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

/*

 * Copyright (c) 2006 INRIA

 *

 * 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: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#include "ns3/simulator-module.h"

#include "ns3/core-module.h"

#include <vector>

#include <deque>

#include <fstream>

#include <iostream>

using namespace ns3;

class LogReader {

public:

  void ReadFromFilename (char const *filename);

  void Run (void);

  void PrintStats (void);

private:

  struct Command {

      enum {

          REMOVE = 100,

          INSERT,

          INSERT_LATER,

          INSERT_REMOVE

      } m_type;

      // uid at which this command is supposed to be executed.

      uint32_t m_uid;

      union {

          struct {

            // time at which the event is supposed to expire

            uint64_t m_evNs;

            uint32_t m_evUid;

          } insert;

          struct {

            // location in the array of events to remove where

            // to insert this event once it is inserted in 

            // the scheduler.

            uint32_t m_evLoc; 

            // time at which the event is supposed to expire

            uint64_t m_evNs;

          } insertRemove;

      };

  };

  void ExecuteLogCommands (uint32_t uid);

  typedef std::vector<struct Command> Commands;

  typedef std::vector<struct Command>::iterator CommandsI;

  typedef std::vector<EventId> RemoveEvents;

  typedef std::vector<EventId>::iterator RemoveEventsI;

  Commands m_commands;

  CommandsI m_command;

  RemoveEvents m_removeEvents;

  uint32_t m_uid;

};

typedef std::vector<std::pair<uint32_t, uint32_t> > Removes;

typedef std::vector<std::pair<uint32_t, uint32_t> >::iterator RemovesI;

void

LogReader::ReadFromFilename (char const *filename)

{

  std::ifstream log;

  std::cout << "read log..." << std::endl;

  Removes removes;

  log.open (filename);

  while (!log.eof ()) 

    {

      std::string type;

      log >> type;

      if (type == "i") 

        {

          uint32_t nowUid, evUid;

          uint64_t nowNs, evNs;

          log >> nowUid >> nowNs >> evUid >> evNs;

          struct Command cmd;

          cmd.m_type = Command::INSERT;

          cmd.m_uid = nowUid;

          cmd.insert.m_evNs = evNs;

          cmd.insert.m_evUid = evUid;

          m_commands.push_back (cmd);

        } 

      else if (type == "r") 

        {

          uint32_t nowUid, evUid;

          uint64_t nowNs, evNs;

          log >> nowUid >> nowNs >> evUid >> evNs;

          struct Command cmd;

          cmd.m_type = Command::REMOVE;

          cmd.m_uid = nowUid;

          m_commands.push_back (cmd);

          removes.push_back (std::make_pair (nowUid, evUid));

        } 

      else if (type == "il") 

        {

          uint32_t nowUid, evUid;

          uint64_t nowNs, evNs;

          log >> nowUid >> nowNs >> evUid >> evNs;

          struct Command cmd;

          cmd.m_type = Command::INSERT_LATER;

          cmd.m_uid = nowUid;

          m_commands.push_back (cmd);

        }

    }

  log.close ();

  std::cout << "gather insert/removes, commands="<<m_commands.size () 

            << ", removes=" << removes.size () << "..." << std::endl;

  for (CommandsI i = m_commands.begin (); i != m_commands.end (); i++) 

    {

      if (i->m_type == Command::INSERT) 

        {

          for (RemovesI j = removes.begin (); j != removes.end (); j++) 

            {

              if (j->second == i->insert.m_evUid) 

                {

                  // this insert will be removed later.

                  uint64_t ns = i->insert.m_evNs;

                  uint32_t uid = i->m_uid;

                  i->m_type = Command::INSERT_REMOVE;

                  i->m_uid = uid;

                  i->insertRemove.m_evNs = ns;

                  i->insertRemove.m_evLoc = j->first;

                  break;

                }

            }

        }

    }

  std::cout << "calculate remove locations..." << std::endl;

  // calculate the final insert/remove location.

  for (CommandsI i = m_commands.begin (); i != m_commands.end (); i++) 

    {

      if (i->m_type == Command::INSERT_REMOVE) 

        {

          uint32_t loc = 0;

          for (CommandsI tmp = i; tmp != m_commands.end (); tmp++) 

            {

              if (tmp->m_type == Command::REMOVE) 

                {

                  if (tmp->m_uid == i->insertRemove.m_evLoc) 

                    {

                      i->insertRemove.m_evLoc = loc;

                      break;

                    }

                  loc++;

                }

            }

        }

    }

}

void

LogReader::ExecuteLogCommands (uint32_t uid)

{

  if (m_command == m_commands.end ()) 

    {

      return;

    }

  //std::cout << "one event, uid=" <<m_uid<< std::endl;

  struct Command cmd = *m_command;

  //std::cout << "cmd uid=" <<cmd.m_uid<< std::endl;

  while (cmd.m_uid == uid) 

    {

      m_command++;

      switch (cmd.m_type) {

      case Command::INSERT:

        //std::Cout << "exec insert now=" << Simulator::Now ().GetNanoSeconds ()

        //<< ", time=" << cmd.insert.m_evNs << std::endl;

        Simulator::Schedule (NanoSeconds (cmd.insert.m_evNs) - Now (), 

                             &LogReader::ExecuteLogCommands, this, m_uid);

        m_uid++;

        break;

      case Command::INSERT_LATER:

          //std::cout << "exec insert later" << std::endl;

          Simulator::ScheduleNow (&LogReader::ExecuteLogCommands, this, m_uid);

          m_uid++;

          break;

      case Command::REMOVE: 

        {

          //std::cout << "exec remove" << std::endl;

          EventId id = m_removeEvents.back ();

          m_removeEvents.pop_back ();

          Simulator::Remove (id);

        } break;

      case Command::INSERT_REMOVE: 

        {

          //std::cout << "exec insert remove" << std::endl;

          EventId id = Simulator::Schedule (NanoSeconds (cmd.insertRemove.m_evNs) - Now (),

                                            &LogReader::ExecuteLogCommands, this, m_uid);

          NS_ASSERT (id.GetUid () == m_uid);

          if (cmd.insertRemove.m_evLoc + 1 > m_removeEvents.size ())

            {

              uint32_t missing = cmd.insertRemove.m_evLoc + 1 - m_removeEvents.size ();

              m_removeEvents.insert (m_removeEvents.begin (),

                                     missing, id);

            }

          uint32_t index = m_removeEvents.size () - cmd.insertRemove.m_evLoc - 1;

          m_removeEvents[index] = id;

          m_uid++;

        } break;

      default:

        NS_ASSERT (false);

        break;

      }

      cmd = *m_command;

  }

}

void

LogReader::PrintStats (void)

{

  uint32_t nInserts = 0;

  uint32_t nRemoves = 0;

  for (CommandsI i = m_commands.begin (); i != m_commands.end (); i++) 

    {

      switch (i->m_type) {

      case Command::INSERT:

          nInserts++;

          break;

      case Command::INSERT_LATER:

          nInserts++;

          break;

      case Command::INSERT_REMOVE:

          nInserts++;

          break;

      case Command::REMOVE:

          nRemoves++;

          break;

      }

    }

  std::cout << "inserts="<<nInserts<<", removes="<<nRemoves<<std::endl;

  std::cout << "run simulation..."<<std::endl;

}

void

LogReader::Run (void)

{

  m_uid = 1;

  SystemWallClockMs time;

  time.Start ();

  m_command = m_commands.begin ();

  ExecuteLogCommands (0);

  Simulator::Run ();

  unsigned long long delta = time.End ();

  double delay = ((double)delta)/1000;

  std::cout << "runtime="<<delay<<"s"<<std::endl;

}

int main (int argc, char *argv[])

{

  char const *input = 0;

  uint32_t n = 1;

  bool is_map = false;

  bool is_list = false;

  bool is_heap = false;

  while (argc > 0) 

    {

      if (strcmp ("--list", argv[0]) == 0) 

        {

          is_list = true;

        } 

      else if (strcmp ("--heap", argv[0]) == 0) 

        {

          is_heap = true;

        } 

      else if (strcmp ("--map", argv[0]) == 0) 

        {

          is_map = true;

        } 

      else if (strncmp ("--n=", argv[0], strlen("--n=")) == 0) 

        {

          n = atoi (argv[0]+strlen ("--n="));

        } 

      else if (strncmp ("--input=", argv[0],strlen ("--input=")) == 0) 

        {

          input = argv[0] + strlen ("--input=");

        } 

      else if (strncmp ("--log=", argv[0],strlen ("--log=")) == 0) 

        {

          char const *filename = argv[0] + strlen ("--log=");

          Simulator::EnableLogTo (filename);

        }

      argc--;

      argv++;

    }

  if (input == 0) 

    {

      std::cerr << "need --input=[filename] option" << std::endl;

      return 1;

    }

  LogReader log;

  log.ReadFromFilename (input);

  std::cout << "start runs..." << std::endl;

  for (uint32_t i = 0; i < n; i++) 

    {

      if (is_map)

        {

          Simulator::SetScheduler (CreateObject<MapScheduler> ());

        }

      else if (is_list)

        {

          Simulator::SetScheduler (CreateObject<ListScheduler> ());

        }

      else if (is_heap)

        {

          Simulator::SetScheduler (CreateObject<HeapScheduler> ());

        }

      log.Run ();

      Simulator::Destroy ();

    }

}