/*
 * Copyright (c) 2011 UPB
 * Copyright (c) 2017 NITK Surathkal
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Radu Lupu <rlupu@elcom.pub.ro>
 *         Ankit Deepak <adadeepak8@gmail.com>
 *         Deepti Rajagopal <deeptir96@gmail.com>
 *
 */

#ifndef DHCP_HELPER_H
#define DHCP_HELPER_H

#include "ns3/application-container.h"
#include "ns3/ipv4-address.h"
#include "ns3/ipv4-interface-container.h"
#include "ns3/net-device-container.h"
#include "ns3/object-factory.h"

#include <stdint.h>

namespace ns3
{

/**
 * @ingroup dhcp
 *
 * @class DhcpHelper
 * @brief The helper class used to configure and install DHCP applications on nodes
 */
class DhcpHelper
{
  public:
    DhcpHelper();

    /**
     * @brief Set DHCP client attributes
     * @param name Name of the attribute
     * @param value Value to be set
     */
    void SetClientAttribute(std::string name, const AttributeValue& value);

    /**
     * @brief Set DHCP server attributes
     * @param name Name of the attribute
     * @param value Value to be set
     */
    void SetServerAttribute(std::string name, const AttributeValue& value);

    /**
     * @brief Install DHCP client of a nodes / NetDevice
     * @param netDevice The NetDevice that the DHCP client will use
     * @return The application container with DHCP client installed
     */
    ApplicationContainer InstallDhcpClient(Ptr<NetDevice> netDevice) const;

    /**
     * @brief Install DHCP client of a set of nodes / NetDevices
     * @param netDevices The NetDevices that the DHCP client will use
     * @return The application container with DHCP client installed
     */
    ApplicationContainer InstallDhcpClient(NetDeviceContainer netDevices) const;

    /**
     * @brief Install DHCP server of a node / NetDevice
     *
     * Note: the server address must be coherent with the pool address, because
     * DHCP relays are not yet supported.
     *
     * @param netDevice The NetDevice on which DHCP server application has to be installed
     * @param serverAddr The Ipv4Address of the server
     * @param poolAddr The Ipv4Address (network part) of the allocated pool
     * @param poolMask The mask of the allocated pool
     * @param minAddr The lower bound of the Ipv4Address pool
     * @param maxAddr The upper bound of the Ipv4Address pool
     * @param gateway The Ipv4Address of default gateway (optional)
     * @return The application container with DHCP server installed
     */
    ApplicationContainer InstallDhcpServer(Ptr<NetDevice> netDevice,
                                           Ipv4Address serverAddr,
                                           Ipv4Address poolAddr,
                                           Ipv4Mask poolMask,
                                           Ipv4Address minAddr,
                                           Ipv4Address maxAddr,
                                           Ipv4Address gateway = Ipv4Address());
    /**
     * @brief Assign a fixed IP addresses to a net device.
     * @param netDevice The NetDevice on which the address has to be installed
     * @param addr The Ipv4Address
     * @param mask The network mask
     * @return the Ipv4 interface container
     */
    Ipv4InterfaceContainer InstallFixedAddress(Ptr<NetDevice> netDevice,
                                               Ipv4Address addr,
                                               Ipv4Mask mask);

  private:
    /**
     * @brief Function to install DHCP client on a node
     * @param netDevice The NetDevice on which DHCP client application has to be installed
     * @return The pointer to the installed DHCP client
     */
    Ptr<Application> InstallDhcpClientPriv(Ptr<NetDevice> netDevice) const;
    ObjectFactory m_clientFactory;           //!< DHCP client factory
    ObjectFactory m_serverFactory;           //!< DHCP server factory
    std::list<Ipv4Address> m_fixedAddresses; //!< list of fixed addresses already allocated.
    std::list<std::pair<Ipv4Address, Ipv4Address>> m_addressPools; //!< list of address pools.
};

} // namespace ns3

#endif /* DHCP_HELPER_H */
