/* -*-    Mode:C++; c-basic-offset:4; tab-width:4; indent-tabs-mode:f -*- */
/*
 * Copyright (c) 2006 INRIA
 * All rights reserved.
 *
 * 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.h"
#include "ns3/event.h"
#include "ns3/event.tcc"
#include "ns3/wall-clock-ms.h"
#include <vector>
#include <deque>
#include <fstream>
#include <iostream>

using namespace ns3;

class LogReader {
public:
    void readFrom_filename (char const *filename);
    void run (void);
    void printStats (void);
private:
    struct Command {
        enum {
            REMOVE,
            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_evUs;
            } 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_evUs;
            } insertRemove;
        };
    };
    void executeLogCommands (uint32_t uid);

    typedef std::deque<struct Command> Commands;
    typedef std::deque<struct Command>::iterator CommandsI;
    typedef std::deque<Event > RemoveEvents;
    

    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::readFrom_filename (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 nowUs, evUs;
            log >> nowUid >> nowUs >> evUid >> evUs;
            struct Command cmd;
            cmd.m_type = Command::INSERT;
            cmd.m_uid = nowUid;
            cmd.insert.m_evUs = evUs;
            m_commands.push_back (cmd);
        } else if (type == "r") {
            uint32_t nowUid, evUid;
            uint64_t nowUs, evUs;
            log >> nowUid >> nowUs >> evUid >> evUs;
            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 nowUs, evUs;
            log >> nowUid >> nowUs >> evUid >> evUs;
            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..." << 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->m_uid) {
                    // this insert will be removed later.
                    uint64_t us = i->insert.m_evUs;
                    uint32_t uid = i->m_uid;
                    i->m_type = Command::INSERT_REMOVE;
                    i->m_uid = uid;
                    i->insertRemove.m_evUs = us;
                    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 &&
                    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::nowUs ()
            //<< ", time=" << cmd.insert.m_evUs << std::endl;
            Simulator::scheduleAbsUs (cmd.insert.m_evUs, 
                         makeEvent (&LogReader::executeLogCommands, this, m_uid));
            m_uid++;
            break;
        case Command::INSERT_LATER:
            //std::cout << "exec insert later" << std::endl;
            Simulator::scheduleNow (makeEvent (&LogReader::executeLogCommands, this, m_uid));
            m_uid++;
            break;
        case Command::REMOVE: {
            //std::cout << "exec remove" << std::endl;
            Event ev = m_removeEvents.front ();
            m_removeEvents.pop_front ();
            Simulator::remove (ev);
        } break;
        case Command::INSERT_REMOVE: {
            //std::cout << "exec insert remove" << std::endl;
            Event ev = makeEvent (&LogReader::executeLogCommands, this, m_uid);
            Simulator::scheduleAbsUs (cmd.insertRemove.m_evUs, ev);
            m_removeEvents[cmd.insertRemove.m_evLoc] = ev;
            m_uid++;
        } 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 = 0;
    WallClockMs time;
    time.start ();
    m_command = m_commands.begin ();
    executeLogCommands (m_uid);
    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;
    while (argc > 0) {
        if (strcmp ("--list", argv[0]) == 0) {
            Simulator::setLinkedList ();
        } else if (strcmp ("--heap", argv[0]) == 0) {
            Simulator::setBinaryHeap ();
        } else if (strcmp ("--map", argv[0]) == 0) {
            Simulator::setStdMap ();
        } 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.readFrom_filename (input);
    for (uint32_t i = 0; i < n; i++) {
        log.run ();
    }
}