/*
 *  anytun
 *
 *  The secure anycast tunneling protocol (satp) defines a protocol used
 *  for communication between any combination of unicast and anycast
 *  tunnel endpoints.  It has less protocol overhead than IPSec in Tunnel
 *  mode and allows tunneling of every ETHER TYPE protocol (e.g.
 *  ethernet, ip, arp ...). satp directly includes cryptography and
 *  message authentication based on the methods used by SRTP.  It is
 *  intended to deliver a generic, scaleable and secure solution for
 *  tunneling and relaying of packets of any protocol.
 *
 *
 *  Copyright (C) 2007-2014 Markus Grüneis, Othmar Gsenger, Erwin Nindl,
 *                          Christian Pointner <satp@wirdorange.org>
 *
 *  This file is part of Anytun.
 *
 *  Anytun is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  Anytun 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 Anytun.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  In addition, as a special exception, the copyright holders give
 *  permission to link the code of portions of this program with the
 *  OpenSSL library under certain conditions as described in each
 *  individual source file, and distribute linked combinations
 *  including the two.
 *  You must obey the GNU General Public License in all respects
 *  for all of the code used other than OpenSSL.  If you modify
 *  file(s) with this exception, you may extend this exception to your
 *  version of the file(s), but you are not obligated to do so.  If you
 *  do not wish to do so, delete this exception statement from your
 *  version.  If you delete this exception statement from all source
 *  files in the program, then also delete it here.
 */

#include <iostream>

#include <boost/asio.hpp>

#include <fcntl.h>
#include <pwd.h>
#include <grp.h>

#include "../datatypes.h"

#include "../log.h"
#include "../signalController.h"
#include "../buffer.h"
#include "connectionList.h"
#include "rtpSessionTable.h"
#include "syncRtpCommand.h"
#include "../syncQueue.h"
#include "../syncClient.h"
#include "syncOnConnect.hpp"

#include "../threadUtils.hpp"

#include "commandHandler.h"
#include "callIdQueue.h"

#include "options.h"
#include "portWindow.h"
#include <map>
#include <fstream>

#define MAX_PACKET_SIZE 1500

void listener(RtpSession::proto::socket* sock1, RtpSession::proto::socket* sock2, std::string call_id, int dir, SyncQueue* queue, bool* running)
{
  cLog.msg(Log::PRIO_NOTICE) << "listener(" << call_id << "/" << dir << ") started";

  try {
    Buffer buf(uint32_t(MAX_PACKET_SIZE));
    RtpSession::proto::endpoint remote_end;

    for(;;) {
      buf.setLength(MAX_PACKET_SIZE);
      uint32_t len=0;
      if(dir == 1) {
        len = 0;  //sock1->recvFromNonBlocking(buf.getBuf(), buf.getLength(), remote_end, 1000);
      } else if(dir == 2) {
        len = 0;  //sock2->recvFromNonBlocking(buf.getBuf(), buf.getLength(), remote_end, 1000);
      } else { break; }

      RtpSession& session = gRtpSessionTable.getSession(call_id);
      if(session.isDead()) {
        cLog.msg(Log::PRIO_NOTICE) << "listener(" << call_id << "/" << dir << ") session is dead, exiting";
        break;
      }

      if(!len) {
        continue;
      }
      buf.setLength(len);

      if((dir == 1 && remote_end != session.getRemoteEnd1()) ||
          (dir == 2 && remote_end != session.getRemoteEnd2())) {
        if(gOpt.getNat() ||
            (!gOpt.getNoNatOnce() && ((dir == 1 && !session.getSeen1()) ||
                                      (dir == 2 && !session.getSeen2())))) {
          cLog.msg(Log::PRIO_NOTICE) << "listener(" << call_id << "/" << dir << ") setting remote host to "
                                     << remote_end;
          if(dir == 1) {
            session.setRemoteEnd1(remote_end);
          }
          if(dir == 2) {
            session.setRemoteEnd2(remote_end);
          }

          if(!gOpt.getNat()) { // with nat enabled sync is not needed
            SyncRtpCommand sc(call_id);
            queue->push(sc);
          }
        } else {
          continue;
        }
      }
      session.setSeen1();
      session.setSeen2();

      if(dir == 1) {
        sock2->send_to(boost::asio::buffer(buf.getBuf(), buf.getLength()), session.getRemoteEnd2());
      } else if(dir == 2) {
        sock1->send_to(boost::asio::buffer(buf.getBuf(), buf.getLength()), session.getRemoteEnd1());
      } else { break; }
    }
  } catch(std::exception& e) {
    cLog.msg(Log::PRIO_ERR) << "listener(" << call_id << "/" << dir << ") exiting because: " << e.what();
  }
  *running = false;
  gCallIdQueue.push(call_id);
}

class ListenerData
{
public:
  ListenerData() : sock1_(ios1_), sock2_(ios2_) {}

  boost::asio::io_service ios1_;
  boost::asio::io_service ios2_;
  RtpSession::proto::socket sock1_;
  RtpSession::proto::socket sock2_;
  boost::thread* thread1_;
  boost::thread* thread2_;
  bool running1_;
  bool running2_;
};

void listenerManager(void* p)
{
  SyncQueue* queue_ = reinterpret_cast<SyncQueue*>(p);

  std::map<std::string, ListenerData*> listenerMap;
  for(;;) {
    try {
      std::string call_id = gCallIdQueue.front(); // waits for semaphor and returns next call_id
      gCallIdQueue.pop();

      RtpSession& session = gRtpSessionTable.getSession(call_id);
      if(!session.isComplete()) {
        continue;
      }

      std::map<std::string, ListenerData*>::iterator it;
      it = listenerMap.find(call_id);
      if(it == listenerMap.end()) { // listener Threads not existing yet
        ListenerData* ld = new ListenerData();

        ld->sock1_.open(session.getLocalEnd1().protocol());
        ld->sock1_.bind(session.getLocalEnd1());

        ld->sock2_.open(session.getLocalEnd2().protocol());
        ld->sock2_.bind(session.getLocalEnd2());

        ld->thread1_ = new boost::thread(boost::bind(listener, &(ld->sock1_), &(ld->sock2_), call_id, 1, queue_, &(ld->running1_)));
        ld->thread2_ = new boost::thread(boost::bind(listener, &(ld->sock1_), &(ld->sock2_), call_id, 2, queue_, &(ld->running2_)));

        std::pair<std::map<std::string, ListenerData*>::iterator, bool> ret;
        ret = listenerMap.insert(std::map<std::string, ListenerData*>::value_type(call_id, ld));
        continue;
      }

      if(!it->second->running1_ && !it->second->running2_) {
        cLog.msg(Log::PRIO_NOTICE) << "listenerManager both threads for '" << call_id << "' exited, cleaning up";
        if(it->second->thread1_) {
          it->second->thread1_->join();
          delete it->second->thread1_;
        }
        if(it->second->thread2_) {
          it->second->thread2_->join();
          delete it->second->thread2_;
        }
        delete it->second;
        listenerMap.erase(it);
        gRtpSessionTable.delSession(call_id);
        continue;
      }
      // TODO: reinit if session changed
    } catch(std::exception& e) {
      cLog.msg(Log::PRIO_ERR) << "listenerManager restarting after exception: " << e.what();
      usleep(500); // in case of an hard error don't block cpu (this is ugly)
    }
  }
  cLog.msg(Log::PRIO_ERR) << "listenerManager exiting because of unknown reason";
}

void chrootAndDrop(string const& chrootdir, string const& username)
{
  if(getuid() != 0) {
    std::cerr << "this program has to be run as root in order to run in a chroot" << std::endl;
    exit(-1);
  }

  struct passwd* pw = getpwnam(username.c_str());
  if(pw) {
    if(chroot(chrootdir.c_str())) {
      std::cerr << "can't chroot to " << chrootdir << std::endl;
      exit(-1);
    }
    std::cout << "we are in chroot jail (" << chrootdir << ") now" << std::endl;
    chdir("/");
    if(initgroups(pw->pw_name, pw->pw_gid) || setgid(pw->pw_gid) || setuid(pw->pw_uid)) {
      std::cerr << "can't drop to user " << username << " " << pw->pw_uid << ":" << pw->pw_gid << std::endl;
      exit(-1);
    }
    std::cout << "dropped user to " << username << " " << pw->pw_uid << ":" << pw->pw_gid << std::endl;
  } else {
    std::cerr << "unknown user " << username << std::endl;
    exit(-1);
  }
}

void daemonize()
{
  pid_t pid;

  pid = fork();
  if(pid) { exit(0); }
  setsid();
  pid = fork();
  if(pid) { exit(0); }

  //  std::cout << "running in background now..." << std::endl;

  int fd;
  //  for (fd=getdtablesize();fd>=0;--fd) // close all file descriptors
  for(fd=0; fd<=2; fd++) { // close all file descriptors
    close(fd);
  }
  fd=open("/dev/null",O_RDWR);        // stdin
  dup(fd);                            // stdout
  dup(fd);                            // stderr
  umask(027);
}

class ThreadParam
{
public:
  ThreadParam(SyncQueue& queue_,OptionConnectTo& connto_)
    : queue(queue_),connto(connto_)
  {};
  SyncQueue& queue;
  OptionConnectTo& connto;
};

void syncConnector(void* p)
{
  ThreadParam* param = reinterpret_cast<ThreadParam*>(p);

  SyncClient sc(param->connto.host, param->connto.port);
  sc.run();
}

void syncListener(SyncQueue* queue)
{
  try {
    boost::asio::io_service io_service;
    SyncTcpConnection::proto::resolver resolver(io_service);
    SyncTcpConnection::proto::endpoint e;
    if(gOpt.getLocalSyncAddr()!="") {
      SyncTcpConnection::proto::resolver::query query(gOpt.getLocalSyncAddr(), gOpt.getLocalSyncPort());
      e = *resolver.resolve(query);
    } else {
      SyncTcpConnection::proto::resolver::query query(gOpt.getLocalSyncPort());
      e = *resolver.resolve(query);
    }


    SyncServer server(io_service,e);
    server.onConnect=boost::bind(syncOnConnect,_1);
    queue->setSyncServerPtr(&server);
    io_service.run();
  } catch(std::exception& e) {
    std::string addr = gOpt.getLocalSyncAddr() == "" ? "*" : gOpt.getLocalSyncAddr();
    cLog.msg(Log::PRIO_ERR) << "sync: cannot bind to " << addr << ":" << gOpt.getLocalSyncPort()
                            << " (" << e.what() << ")" << std::endl;
  }

}

int main(int argc, char* argv[])
{
  //  std::cout << "anyrtpproxy" << std::endl;
  if(!gOpt.parse(argc, argv)) {
    gOpt.printUsage();
    exit(-1);
  }

  cLog.setLogName("anyrtpproxy");
  cLog.msg(Log::PRIO_NOTICE) << "anyrtpproxy started...";

  std::ofstream pidFile;
  if(gOpt.getPidFile() != "") {
    pidFile.open(gOpt.getPidFile().c_str());
    if(!pidFile.is_open()) {
      std::cout << "can't open pid file" << std::endl;
    }
  }

  if(gOpt.getChroot()) {
    chrootAndDrop(gOpt.getChrootDir(), gOpt.getUsername());
  }
  if(gOpt.getDaemonize()) {
    daemonize();
  }

  if(pidFile.is_open()) {
    pid_t pid = getpid();
    pidFile << pid;
    pidFile.close();
  }

  SignalController sig;
  sig.init();

  SyncQueue queue;


  boost::thread listenerManagerThread(boost::bind(listenerManager,&queue));


  // #ifndef ANYTUN_NOSYNC
  //     boost::thread * syncListenerThread;
  //     if(gOpt.getLocalSyncPort() != "")
  //       syncListenerThread = new boost::thread(boost::bind(syncListener,&queue));

  //     std::list<boost::thread *> connectThreads;
  //     for(ConnectToList::iterator it = connect_to.begin() ;it != connect_to.end(); ++it) {
  //       ThreadParam * point = new ThreadParam(dev, *src, cl, queue,*it);
  //       connectThreads.push_back(new boost::thread(boost::bind(syncConnector,point)));
  //     }
  // #endif



  //   pthread_t syncListenerThread;

  // 	ConnectToList connect_to = gOpt.getConnectTo();
  // 	ThreadParam p( queue,*(new OptionConnectTo()));
  //   if ( gOpt.getLocalSyncPort())
  //     pthread_create(&syncListenerThread, NULL, syncListener, &p);

  //   std::list<pthread_t> connectThreads;
  //   for(ConnectToList::iterator it = connect_to.begin() ;it != connect_to.end(); ++it)
  //   {
  //     connectThreads.push_back(pthread_t());
  //     ThreadParam * point = new ThreadParam(queue,*it);
  //     pthread_create(& connectThreads.back(),  NULL, syncConnector, point);
  //   }

  PortWindow port_window(gOpt.getRtpStartPort(),gOpt.getRtpEndPort());
  CommandHandler cmd(queue, gOpt.getControlInterface().addr_, gOpt.getControlInterface().port_,port_window);

  int ret = sig.run();
  return ret;
}