/*
 * Copyright (c) 2008-2009 Strasbourg University
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: David Gross <gdavid.devel@gmail.com>
 */

#ifndef IPV6_OPTION_HEADER_H
#define IPV6_OPTION_HEADER_H

#include "ns3/header.h"

#include <ostream>

namespace ns3
{

/**
 * @ingroup ipv6HeaderExt
 *
 * @brief Header for IPv6 Option.
 */
class Ipv6OptionHeader : public Header
{
  public:
    /**
     * @struct Alignment
     * @brief represents the alignment requirements of an option header
     *
     * Represented as factor*n+offset (eg. 8n+2) See \RFC{2460}.
     * No alignment is represented as 1n+0.
     */
    struct Alignment
    {
        uint8_t factor; /**< Factor */
        uint8_t offset; /**< Offset */
    };

    /**
     * @brief Get the type identificator.
     * @return type identificator
     */
    static TypeId GetTypeId();

    /**
     * @brief Get the instance type ID.
     * @return instance type ID
     */
    TypeId GetInstanceTypeId() const override;

    /**
     * @brief Constructor.
     */
    Ipv6OptionHeader();

    /**
     * @brief Destructor.
     */
    ~Ipv6OptionHeader() override;

    /**
     * @brief Set the type of the option.
     * @param type the type of the option
     */
    void SetType(uint8_t type);

    /**
     * @brief Get the type of the option.
     * @return the type of the option
     */
    uint8_t GetType() const;

    /**
     * @brief Set the option length.
     * @param length the option length
     */
    void SetLength(uint8_t length);

    /**
     * @brief Get the option length.
     * @return the option length
     */
    uint8_t GetLength() const;

    /**
     * @brief Print some information about the packet.
     * @param os output stream
     */
    void Print(std::ostream& os) const override;

    /**
     * @brief Get the serialized size of the packet.
     * @return size
     */
    uint32_t GetSerializedSize() const override;

    /**
     * @brief Serialize the packet.
     * @param start Buffer iterator
     */
    void Serialize(Buffer::Iterator start) const override;

    /**
     * @brief Deserialize the packet.
     * @param start Buffer iterator
     * @return size of the packet
     */
    uint32_t Deserialize(Buffer::Iterator start) override;

    /**
     * @brief Get the Alignment requirement of this option header
     * @return The required alignment
     *
     * Subclasses should only implement this method, if special alignment is
     * required. Default is no alignment (1n+0).
     */
    virtual Alignment GetAlignment() const;

  private:
    /**
     * @brief The type of the option.
     */
    uint8_t m_type;

    /**
     * @brief The option length.
     */
    uint8_t m_length;

    /**
     * @brief The anonymous data of this option
     */
    Buffer m_data;
};

/**
 * @ingroup ipv6HeaderExt
 *
 * @brief Header of IPv6 Option Pad1
 */
class Ipv6OptionPad1Header : public Ipv6OptionHeader
{
  public:
    /**
     * @brief Get the type identificator.
     * @return type identificator
     */
    static TypeId GetTypeId();

    /**
     * @brief Get the instance type ID.
     * @return instance type ID
     */
    TypeId GetInstanceTypeId() const override;

    /**
     * @brief Constructor.
     */
    Ipv6OptionPad1Header();

    /**
     * @brief Destructor.
     */
    ~Ipv6OptionPad1Header() override;

    /**
     * @brief Print some information about the packet.
     * @param os output stream
     */
    void Print(std::ostream& os) const override;

    /**
     * @brief Get the serialized size of the packet.
     * @return size
     */
    uint32_t GetSerializedSize() const override;

    /**
     * @brief Serialize the packet.
     * @param start Buffer iterator
     */
    void Serialize(Buffer::Iterator start) const override;

    /**
     * @brief Deserialize the packet.
     * @param start Buffer iterator
     * @return size of the packet
     */
    uint32_t Deserialize(Buffer::Iterator start) override;
};

/**
 * @ingroup ipv6HeaderExt
 *
 * @brief Header of IPv6 Option Padn
 */
class Ipv6OptionPadnHeader : public Ipv6OptionHeader
{
  public:
    /**
     * @brief Get the type identificator.
     * @return type identificator
     */
    static TypeId GetTypeId();

    /**
     * @brief Get the instance type ID.
     * @return instance type ID
     */
    TypeId GetInstanceTypeId() const override;

    /**
     * @brief Constructor.
     * @param pad Number of bytes to pad (>=2)
     */
    Ipv6OptionPadnHeader(uint32_t pad = 2);

    /**
     * @brief Destructor.
     */
    ~Ipv6OptionPadnHeader() override;

    /**
     * @brief Print some information about the packet.
     * @param os output stream
     */
    void Print(std::ostream& os) const override;

    /**
     * @brief Get the serialized size of the packet.
     * @return size
     */
    uint32_t GetSerializedSize() const override;

    /**
     * @brief Serialize the packet.
     * @param start Buffer iterator
     */
    void Serialize(Buffer::Iterator start) const override;

    /**
     * @brief Deserialize the packet.
     * @param start Buffer iterator
     * @return size of the packet
     */
    uint32_t Deserialize(Buffer::Iterator start) override;
};

/**
 * @ingroup ipv6HeaderExt
 *
 * @brief Header of IPv6 Option Jumbogram
 */
class Ipv6OptionJumbogramHeader : public Ipv6OptionHeader
{
  public:
    /**
     * @brief Get the type identificator.
     * @return type identificator
     */
    static TypeId GetTypeId();

    /**
     * @brief Get the instance type ID.
     * @return instance type ID
     */
    TypeId GetInstanceTypeId() const override;

    /**
     * @brief Constructor.
     */
    Ipv6OptionJumbogramHeader();

    /**
     * @brief Destructor.
     */
    ~Ipv6OptionJumbogramHeader() override;

    /**
     * @brief Set the data length.
     * @param dataLength the data length
     */
    void SetDataLength(uint32_t dataLength);

    /**
     * @brief Get the data length.
     * @return the data length
     */
    uint32_t GetDataLength() const;

    /**
     * @brief Print some information about the packet.
     * @param os output stream
     */
    void Print(std::ostream& os) const override;

    /**
     * @brief Get the serialized size of the packet.
     * @return size
     */
    uint32_t GetSerializedSize() const override;

    /**
     * @brief Serialize the packet.
     * @param start Buffer iterator
     */
    void Serialize(Buffer::Iterator start) const override;

    /**
     * @brief Deserialize the packet.
     * @param start Buffer iterator
     * @return size of the packet
     */
    uint32_t Deserialize(Buffer::Iterator start) override;

    /**
     * @brief Get the Alignment requirement of this option header
     * @return The required alignment
     */
    Alignment GetAlignment() const override;

  private:
    /**
     * @brief The data length.
     */
    uint32_t m_dataLength;
};

/**
 * @ingroup ipv6HeaderExt
 *
 * @brief Header of IPv6 Option Router Alert
 */
class Ipv6OptionRouterAlertHeader : public Ipv6OptionHeader
{
  public:
    /**
     * @brief Get the type identificator.
     * @return type identificator
     */
    static TypeId GetTypeId();

    /**
     * @brief Get the instance type ID.
     * @return instance type ID
     */
    TypeId GetInstanceTypeId() const override;

    /**
     * @brief Constructor.
     */
    Ipv6OptionRouterAlertHeader();

    /**
     * @brief Destructor.
     */
    ~Ipv6OptionRouterAlertHeader() override;

    /**
     * @brief Set the field "value".
     * @param value the value to be set.
     */
    void SetValue(uint16_t value);

    /**
     * @brief Get the field "value".
     * @return the field "value"
     */
    uint16_t GetValue() const;

    /**
     * @brief Print some information about the packet.
     * @param os output stream
     */
    void Print(std::ostream& os) const override;

    /**
     * @brief Get the serialized size of the packet.
     * @return size
     */
    uint32_t GetSerializedSize() const override;

    /**
     * @brief Serialize the packet.
     * @param start Buffer iterator
     */
    void Serialize(Buffer::Iterator start) const override;

    /**
     * @brief Deserialize the packet.
     * @param start Buffer iterator
     * @return size of the packet
     */
    uint32_t Deserialize(Buffer::Iterator start) override;

    /**
     * @brief Get the Alignment requirement of this option header
     * @return The required alignment
     */
    Alignment GetAlignment() const override;

  private:
    /**
     * @brief The value.
     */
    uint16_t m_value;
};

} // namespace ns3

#endif /* IPV6_OPTION_HEADER_H */
