/* -*- 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/simulator.h>

#include <ns3/lte-amc.h>

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

NS_LOG_COMPONENT_DEFINE ("PfFfMacScheduler");

namespace ns3 {

int PfType0AllocationRbg[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 (PfFfMacScheduler);

class PfSchedulerMemberCschedSapProvider : public FfMacCschedSapProvider

{

public:

  PfSchedulerMemberCschedSapProvider (PfFfMacScheduler* 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:

  PfSchedulerMemberCschedSapProvider ();

  PfFfMacScheduler* m_scheduler;

};

PfSchedulerMemberCschedSapProvider::PfSchedulerMemberCschedSapProvider ()

{

}

PfSchedulerMemberCschedSapProvider::PfSchedulerMemberCschedSapProvider (PfFfMacScheduler* scheduler) : m_scheduler (scheduler)

{

}

void

PfSchedulerMemberCschedSapProvider::CschedCellConfigReq (const struct CschedCellConfigReqParameters& params)

{

  m_scheduler->DoCschedCellConfigReq (params);

}

void

PfSchedulerMemberCschedSapProvider::CschedUeConfigReq (const struct CschedUeConfigReqParameters& params)

{

  m_scheduler->DoCschedUeConfigReq (params);

}

void

PfSchedulerMemberCschedSapProvider::CschedLcConfigReq (const struct CschedLcConfigReqParameters& params)

{

  m_scheduler->DoCschedLcConfigReq (params);

}

void

PfSchedulerMemberCschedSapProvider::CschedLcReleaseReq (const struct CschedLcReleaseReqParameters& params)

{

  m_scheduler->DoCschedLcReleaseReq (params);

}

void

PfSchedulerMemberCschedSapProvider::CschedUeReleaseReq (const struct CschedUeReleaseReqParameters& params)

{

  m_scheduler->DoCschedUeReleaseReq (params);

}

class PfSchedulerMemberSchedSapProvider : public FfMacSchedSapProvider

{

public:

  PfSchedulerMemberSchedSapProvider (PfFfMacScheduler* 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:

  PfSchedulerMemberSchedSapProvider ();

  PfFfMacScheduler* m_scheduler;

};

PfSchedulerMemberSchedSapProvider::PfSchedulerMemberSchedSapProvider ()

{

}

PfSchedulerMemberSchedSapProvider::PfSchedulerMemberSchedSapProvider (PfFfMacScheduler* scheduler)

  : m_scheduler (scheduler)

{

}

void

PfSchedulerMemberSchedSapProvider::SchedDlRlcBufferReq (const struct SchedDlRlcBufferReqParameters& params)

{

  m_scheduler->DoSchedDlRlcBufferReq (params);

}

void

PfSchedulerMemberSchedSapProvider::SchedDlPagingBufferReq (const struct SchedDlPagingBufferReqParameters& params)

{

  m_scheduler->DoSchedDlPagingBufferReq (params);

}

void

PfSchedulerMemberSchedSapProvider::SchedDlMacBufferReq (const struct SchedDlMacBufferReqParameters& params)

{

  m_scheduler->DoSchedDlMacBufferReq (params);

}

void

PfSchedulerMemberSchedSapProvider::SchedDlTriggerReq (const struct SchedDlTriggerReqParameters& params)

{

  m_scheduler->DoSchedDlTriggerReq (params);

}

void

PfSchedulerMemberSchedSapProvider::SchedDlRachInfoReq (const struct SchedDlRachInfoReqParameters& params)

{

  m_scheduler->DoSchedDlRachInfoReq (params);

}

void

PfSchedulerMemberSchedSapProvider::SchedDlCqiInfoReq (const struct SchedDlCqiInfoReqParameters& params)

{

  m_scheduler->DoSchedDlCqiInfoReq (params);

}

void

PfSchedulerMemberSchedSapProvider::SchedUlTriggerReq (const struct SchedUlTriggerReqParameters& params)

{

  m_scheduler->DoSchedUlTriggerReq (params);

}

void

PfSchedulerMemberSchedSapProvider::SchedUlNoiseInterferenceReq (const struct SchedUlNoiseInterferenceReqParameters& params)

{

  m_scheduler->DoSchedUlNoiseInterferenceReq (params);

}

void

PfSchedulerMemberSchedSapProvider::SchedUlSrInfoReq (const struct SchedUlSrInfoReqParameters& params)

{

  m_scheduler->DoSchedUlSrInfoReq (params);

}

void

PfSchedulerMemberSchedSapProvider::SchedUlMacCtrlInfoReq (const struct SchedUlMacCtrlInfoReqParameters& params)

{

  m_scheduler->DoSchedUlMacCtrlInfoReq (params);

}

void

PfSchedulerMemberSchedSapProvider::SchedUlCqiInfoReq (const struct SchedUlCqiInfoReqParameters& params)

{

  m_scheduler->DoSchedUlCqiInfoReq (params);

}

PfFfMacScheduler::PfFfMacScheduler ()

  :   m_cschedSapUser (0),

    m_schedSapUser (0),

    m_timeWindow (99.0),

    m_schedTtiDelay (2),

    // WILD ACK: based on a m_macChTtiDelay = 1

    m_nextRntiUl (0)

{

  m_cschedSapProvider = new PfSchedulerMemberCschedSapProvider (this);

  m_schedSapProvider = new PfSchedulerMemberSchedSapProvider (this);

}

PfFfMacScheduler::~PfFfMacScheduler ()

{

  NS_LOG_FUNCTION (this);

}

void

PfFfMacScheduler::DoDispose ()

{

  NS_LOG_FUNCTION (this);

  delete m_cschedSapProvider;

  delete m_schedSapProvider;

}

TypeId

PfFfMacScheduler::GetTypeId (void)

{

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

    .SetParent<FfMacScheduler> ()

    .AddConstructor<PfFfMacScheduler> ()

    .AddAttribute ("CqiTimerThreshold",

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

                   UintegerValue (1000),

                   MakeUintegerAccessor (&PfFfMacScheduler::m_cqiTimersThreshold),

                   MakeUintegerChecker<uint32_t> ())

    ;

  return tid;

}

void

PfFfMacScheduler::SetFfMacCschedSapUser (FfMacCschedSapUser* s)

{

  m_cschedSapUser = s;

}

void

PfFfMacScheduler::SetFfMacSchedSapUser (FfMacSchedSapUser* s)

{

  m_schedSapUser = s;

}

FfMacCschedSapProvider*

PfFfMacScheduler::GetFfMacCschedSapProvider ()

{

  return m_cschedSapProvider;

}

FfMacSchedSapProvider*

PfFfMacScheduler::GetFfMacSchedSapProvider ()

{

  return m_schedSapProvider;

}

void

PfFfMacScheduler::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

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

{

  NS_LOG_FUNCTION (this);

  // Not used at this stage

  return;

}

void

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

{

  NS_LOG_FUNCTION (this << " New LC, rnti: "  << params.m_rnti);

  std::map <uint16_t, pfsFlowPerf_t>::iterator it;

  for (uint16_t i = 0; i < params.m_logicalChannelConfigList.size (); i++)

    {

      it = m_flowStatsDl.find (params.m_rnti);

      if (it == m_flowStatsDl.end ())

        {

          pfsFlowPerf_t flowStatsDl;

          flowStatsDl.flowStart = Simulator::Now ();

          flowStatsDl.totalBytesTransmitted = 0;

          flowStatsDl.lastTtiBytesTrasmitted = 0;

          flowStatsDl.lastAveragedThroughput = 1;

          m_flowStatsDl.insert (std::pair<uint16_t, pfsFlowPerf_t> (params.m_rnti, flowStatsDl));

          pfsFlowPerf_t flowStatsUl;

          flowStatsUl.flowStart = Simulator::Now ();

          flowStatsUl.totalBytesTransmitted = 0;

          flowStatsUl.lastTtiBytesTrasmitted = 0;

          flowStatsUl.lastAveragedThroughput = 1;

          m_flowStatsUl.insert (std::pair<uint16_t, pfsFlowPerf_t> (params.m_rnti, flowStatsUl));

        }

      else

        {

          NS_LOG_ERROR ("RNTI already exists");

        }

    }

  return;

}

void

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

{

  NS_LOG_FUNCTION (this);

  // TODO: Implementation of the API

  return;

}

void

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

{

  NS_LOG_FUNCTION (this);

  // TODO: Implementation of the API

  return;

}

void

PfFfMacScheduler::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::map <LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator it;

  LteFlowId_t flow (params.m_rnti, params.m_logicalChannelIdentity);

  it =  m_rlcBufferReq.find (flow);

  if (it == m_rlcBufferReq.end ())

    {

      m_rlcBufferReq.insert (std::pair <LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters> (flow, params));

    }

  else

    {

      (*it).second = params;

    }

  return;

}

void

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

{

  NS_LOG_FUNCTION (this);

  // TODO: Implementation of the API

  return;

}

void

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

{

  NS_LOG_FUNCTION (this);

  // TODO: Implementation of the API

  return;

}

int

PfFfMacScheduler::GetRbgSize (int dlbandwidth)

{

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

    {

      if (dlbandwidth < PfType0AllocationRbg[i])

        {

          return (i + 1);

        }

    }

  return (-1);

}

int 

PfFfMacScheduler::LcActivePerFlow (uint16_t rnti)

{

  std::map <LteFlowId_t, FfMacSchedSapProvider::SchedDlRlcBufferReqParameters>::iterator it;

  int lcActive = 0;

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

    {

      if (((*it).first.m_rnti == rnti) && (((*it).second.m_rlcTransmissionQueueSize > 0)

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

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

        {

          lcActive++;

        }

      if ((*it).first.m_rnti > rnti)

        {

          break;

        }

    }

  return (lcActive);

}

void

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

{

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

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

  // evaluate the relative channel quality indicator for each UE per each RBG 

  // (since we are using allocation type 0 the small unit of allocation is RBG)

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

  RefreshDlCqiMaps ();

  int rbgSize = GetRbgSize (m_cschedCellConfig.m_dlBandwidth);

  int rbgNum = m_cschedCellConfig.m_dlBandwidth / rbgSize;

  //std::vector <LteFlowId_t> rbgAllocationMap;

  std::map <uint16_t, std::vector <uint16_t> > allocationMap;

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

    {

//       NS_LOG_DEBUG (this << " ALLOCATION for RBG " << i << " of " << rbgNum);

      std::map <uint16_t, pfsFlowPerf_t>::iterator it;

      std::map <uint16_t, pfsFlowPerf_t>::iterator itMax = m_flowStatsDl.end ();

      double rcqiMax = 0.0;

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

        {

          std::map <uint16_t,SbMeasResult_s>::iterator itCqi;

          itCqi = m_a30CqiRxed.find ((*it).first);

          uint8_t cqi = 0;

          if (itCqi == m_a30CqiRxed.end ())

            {

//               NS_LOG_DEBUG (this << " No DL-CQI for this UE " << (*it).first);

              cqi = 1;  // start with lowest value

            }

          else

            {

              cqi = (*itCqi).second.m_higherLayerSelected.at (i).m_sbCqi.at (0);

//               NS_LOG_INFO (this << " CQI " << (uint32_t)cqi);

            }

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

            {

//               NS_LOG_DEBUG (this << " LC active " << LcActivePerFlow ((*it).first));

              if (LcActivePerFlow ((*it).first) > 0)

                {

                  // this UE has data to transmit

                  uint8_t mcs = LteAmc::GetMcsFromCqi (cqi);

                  double achievableRate = ((LteAmc::GetTbSizeFromMcs (mcs, 1) / 8) / 0.001); // = TB size / TTI

                  double rcqi = achievableRate / (*it).second.lastAveragedThroughput;

//                   NS_LOG_DEBUG (this << " RNTI " << (*it).first << " MCS " << (uint32_t)mcs << " achievableRate " << achievableRate << " avgThr " << (*it).second.lastAveragedThroughput << " RCQI " << rcqi);

                  if (rcqi > rcqiMax)

                    {

                      rcqiMax = rcqi;

                      itMax = it;

                    }

                }

            }   // end if cqi

        } // end for m_rlcBufferReq

      if (itMax == m_flowStatsDl.end ())

        {

          // no UE available for this RB

          NS_LOG_DEBUG (this << " no UE found");

        }

      else

        {

          std::map <uint16_t, std::vector <uint16_t> >::iterator itMap;

          itMap = allocationMap.find ((*itMax).first);

          if (itMap == allocationMap.end ())

            {

              // insert new element

              std::vector <uint16_t> tempMap;

              tempMap.push_back (i);

              allocationMap.insert (std::pair <uint16_t, std::vector <uint16_t> > ((*itMax).first, tempMap));

            }

          else

            {

              (*itMap).second.push_back (i);

            }

//           NS_LOG_DEBUG (this << " UE assigned " << (*itMax).first);

        }

    } // end for RBGs

  // reset TTI stats of users

  std::map <uint16_t, pfsFlowPerf_t>::iterator itStats;

  for (itStats = m_flowStatsDl.begin (); itStats != m_flowStatsDl.end (); itStats++)

    {

      (*itStats).second.lastTtiBytesTrasmitted = 0;

    }