/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2011, 2012 Centre Tecnologic de Telecomunicacions de Catalunya (CTTC)

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Authors: Nicola Baldo <nbaldo@cttc.es>

 *          Marco Miozzo <mmiozzo@cttc.es>

 *          Manuel Requena <manuel.requena@cttc.es> 

 */

#ifndef LTE_ENB_RRC_H

#define LTE_ENB_RRC_H

#include <ns3/nstime.h>

#include <ns3/object.h>

#include <ns3/packet.h>

#include <ns3/lte-enb-cmac-sap.h>

#include <ns3/lte-mac-sap.h>

#include <ns3/ff-mac-sched-sap.h>

#include <ns3/lte-pdcp-sap.h>

#include <ns3/epc-x2-sap.h>

#include <ns3/epc-enb-s1-sap.h>

#include <ns3/lte-enb-cphy-sap.h>

#include <ns3/lte-rrc-sap.h>

#include <ns3/traced-callback.h>

#include <map>

#include <set>

namespace ns3 {

class LteRadioBearerInfo;

class LteSignalingRadioBearerInfo;

class LteDataRadioBearerInfo;

class EpcEnbS1SapUser;

class EpcEnbS1SapProvider;

class LteUeRrc;

class LteEnbRrc;

/**

 * Manages all the radio bearer information possessed by the ENB RRC for a single UE

 *

 */

class UeManager : public Object

{

  friend class LtePdcpSpecificLtePdcpSapUser<UeManager>;

public:

  /**

   * The state of the UeManager at the eNB RRC

   * 

   */

  enum State

    {

      INITIAL_RANDOM_ACCESS = 0,

      CONNECTION_SETUP,

      CONNECTED_NORMALLY,

      CONNECTION_RECONFIGURATION,

      CONNECTION_REESTABLISHMENT,

      HANDOVER_JOINING,

      HANDOVER_LEAVING,

      NUM_STATES

    };

  UeManager ();

  /** 

   * UeManager constructor

   * 

   * \param rrc pointer to the LteEnbRrc holding this UeManager

   * \param rnti RNTI of the UE

   * \param s initial state of the UeManager

   * 

   * \return 

   */

  UeManager (Ptr<LteEnbRrc> rrc, uint16_t rnti, State s);

  virtual ~UeManager (void);

  // inherited from Object

protected:

  virtual void DoDispose ();

public: 

  static TypeId GetTypeId (void);

  /** 

   * Set the identifiers of the source eNB for the case where a UE

   * joins the current eNB as part of a handover procedure 

   * 

   * \param sourceCellId 

   * \param sourceX2apId 

   */

  void SetSource (uint16_t sourceCellId, uint16_t sourceX2apId);

  /** 

   * Setup a new data radio bearer, including both the configuration

   * within the eNB and the necessary RRC signaling with the UE

   * 

   * \param bearer 

   * \param gtpTeid S1-bearer GTP tunnel endpoint identifier, see 36.423 9.2.1

   * \param transportLayerAddress  IP Address of the SGW, see 36.423 9.2.1

   * 

   * \return the EPS Bearer Id

   */

  uint8_t SetupDataRadioBearer (EpsBearer bearer, uint32_t gtpTeid, Ipv4Address transportLayerAddress);

  /**

   *

   * Release a given radio bearer

   *

   * \param drbid the data radio bearer id of the bearer to be released

   */

  void ReleaseDataRadioBearer (uint8_t drbid);

  /** 

   * schedule an RRC Connection Reconfiguration procedure with the UE

   * 

   */

  void ScheduleRrcConnectionReconfiguration ();

  /** 

   * In the X2-based handover procedure, at the source eNB, trigger

   * handover by sending to the UE a RRC Connection 

   * Reconfiguration message including Mobility Control Info

   * 

   * \param rcr the RrcConnectionReconfiguration message including the

   * Mobility Control Info. The content of this struct shall be

   * provided by the target eNB.

   */

  void SendHandoverCommand (LteRrcSap::RrcConnectionReconfiguration rcr);

  /** 

   * 

   * \return the HandoverPreparationInfo sent by the source eNB to the

   * target eNB in the X2-based handover procedure

   */

  LteRrcSap::RadioResourceConfigDedicated GetRadioResourceConfigForHandoverPreparationInfo ();

  /** 

   * 

   * \return retrieve the data that the target eNB needs to send to the source

   * eNB as the Handover Command in the X2-based handover

   * procedure.

   */

  LteRrcSap::RrcConnectionReconfiguration GetHandoverCommand ();

  /** 

   * Send a data packet over the appropriate Data Radio Bearer

   * 

   * \param bid the corresponding EPS Bearer ID

   * \param p the packet

   */

  void SendData (uint8_t bid, Ptr<Packet> p);

  /** 

   * 

   * \return a list of ERAB-to-be-setup items to be put in a X2 HO REQ message

   */

  std::vector<EpcX2Sap::ErabToBeSetupItem> GetErabList ();

  // methods forwarded from RRC SAP

  void CompleteSetupUe (LteEnbRrcSapProvider::CompleteSetupUeParameters params);

  void RecvRrcConnectionRequest (LteRrcSap::RrcConnectionRequest msg);

  void RecvRrcConnectionSetupCompleted (LteRrcSap::RrcConnectionSetupCompleted msg);

  void RecvRrcConnectionReconfigurationCompleted (LteRrcSap::RrcConnectionReconfigurationCompleted msg);

  void RecvRrcConnectionReestablishmentRequest (LteRrcSap::RrcConnectionReestablishmentRequest msg);

  void RecvRrcConnectionReestablishmentComplete (LteRrcSap::RrcConnectionReestablishmentComplete msg);

  // methods forwarded from CMAC SAP

  void CmacUeConfigUpdateInd (LteEnbCmacSapUser::UeConfig cmacParams);

  // methods forwarded from PDCP SAP

  void DoReceivePdcpSdu (LtePdcpSapUser::ReceivePdcpSduParameters params);

  /** 

   * 

   * \return the RNTI, i.e., an UE identifier that is unique within

   * the cell

   */

  uint16_t GetRnti (void);

  /** 

   *

   * \return the IMSI, i.e., a globally unique UE identifier

   */

  uint64_t GetImsi (void);

  /** 

   * 

   * \return the SRS Configuration Index

   */

  uint16_t GetSrsConfigurationIndex (void);  

  /** 

   * Set the SRS configuration index and do the necessary reconfiguration

   * 

   * \param srsConfIndex 

   */

  void SetSrsConfigurationIndex (uint16_t srsConfIndex);

  /** 

   * 

   * \return the current state

   */

  State GetState ();

private:

  /** 

   * Add a new LteDataRadioBearerInfo structure to the UeManager

   * 

   * \param radioBearerInfo 

   * 

   * \return the id of the newly added data radio bearer structure

   */

  uint8_t AddDataRadioBearerInfo (Ptr<LteDataRadioBearerInfo> radioBearerInfo);

  /** 

   * \param drbid the Data Radio Bearer id

   * 

   * \return the corresponding LteDataRadioBearerInfo

   */

  Ptr<LteDataRadioBearerInfo> GetDataRadioBearerInfo (uint8_t drbid);

  /** 

   * remove the LteDataRadioBearerInfo corresponding to a bearer being released

   *

   * \param drbid the Data Radio Bearer id

   */

  void RemoveDataRadioBearerInfo (uint8_t drbid);

  /** 

   * 

   * \return an RrcConnectionReconfiguration struct built based on the

   * current configuration

   */

  LteRrcSap::RrcConnectionReconfiguration BuildRrcConnectionReconfiguration ();

  /** 

   * 

   * \return a RadioResourceConfigDedicated struct built based on the

   * current configuration

   */

  LteRrcSap::RadioResourceConfigDedicated BuildRadioResourceConfigDedicated ();

  /** 

   * 

   * \return a newly allocated identifier for a new RRC transaction

   */

  uint8_t GetNewRrcTransactionIdentifier ();

  /** 

   * \param lcid a Logical Channel Identifier

   * 

   * \return the corresponding Data Radio Bearer Id

   */

  uint8_t Lcid2Drbid (uint8_t lcid);

  /** 

   * \param drbid a Data Radio Bearer Id

   * 

   * \return the corresponding  Logical Channel Identifier

   */

  uint8_t Drbid2Lcid (uint8_t drbid);

  /** 

   * \param lcid a  Logical Channel Identifier

   * 

   * \return the corresponding EPS Bearer Identifier

   */

  uint8_t Lcid2Bid (uint8_t lcid);

  /** 

   * \param bid  an EPS Bearer Identifier

   * 

   * \return the corresponding Logical Channel Identifier

   */

  uint8_t Bid2Lcid (uint8_t bid);

  /** 

   * \param drbid Data Radio Bearer Id

   * 

   * \return the corresponding EPS Bearer Identifier

   */

  uint8_t Drbid2Bid (uint8_t drbid);

  /** 

   * \param bid an EPS Bearer Identifier

   * 

   * \return the corresponding Data Radio Bearer Id

   */

  uint8_t Bid2Drbid (uint8_t bid);

  /** 

   * Switch the UeManager to the given state

   * 

   * \param s the given state

   */

  void SwitchToState (State s);

  std::map <uint8_t, Ptr<LteDataRadioBearerInfo> > m_drbMap;

  Ptr<LteSignalingRadioBearerInfo> m_srb0;

  Ptr<LteSignalingRadioBearerInfo> m_srb1;

  uint8_t m_lastAllocatedDrbid;

  uint16_t m_rnti;

  uint64_t m_imsi;

  uint8_t m_lastRrcTransactionIdentifier;

  LteRrcSap::PhysicalConfigDedicated m_physicalConfigDedicated;

  Ptr<LteEnbRrc> m_rrc;

  State m_state;

  LtePdcpSapUser* m_pdcpSapUser;

  bool m_pendingRrcConnectionReconfiguration;

  TracedCallback<State, State> m_stateTransitionCallback;

  uint16_t m_sourceX2apId;

  uint16_t m_sourceCellId;

};

/**

 * \ingroup lte

 * 

 * The LTE Radio Resource Control entity at the eNB

 */

class LteEnbRrc : public Object

{

  friend class EnbRrcMemberLteEnbCmacSapUser;

  friend class MemberLteEnbRrcSapProvider<LteEnbRrc>;

  friend class MemberEpcEnbS1SapUser<LteEnbRrc>;

  friend class EpcX2SpecificEpcX2SapUser<LteEnbRrc>;

  friend class UeManager;

public:

  /**

   * create an RRC instance for use within an eNB

   *

   */

  LteEnbRrc ();

  /**

   * Destructor

   */

  virtual ~LteEnbRrc ();

  // inherited from Object

protected:

  virtual void DoDispose (void);

public:

  static TypeId GetTypeId (void);

  /**

   * Set the X2 SAP this RRC should interact with

   * \param s the X2 SAP Provider to be used by this RRC entity

   */

  void SetEpcX2SapProvider (EpcX2SapProvider* s);

  /** 

   * Get the X2 SAP offered by this RRC

   * \return s the X2 SAP User interface offered to the X2 entity by this RRC entity

   */

  EpcX2SapUser* GetEpcX2SapUser ();

  /**

   * set the CMAC SAP this RRC should interact with

   *

   * \param s the CMAC SAP Provider to be used by this RRC

   */

  void SetLteEnbCmacSapProvider (LteEnbCmacSapProvider * s);

  /** 

   * Get the CMAC SAP offered by this RRC

   * \return s the CMAC SAP User interface offered to the MAC by this RRC

   */

  LteEnbCmacSapUser* GetLteEnbCmacSapUser ();

  /**

   * set the RRC SAP this RRC should interact with

   *

   * \param s the RRC SAP User to be used by this RRC

   */

  void SetLteEnbRrcSapUser (LteEnbRrcSapUser * s);

  /**

   *

   *

   * \return s the RRC SAP Provider interface offered to the MAC by this RRC

   */

  LteEnbRrcSapProvider* GetLteEnbRrcSapProvider ();

  /**

   * set the MAC SAP provider. The eNB RRC does not use this

   * directly, but it needs to provide it to newly created RLC instances.

   *

   * \param s the MAC SAP provider that will be used by all

   * newly created RLC instances

   */

  void SetLteMacSapProvider (LteMacSapProvider* s);

  /** 

   * Set the S1 SAP Provider

   * 

   * \param s the S1 SAP Provider

   */

  void SetS1SapProvider (EpcEnbS1SapProvider * s);

  /** 

   * 

   * \return the S1 SAP user

   */

  EpcEnbS1SapUser* GetS1SapUser ();

  /**

   * set the CPHY SAP this RRC should use to interact with the PHY

   *

   * \param s the CPHY SAP Provider

   */

  void SetLteEnbCphySapProvider (LteEnbCphySapProvider * s);

  /**

   *

   *

   * \return s the CPHY SAP User interface offered to the PHY by this RRC

   */

  LteEnbCphySapUser* GetLteEnbCphySapUser ();

  /** 

   * 

   * 

   * \param rnti the identifier of an UE

   * 

   * \return the corresponding UeManager instance

   */

  Ptr<UeManager> GetUeManager (uint16_t rnti);

  /**

   * configure cell-specific parameters

   *

   * \param ulBandwidth the uplink bandwdith in number of RB

   * \param dlBandwidth the downlink bandwidth in number of RB

   * \param ulEarfcn the UL EARFCN

   * \param dlEarfcn the DL EARFCN

   * \param cellId the ID of the cell

   */

  void ConfigureCell (uint8_t ulBandwidth,

                      uint8_t dlBandwidth,

                      uint16_t ulEarfcn, 

                      uint16_t dlEarfcn,

                      uint16_t cellId);

  /** 

   * set the cell id of this eNB

   * 

   * \param m_cellId 

   */

  void SetCellId (uint16_t m_cellId);

  /** 

   * Enqueue an IP data packet on the proper bearer for downlink

   * transmission. Normally expected to be called by the NetDevice

   * forwarding a packet coming from the EpcEnbApplication 

   * 

   * \param p the packet

   * 

   * \return true if successful, false if an error occurred

   */

  bool SendData (Ptr<Packet> p);