/*
 * Copyright (c) 2011 Universita' di Firenze, Italy
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Tommaso Pecorella <tommaso.pecorella@unifi.it>
 */

#ifndef SIXLOWPAN_HELPER_H
#define SIXLOWPAN_HELPER_H

#include "ns3/net-device-container.h"
#include "ns3/object-factory.h"

#include <string>

namespace ns3
{

class Node;
class AttributeValue;
class Time;

/**
 * @ingroup sixlowpan
 *
 * @brief Setup a sixlowpan stack to be used as a shim between IPv6 and a generic NetDevice.
 */
class SixLowPanHelper
{
  public:
    /*
     * Construct a SixlowpanHelper
     */
    SixLowPanHelper();
    /**
     * Set an attribute on each ns3::SixlowpanNetDevice created by
     * SixlowpanHelper::Install.
     *
     * @param n1 [in] The name of the attribute to set.
     * @param v1 [in] The value of the attribute to set.
     */
    void SetDeviceAttribute(std::string n1, const AttributeValue& v1);

    /**
     * @brief Install the SixLoWPAN stack on top of an existing NetDevice.
     *
     * This function requires a set of properly configured NetDevices
     * passed in as the parameter "c". The new NetDevices will have to
     * be used instead of the original ones. In this way these
     * SixLoWPAN devices will behave as shims between the NetDevices
     * passed in and IPv6.
     *
     * Note that only IPv6 (and related protocols, such as ICMPv6) can
     * be transmitted over a 6LoWPAN interface.
     * Any other protocol (e.g., IPv4) will be discarded by 6LoWPAN.
     *
     * Other protocols (e.g., IPv4) could be used on the original NetDevices
     * with some limitations.
     * See the manual for a complete discussion.
     *
     * @note IPv6 stack must be installed \a after SixLoWPAN,
     * using the SixLoWPAN NetDevices. See the example in the
     * examples directory.
     *
     *
     * @param [in] c The NetDevice container.
     * @return A container with the newly created SixLowPanNetDevices.
     */
    NetDeviceContainer Install(NetDeviceContainer c);

    /**
     * @brief Adds a compression Context to a set of NetDevices.
     *
     * This function installs one Compression Context on a set of NetDevices.
     * The context is used only in IPHC compression and decompression.
     *
     * @param [in] c The NetDevice container.
     * @param [in] contextId The context id (must be less than 16).
     * @param [in] context The context prefix.
     * @param [in] validity the context validity time (relative to the actual time).
     */
    void AddContext(NetDeviceContainer c, uint8_t contextId, Ipv6Prefix context, Time validity);

    /**
     * @brief Renew a compression Context in a set of NetDevices.
     *
     * The context will have its lifetime extended and its validity for compression re-enabled.
     *
     * @param [in] c The NetDevice container.
     * @param [in] contextId The context id (must be less than 16).
     * @param [in] validity the context validity time (relative to the actual time).
     */
    void RenewContext(NetDeviceContainer c, uint8_t contextId, Time validity);

    /**
     * @brief Invalidates a compression Context in a set of NetDevices.
     *
     * An invalid context is used only in IPHC decompression and not
     * in IPHC compression.
     *
     * This is necessary to avoid that a context reaching its validity lifetime
     * can not be used for decompression whie packets are traveling the network.
     *
     * @param [in] c The NetDevice container.
     * @param [in] contextId The context id (must be less than 16).
     */
    void InvalidateContext(NetDeviceContainer c, uint8_t contextId);

    /**
     * @brief Remove a compression Context in a set of NetDevices.
     *
     * The context is removed immediately from the contexts in the devices.
     *
     * @param [in] c The NetDevice container.
     * @param [in] contextId The context id (must be less than 16).
     */
    void RemoveContext(NetDeviceContainer c, uint8_t contextId);

    /**
     * Assign a fixed random variable stream number to the random variables
     * used by this model. Return the number of streams (possibly zero) that
     * have been assigned. The Install() method should have previously been
     * called by the user.
     *
     * @param [in] c NetDeviceContainer of the set of net devices for which the
     *          SixLowPanNetDevice should be modified to use a fixed stream.
     * @param [in] stream First stream index to use.
     * @return The number of stream indices assigned by this helper.
     */
    int64_t AssignStreams(NetDeviceContainer c, int64_t stream);

  private:
    ObjectFactory m_deviceFactory; //!< Object factory.
};

} // namespace ns3

#endif /* SIXLOWPAN_HELPER_H */
