/* <!-- copyright */
/*
 * aria2 - a simple utility for downloading files faster
 *
 * Copyright (C) 2006 Tatsuhiro Tsujikawa
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * 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
 */
/* copyright --> */
#include "DownloadEngine.h"
#include "Util.h"
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <algorithm>

using namespace std;

DownloadEngine::DownloadEngine():noWait(false), segmentMan(NULL) {}

DownloadEngine::~DownloadEngine() {
  assert(rsockets.empty());
  assert(wsockets.empty());
}

void DownloadEngine::run() {
  initStatistics();
  while(!commands.empty()) {
    int max = commands.size();
    for(int i = 0; i < max; i++) {
      Command* com = commands.front();
      commands.pop();
      if(com->execute()) {
	delete(com);
      }
    }
    shortSleep();
    if(!noWait && !commands.empty()) {
      waitData();
    }
    noWait = false;
    calculateStatistics();
  }
  onEndOfRun();
}

void DownloadEngine::shortSleep() const {
  struct timeval tv;
  tv.tv_sec = 0;
  tv.tv_usec = 1000;
  fd_set rfds;
  FD_ZERO(&rfds);
  select(0, &rfds, NULL, NULL, &tv);
}

void DownloadEngine::waitData() {
  fd_set rfds;
  fd_set wfds;
  struct timeval tv;
  int retval;

  FD_ZERO(&rfds);
  FD_ZERO(&wfds);
  int max = 0;
  for(Sockets::iterator itr = rsockets.begin(); itr != rsockets.end(); itr++) {
    FD_SET((*itr)->getSockfd(), &rfds);
    if(max < (*itr)->getSockfd()) {
      max = (*itr)->getSockfd();
    }
  }
  for(Sockets::iterator itr = wsockets.begin(); itr != wsockets.end(); itr++) {
    FD_SET((*itr)->getSockfd(), &wfds);
    if(max < (*itr)->getSockfd()) {
      max = (*itr)->getSockfd();
    }
  }
  tv.tv_sec = 1;
  tv.tv_usec = 0;

  retval = select(max+1, &rfds, /*&wfds*/NULL, NULL, &tv);
}

bool DownloadEngine::addSocket(Sockets& sockets, Socket* socket) {
  Sockets::iterator itr = find(sockets.begin(),
			       sockets.end(),
			       socket);
  if(itr == sockets.end()) {
    sockets.push_back(socket);
    return true;
  } else {
    return false;
  }
}

bool DownloadEngine::deleteSocket(Sockets& sockets, Socket* socket) {
  Sockets::iterator itr = find(sockets.begin(),
			       sockets.end(),
			       socket);
  if(itr != sockets.end()) {
    sockets.erase(itr);
    return true;
  } else {
    return false;
  }
}

bool DownloadEngine::addSocketForReadCheck(Socket* socket) {
  return addSocket(rsockets, socket);
}

bool DownloadEngine::deleteSocketForReadCheck(Socket* socket) {
  return deleteSocket(rsockets , socket);
}

bool DownloadEngine::addSocketForWriteCheck(Socket* socket) {
  return addSocket(wsockets, socket);
}

bool DownloadEngine::deleteSocketForWriteCheck(Socket* socket) {
  return deleteSocket(wsockets, socket);
}