuRtsRuAllocation instead).
     *
     * @return the RU this User Info field is allocating
     */
    WifiRu::RuSpec GetRuAllocation() const;
    /**
     * Set the RU Allocation subfield based on the given value for the B7-B1 bits.
     * This method can only be called on MU-RTS Trigger Frames.
     *
     * B7–B1 of the RU Allocation subfield is set to indicate the primary 20 MHz channel
     * as follows:
     * - 61 if the primary 20 MHz channel is the only 20 MHz channel or the lowest frequency
     *   20 MHz channel in the primary 40 MHz channel or primary 80 MHz channel
     * - 62 if the primary 20 MHz channel is the second lowest frequency 20 MHz channel in the
     *   primary 40 MHz channel or primary 80 MHz channel
     * - 63 if the primary 20 MHz channel is the third lowest frequency 20 MHz channel in the
     *   primary 80 MHz channel
     * - 64 if the primary 20 MHz channel is the fourth lowest frequency 20 MHz channel in the
     *   primary 80 MHz channel
     *
     * B7–B1 of the RU Allocation subfield is set to indicate the primary 40 MHz channel
     * as follows:
     * - 65 if the primary 40 MHz channel is the only 40 MHz channel or the lowest frequency
     *   40 MHz channel in the primary 80 MHz channel
     * - 66 if the primary 40 MHz channel is the second lowest frequency 40 MHz channel in the
     *   primary 80 MHz channel
     *
     * B7–B1 of the RU Allocation subfield is set to 67 to indicate the primary 80 MHz channel.
     *
     * B7–B1 of the RU Allocation subfield is set to 68 to indicate the primary and secondary
     * 80 MHz channel.
     *
     * @param value the value for B7–B1 of the RU Allocation subfield
     */
    void SetMuRtsRuAllocation(uint8_t value);
    /**
     * This method can only be called on MU-RTS Trigger Frames.
     *
     * @return the value of B7–B1 of the RU Allocation subfield (\see SetMuRtsRuAllocation)
     */
    uint8_t GetMuRtsRuAllocation() const;
    /**
     * Set the UL FEC Coding Type subfield, which indicates whether BCC or LDPC is used
     *
     * @param ldpc whether to use LDPC or not
     */
    void SetUlFecCodingType(bool ldpc);
    /**
     * Get the UL FEC Coding Type subfield, which indicates whether BCC or LDPC is used
     *
     * @return true if LDPC is used
     */
    bool GetUlFecCodingType() const;
    /**
     * Set the UL MCS subfield, which indicates the MCS of the solicited HE TB PPDU
     *
     * @param mcs the MCS index (a value between 0 and 11)
     */
    void SetUlMcs(uint8_t mcs);
    /**
     * Get the UL MCS subfield, which indicates the MCS of the solicited HE TB PPDU
     *
     * @return the MCS index (a value between 0 and 11)
     */
    uint8_t GetUlMcs() const;
    /**
     * Set the UL DCM subfield, which indicates whether or not DCM is used.
     * This method can only be used with HE variant User Info field.
     *
     * @param dcm whether to use DCM or not
     */
    void SetUlDcm(bool dcm);
    /**
     * Get the UL DCM subfield, which indicates whether or not DCM is used
     * This method can only be used with HE variant User Info field.
     *
     * @return true if DCM is used
     */
    bool GetUlDcm() const;
    /**
     * Set the SS Allocation subfield, which is present when the AID12 subfield
     * is neither 0 nor 2045. This method must be called after setting the AID12
     * subfield to a value other than 0 and 2045.
     *
     * @param startingSs the starting spatial stream (a value from 1 to 8)
     * @param nSs the number of spatial streams (a value from 1 to 8)
     */
    void SetSsAllocation(uint8_t startingSs, uint8_t nSs);
    /**
     * Get the starting spatial stream.
     *
     * @return the starting spatial stream (a value between 1 and 8)
     */
    uint8_t GetStartingSs() const;
    /**
     * Get the number of spatial streams.
     *
     * @return the number of spatial streams (a value between 1 and 8)
     */
    uint8_t GetNss() const;
    /**
     * Set the RA-RU Information subfield, which is present when the AID12 subfield
     * is 0 or 2045. This method must be called after setting the AID12 subfield to
     * 0 or 2045.
     *
     * @param nRaRu the number (from 1 to 32) of contiguous RUs allocated for Random Access.
     * @param moreRaRu whether RA-RUs are allocated in subsequent Trigger frames
     */
    void SetRaRuInformation(uint8_t nRaRu, bool moreRaRu);
    /**
     * Get the number of contiguous RUs for Random Access. This method can only be
     * called if the AID12 subfield has been set to 0 or 2045
     *
     * @return the number of contiguous RA-RUs (a value between 1 and 32)
     */
    uint8_t GetNRaRus() const;
    /**
     * Return true if more RA-RUs are allocated in subsequent Trigger frames
     * that are sent before the end of the current TXOP. This method can only be
     * called if the AID12 subfield has been set to 0 or 2045
     *
     * @return true if more RA-RUs are allocated in subsequent Trigger frames
     */
    bool GetMoreRaRu() const;
    /**
     * Set the UL Target Receive Power subfield to indicate to the station to transmit an
     * HE TB PPDU response at its maximum transmit power for the assigned MCS
     */
    void SetUlTargetRxPowerMaxTxPower();
    /**
     * Set the UL Target Receive Power subfield to indicate the expected receive signal
     * power in dBm
     *
     * @param dBm the expected receive signal power (a value between -110 and -20)
     */
    void SetUlTargetRxPower(int8_t dBm);
    /**
     * Return true if the UL Target Receive Power subfield indicates to the station to transmit
     * an HE TB PPDU response at its maximum transmit power for the assigned MCS
     *
     * @return true if the UL Target Receive Power subfield indicates to the station to transmit
     * an HE TB PPDU response at its maximum transmit power for the assigned MCS
     */
    bool IsUlTargetRxPowerMaxTxPower() const;
    /**
     * Get the expected receive signal power for the solicited HE TB PPDU. This
     * method can only be called if IsUlTargetRxPowerMaxTxPower returns false.
     *
     * @return the expected receive signal power in dBm
     */
    int8_t GetUlTargetRxPower() const;
    /**
     * Set the Trigger Dependent User Info subfield for Basic Trigger frames.
     *
     * @param spacingFactor the MPDU MU spacing factor
     * @param tidLimit the value for the TID Aggregation Limit subfield
     * @param prefAc the lowest AC recommended for aggregation of MPDUs
     */
    void SetBasicTriggerDepUserInfo(uint8_t spacingFactor, uint8_t tidLimit, AcIndex prefAc);
    /**
     * Get the MPDU MU spacing factor. This method can only be called if this
     * User Info field is included in a Basic Trigger frame.
     *
     * @return the MPDU MU spacing factor
     */
    uint8_t GetMpduMuSpacingFactor() const;
    /**
     * Get the TID Aggregation Limit. This method can only be called if this
     * User Info field is included in a Basic Trigger frame.
     *
     * @return the TID Aggregation Limit
     */
    uint8_t GetTidAggregationLimit() const;
    /**
     * Get the Preferred AC subfield. This method can only be called if this
     * User Info field is included in a Basic Trigger frame.
     *
     * @return the Preferred AC subfield
     */
    AcIndex GetPreferredAc() const;
    /**
     * Set the Trigger Dependent User Info subfield for the MU-BAR variant of
     * Trigger frames, which includes a BAR Control subfield and a BAR Information
     * subfield. The BAR Control subfield must indicate either a Compressed
     * BlockAckReq variant or a Multi-TID BlockAckReq variant.
     *
     * @param bar the BlockAckRequest header object including the BAR Control
     *            subfield and the BAR Information subfield
     */
    void SetMuBarTriggerDepUserInfo(const CtrlBAckRequestHeader& bar);
    /**
     * Get the Trigger Dependent User Info subfield for the MU-BAR variant of
     * Trigger frames, which includes a BAR Control subfield and a BAR Information
     * subfield. The BAR Control subfield must indicate either a Compressed
     * BlockAckReq variant or a Multi-TID BlockAckReq variant.
     *
     * @return the BlockAckRequest header object including the BAR Control
     *         subfield and the BAR Information subfield
     */
    const CtrlBAckRequestHeader& GetMuBarTriggerDepUserInfo() const;

  private:
    TriggerFrameVariant m_variant; //!< User Info field variant

    uint16_t m_aid12;       //!< Association ID of the addressed station
    uint8_t m_ruAllocation; //!< RU Allocation
    bool m_ulFecCodingType; //!< UL FEC Coding Type
    uint8_t m_ulMcs;        //!< MCS to be used by the addressed station
    bool m_ulDcm;           //!< whether or not to use Dual Carrier Modulation (HE variant only)
    bool m_ps160;           //!< identifies the location of the RU (EHT variant only)

    union {
        struct
        {
            uint8_t startingSs; //!< Starting spatial stream
            uint8_t nSs;        //!< Number of spatial streams
        } ssAllocation;         //!< Used when AID12 is neither 0 nor 2045

        struct
        {
            uint8_t nRaRu; //!< Number of Random Access RUs
            bool moreRaRu; //!< More RA-RU in subsequent Trigger frames
        } raRuInformation; //!< Used when AID12 is 0 or 2045
    } m_bits26To31;        //!< Fields occupying bits 26-31 in the User Info field

    uint8_t m_ulTargetRxPower;               //!< Expected receive signal power
    TriggerFrameType m_triggerType;          //!< Trigger frame type
    uint8_t m_basicTriggerDependentUserInfo; //!< Basic Trigger variant of Trigger Dependent User
                                             //!< Info subfield
    CtrlBAckRequestHeader
        m_muBarTriggerDependentUserInfo; //!< MU-BAR variant of Trigger Dependent User Info subfield
};

/**
 * @ingroup wifi
 * @brief Special User Info field of Trigger frames.
 *
 * Trigger frames have been extended by 802.11be amendment and may include one Special User Info
 * field for a solicited EHT TB PPDU (see Section 9.3.1.22.3 of D7.0). The Special User Info field
 * is located immediately after the Common Info field, it does not carry user specific information
 * but carries extended common information not provided in the Common Info field.
 */
class CtrlTriggerSpecialUserInfoField
{
  public:
    /**
     * Constructor
     *
     * @param triggerType the Trigger frame type
     */
    explicit CtrlTriggerSpecialUserInfoField(TriggerFrameType triggerType);

    /**
     * Copy assignment operator.
     *
     * @param other the Special User Info field to copy
     * @return a reference to the copied object
     *
     * Checks that the given Special User Info fields is included in the same type of Trigger Frame.
     */
    CtrlTriggerSpecialUserInfoField& operator=(const CtrlTriggerSpecialUserInfoField& other);

    /**
     * Get the expected size of this Special User Info field
     *
     * @return the expected size of this Special User Info field.
     */
    uint32_t GetSerializedSize() const;

    /**
     * Serialize the Special User Info field to the given buffer.
     *
     * @param start an iterator which points to where the header should
     *        be written
     * @return Buffer::Iterator to the next available buffer
     */
    Buffer::Iterator Serialize(Buffer::Iterator start) const;

    /**
     * Deserialize the Special User Info field from the given buffer.
     *
     * @param start an iterator which points to where the header should
     *        read from
     * @return Buffer::Iterator to the next available buffer
     */
    Buffer::Iterator Deserialize(Buffer::Iterator start);

    /**
     * Get the type of the Trigger Frame this Special User Info field belongs to.
     *
     * @return the type of the Trigger Frame this Special User Info field belongs to
     */
    TriggerFrameType GetType() const;

    /**
     * Set the UL Bandwidth Extension subfield value of the solicited EHT TB PPDU.
     *
     * @param bw bandwidth (allowed values: 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz)
     */
    void SetUlBwExt(MHz_u bw);

    /**
     * Get the UL Bandwidth Extension subfield value of the solicited EHT TB PPDU.
     *
     * @return the UL Bandwidth Extension subfield value
     */
    uint8_t GetUlBwExt() const;

    /**
     * Set the Trigger Dependent Special User Info subfield for the MU-BAR variant of Trigger
     * frames, which includes the BAR Type subfield. The BAR Type subfield must indicate a
     * Compressed BAR in an MU BAR Trigger frame.
     *
     * @param bar the BlockAckRequest header object including the BAR Control
     *            subfield and the BAR Information subfield
     */
    void SetMuBarTriggerDepUserInfo(const CtrlBAckRequestHeader& bar);

    /**
     * Get the Trigger Dependent Special User Info subfield for the MU-BAR variant of
     * Trigger frames, which includes a BAR Type subfield.
     *
     * @return the BlockAckRequest header object including the BAR Control
     *         subfield and the BAR Information subfield
     */
    const CtrlBAckRequestHeader& GetMuBarTriggerDepUserInfo() const;

  private:
    TriggerFrameType m_triggerType{};                        //!< Trigger type
    uint8_t m_ulBwExt{};                                     //!< UL Bandwidth Extension
    CtrlBAckRequestHeader m_muBarTriggerDependentUserInfo{}; //!< MU-BAR variant of Trigger
                                                             //!< Dependent User Info subfield
};

/**
 * @ingroup wifi
 * @brief Headers for Trigger frames.
 *
 * 802.11ax amendment defines eight types of Trigger frames (see Section 9.3.1.23 of D3.0):
 *   - Basic
 *   - Beamforming Report Poll (BFRP)
 *   - Multi-User Block Ack Request (MU-BAR)
 *   - Multi-User Request To Send (MU-RTS)
 *   - Buffer Status Report Poll (BSRP)
 *   - Groupcast with Retries (GCR) MU-BAR
 *   - Bandwidth Query Report Poll (BQRP)
 *   - NDP Feedback Report Poll (NFRP)
 * For now only the Basic, MU-BAR, MU-RTS, BSRP and BQRP variants are supported.
 * Basic Trigger is also the default variant.
 *
 * The Padding field is optional, given that other techniques (post-EOF A-MPDU
 * padding, aggregating other MPDUs in the A-MPDU) are available to satisfy the
 * minimum time requirement. The size in bytes of the Padding field is configurable.
 */
class CtrlTriggerHeader : public Header
{
  public:
    CtrlTriggerHeader();
    /**
     * @brief Constructor
     *
     * Construct a Trigger Frame of the given type from the values stored in the
     * given TX vector. In particular:
     *   - the UL Bandwidth, UL Length and GI And LTF Type subfields of the Common Info
     *     field are set based on the values stored in the TX vector;
     *   - as many User Info fields as the number of entries in the HeMuUserInfoMap
     *     of the TX vector are added to the Trigger Frame. The AID12, RU Allocation,
     *     UL MCS and SS Allocation subfields of each User Info field are set based
     *     on the values stored in the corresponding entry of the HeMuUserInfoMap.
     *
     * This constructor cannot be used to construct MU-RTS Trigger Frames.
     *
     * @param type the Trigger frame type
     * @param txVector the TX vector used to build this Trigger Frame
     */
    CtrlTriggerHeader(TriggerFrameType type, const WifiTxVector& txVector);
    ~CtrlTriggerHeader() override;
    /**
     * Copy assignment operator.
     *
     * @param trigger the Trigger frame to copy
     * @return a reference to the copied object
     *
     * Ensure that the type of this Trigger Frame is set to the type of the given
     * Trigger Frame before copying the User Info fields.
     */
    CtrlTriggerHeader& operator=(const CtrlTriggerHeader& trigger);
    /**
     * @brief Get the type ID.
     * @return the object TypeId
     */
    static TypeId GetTypeId();
    TypeId GetInstanceTypeId() const override;
    void Print(std::ostream& os) const override;
    uint32_t GetSerializedSize() const override;
    void Serialize(Buffer::Iterator start) const override;
    uint32_t Deserialize(Buffer::Iterator start) override;

    /**
     * Set the Common Info field variant.
     *
     * For the moment, all User Info fields are of the same variant type, hence we
     * forbid changing the Common Info field variant type after adding User Info fields.
     *
     * @param variant the Common Info field variant
     */
    void SetVariant(TriggerFrameVariant variant);
    /**
     * Get the Common Info field variant.
     *
     * @return the Common Info field variant
     */
    TriggerFrameVariant GetVariant() const;
    /**
     * Set the Trigger frame type.
     *
     * @param type the Trigger frame type
     */
    void SetType(TriggerFrameType type);
    /**
     * Get the Trigger Frame type.
     *
     * @return the Trigger Frame type
     */
    TriggerFrameType GetType() const;
    /**
     * Return a string corresponding to the Trigger Frame type.
     *
     * @returns a string corresponding to the Trigger Frame type.
     */
    const char* GetTypeString() const;
    /**
     * Return a string corresponding to the given Trigger Frame type.
     *
     * @param type the Trigger Frame type
     * @returns a string corresponding to the Trigger Frame type.
     */
    static const char* GetTypeString(TriggerFrameType type);
    /**
     * Check if this is a Basic Trigger frame.
     *
     * @return true if this is a Basic Trigger frame,
     *         false otherwise
     */
    bool IsBasic() const;
    /**
     * Check if this is a Beamforming Report Poll Trigger frame.
     *
     * @return true if this is a Beamforming Report Poll Trigger frame,
     *         false otherwise
     */
    bool IsBfrp() const;
    /**
     * Check if this is a MU-BAR Trigger frame.
     *
     * @return true if this is a MU-BAR Trigger frame,
     *         false otherwise
     */
    bool IsMuBar() const;
    /**
     * Check if this is a MU-RTS Trigger frame.
     *
     * @return true if this is a MU-RTS Trigger frame,
     *         false otherwise
     */
    bool IsMuRts() const;
    /**
     * Check if this is a Buffer Status Report Poll Trigger frame.
     *
     * @return true if this is a Buffer Status Report Poll Trigger frame,
     *         false otherwise
     */
    bool IsBsrp() const;
    /**
     * Check if this is a Groupcast with Retries (GCR) MU-BAR Trigger frame.
     *
     * @return true if this is a Groupcast with Retries (GCR) MU-BAR Trigger frame,
     *         false otherwise
     */
    bool IsGcrMuBar() const;
    /**
     * Check if this is a Bandwidth Query Report Poll Trigger frame.
     *
     * @return true if this is a Bandwidth Query Report Poll Trigger frame,
     *         false otherwise
     */
    bool IsBqrp() const;
    /**
     * Check if this is a NDP Feedback Report Poll Trigger frame.
     *
     * @return true if this is a NDP Feedback Report Poll Trigger frame,
     *         false otherwise
     */
    bool IsNfrp() const;
    /**
     * Set the UL Length subfield of the Common Info field.
     *
     * @param len the value for the UL Length subfield
     */
    void SetUlLength(uint16_t len);
    /**
     * Get the UL Length subfield of the Common Info field.
     *
     * @return the UL Length subfield
     */
    uint16_t GetUlLength() const;
    /**
     * Get the TX vector that the station with the given STA-ID will use to send
     * the HE TB PPDU solicited by this Trigger Frame. Note that the TX power
     * level is not set by this method.
     *
     * @param staId the STA-ID of a station addressed by this Trigger Frame
     * @return the TX vector of the solicited HE TB PPDU
     */
    WifiTxVector GetHeTbTxVector(uint16_t staId) const;
    /**
     * Set the More TF subfield of the Common Info field.
     *
     * @param more the value for the More TF subfield
     */
    void SetMoreTF(bool more);
    /**
     * Get the More TF subfield of the Common Info field.
     *
     * @return the More TF subfield
     */
    bool GetMoreTF() const;
    /**
     * Set the CS Required subfield of the Common Info field.
     *
     * @param cs the value for the CS Required subfield
     */
    void SetCsRequired(bool cs);
    /**
     * Get the CS Required subfield of the Common Info field.
     *
     * @return the CS Required subfield
     */
    bool GetCsRequired() const;
    /**
     * Set the bandwidth of the solicited HE/EHT TB PPDU.
     *
     * @param bw bandwidth (allowed values: 20, 40, 80, 160, 320)
     */
    void SetUlBandwidth(MHz_u bw);
    /**
     * Get the bandwidth of the solicited HE/EHT TB PPDU.
     *
     * @return the bandwidth (20, 40, 80, 160 or 320)
     */
    MHz_u GetUlBandwidth() const;
    /**
     * Set the GI And LTF Type subfield of the Common Info field.
     * Allowed combinations are:
     *   - 1x LTF + 1.6us GI
     *   - 2x LTF + 1.6us GI
     *   - 4x LTF + 3.2us GI
     *
     * @param guardInterval the guard interval duration
     * @param ltfType the HE-LTF type (1, 2 or 4)
     */
    void SetGiAndLtfType(Time guardInterval, uint8_t ltfType);
    /**
     * Get the guard interval duration of the solicited HE/EHT TB PPDU.
     *
     * @return the guard interval duration of the solicited HE/EHT TB PPDU
     */
    Time GetGuardInterval() const;
    /**
     * Get the LTF type of the solicited HE/EHT TB PPDU.
     *
     * @return the LTF type of the solicited HE/EHT TB PPDU
     */
    uint8_t GetLtfType() const;
    /**
     * Set the AP TX Power subfield of the Common Info field.
     *
     * @param power the value (from -20 to 40) for the AP TX Power (dBm)
     */
    void SetApTxPower(int8_t power);
    /**
     * Get the power value (dBm) indicated by the AP TX Power subfield of the
     * Common Info field.
     *
     * @return the AP TX Power (dBm) per 20 MHz
     */
    int8_t GetApTxPower() const;
    /**
     * Set the UL Spatial Reuse subfield of the Common Info field.
     *
     * @param sr the value for the UL Spatial Reuse subfield
     */
    void SetUlSpatialReuse(uint16_t sr);
    /**
     * Get the UL Spatial Reuse subfield of the Common Info field.
     *
     * @return the UL Spatial Reuse subfield
     */
    uint16_t GetUlSpatialReuse() const;
    /**
     * Set the size in bytes of the Padding field. The Padding field, if present,
     * shall be at least two octets in length.
     *
     * @param size the size in bytes of the Padding field
     */
    void SetPaddingSize(std::size_t size);
    /**
     * @return the size in bytes of the Padding field
     */
    std::size_t GetPaddingSize() const;
    /**
     * Get a copy of the Common Info field of this Trigger frame.
     * Note that the User Info fields are excluded.
     *
     * @return a Trigger frame including a copy of the Common Info field of this frame.
     */
    CtrlTriggerHeader GetCommonInfoField() const;

    /**
     * Append a new User Info field to this Trigger frame and return
     * a non-const reference to it. Make sure to call this method after
     * setting the type of the Trigger frame.
     *
     * @return a non-const reference to the newly added User Info field
     */
    CtrlTriggerUserInfoField& AddUserInfoField();
    /**
     * Append the given User Info field to this Trigger frame and return
     * a non-const reference to it. Make sure that the type of the given
     * User Info field matches the type of this Trigger Frame.
     *
     * @param userInfo the User Info field to append to this Trigger Frame
     * @return a non-const reference to the newly added User Info field
     */
    CtrlTriggerUserInfoField& AddUserInfoField(const CtrlTriggerUserInfoField& userInfo);

    /// User Info fields list const iterator
    typedef std::list<CtrlTriggerUserInfoField>::const_iterator ConstIterator;

    /// User Info fields list iterator
    typedef std::list<CtrlTriggerUserInfoField>::iterator Iterator;

    /**
     * Remove a User Info field from the Trigger Frame.
     *
     * @param userInfoIt an iterator pointing to the User Info field to remove
     * @return an iterator following the removed User Info field
     */
    Iterator RemoveUserInfoField(ConstIterator userInfoIt);

    /**
     * @brief Get a const iterator pointing to the first User Info field in the list.
     *
     * @return a const iterator pointing to the first User Info field in the list
     */
    ConstIterator begin() const;
    /**
     * @brief Get a const iterator indicating past-the-last User Info field in the list.
     *
     * @return a const iterator indicating past-the-last User Info field in the list
     */
    ConstIterator end() const;
    /**
     * @brief Get an iterator pointing to the first User Info field in the list.
     *
     * @return an iterator pointing to the first User Info field in the list
     */
    Iterator begin();
    /**
     * @brief Get an iterator indicating past-the-last User Info field in the list.
     *
     * @return an iterator indicating past-the-last User Info field in the list
     */
    Iterator end();
    /**
     * @brief Get the number of User Info fields in this Trigger Frame.
     *
     * @return the number of User Info fields in this Trigger Frame
     */
    std::size_t GetNUserInfoFields() const;
    /**
     * Get a const iterator pointing to the first User Info field found (starting from
     * the one pointed to by the given iterator) whose AID12 subfield is set to
     * the given value.
     *
     * @param start a const iterator pointing to the User Info field to start the search from
     * @param aid12 the value of the AID12 subfield to match
     * @return a const iterator pointing to the User Info field matching the specified
     * criterion, if any, or an iterator indicating past-the-last User Info field.
     */
    ConstIterator FindUserInfoWithAid(ConstIterator start, uint16_t aid12) const;
    /**
     * Get a const iterator pointing to the first User Info field found whose AID12
     * subfield is set to the given value.
     *
     * @param aid12 the value of the AID12 subfield to match
     * @return a const iterator pointing to the User Info field matching the specified
     * criterion, if any, or an iterator indicating past-the-last User Info field.
     */
    ConstIterator FindUserInfoWithAid(uint16_t aid12) const;
    /**
     * Get a const iterator pointing to the first User Info field found (starting from
     * the one pointed to by the given iterator) which allocates a Random Access
     * RU for associated stations.
     *
     * @param start a const iterator pointing to the User Info field to start the search from
     * @return a const iterator pointing to the User Info field matching the specified
     * criterion, if any, or an iterator indicating past-the-last User Info field.
     */
    ConstIterator FindUserInfoWithRaRuAssociated(ConstIterator start) const;
    /**
     * Get a const iterator pointing to the first User Info field found which allocates
     * a Random Access RU for associated stations.
     *
     * @return a const iterator pointing to the User Info field matching the specified
     * criterion, if any, or an iterator indicating past-the-last User Info field.
     */
    ConstIterator FindUserInfoWithRaRuAssociated() const;
    /**
     * Get a const iterator pointing to the first User Info field found (starting from
     * the one pointed to by the given iterator) which allocates a Random Access
     * RU for unassociated stations.
     *
     * @param start a const iterator pointing to the User Info field to start the search from
     * @return a const iterator pointing to the User Info field matching the specified
     * criterion, if any, or an iterator indicating past-the-last User Info field.
     */
    ConstIterator FindUserInfoWithRaRuUnassociated(ConstIterator start) const;
    /**
     * Get a const iterator pointing to the first User Info field found which allocates
     * a Random Access RU for unassociated stations.
     *
     * @return a const iterator pointing to the User Info field matching the specified
     * criterion, if any, or an iterator indicating past-the-last User Info field.
     */
    ConstIterator FindUserInfoWithRaRuUnassociated() const;
    /**
     * Check the validity of this Trigger frame.
     * TODO Implement the checks listed in Section 27.5.3.2.3 of 802.11ax amendment
     * D3.0 (Allowed settings of the Trigger frame fields and TRS Control subfield).
     *
     * This function shall be invoked before transmitting and upon receiving
     * a Trigger frame.
     *
     * @return true if the Trigger frame is valid, false otherwise.
     */
    bool IsValid() const;

  private:
    /**
     * Common Info field
     */
    TriggerFrameVariant m_variant;  //!< Common Info field variant
    TriggerFrameType m_triggerType; //!< Trigger type
    uint16_t m_ulLength;            //!< Value for the L-SIG Length field
    bool m_moreTF;                  //!< True if a subsequent Trigger frame follows
    bool m_csRequired;              //!< Carrier Sense required
    uint8_t m_ulBandwidth;          //!< UL BW subfield
    uint8_t m_giAndLtfType;         //!< GI And LTF Type subfield
    uint8_t m_apTxPower;            //!< Tx Power used by AP to transmit the Trigger Frame
    uint16_t m_ulSpatialReuse;      //!< Value for the Spatial Reuse field in HE-SIG-A
    std::size_t m_padding;          //!< the size in bytes of the Padding field

    std::optional<CtrlTriggerSpecialUserInfoField>
        m_specialUserInfoField; //!< Special User Info field (EHT variant only)

    /**
     * List of User Info fields
     */
    std::list<CtrlTriggerUserInfoField> m_userInfoFields; //!< list of User Info fields
};

} // namespace ns3

#endif /* CTRL_HEADERS_H */
