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

/*

 * Copyright (c) 2014 Piotr Gawlowicz

 *

 * 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: Piotr Gawlowicz <gawlowicz.p@gmail.com>

 *

 */

#include "lte-ffr-enhanced-algorithm.h"

#include "ns3/ff-mac-common.h"

#include "ns3/lte-common.h"

#include "ns3/lte-vendor-specific-parameters.h"

#include <ns3/log.h>

#include "ns3/boolean.h"

#include <ns3/double.h>

#include <cfloat>

NS_OBJECT_ENSURE_REGISTERED (LteFfrEnhancedAlgorithm);

static const double SpectralEfficiencyForCqi[16] = {

  0.0, // out of range

  0.15, 0.23, 0.38, 0.6, 0.88, 1.18,

  1.48, 1.91, 2.41,

  2.73, 3.32, 3.9, 4.52, 5.12, 5.55

};

static const struct FfrEnhancedDownlinkDefaultConfiguration

{

  uint8_t cellId;

  uint8_t dlBandwidth;

  uint8_t dlSubBandOffset;

  uint8_t dlReuse3SubBandwidth;

  uint8_t dlReuse1SubBandwidth;

} g_ffrEnhancedDownlinkDefaultConfiguration[] = {

  { 1, 25, 0, 4, 4},

  { 2, 25, 8, 4, 4},

  { 3, 25, 16, 4, 4},

  { 1, 50, 0, 9, 6},

  { 2, 50, 15, 9, 6},

  { 3, 50, 30, 9, 6},

  { 1, 75, 0, 8, 16},

  { 2, 75, 24, 8, 16},

  { 3, 75, 48, 8, 16},

  { 1, 100, 0, 16, 16},

  { 2, 100, 32, 16, 16},

  { 3, 100, 64, 16, 16}

};

static const struct FfrEnhancedUplinkDefaultConfiguration

{

  uint8_t cellId;

  uint8_t ulBandwidth;

  uint8_t ulSubBandOffset;

  uint8_t ulReuse3SubBandwidth;

  uint8_t ulReuse1SubBandwidth;

} g_ffrEnhancedUplinkDefaultConfiguration[] = {

  { 1, 25, 0, 4, 4},

  { 2, 25, 8, 4, 4},

  { 3, 25, 16, 4, 4},

  { 1, 50, 0, 9, 6},

  { 2, 50, 15, 9, 6},

  { 3, 50, 30, 9, 6},

  { 1, 75, 0, 8, 16},

  { 2, 75, 24, 8, 16},

  { 3, 75, 48, 8, 16},

  { 1, 100, 0, 16, 16},

  { 2, 100, 32, 16, 16},

  { 3, 100, 64, 16, 16}

};

const uint16_t NUM_DOWNLINK_CONFS (sizeof (g_ffrEnhancedDownlinkDefaultConfiguration) / sizeof (FfrEnhancedDownlinkDefaultConfiguration));

const uint16_t NUM_UPLINK_CONFS (sizeof (g_ffrEnhancedUplinkDefaultConfiguration) / sizeof (FfrEnhancedUplinkDefaultConfiguration));

LteFfrEnhancedAlgorithm::LteFfrEnhancedAlgorithm ()

  : m_ffrSapUser (0),

    m_ffrRrcSapUser (0),

    m_measId (0)

{

  NS_LOG_FUNCTION (this);

  m_ffrSapProvider = new MemberLteFfrSapProvider<LteFfrEnhancedAlgorithm> (this);

  m_ffrRrcSapProvider = new MemberLteFfrRrcSapProvider<LteFfrEnhancedAlgorithm> (this);

}

LteFfrEnhancedAlgorithm::~LteFfrEnhancedAlgorithm ()

{

  NS_LOG_FUNCTION (this);

}

void

LteFfrEnhancedAlgorithm::DoDispose ()

{

  NS_LOG_FUNCTION (this);

  delete m_ffrSapProvider;

  delete m_ffrRrcSapProvider;

}

TypeId

LteFfrEnhancedAlgorithm::GetTypeId ()

{

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

    .SetParent<LteFfrAlgorithm> ()

    .AddConstructor<LteFfrEnhancedAlgorithm> ()

    .AddAttribute ("UlSubBandOffset",

                   "Uplink SubBand Offset for this cell in number of Resource Block Groups",

                   UintegerValue (0),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_ulSubBandOffset),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("UlReuse3SubBandwidth",

                   "Uplink Reuse 3 SubBandwidth Configuration in number of Resource Block Groups",

                   UintegerValue (4),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_ulReuse3SubBandwidth),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("UlReuse1SubBandwidth",

                   "Uplink Reuse 1 SubBandwidth Configuration in number of Resource Block Groups",

                   UintegerValue (4),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_ulReuse1SubBandwidth),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("DlSubBandOffset",

                   "Downlink SubBand Offset for this cell in number of Resource Block Groups",

                   UintegerValue (0),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_dlSubBandOffset),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("DlReuse3SubBandwidth",

                   "Downlink Reuse 3 SubBandwidth Configuration in number of Resource Block Groups",

                   UintegerValue (4),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_dlReuse3SubBandwidth),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("DlReuse1SubBandwidth",

                   "Downlink Reuse 1 SubBandwidth Configuration in number of Resource Block Groups",

                   UintegerValue (4),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_dlReuse1SubBandwidth),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("RsrqThreshold",

                   "If the RSRQ of is worse than this threshold, UE should be served in Edge sub-band",

                   UintegerValue (26),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_rsrqThreshold),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("CenterAreaPowerOffset",

                   "PdschConfigDedicated::Pa value for Center Sub-band, default value dB0",

                   UintegerValue (5),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_centerAreaPowerOffset),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("EdgeAreaPowerOffset",

                   "PdschConfigDedicated::Pa value for Edge Sub-band, default value dB0",

                   UintegerValue (5),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_edgeAreaPowerOffset),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("DlCqiThreshold",

                   "If the DL-CQI for RBG of is higher than this threshold, transmission on RBG is possible",

                   UintegerValue (15),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_dlCqiThreshold),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("UlCqiThreshold",

                   "If the UL-CQI for RBG of is higher than this threshold, transmission on RBG is possible",

                   UintegerValue (15),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_ulCqiThreshold),

                   MakeUintegerChecker <uint8_t> ())

    .AddAttribute ("CenterAreaTpc",

                   "TPC value which will be set in DL-DCI for UEs in center area"

                   "Absolute mode is used, default value 1 is mapped to -1 according to"

                   "TS36.213 Table 5.1.1.1-2",

                   UintegerValue (1),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_centerAreaTpc),

                   MakeUintegerChecker<uint8_t> ())

    .AddAttribute ("EdgeAreaTpc",

                   "TPC value which will be set in DL-DCI for UEs in edge area"

                   "Absolute mode is used, default value 1 is mapped to -1 according to"

                   "TS36.213 Table 5.1.1.1-2",

                   UintegerValue (1),

                   MakeUintegerAccessor (&LteFfrEnhancedAlgorithm::m_edgeAreaTpc),

                   MakeUintegerChecker<uint8_t> ())

  ;

  return tid;

}

void

LteFfrEnhancedAlgorithm::SetLteFfrSapUser (LteFfrSapUser* s)

{

  NS_LOG_FUNCTION (this << s);

  m_ffrSapUser = s;

}

LteFfrSapProvider*

LteFfrEnhancedAlgorithm::GetLteFfrSapProvider ()

{

  NS_LOG_FUNCTION (this);

  return m_ffrSapProvider;

}

void

LteFfrEnhancedAlgorithm::SetLteFfrRrcSapUser (LteFfrRrcSapUser* s)

{

  NS_LOG_FUNCTION (this << s);

  m_ffrRrcSapUser = s;

}

LteFfrRrcSapProvider*

LteFfrEnhancedAlgorithm::GetLteFfrRrcSapProvider ()

{

  NS_LOG_FUNCTION (this);

  return m_ffrRrcSapProvider;

}

void

LteFfrEnhancedAlgorithm::DoInitialize ()

{

  NS_LOG_FUNCTION (this);

  LteFfrAlgorithm::DoInitialize ();

  NS_ASSERT_MSG (m_dlBandwidth > 24,"DlBandwidth must be at least 25 to use EFFR algorithm");

  NS_ASSERT_MSG (m_ulBandwidth > 24,"UlBandwidth must be at least 25 to use EFFR algorithm");

  if (m_frCellTypeId != 0)

    {

      SetDownlinkConfiguration (m_frCellTypeId, m_dlBandwidth);

      SetUplinkConfiguration (m_frCellTypeId, m_ulBandwidth);

    }

  NS_LOG_LOGIC (this << " requesting Event A1 measurements"

                     << " (threshold = 0" << ")");

  LteRrcSap::ReportConfigEutra reportConfig;

  reportConfig.eventId = LteRrcSap::ReportConfigEutra::EVENT_A1;

  reportConfig.threshold1.choice = LteRrcSap::ThresholdEutra::THRESHOLD_RSRQ;

  reportConfig.threshold1.range = 0;

  reportConfig.triggerQuantity = LteRrcSap::ReportConfigEutra::RSRQ;

  reportConfig.reportInterval = LteRrcSap::ReportConfigEutra::MS120;

  m_measId = m_ffrRrcSapUser->AddUeMeasReportConfigForFfr (reportConfig);

}

void

LteFfrEnhancedAlgorithm::Reconfigure ()

{

  NS_LOG_FUNCTION (this);

  if (m_frCellTypeId != 0)

    {

      SetDownlinkConfiguration (m_frCellTypeId, m_dlBandwidth);

      SetUplinkConfiguration (m_frCellTypeId, m_ulBandwidth);

    }

  InitializeDownlinkRbgMaps ();

  InitializeUplinkRbgMaps ();

  m_needReconfiguration = false;

}

void

LteFfrEnhancedAlgorithm::SetDownlinkConfiguration (uint16_t cellId, uint8_t bandwidth)

{

  NS_LOG_FUNCTION (this);

  for (uint16_t i = 0; i < NUM_DOWNLINK_CONFS; ++i)

    {

      if ((g_ffrEnhancedDownlinkDefaultConfiguration[i].cellId == cellId)

          && g_ffrEnhancedDownlinkDefaultConfiguration[i].dlBandwidth == m_dlBandwidth)

        {

          m_dlSubBandOffset = g_ffrEnhancedDownlinkDefaultConfiguration[i].dlSubBandOffset;

          m_dlReuse3SubBandwidth = g_ffrEnhancedDownlinkDefaultConfiguration[i].dlReuse3SubBandwidth;

          m_dlReuse1SubBandwidth = g_ffrEnhancedDownlinkDefaultConfiguration[i].dlReuse1SubBandwidth;

        }

    }

}

void

LteFfrEnhancedAlgorithm::SetUplinkConfiguration (uint16_t cellId, uint8_t bandwidth)

{

  NS_LOG_FUNCTION (this);

  for (uint16_t i = 0; i < NUM_UPLINK_CONFS; ++i)

    {

      if ((g_ffrEnhancedUplinkDefaultConfiguration[i].cellId == cellId)

          && g_ffrEnhancedUplinkDefaultConfiguration[i].ulBandwidth == m_ulBandwidth)

        {

          m_ulSubBandOffset = g_ffrEnhancedUplinkDefaultConfiguration[i].ulSubBandOffset;

          m_ulReuse3SubBandwidth = g_ffrEnhancedUplinkDefaultConfiguration[i].ulReuse3SubBandwidth;

          m_ulReuse1SubBandwidth = g_ffrEnhancedUplinkDefaultConfiguration[i].ulReuse1SubBandwidth;

        }

    }

}

int

LteFfrEnhancedAlgorithm::GetCqiFromSpectralEfficiency (double s)

{

  NS_LOG_FUNCTION (s);

  NS_ASSERT_MSG (s >= 0.0, "negative spectral efficiency = " << s);

  int cqi = 0;

  while ((cqi < 15) && (SpectralEfficiencyForCqi[cqi + 1] < s))

    {

      ++cqi;

    }

  NS_LOG_LOGIC ("cqi = " << cqi);

  return cqi;

}

void

LteFfrEnhancedAlgorithm::InitializeDownlinkRbgMaps ()

{

  m_dlRbgMap.clear ();

  m_dlReuse3RbgMap.clear ();

  m_dlReuse1RbgMap.clear ();

  m_dlPrimarySegmentRbgMap.clear ();

  m_dlSecondarySegmentRbgMap.clear ();

  int rbgSize = GetRbgSize (m_dlBandwidth);

  m_dlRbgMap.resize (m_dlBandwidth / rbgSize, true);

  m_dlReuse3RbgMap.resize (m_dlBandwidth / rbgSize, false);

  m_dlReuse1RbgMap.resize (m_dlBandwidth / rbgSize, false);

  m_dlPrimarySegmentRbgMap.resize (m_dlBandwidth / rbgSize, false);

  m_dlSecondarySegmentRbgMap.resize (m_dlBandwidth / rbgSize, true);

  NS_ASSERT_MSG (m_dlSubBandOffset <= m_dlBandwidth,"DlSubBandOffset higher than DlBandwidth");

  NS_ASSERT_MSG (m_dlSubBandOffset + m_dlReuse3SubBandwidth + m_dlReuse1SubBandwidth <= m_dlBandwidth,

                 "DlSubBandOffset + DlReuse3SubBandwidth + DlReuse1SubBandwidth  higher than DlBandwidth");

  for (uint8_t i = 0; i < m_dlReuse3SubBandwidth / rbgSize; i++)

    {

      int offset = m_dlSubBandOffset / rbgSize;

      uint8_t index = offset + i;

      m_dlReuse3RbgMap[index] = true;

      m_dlPrimarySegmentRbgMap[index] = true;

      m_dlRbgMap[index] = false;

    }

  for (uint8_t i = 0; i < m_dlReuse1SubBandwidth / rbgSize; i++)

    {

      int offset = (m_dlSubBandOffset + m_dlReuse3SubBandwidth) / rbgSize;

      uint8_t index = offset + i;

      m_dlReuse1RbgMap[index] = true;

      m_dlPrimarySegmentRbgMap[index] = true;

      m_dlSecondarySegmentRbgMap[index] = false;

      m_dlRbgMap[index] = false;

    }

  for (uint8_t i = 0; i < m_dlReuse3SubBandwidth / rbgSize; i++)

    {

      uint8_t offset = (m_dlReuse3SubBandwidth + m_dlReuse1SubBandwidth) / rbgSize;

      uint8_t index = 0 * offset + i;

      m_dlSecondarySegmentRbgMap[index] = false;

      index = 1 * offset + i;

      m_dlSecondarySegmentRbgMap[index] = false;

      index = 2 * offset + i;

      m_dlSecondarySegmentRbgMap[index] = false;

    }

}

void

LteFfrEnhancedAlgorithm::InitializeUplinkRbgMaps ()

{

  m_ulRbgMap.clear ();

  m_ulReuse3RbgMap.clear ();

  m_ulReuse1RbgMap.clear ();

  m_ulPrimarySegmentRbgMap.clear ();

  m_ulSecondarySegmentRbgMap.clear ();

  if (!m_enabledInUplink)

    {

      m_ulRbgMap.resize (m_ulBandwidth, false);

      return;

    }

  m_ulRbgMap.resize (m_ulBandwidth, true);

  m_ulReuse3RbgMap.resize (m_ulBandwidth, false);

  m_ulReuse1RbgMap.resize (m_ulBandwidth, false);

  m_ulPrimarySegmentRbgMap.resize (m_ulBandwidth, false);

  m_ulSecondarySegmentRbgMap.resize (m_ulBandwidth, true);

  NS_ASSERT_MSG (m_ulSubBandOffset <= m_ulBandwidth, "UlSubBandOffset higher than UlBandwidth");

  NS_ASSERT_MSG (m_ulSubBandOffset + m_ulReuse3SubBandwidth + m_ulReuse1SubBandwidth <= m_ulBandwidth,

                 "UlSubBandOffset + UlReuse3SubBandwidth + UlReuse1SubBandwidth higher than UlBandwidth");

  for (uint8_t i = 0; i < m_ulReuse3SubBandwidth; i++)

    {

      int offset = m_ulSubBandOffset;

      uint8_t index = offset + i;

      m_ulReuse3RbgMap[index] = true;

      m_ulPrimarySegmentRbgMap[index] = true;

      m_ulRbgMap[index] = false;

    }

  for (uint8_t i = 0; i < m_ulReuse1SubBandwidth; i++)

    {

      int offset = (m_ulSubBandOffset + m_ulReuse3SubBandwidth);

      uint8_t index = offset + i;

      m_ulReuse1RbgMap[index] = true;

      m_ulPrimarySegmentRbgMap[index] = true;

      m_ulSecondarySegmentRbgMap[index] = false;

      m_ulRbgMap[index] = false;

    }

  for (uint8_t i = 0; i < m_ulReuse3SubBandwidth; i++)

    {

      uint8_t offset = m_ulReuse3SubBandwidth + m_ulReuse1SubBandwidth;

      uint8_t index = 0 * offset + i;

      m_ulSecondarySegmentRbgMap[index] = false;

      index = 1 * offset + i;

      m_ulSecondarySegmentRbgMap[index] = false;

      index = 2 * offset + i;

      m_ulSecondarySegmentRbgMap[index] = false;

    }

}

std::vector <bool>

LteFfrEnhancedAlgorithm::DoGetAvailableDlRbg ()

{

  NS_LOG_FUNCTION (this);

  if (m_needReconfiguration)

    {

      Reconfigure ();

    }

  if (m_dlRbgMap.empty ())

    {

      InitializeDownlinkRbgMaps ();

    }

  std::vector <bool> rbgMap = m_dlRbgMap;

  std::map <uint16_t, std::vector<bool> >::iterator it;

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

    {

      NS_LOG_INFO ("RNTI : " << it->first);

      std::vector<bool> rbgAvailableMap = it->second;

      for (uint32_t i = 0; i < rbgMap.size (); i++)

        {

          NS_LOG_INFO ("\t rbgId: " << i << " available " << (int)rbgAvailableMap.at (i));

          if ( rbgAvailableMap.at (i) == true)

            {

              rbgMap.at (i) = false;

            }

        }

    }

  return rbgMap;

}

bool

LteFfrEnhancedAlgorithm::DoIsDlRbgAvailableForUe (int rbgId, uint16_t rnti)

{

  NS_LOG_FUNCTION (this);

  bool isReuse3Rbg = m_dlReuse3RbgMap[rbgId];

  bool isReuse1Rbg = m_dlReuse1RbgMap[rbgId];

  bool isPrimarySegmentRbg     = m_dlPrimarySegmentRbgMap[rbgId];

  bool isSecondarySegmentRbg   = m_dlSecondarySegmentRbgMap[rbgId];

  std::map< uint16_t, uint8_t >::iterator it = m_ues.find (rnti);

  if (it == m_ues.end ())

    {

      m_ues.insert (std::pair< uint16_t, uint8_t > (rnti, AreaUnset));

    }

  it = m_ues.find (rnti);

  //if UE area is unknown, serve UE in edge area RBGs

  if (it->second == AreaUnset)

    {

      return isReuse3Rbg;

    }

  bool isCenterUe = false;

  bool isEdgeUe   = false;

  if (it->second == CenterArea )

    {

      isCenterUe = true;

    }

  else if (it->second == EdgeArea)

    {

      isEdgeUe = true;

    }

  if (isPrimarySegmentRbg)

    {

      NS_LOG_INFO ("PRIMARY SEGMENT RNTI: " << rnti  << "  rbgId: " << rbgId );

      return (isReuse1Rbg && isCenterUe) || (isReuse3Rbg && isEdgeUe);

    }

  else if (isSecondarySegmentRbg && isCenterUe)

    {

      //check if RB can be used by UE based on CQI information

      NS_LOG_INFO ("SECONDARY SEGMENT RNTI: " << rnti  << "  rbgId: " << rbgId );

      std::map <uint16_t, std::vector<bool> >::iterator it = m_dlRbgAvailableforUe.find (rnti);

      if (it != m_dlRbgAvailableforUe.end ())

        {

          NS_LOG_INFO ("RNTI: " << rnti  << "  rbgId: " << rbgId << "  available: " << it->second.at (rbgId));

          if (it->second.at (rbgId) == true)

            {

              return true;

            }

        }

      return false;

    }

  return false;

}