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

/*

 * Copyright (c) 2011 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

 *

 * Author: Marco Miozzo <marco.miozzo@cttc.es>

 */

#include <ns3/log.h>

#include <ns3/pointer.h>

#include <ns3/lte-amc.h>

#include <ns3/rr-ff-mac-scheduler.h>

#include <ns3/simulator.h>

#include <ns3/lte-common.h>

NS_LOG_COMPONENT_DEFINE ("RrFfMacScheduler");

namespace ns3 {

int Type0AllocationRbg[4] = {

  10,       // RGB size 1

  26,       // RGB size 2

  63,       // RGB size 3

  110       // RGB size 4

};  // see table 7.1.6.1-1 of 36.213

NS_OBJECT_ENSURE_REGISTERED (RrFfMacScheduler);

class RrSchedulerMemberCschedSapProvider : public FfMacCschedSapProvider

{

public:

  RrSchedulerMemberCschedSapProvider (RrFfMacScheduler* scheduler);

  // inherited from FfMacCschedSapProvider

  virtual void CschedCellConfigReq (const struct CschedCellConfigReqParameters& params);

  virtual void CschedUeConfigReq (const struct CschedUeConfigReqParameters& params);

  virtual void CschedLcConfigReq (const struct CschedLcConfigReqParameters& params);

  virtual void CschedLcReleaseReq (const struct CschedLcReleaseReqParameters& params);

  virtual void CschedUeReleaseReq (const struct CschedUeReleaseReqParameters& params);

private:

  RrSchedulerMemberCschedSapProvider ();

  RrFfMacScheduler* m_scheduler;

};

RrSchedulerMemberCschedSapProvider::RrSchedulerMemberCschedSapProvider ()

{

}

RrSchedulerMemberCschedSapProvider::RrSchedulerMemberCschedSapProvider (RrFfMacScheduler* scheduler) : m_scheduler (scheduler)

{

}

void

RrSchedulerMemberCschedSapProvider::CschedCellConfigReq (const struct CschedCellConfigReqParameters& params)

{

  m_scheduler->DoCschedCellConfigReq (params);

}

void

RrSchedulerMemberCschedSapProvider::CschedUeConfigReq (const struct CschedUeConfigReqParameters& params)

{

  m_scheduler->DoCschedUeConfigReq (params);

}

void

RrSchedulerMemberCschedSapProvider::CschedLcConfigReq (const struct CschedLcConfigReqParameters& params)

{

  m_scheduler->DoCschedLcConfigReq (params);

}

void

RrSchedulerMemberCschedSapProvider::CschedLcReleaseReq (const struct CschedLcReleaseReqParameters& params)

{

  m_scheduler->DoCschedLcReleaseReq (params);

}

void

RrSchedulerMemberCschedSapProvider::CschedUeReleaseReq (const struct CschedUeReleaseReqParameters& params)

{

  m_scheduler->DoCschedUeReleaseReq (params);

}

class RrSchedulerMemberSchedSapProvider : public FfMacSchedSapProvider

{

public:

  RrSchedulerMemberSchedSapProvider (RrFfMacScheduler* scheduler);

  // inherited from FfMacSchedSapProvider

  virtual void SchedDlRlcBufferReq (const struct SchedDlRlcBufferReqParameters& params);

  virtual void SchedDlPagingBufferReq (const struct SchedDlPagingBufferReqParameters& params);

  virtual void SchedDlMacBufferReq (const struct SchedDlMacBufferReqParameters& params);

  virtual void SchedDlTriggerReq (const struct SchedDlTriggerReqParameters& params);

  virtual void SchedDlRachInfoReq (const struct SchedDlRachInfoReqParameters& params);

  virtual void SchedDlCqiInfoReq (const struct SchedDlCqiInfoReqParameters& params);

  virtual void SchedUlTriggerReq (const struct SchedUlTriggerReqParameters& params);

  virtual void SchedUlNoiseInterferenceReq (const struct SchedUlNoiseInterferenceReqParameters& params);

  virtual void SchedUlSrInfoReq (const struct SchedUlSrInfoReqParameters& params);

  virtual void SchedUlMacCtrlInfoReq (const struct SchedUlMacCtrlInfoReqParameters& params);

  virtual void SchedUlCqiInfoReq (const struct SchedUlCqiInfoReqParameters& params);

private:

  RrSchedulerMemberSchedSapProvider ();

  RrFfMacScheduler* m_scheduler;

};

RrSchedulerMemberSchedSapProvider::RrSchedulerMemberSchedSapProvider ()

{

}

RrSchedulerMemberSchedSapProvider::RrSchedulerMemberSchedSapProvider (RrFfMacScheduler* scheduler)

  : m_scheduler (scheduler)

{

}

void

RrSchedulerMemberSchedSapProvider::SchedDlRlcBufferReq (const struct SchedDlRlcBufferReqParameters& params)

{

  m_scheduler->DoSchedDlRlcBufferReq (params);

}

void

RrSchedulerMemberSchedSapProvider::SchedDlPagingBufferReq (const struct SchedDlPagingBufferReqParameters& params)

{

  m_scheduler->DoSchedDlPagingBufferReq (params);

}

void

RrSchedulerMemberSchedSapProvider::SchedDlMacBufferReq (const struct SchedDlMacBufferReqParameters& params)

{

  m_scheduler->DoSchedDlMacBufferReq (params);

}

void

RrSchedulerMemberSchedSapProvider::SchedDlTriggerReq (const struct SchedDlTriggerReqParameters& params)

{

  m_scheduler->DoSchedDlTriggerReq (params);

}

void

RrSchedulerMemberSchedSapProvider::SchedDlRachInfoReq (const struct SchedDlRachInfoReqParameters& params)

{

  m_scheduler->DoSchedDlRachInfoReq (params);

}

void

RrSchedulerMemberSchedSapProvider::SchedDlCqiInfoReq (const struct SchedDlCqiInfoReqParameters& params)

{

  m_scheduler->DoSchedDlCqiInfoReq (params);

}

void

RrSchedulerMemberSchedSapProvider::SchedUlTriggerReq (const struct SchedUlTriggerReqParameters& params)

{

  m_scheduler->DoSchedUlTriggerReq (params);

}

void

RrSchedulerMemberSchedSapProvider::SchedUlNoiseInterferenceReq (const struct SchedUlNoiseInterferenceReqParameters& params)

{

  m_scheduler->DoSchedUlNoiseInterferenceReq (params);

}

void

RrSchedulerMemberSchedSapProvider::SchedUlSrInfoReq (const struct SchedUlSrInfoReqParameters& params)

{

  m_scheduler->DoSchedUlSrInfoReq (params);

}

void

RrSchedulerMemberSchedSapProvider::SchedUlMacCtrlInfoReq (const struct SchedUlMacCtrlInfoReqParameters& params)

{

  m_scheduler->DoSchedUlMacCtrlInfoReq (params);

}

void

RrSchedulerMemberSchedSapProvider::SchedUlCqiInfoReq (const struct SchedUlCqiInfoReqParameters& params)

{

  m_scheduler->DoSchedUlCqiInfoReq (params);

}

RrFfMacScheduler::RrFfMacScheduler ()

  :   m_cschedSapUser (0),

    m_schedSapUser (0),

    m_nextRntiDl (0),

    m_nextRntiUl (0)

{

  m_amc = CreateObject <LteAmc> ();

  m_cschedSapProvider = new RrSchedulerMemberCschedSapProvider (this);

  m_schedSapProvider = new RrSchedulerMemberSchedSapProvider (this);

}

RrFfMacScheduler::~RrFfMacScheduler ()

{

  NS_LOG_FUNCTION (this);

}

void

RrFfMacScheduler::DoDispose ()

{

  NS_LOG_FUNCTION (this);

  delete m_cschedSapProvider;

  delete m_schedSapProvider;

}

TypeId

RrFfMacScheduler::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::RrFfMacScheduler")

    .SetParent<FfMacScheduler> ()

    .AddConstructor<RrFfMacScheduler> ()

    .AddAttribute ("CqiTimerThreshold",

                   "The number of TTIs a CQI is valid (default 1000 - 1 sec.)",

                   UintegerValue (1000),

                   MakeUintegerAccessor (&RrFfMacScheduler::m_cqiTimersThreshold),

                   MakeUintegerChecker<uint32_t> ())

    ;

  return tid;

}

void

RrFfMacScheduler::SetFfMacCschedSapUser (FfMacCschedSapUser* s)

{

  m_cschedSapUser = s;

}

void

RrFfMacScheduler::SetFfMacSchedSapUser (FfMacSchedSapUser* s)

{

  m_schedSapUser = s;

}

FfMacCschedSapProvider*

RrFfMacScheduler::GetFfMacCschedSapProvider ()

{

  return m_cschedSapProvider;

}

FfMacSchedSapProvider*

RrFfMacScheduler::GetFfMacSchedSapProvider ()

{

  return m_schedSapProvider;

}

void

RrFfMacScheduler::DoCschedCellConfigReq (const struct FfMacCschedSapProvider::CschedCellConfigReqParameters& params)

{

  NS_LOG_FUNCTION (this);

  // Read the subset of parameters used

  m_cschedCellConfig = params;

  FfMacCschedSapUser::CschedUeConfigCnfParameters cnf;

  cnf.m_result = SUCCESS;

  m_cschedSapUser->CschedUeConfigCnf (cnf);

  return;

}

void

RrFfMacScheduler::DoCschedUeConfigReq (const struct FfMacCschedSapProvider::CschedUeConfigReqParameters& params)

{

  NS_LOG_FUNCTION (this << " RNTI " << params.m_rnti << " txMode " << (uint16_t)params.m_transmissionMode);

  std::map <uint16_t,uint8_t>::iterator it = m_uesTxMode.find (params.m_rnti);

  if (it==m_uesTxMode.end ())

    {

      m_uesTxMode.insert (std::pair <uint16_t, double> (params.m_rnti, params.m_transmissionMode));

    }

  else

    {

      (*it).second = params.m_transmissionMode;

    }

  return;

}

void

RrFfMacScheduler::DoCschedLcConfigReq (const struct FfMacCschedSapProvider::CschedLcConfigReqParameters& params)

{

  NS_LOG_FUNCTION (this);

  // Not used at this stage

  return;

}

void

RrFfMacScheduler::DoCschedLcReleaseReq (const struct FfMacCschedSapProvider::CschedLcReleaseReqParameters& params)

{

  NS_LOG_FUNCTION (this);

  // TODO: Implementation of the API

  return;

}

void

RrFfMacScheduler::DoCschedUeReleaseReq (const struct FfMacCschedSapProvider::CschedUeReleaseReqParameters& params)

{

  NS_LOG_FUNCTION (this);

  // TODO: Implementation of the API

  return;

}

void

RrFfMacScheduler::DoSchedDlRlcBufferReq (const struct FfMacSchedSapProvider::SchedDlRlcBufferReqParameters& params)

{

  NS_LOG_FUNCTION (this << params.m_rnti << (uint32_t) params.m_logicalChannelIdentity);

  // API generated by RLC for updating RLC parameters on a LC (tx and retx queues)

  std::list<FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator it = m_rlcBufferReq.begin ();

  bool newLc = true;

  while (it != m_rlcBufferReq.end ())

    {

      // remove old entries of this UE-LC

      if (((*it).m_rnti == params.m_rnti)&&((*it).m_logicalChannelIdentity == params.m_logicalChannelIdentity))

        {

          it = m_rlcBufferReq.erase (it);

          newLc = false;

        }

      else

        {

          ++it;

        }

    }

  // add the new parameters

  m_rlcBufferReq.insert (it, params);

  // initialize statistics of the flow in case of new flows

  if (newLc == true)

    {

      m_p10CqiRxed.insert ( std::pair<uint16_t, uint8_t > (params.m_rnti, 1)); // only codeword 0 at this stage (SISO)

      // initialized to 1 (i.e., the lowest value for transmitting a signal)

      m_p10CqiTimers.insert ( std::pair<uint16_t, uint32_t > (params.m_rnti, m_cqiTimersThreshold));

    }

  return;

}

void

RrFfMacScheduler::DoSchedDlPagingBufferReq (const struct FfMacSchedSapProvider::SchedDlPagingBufferReqParameters& params)

{

  NS_LOG_FUNCTION (this);

  // TODO: Implementation of the API

  return;

}

void

RrFfMacScheduler::DoSchedDlMacBufferReq (const struct FfMacSchedSapProvider::SchedDlMacBufferReqParameters& params)

{

  NS_LOG_FUNCTION (this);

  // TODO: Implementation of the API

  return;

}

int

RrFfMacScheduler::GetRbgSize (int dlbandwidth)

{

  for (int i = 0; i < 4; i++)

    {

      if (dlbandwidth < Type0AllocationRbg[i])

        {

          return (i + 1);

        }

    }

  return (-1);

}

bool

RrFfMacScheduler::SortRlcBufferReq (FfMacSchedSapProvider::SchedDlRlcBufferReqParameters i,FfMacSchedSapProvider::SchedDlRlcBufferReqParameters j)

{

  return (i.m_rnti<j.m_rnti);

}

void

RrFfMacScheduler::DoSchedDlTriggerReq (const struct FfMacSchedSapProvider::SchedDlTriggerReqParameters& params)

{

  NS_LOG_FUNCTION (this << " DL Frame no. " << (params.m_sfnSf >> 4) << " subframe no. " << (0xF & params.m_sfnSf));

  // API generated by RLC for triggering the scheduling of a DL subframe

  RefreshDlCqiMaps ();

  // Get the actual active flows (queue!=0)

  std::list<FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator it;

  m_rlcBufferReq.sort (SortRlcBufferReq);

  int nflows = 0;

  int nTbs = 0;

  std::map <uint16_t,uint8_t> lcActivesPerRnti;

  std::map <uint16_t,uint8_t>::iterator itLcRnti;

  for (it = m_rlcBufferReq.begin (); it != m_rlcBufferReq.end (); it++)

    {

//       NS_LOG_INFO (this << " User " << (*it).m_rnti << " LC " << (uint16_t)(*it).m_logicalChannelIdentity);

      // remove old entries of this UE-LC

      if ( ((*it).m_rlcTransmissionQueueSize > 0)

           || ((*it).m_rlcRetransmissionQueueSize > 0)

           || ((*it).m_rlcStatusPduSize > 0) )

        {

          std::map <uint16_t,uint8_t>::iterator itCqi = m_p10CqiRxed.find ((*it).m_rnti);

          uint8_t cqi = 0;

          if (itCqi != m_p10CqiRxed.end ())

            {

              cqi = (*itCqi).second;

            }

          else

            {

              cqi = 1; // lowest value fro trying a transmission

            }

          if (cqi != 0)

            {

              // CQI == 0 means "out of range" (see table 7.2.3-1 of 36.213)

              nflows++;

              itLcRnti = lcActivesPerRnti.find ((*it).m_rnti);

              if (itLcRnti != lcActivesPerRnti.end ())

                {

                  (*itLcRnti).second++;

                }

              else

                {

                  lcActivesPerRnti.insert (std::pair<uint16_t, uint8_t > ((*it).m_rnti, 1));

                  nTbs++;

                }

            }

        }

    }

  if (nflows == 0)

    {

      return;

    }

  // Divide the resource equally among the active users according to

  // Resource allocation type 0 (see sec 7.1.6.1 of 36.213)

  int rbgSize = GetRbgSize (m_cschedCellConfig.m_dlBandwidth);

  int rbgNum = m_cschedCellConfig.m_dlBandwidth / rbgSize;

  int rbgPerTb = rbgNum / nTbs;

  if (rbgPerTb == 0)

    {

      rbgPerTb = 1;                // at least 1 rbg per TB (till available resource)

    }

  int rbgAllocated = 0;

  FfMacSchedSapUser::SchedDlConfigIndParameters ret;

  // round robin assignment to all UE-LC registered starting from the subsequent of the one

  // served last scheduling trigger

  //NS_LOG_DEBUG (this << " next to be served " << m_nextRntiDl << " nflows " << nflows);

  if (m_nextRntiDl != 0)

    {

      for (it = m_rlcBufferReq.begin (); it != m_rlcBufferReq.end (); it++)

        {

          if ((*it).m_rnti == m_nextRntiDl)

            {

              break;

            }

        }

      if (it == m_rlcBufferReq.end ())

        {

          NS_LOG_ERROR (this << " no user found");

        }

    }

  else

    {

      it = m_rlcBufferReq.begin ();

      m_nextRntiDl = (*it).m_rnti;

    }

  std::map <uint16_t,uint8_t>::iterator itTxMode;

  do

    {

      itLcRnti = lcActivesPerRnti.find ((*it).m_rnti);

      if (itLcRnti == lcActivesPerRnti.end ())

        {

          // skip this entry

          it++;

          if (it == m_rlcBufferReq.end ())

            {

              // restart from the first

              it = m_rlcBufferReq.begin ();

            }

          continue;

        }

      itTxMode = m_uesTxMode.find ((*it).m_rnti);

      if (itTxMode == m_uesTxMode.end())

        {

          NS_FATAL_ERROR ("No Transmission Mode info on user " << (*it).m_rnti);