#pragma once

#include "Layer.h"

/// @file

/// @namespace pcpp

/// @brief The main namespace for the PcapPlusPlus lib

namespace pcpp

{

#pragma pack(push, 1)

  /// @struct llc_header

  /// Logical Link Control (LLC) header

  struct llc_header

  {

    /// Destination Service Access Point

    uint8_t dsap,

        /// Source Service Access Point

        ssap,

        /// Control Field

        control;

  };

#pragma pack(pop)

  static_assert(sizeof(llc_header) == 3, "llc_header size is not 3 bytes");

  /// @class LLCLayer

  /// Represents Logical Link Control layer messages

  class LLCLayer : public Layer

  {

  public:

    /// A constructor that creates the layer from an existing packet raw data

    /// @param[in] data A pointer to the raw data (will be casted to llc_header)

    /// @param[in] dataLen Size of the data in bytes

    /// @param[in] prevLayer A pointer to the previous layer

    /// @param[in] packet A pointer to the Packet instance where layer will be stored in

    LLCLayer(uint8_t* data, size_t dataLen, Layer* prevLayer, Packet* packet)

        : Layer(data, dataLen, prevLayer, packet, LLC)

    {}

    /// A constructor that creates the LLC layer from provided values

    /// @param[in] dsap Destination Service Access Point

    /// @param[in] ssap Source Service Access Point

    /// @param[in] control Control Field

    LLCLayer(uint8_t dsap, uint8_t ssap, uint8_t control);

    /// Get a pointer to Logical Link Control (LLC) layer header

    /// @return Pointer to LLC header

    inline llc_header* getLlcHeader() const

    {

      return reinterpret_cast<llc_header*>(m_Data);

    };

    // overridden methods

    /// Parses the next layer. Currently only STP supported as next layer

    void parseNextLayer() override;

    /// Does nothing for this layer

    void computeCalculateFields() override

    {}

    /// @return Get the size of the LLC header

    size_t getHeaderLen() const override

    {

      return sizeof(llc_header);

    }

    /// @return Returns the protocol info as readable string

    std::string toString() const override;

    /// @return The OSI layer level of LLC (Data Link Layer).

    OsiModelLayer getOsiModelLayer() const override

    {

      return OsiModelDataLinkLayer;

    }

    /// A static method that validates the input data

    /// @param[in] data The pointer to the beginning of a byte stream of an LLC packet

    /// @param[in] dataLen The length of the byte stream

    /// @return True if the data is valid and can represent an LLC packet

    static bool isDataValid(const uint8_t* data, size_t dataLen);

  };

}  // namespace pcpp