qBittorrent/src/bittorrent.cpp

/*
 * Bittorrent Client using Qt4 and libtorrent.
 * Copyright (C) 2006  Christophe Dumez
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Contact : chris@qbittorrent.org
 */

#include <QDir>
#include <QTime>
#include <QString>
#include <QTimer>

#include "bittorrent.h"
#include "misc.h"
#include "downloadThread.h"
#include "deleteThread.h"

#include <libtorrent/extensions/metadata_transfer.hpp>
#include <libtorrent/extensions/ut_pex.hpp>
#include <libtorrent/entry.hpp>
#include <libtorrent/bencode.hpp>
#include <libtorrent/identify_client.hpp>
#include <libtorrent/alert_types.hpp>
#include <libtorrent/torrent_info.hpp>
#include <boost/filesystem/exception.hpp>

#define ETAS_MAX_VALUES 3
#define ETA_REFRESH_INTERVAL 10000
#define MAX_TRACKER_ERRORS 2

// Main constructor
bittorrent::bittorrent() : timerScan(0), DHTEnabled(false), preAllocateAll(false), addInPause(false), maxConnecsPerTorrent(500), maxUploadsPerTorrent(4), max_ratio(-1) {
  // To avoid some exceptions
  fs::path::default_name_check(fs::no_check);
  // Creating bittorrent session
  s = new session(fingerprint("qB", VERSION_MAJOR, VERSION_MINOR, VERSION_BUGFIX, 0));
  // Set severity level of libtorrent session
  s->set_severity_level(alert::info);
  // Enabling metadata plugin
  s->add_extension(&create_metadata_plugin);
  timerAlerts = new QTimer();
  connect(timerAlerts, SIGNAL(timeout()), this, SLOT(readAlerts()));
  timerAlerts->start(3000);
  ETARefresher = new QTimer();
  connect(ETARefresher, SIGNAL(timeout()), this, SLOT(updateETAs()));
  ETARefresher->start(ETA_REFRESH_INTERVAL);
  fastResumeSaver = new QTimer();
  connect(fastResumeSaver, SIGNAL(timeout()), this, SLOT(saveFastResumeAndRatioData()));
  fastResumeSaver->start(60000);
  // To download from urls
  downloader = new downloadThread(this);
  connect(downloader, SIGNAL(downloadFinished(QString, QString)), this, SLOT(processDownloadedFile(QString, QString)));
  connect(downloader, SIGNAL(downloadFailure(QString, QString)), this, SLOT(handleDownloadFailure(QString, QString)));
  // File deleter (thread)
  deleter = new deleteThread(this);
  qDebug("* BTSession constructed");
}

// Main destructor
bittorrent::~bittorrent() {
  // Disable directory scanning
  disableDirectoryScanning();
  // Delete our objects
  delete deleter;
  delete fastResumeSaver;
  delete timerAlerts;
  delete ETARefresher;
  delete downloader;
  // Delete BT session
  delete s;
}

void bittorrent::preAllocateAllFiles(bool b) {
  bool change = (preAllocateAll != b);
  if(change) {
    qDebug("PreAllocateAll changed, reloading all torrents!");
    preAllocateAll = b;
    // Reload All unfinished torrents
    QString hash;
    foreach(hash, unfinishedTorrents) {
      QTorrentHandle h = getTorrentHandle(hash);
      if(!h.is_valid()) {
        qDebug("/!\\ Error: Invalid handle");
        continue;
      }
      reloadTorrent(h, b);
    }
  }
}

void bittorrent::deleteBigRatios() {
  if(max_ratio == -1) return;
  QString hash;
  foreach(hash, finishedTorrents) {
    QTorrentHandle h = getTorrentHandle(hash);
    if(!h.is_valid()) {
      qDebug("/!\\ Error: Invalid handle");
      continue;
    }
    QString hash = h.hash();
    if(getRealRatio(hash) > max_ratio) {
      QString fileName = h.name();
      deleteTorrent(hash);
      emit torrent_deleted(hash, fileName, true);
    }
  }
}

void bittorrent::setDownloadLimit(QString hash, long val) {
  QTorrentHandle h = getTorrentHandle(hash);
  if(h.is_valid())
    h.set_download_limit(val);
  saveTorrentSpeedLimits(hash);
}

void bittorrent::setUploadLimit(QString hash, long val) {
  qDebug("Set upload limit rate to %ld", val);
  QTorrentHandle h = getTorrentHandle(hash);
  if(h.is_valid())
    h.set_upload_limit(val);
  saveTorrentSpeedLimits(hash);
}

void bittorrent::handleDownloadFailure(QString url, QString reason) {
  emit downloadFromUrlFailure(url, reason);
}

void bittorrent::startTorrentsInPause(bool b) {
  addInPause = b;
}

void bittorrent::updateETAs() {
  QString hash;
  foreach(hash, unfinishedTorrents) {
    QTorrentHandle h = getTorrentHandle(hash);
    if(h.is_valid()) {
      if(h.is_paused()) continue;
      QString hash = h.hash();
      QList<qlonglong> listEtas = ETAstats.value(hash, QList<qlonglong>());
      // XXX: We can still get an overflow if remaining file size is approximately
      // 8.38*10^5 TiB (let's assume this can't happen)
      if(h.download_payload_rate() > 0.1) {
        if(listEtas.size() == ETAS_MAX_VALUES) {
            listEtas.removeFirst();
        }
        listEtas << (qlonglong)((h.actual_size()-h.total_wanted_done())/(double)h.download_payload_rate());
        ETAstats[hash] = listEtas;
        qlonglong moy = 0;
        qlonglong val;
        unsigned int nbETAs = listEtas.size();
        Q_ASSERT(nbETAs);
        foreach(val, listEtas) {
          moy += (qlonglong)((double)val/(double)nbETAs);
        }
        Q_ASSERT(moy >= 0);
        ETAs[hash] = moy;
      } else {
        // Speed is too low, we don't want an overflow.
        if(ETAstats.contains(hash)) {
          ETAstats.remove(hash);
        }
        if(ETAs.contains(hash)) {
          ETAs.remove(hash);
        }
      }
    }
  }
  // Delete big ratios
  if(max_ratio != -1)
    deleteBigRatios();
}

long bittorrent::getETA(QString hash) const{
  return ETAs.value(hash, -1);
}

// Return the torrent handle, given its hash
QTorrentHandle bittorrent::getTorrentHandle(QString hash) const{
  return QTorrentHandle(s->find_torrent(misc::fromString<sha1_hash>((hash.toStdString()))));
}

// Return true if the torrent corresponding to the
// hash is paused
bool bittorrent::isPaused(QString hash) const{
  QTorrentHandle h = getTorrentHandle(hash);
  if(!h.is_valid()) {
    qDebug("/!\\ Error: Invalid handle");
    return true;
  }
  if(torrentsToPauseAfterChecking.contains(hash))
    return true;
  return h.is_paused();
}

// Delete a torrent from the session, given its hash
// permanent = true means that the torrent will be removed from the hard-drive too
void bittorrent::deleteTorrent(QString hash, bool permanent) {
  qDebug("Deleting torrent with hash: %s", hash.toUtf8().data());
  QTorrentHandle h = getTorrentHandle(hash);
  if(!h.is_valid()) {
    qDebug("/!\\ Error: Invalid handle");
    return;
  }
  QString savePath = h.save_path();
  QString fileName = h.name();
  arborescence *files_arb = 0;
  if(permanent){
    files_arb = new arborescence(h.get_torrent_info());
  }
  // Remove it from session
  s->remove_torrent(h.get_torrent_handle());
  // Remove it from torrent backup directory
  QDir torrentBackup(misc::qBittorrentPath() + "BT_backup");
  QStringList filters;
  filters << hash+".*";
  QStringList files = torrentBackup.entryList(filters, QDir::Files, QDir::Unsorted);
  QString file;
  foreach(file, files) {
    torrentBackup.remove(file);
  }
  // Remove it from ETAs hash tables
  ETAstats.remove(hash);
  ETAs.remove(hash);
  // Remove tracker errors
  trackersErrors.remove(hash);
  // Remove it from ratio table
  ratioData.remove(hash);
  int index = finishedTorrents.indexOf(hash);
  if(index != -1) {
    finishedTorrents.removeAt(index);
  }else{
    index = unfinishedTorrents.indexOf(hash);
    if(index != -1) {
      unfinishedTorrents.removeAt(index);
    }else{
      std::cerr << "Error: Torrent " << hash.toStdString() << " is neither in finished or unfinished list\n";
    }
  }
  if(permanent && files_arb != 0) {
    // Remove from Hard drive
    qDebug("Removing this on hard drive: %s", qPrintable(savePath+QDir::separator()+fileName));
    // Deleting in a thread to avoid GUI freeze
    deleter->deleteTorrent(savePath, files_arb);
  }
}

// Return a list of hashes for the finished torrents
QStringList bittorrent::getFinishedTorrents() const {
  return finishedTorrents;
}

QStringList bittorrent::getUnfinishedTorrents() const {
  return unfinishedTorrents;
}

bool bittorrent::isFinished(QString hash) const {
  return finishedTorrents.contains(hash);
}

// Remove the given hash from the list of finished torrents
void bittorrent::setUnfinishedTorrent(QString hash) {
  if(QFile::exists(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".finished")){
    QFile::remove(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".finished");
  }
  int index = finishedTorrents.indexOf(hash);
  if(index != -1) {
    finishedTorrents.removeAt(index);
  }
  if(!unfinishedTorrents.contains(hash)) {
    unfinishedTorrents << hash;
  }
}

// Add the given hash to the list of finished torrents
void bittorrent::setFinishedTorrent(QString hash) {
  if(!QFile::exists(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".finished")) {
    QFile finished_file(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".finished");
    finished_file.open(QIODevice::WriteOnly | QIODevice::Text);
    finished_file.close();
  }
  if(!finishedTorrents.contains(hash)) {
    finishedTorrents << hash;
  }
  int index = unfinishedTorrents.indexOf(hash);
  if(index != -1) {
    unfinishedTorrents.removeAt(index);
  }
  // Remove it from ETAs hash tables
  ETAstats.remove(hash);
  ETAs.remove(hash);
}

// Pause a running torrent
bool bittorrent::pauseTorrent(QString hash) {
  bool change = false;
  QTorrentHandle h = getTorrentHandle(hash);
  if(h.is_valid() && !h.is_paused()) {
    h.pause();
    change = true;
    qDebug("Torrent paused successfully");
  }else{
    if(!h.is_valid()) {
      qDebug("Could not pause torrent %s, reason: invalid", hash.toUtf8().data());
    }else{
      qDebug("Could not pause torrent %s, reason: already paused", hash.toUtf8().data());
    }
  }
  // Create .paused file if necessary
  if(!QFile::exists(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".paused")) {
    QFile paused_file(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".paused");
    paused_file.open(QIODevice::WriteOnly | QIODevice::Text);
    paused_file.close();
  }
  // Remove it from ETAs hash tables
  ETAstats.remove(hash);
  ETAs.remove(hash);
  return change;
}

// Resume a torrent in paused state
bool bittorrent::resumeTorrent(QString hash) {
  bool success = false;
  QTorrentHandle h = getTorrentHandle(hash);
  if(h.is_valid() && h.is_paused()) {
    h.resume();
    success = true;
  }
  // Delete .paused file
  if(QFile::exists(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".paused"))
    QFile::remove(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".paused");
  int index = torrentsToPauseAfterChecking.indexOf(hash);
  if(index != -1) {
    torrentsToPauseAfterChecking.removeAt(index);
    success = true;
  }
  return success;
}

void bittorrent::loadWebSeeds(QString hash) {
  QFile urlseeds_file(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".urlseeds");
  if(!urlseeds_file.open(QIODevice::ReadOnly | QIODevice::Text)) return;
  QByteArray urlseeds_lines = urlseeds_file.readAll();
  urlseeds_file.close();
  QList<QByteArray> url_seeds = urlseeds_lines.split('\n');
  QByteArray url_seed;
  QTorrentHandle h = getTorrentHandle(hash);
  // First remove from the torrent the url seeds that were deleted
  // in a previous session
  QStringList seeds_to_delete;
  QStringList existing_seeds = h.url_seeds();
  QString existing_seed;
  foreach(existing_seed, existing_seeds) {
    if(!url_seeds.contains(existing_seed.toUtf8())) {
      seeds_to_delete << existing_seed;
    }
  }
  foreach(existing_seed, seeds_to_delete) {
    h.remove_url_seed(existing_seed);
  }
  // Add the ones that were added in a previous session
  foreach(url_seed, url_seeds) {
    if(!url_seed.isEmpty()) {
      // XXX: Should we check if it is already in the list before adding it
      // or is libtorrent clever enough to know
      h.add_url_seed(url_seed);
    }
  }
}

// Add a torrent to the bittorrent session
void bittorrent::addTorrent(QString path, bool fromScanDir, QString from_url, bool resumed) {
  QTorrentHandle h;
  entry resume_data;
  bool fastResume=false;
  QDir torrentBackup(misc::qBittorrentPath() + "BT_backup");
  QString file, dest_file, scan_dir;

  // Checking if BT_backup Dir exists
  // create it if it is not
  if(! torrentBackup.exists()) {
    if(! torrentBackup.mkpath(torrentBackup.path())) {
      std::cerr << "Couldn't create the directory: '" << torrentBackup.path().toUtf8().data() << "'\n";
      exit(1);
    }
  }
  // Processing torrents
  file = path.trimmed().replace("file://", "", Qt::CaseInsensitive);
  if(file.isEmpty()) {
    return;
  }
  Q_ASSERT(!file.startsWith("http://", Qt::CaseInsensitive) && !file.startsWith("https://", Qt::CaseInsensitive) && !file.startsWith("ftp://", Qt::CaseInsensitive));
  qDebug("Adding %s to download list", file.toUtf8().data());
  std::ifstream in(file.toUtf8().data(), std::ios_base::binary);
  in.unsetf(std::ios_base::skipws);
  try{
    // Decode torrent file
    entry e = bdecode(std::istream_iterator<char>(in), std::istream_iterator<char>());
    // Getting torrent file informations
    boost::intrusive_ptr<torrent_info> t(new torrent_info(e));
    qDebug(" -> Hash: %s", misc::toString(t->info_hash()).c_str());
    qDebug(" -> Name: %s", t->name().c_str());
    QString hash = misc::toQString(t->info_hash());
    if(file.startsWith(torrentBackup.path())) {
      QFileInfo fi(file);
      QString old_hash = fi.baseName();
      if(old_hash != hash){
        qDebug("* ERROR: Strange, hash changed from %s to %s", old_hash.toUtf8().data(), hash.toUtf8().data());
      }
    }
    if(s->find_torrent(t->info_hash()).is_valid()) {
      qDebug("/!\\ Torrent is already in download list");
      // Update info Bar
      if(!fromScanDir) {
        if(!from_url.isNull()) {
          // If download from url, remove temp file
           QFile::remove(file);
          emit duplicateTorrent(from_url);
        }else{
          emit duplicateTorrent(file);
        }
      }else{
        // Delete torrent from scan dir
        QFile::remove(file);
      }
      return;
    }
    //Getting fast resume data if existing
    if(torrentBackup.exists(hash+".fastresume")) {
      try{
        std::stringstream strStream;
        strStream << hash.toStdString() << ".fastresume";
        boost::filesystem::ifstream resume_file(fs::path(torrentBackup.path().toUtf8().data()) / strStream.str(), std::ios_base::binary);
        resume_file.unsetf(std::ios_base::skipws);
        resume_data = bdecode(std::istream_iterator<char>(resume_file), std::istream_iterator<char>());
        fastResume=true;
      }catch (invalid_encoding&) {}
      catch (fs::filesystem_error&) {}
    }
    QString savePath = getSavePath(hash);
    // Adding files to bittorrent session
    if(preAllocateAll) {
      h = s->add_torrent(t, fs::path(savePath.toUtf8().data()), resume_data, storage_mode_allocate, true);
      qDebug(" -> Full allocation mode");
    }else{
      h = s->add_torrent(t, fs::path(savePath.toUtf8().data()), resume_data, storage_mode_sparse, true);
      qDebug(" -> Sparse allocation mode");
    }
    if(!h.is_valid()) {
      // No need to keep on, it failed.
      qDebug("/!\\ Error: Invalid handle");
      // If download from url, remove temp file
      if(!from_url.isNull()) QFile::remove(file);
      return;
    }
    // Connections limit per torrent
    h.set_max_connections(maxConnecsPerTorrent);
    // Uploads limit per torrent
    h.set_max_uploads(maxUploadsPerTorrent);
    // Load filtered files
    loadFilesPriorities(h);
    // Load custom url seeds
    loadWebSeeds(hash);
    // Load speed limit from hard drive
    loadTorrentSpeedLimits(hash);
    // Load ratio data
    loadDownloadUploadForTorrent(hash);
    // Load trackers
    bool loaded_trackers = loadTrackerFile(hash);
    // Doing this to order trackers well
    if(!loaded_trackers) {
      saveTrackerFile(hash);
      loadTrackerFile(hash);
    }
    QString newFile = torrentBackup.path() + QDir::separator() + hash + ".torrent";
    if(file != newFile) {
      // Delete file from torrentBackup directory in case it exists because
      // QFile::copy() do not overwrite
      QFile::remove(newFile);
      // Copy it to torrentBackup directory
      QFile::copy(file, newFile);
    }
    // Pause torrent if it was paused last time
    if((!resumed && addInPause) || QFile::exists(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".paused")) {
      torrentsToPauseAfterChecking << hash;
      qDebug("Adding a torrent to the torrentsToPauseAfterChecking list");
    }
    // Incremental download
    if(QFile::exists(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".incremental")) {
      qDebug("Incremental download enabled for %s", t->name().c_str());
      h.set_sequenced_download_threshold(1);
    }
    // Start torrent because it was added in paused state
    h.resume();
    if(QFile::exists(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".finished")) {
      finishedTorrents << hash;
    }else{
      unfinishedTorrents << hash;
    }
    // If download from url, remove temp file
    if(!from_url.isNull()) QFile::remove(file);
    // Delete from scan dir to avoid trying to download it again
    if(fromScanDir) {
      QFile::remove(file);
    }
    // Send torrent addition signal
    if(!from_url.isNull()) {
      emit addedTorrent(from_url, h, fastResume);
    }else{
      emit addedTorrent(file, h, fastResume);
    }
  }catch (invalid_encoding& e) { // Raised by bdecode()
    std::cerr << "Could not decode file, reason: " << e.what() << '\n';
    // Display warning to tell user we can't decode the torrent file
    if(!from_url.isNull()) {
      emit invalidTorrent(from_url);
    }else{
      emit invalidTorrent(file);
    }
    if(fromScanDir) {
      // Remove .corrupt file in case it already exists
      QFile::remove(file+".corrupt");
      //Rename file extension so that it won't display error message more than once
      QFile::rename(file,file+".corrupt");
    }
  }
  catch (invalid_torrent_file&) { // Raised by torrent_info constructor
    // Display warning to tell user we can't decode the torrent file
    if(!from_url.isNull()) {
      emit invalidTorrent(from_url);
    }else{
      emit invalidTorrent(file);
    }
    if(fromScanDir) {
      // Remove .corrupt file in case it already exists
      QFile::remove(file+".corrupt");
      //Rename file extension so that it won't display error message more than once
      QFile::rename(file,file+".corrupt");
    }
  }
}

// Check in .priorities file if the user filtered files
// in this torrent.
bool bittorrent::has_filtered_files(QString hash) const{
  QFile pieces_file(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".priorities");
  // Read saved file
  if(!pieces_file.open(QIODevice::ReadOnly | QIODevice::Text)) {
    return false;
  }
  QByteArray pieces_text = pieces_file.readAll();
  pieces_file.close();
  QList<QByteArray> pieces_priorities_list = pieces_text.split('\n');
  unsigned int listSize = pieces_priorities_list.size();
  for(unsigned int i=0; i<listSize-1; ++i) {
    int priority = pieces_priorities_list.at(i).toInt();
    if( priority < 0 || priority > 7) {
      priority = 1;
    }
    if(!priority) {
      return true;
    }
  }
  return false;
}

// Set the maximum number of opened connections
void bittorrent::setMaxConnections(int maxConnec) {
  s->set_max_connections(maxConnec);
}

void bittorrent::setMaxConnectionsPerTorrent(int max) {
  maxConnecsPerTorrent = max;
  // Apply this to all session torrents
  std::vector<torrent_handle> handles = s->get_torrents();
  unsigned int nbHandles = handles.size();
  for(unsigned int i=0; i<nbHandles; ++i) {
    QTorrentHandle h = handles[i];
    if(!h.is_valid()) {
      qDebug("/!\\ Error: Invalid handle");
      continue;
    }
    h.set_max_connections(max);
  }
}

void bittorrent::setMaxUploadsPerTorrent(int max) {
  maxUploadsPerTorrent = max;
  // Apply this to all session torrents
  std::vector<torrent_handle> handles = s->get_torrents();
  unsigned int nbHandles = handles.size();
  for(unsigned int i=0; i<nbHandles; ++i) {
    QTorrentHandle h = handles[i];
    if(!h.is_valid()) {
      qDebug("/!\\ Error: Invalid handle");
      continue;
    }
    h.set_max_uploads(max);
  }
}

// Return DHT state
bool bittorrent::isDHTEnabled() const{
  return DHTEnabled;
}

void bittorrent::enableUPnP(bool b) {
  if(b) {
    s->start_upnp();
  } else {
    s->stop_upnp();
  }
}

void bittorrent::enableNATPMP(bool b) {
  if(b) {
    s->start_natpmp();
  } else {
    s->stop_natpmp();
  }
}

void bittorrent::enableLSD(bool b) {
  if(b) {
    s->start_lsd();
  } else {
    s->stop_lsd();
  }
}

// Enable DHT
bool bittorrent::enableDHT(bool b) {
  if(b) {
    if(!DHTEnabled) {
      boost::filesystem::ifstream dht_state_file((misc::qBittorrentPath()+QString::fromUtf8("dht_state")).toUtf8().data(), std::ios_base::binary);
      dht_state_file.unsetf(std::ios_base::skipws);
      entry dht_state;
      try{
        dht_state = bdecode(std::istream_iterator<char>(dht_state_file), std::istream_iterator<char>());
      }catch (std::exception&) {}
      try {
	s->start_dht(dht_state);
	s->add_dht_router(std::make_pair(std::string("router.bittorrent.com"), 6881));
	s->add_dht_router(std::make_pair(std::string("router.utorrent.com"), 6881));
	s->add_dht_router(std::make_pair(std::string("router.bitcomet.com"), 6881));
	DHTEnabled = true;
	qDebug("DHT enabled");
       }catch(std::exception e) {
         qDebug("Could not enable DHT, reason: %s", e.what());
          return false;
       }
    }
  } else {
    if(DHTEnabled) {
      DHTEnabled = false;
      s->stop_dht();
      qDebug("DHT disabled");
    }
  }
  return true;
}

void bittorrent::saveTorrentSpeedLimits(QString hash) {
  qDebug("Saving speedLimits file for %s", hash.toUtf8().data());
  QTorrentHandle h = getTorrentHandle(hash);
  int download_limit = h.download_limit();
  int upload_limit = h.upload_limit();
  QFile speeds_file(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".speedLimits");
  if(!speeds_file.open(QIODevice::WriteOnly | QIODevice::Text)) {
    qDebug("* Error: Couldn't open speed limits file for torrent: %s", hash.toUtf8().data());
    return;
  }
  speeds_file.write(misc::toQByteArray(download_limit)+QByteArray(" ")+misc::toQByteArray(upload_limit));
  speeds_file.close();
}

void bittorrent::loadTorrentSpeedLimits(QString hash) {
//   qDebug("Loading speedLimits file for %s", hash.toUtf8().data());
  QTorrentHandle h = getTorrentHandle(hash);
  QFile speeds_file(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".speedLimits");
  if(!speeds_file.open(QIODevice::ReadOnly | QIODevice::Text)) {
    return;
  }
  QByteArray speed_limits = speeds_file.readAll();
  speeds_file.close();
  QList<QByteArray> speeds = speed_limits.split(' ');
  if(speeds.size() != 2) {
    std::cerr << "Invalid .speedLimits file for " << hash.toStdString() << '\n';
    return;
  }
  h.set_download_limit(speeds.at(0).toInt());
  h.set_upload_limit(speeds.at(1).toInt());
}

// Read pieces priorities from .priorities file
// and ask QTorrentHandle to consider them
void bittorrent::loadFilesPriorities(QTorrentHandle &h) {
  qDebug("Applying pieces priorities");
  if(!h.is_valid()) {
    qDebug("/!\\ Error: Invalid handle");
    return;
  }
  unsigned int nbFiles = h.num_files();
  QString hash = h.hash();
  QFile pieces_file(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".priorities");
  if(!pieces_file.exists()){
    return;
  }
  // Read saved file
  if(!pieces_file.open(QIODevice::ReadOnly | QIODevice::Text)) {
    qDebug("* Error: Couldn't open priorities file: %s", hash.toUtf8().data());
    return;
  }
  QByteArray pieces_priorities = pieces_file.readAll();
  pieces_file.close();
  QList<QByteArray> pieces_priorities_list = pieces_priorities.split('\n');
  if((unsigned int)pieces_priorities_list.size() != nbFiles+1) {
    std::cerr << "* Error: Corrupted priorities file\n";
    return;
  }
  std::vector<int> v;
  for(unsigned int i=0; i<nbFiles; ++i) {
    int priority = pieces_priorities_list.at(i).toInt();
    if( priority < 0 || priority > 7) {
      priority = 1;
    }
    //qDebug("Setting piece piority to %d", priority);
    v.push_back(priority);
  }
  h.prioritize_files(v);
}

void bittorrent::loadDownloadUploadForTorrent(QString hash) {
  QDir torrentBackup(misc::qBittorrentPath() + "BT_backup");
  // Checking if torrentBackup Dir exists
  // create it if it is not
  if(! torrentBackup.exists()) {
    torrentBackup.mkpath(torrentBackup.path());
  }
//   qDebug("Loading ratio data for %s", hash.toUtf8().data());
  QFile ratio_file(torrentBackup.path()+QDir::separator()+ hash + ".ratio");
  if(!ratio_file.exists() || !ratio_file.open(QIODevice::ReadOnly | QIODevice::Text)) {
    return;
  }
  QByteArray data = ratio_file.readAll();
  QList<QByteArray> data_list = data.split(' ');
  if(data_list.size() != 2) {
    std::cerr << "Corrupted ratio file for torrent: " << hash.toStdString() << '\n';
    return;
  }
  QPair<size_type,size_type> downUp;
  downUp.first = (size_type)data_list.at(0).toLongLong();
  downUp.second = (size_type)data_list.at(1).toLongLong();
  if(downUp.first < 0 || downUp.second < 0) {
    qDebug("** Overflow in ratio!!! fixing...");
    downUp.first = 0;
    downUp.second = 0;
  }
  ratioData[hash] = downUp;
}

float bittorrent::getRealRatio(QString hash) const{
  QPair<size_type,size_type> downUpInfo = ratioData.value(hash, QPair<size_type,size_type>(0,0));
  size_type download = downUpInfo.first;
  size_type upload =  downUpInfo.second;
  QTorrentHandle h = getTorrentHandle(hash);
  download += h.total_payload_download();
  Q_ASSERT(download >= 0);
  upload += h.total_payload_upload();
  Q_ASSERT(upload >= 0);
  if(download == 0){
    if(upload == 0)
      return 1.;
    return 10.;
  }
  float ratio = (double)upload / (double)download;
  Q_ASSERT(ratio >= 0.);
  if(ratio > 10.)
    ratio = 10.;
  return ratio;
}

// To remember share ratio or a torrent, we must save current
// total_upload and total_upload and reload them on startup
void bittorrent::saveDownloadUploadForTorrent(QString hash) {
  qDebug("Saving ratio data for torrent %s", hash.toUtf8().data());
  QDir torrentBackup(misc::qBittorrentPath() + QString::fromUtf8("BT_backup"));
  // Checking if torrentBackup Dir exists
  // create it if it is not
  if(! torrentBackup.exists()) {
    torrentBackup.mkpath(torrentBackup.path());
  }
  QTorrentHandle h = getTorrentHandle(hash);
  if(!h.is_valid()) {
    qDebug("/!\\ Error: Invalid handle");
    return;
  }
  QPair<size_type,size_type> ratioInfo = ratioData.value(hash, QPair<size_type, size_type>(0,0));
  size_type download = h.total_payload_download();
  download += ratioInfo.first;
  size_type upload = h.total_payload_upload();
  upload += ratioInfo.second;
  Q_ASSERT(download >= 0 && upload >= 0);
  QFile ratio_file(torrentBackup.path()+QDir::separator()+ hash + QString::fromUtf8(".ratio"));
  if(!ratio_file.open(QIODevice::WriteOnly | QIODevice::Text)) {
    std::cerr << "Couldn't save ratio data for torrent: " << hash.toStdString() << '\n';
    return;
  }
  ratio_file.write(misc::toQByteArray(download) + QByteArray(" ") + misc::toQByteArray(upload));
  ratio_file.close();
}

// Save fastresume data for all torrents (called periodically)
void bittorrent::saveFastResumeAndRatioData() {
  qDebug("Saving fast resume and ratio data");
  QString file;
  QDir torrentBackup(misc::qBittorrentPath() + "BT_backup");
  // Checking if torrentBackup Dir exists
  // create it if it is not
  if(! torrentBackup.exists()) {
    torrentBackup.mkpath(torrentBackup.path());
  }
  std::vector<torrent_handle> handles = s->get_torrents();
  // It is not necessary to pause the torrents before saving fastresume data anymore
  // because we either use Full allocation or sparse mode.
  // Write fast resume data
  for(unsigned int i=0; i<handles.size(); ++i) {
    QTorrentHandle h = handles[i];
    if(!h.is_valid()) {
      qDebug("/!\\ Error: Invalid handle");
      continue;
    }
    QString hash = h.hash();
    // Extracting resume data
    if (h.has_metadata() && h.state() != torrent_status::checking_files && h.state() != torrent_status::queued_for_checking) {
      if(QFile::exists(torrentBackup.path()+QDir::separator()+hash+".torrent")) {
        // Remove old .fastresume data in case it exists
        QFile::remove(torrentBackup.path()+QDir::separator()+hash + ".fastresume");
        // Write fast resume data
        entry resumeData = h.write_resume_data();
        file = hash + ".fastresume";
        boost::filesystem::ofstream out(fs::path(torrentBackup.path().toUtf8().data()) / file.toUtf8().data(), std::ios_base::binary);
        out.unsetf(std::ios_base::skipws);
        bencode(std::ostream_iterator<char>(out), resumeData);
      }
      // Save ratio data
      saveDownloadUploadForTorrent(hash);
    }
  }
  qDebug("Fast resume and ratio data saved");
}

bool bittorrent::isFilePreviewPossible(QString hash) const{
  // See if there are supported files in the torrent
  QTorrentHandle h = getTorrentHandle(hash);
  if(!h.is_valid()) {
    qDebug("/!\\ Error: Invalid handle");
    return false;
  }
  unsigned int nbFiles = h.num_files();
  for(unsigned int i=0; i<nbFiles; ++i) {
    QString fileName = h.file_at(i);
    QString extension = fileName.split('.').last();
    if(misc::isPreviewable(extension))
      return true;
  }
  return false;
}

// Scan the first level of the directory for torrent files
// and add them to download list
void bittorrent::scanDirectory() {
  QString file;
  if(!scan_dir.isNull()) {
    QStringList to_add;
    QDir dir(scan_dir);
    QStringList filters;
    filters << "*.torrent";
    QStringList files = dir.entryList(filters, QDir::Files, QDir::Unsorted);
    foreach(file, files) {
      QString fullPath = dir.path()+QDir::separator()+file;
      QFile::rename(fullPath, fullPath+QString::fromUtf8(".old"));
      to_add << fullPath+QString::fromUtf8(".old");
    }
    emit scanDirFoundTorrents(to_add);
  }
}

void bittorrent::setDefaultSavePath(QString savepath) {
  defaultSavePath = savepath;
}

// Enable directory scanning
void bittorrent::enableDirectoryScanning(QString _scan_dir) {
  if(!_scan_dir.isEmpty()) {
    scan_dir = _scan_dir;
    timerScan = new QTimer(this);
    connect(timerScan, SIGNAL(timeout()), this, SLOT(scanDirectory()));
    timerScan->start(5000);
  }
}

// Disable directory scanning
void bittorrent::disableDirectoryScanning() {
  if(!scan_dir.isNull()) {
    scan_dir = QString::null;
    if(timerScan->isActive()) {
      timerScan->stop();
    }
  }
  if(timerScan != 0)
    delete timerScan;
}

// Set the ports range in which is chosen the port the bittorrent
// session will listen to
void bittorrent::setListeningPortsRange(std::pair<unsigned short, unsigned short> ports) {
  s->listen_on(ports);
}

// Set download rate limit
// -1 to disable
void bittorrent::setDownloadRateLimit(long rate) {
  qDebug("Setting a global download rate limit at %ld", rate);
  s->set_download_rate_limit(rate);
}

session* bittorrent::getSession() const{
  return s;
}

// Set upload rate limit
// -1 to disable
void bittorrent::setUploadRateLimit(long rate) {
  qDebug("set upload_limit to %fkb/s", rate/1024.);
  s->set_upload_rate_limit(rate);
}

// libtorrent allow to adjust ratio for each torrent
// This function will apply to same ratio to all torrents
void bittorrent::setGlobalRatio(float ratio) {
  if(ratio != -1 && ratio < 1.) ratio = 1.;
  if(ratio == -1) {
    // 0 means unlimited for libtorrent
    ratio = 0;
  }
  std::vector<torrent_handle> handles = s->get_torrents();
  unsigned int nbHandles = handles.size();
  for(unsigned int i=0; i<nbHandles; ++i) {
    QTorrentHandle h = handles[i];
    if(!h.is_valid()) {
      qDebug("/!\\ Error: Invalid handle");
      continue;
    }
    h.set_ratio(ratio);
  }
}

// Torrents will a ratio superior to the given value will
// be automatically deleted
void bittorrent::setDeleteRatio(float ratio) {
  if(ratio != -1 && ratio < 1.) ratio = 1.;
  max_ratio = ratio;
  qDebug("* Set deleteRatio to %.1f", max_ratio);
  deleteBigRatios();
}

bool bittorrent::loadTrackerFile(QString hash) {
  QDir torrentBackup(misc::qBittorrentPath() + "BT_backup");
  QFile tracker_file(torrentBackup.path()+QDir::separator()+ hash + ".trackers");
  if(!tracker_file.exists()) return false;
  tracker_file.open(QIODevice::ReadOnly | QIODevice::Text);
  QStringList lines = QString::fromUtf8(tracker_file.readAll().data()).split("\n");
  std::vector<announce_entry> trackers;
  QString line;
  foreach(line, lines) {
    QStringList parts = line.split("|");
    if(parts.size() != 2) continue;
    announce_entry t(parts[0].toStdString());
    t.tier = parts[1].toInt();
    trackers.push_back(t);
  }
  if(trackers.size() != 0) {
    QTorrentHandle h = getTorrentHandle(hash);
    h.replace_trackers(trackers);
    return true;
  }else{
    return false;
  }
}

void bittorrent::saveTrackerFile(QString hash) {
  qDebug("Saving tracker file for %s", hash.toUtf8().data());
  QDir torrentBackup(misc::qBittorrentPath() + "BT_backup");
  QFile tracker_file(torrentBackup.path()+QDir::separator()+ hash + ".trackers");
  if(tracker_file.exists()) {
    tracker_file.remove();
  }
  tracker_file.open(QIODevice::WriteOnly | QIODevice::Text);
  QTorrentHandle h = getTorrentHandle(hash);
  std::vector<announce_entry> trackers = h.trackers();
  for(unsigned int i=0; i<trackers.size(); ++i) {
    tracker_file.write(QByteArray(trackers[i].url.c_str())+QByteArray("|")+QByteArray(misc::toString(i).c_str())+QByteArray("\n"));
  }
  tracker_file.close();
}

// Add uT PeX extension to bittorrent session
void bittorrent::enablePeerExchange() {
  qDebug("Enabling Peer eXchange");
  s->add_extension(&create_ut_pex_plugin);
}

// Set DHT port (>= 1000)
void bittorrent::setDHTPort(int dht_port) {
  if(dht_port >= 1000) {
    struct dht_settings DHTSettings;
    DHTSettings.service_port = dht_port;
    s->set_dht_settings(DHTSettings);
    qDebug("Set DHT Port to %d", dht_port);
  }
}

// Enable IP Filtering
void bittorrent::enableIPFilter(ip_filter filter) {
  qDebug("Enabling IPFiler");
  s->set_ip_filter(filter);
}

// Disable IP Filtering
void bittorrent::disableIPFilter() {
  qDebug("Disabling IPFilter");
  s->set_ip_filter(ip_filter());
}

// Set BT session settings (user_agent)
void bittorrent::setSessionSettings(session_settings sessionSettings) {
  qDebug("Set session settings");
  s->set_settings(sessionSettings);
}

// Set Proxy
void bittorrent::setProxySettings(proxy_settings proxySettings, bool trackers, bool peers, bool web_seeds, bool dht) {
  qDebug("Set Proxy settings");
  if(trackers)
    s->set_tracker_proxy(proxySettings);
  if(peers)
    s->set_peer_proxy(proxySettings);
  if(web_seeds)
    s->set_web_seed_proxy(proxySettings);
  if(DHTEnabled && dht) {
    s->set_dht_proxy(proxySettings);
  }
}

// Read alerts sent by the bittorrent session
void bittorrent::readAlerts() {
  // look at session alerts and display some infos
  std::auto_ptr<alert> a = s->pop_alert();
  while (a.get()) {
    if (torrent_finished_alert* p = dynamic_cast<torrent_finished_alert*>(a.get())) {
      QTorrentHandle h(p->handle);
      if(h.is_valid()){
        QString hash = h.hash();
        qDebug("Received finished alert for %s", h.name().toUtf8().data());
        setFinishedTorrent(hash);
        emit finishedTorrent(h);
      }
    }
    else if (file_error_alert* p = dynamic_cast<file_error_alert*>(a.get())) {
      QTorrentHandle h(p->handle);
      qDebug("File Error: %s", p->msg().c_str());
      if(h.is_valid())
        emit fullDiskError(h);
    }
    else if (dynamic_cast<listen_failed_alert*>(a.get())) {
      // Level: fatal
      emit portListeningFailure();
    }
    else if (tracker_alert* p = dynamic_cast<tracker_alert*>(a.get())) {
      // Level: fatal
      QTorrentHandle h(p->handle);
      if(h.is_valid()){
        QString hash = h.hash();
        QList<QPair<QString, QString> > errors = trackersErrors.value(hash, QList<QPair<QString, QString> >());
        if(errors.size() > MAX_TRACKER_ERRORS)
          errors.removeAt(0);
        errors << QPair<QString,QString>(QTime::currentTime().toString("hh:mm:ss"), QString::fromUtf8(a->msg().c_str()));
        trackersErrors[hash] = errors;
        // Authentication
        if(p->status_code == 401) {
          emit trackerAuthenticationRequired(h);
        }
      }
    }
    else if (peer_blocked_alert* p = dynamic_cast<peer_blocked_alert*>(a.get())) {
      emit peerBlocked(QString::fromUtf8(p->ip.to_string().c_str()));
    }
    else if (fastresume_rejected_alert* p = dynamic_cast<fastresume_rejected_alert*>(a.get())) {
      QTorrentHandle h(p->handle);
      if(h.is_valid()){
        qDebug("/!\\ Fast resume failed for %s, reason: %s", h.name().toUtf8().data(), p->msg().c_str());
        emit fastResumeDataRejected(h.name());
      }
    }
    else if (url_seed_alert* p = dynamic_cast<url_seed_alert*>(a.get())) {
      emit urlSeedProblem(QString::fromUtf8(p->url.c_str()), QString::fromUtf8(p->msg().c_str()));
    }
    else if (torrent_checked_alert* p = dynamic_cast<torrent_checked_alert*>(a.get())) {
      QTorrentHandle h(p->handle);
      if(h.is_valid()){
        QString hash = h.hash();
        qDebug("%s have just finished checking", hash.toUtf8().data());
        int index = torrentsToPauseAfterChecking.indexOf(hash);
        if(index != -1) {
          torrentsToPauseAfterChecking.removeAt(index);
          // Pause torrent
          pauseTorrent(hash);
          qDebug("%s was paused after checking", hash.toUtf8().data());
        }
        emit torrentFinishedChecking(hash);
      }
    }
    a = s->pop_alert();
  }
}

QList<QPair<QString, QString> > bittorrent::getTrackersErrors(QString hash) const{
  return trackersErrors.value(hash, QList<QPair<QString, QString> >());
}

QStringList bittorrent::getTorrentsToPauseAfterChecking() const{
  return torrentsToPauseAfterChecking;
}

// Reload a torrent with full allocation mode
void bittorrent::reloadTorrent(const QTorrentHandle &h, bool full_alloc) {
  qDebug("** Reloading a torrent");
  if(!h.is_valid()) {
    qDebug("/!\\ Error: Invalid handle");
    return;
  }
  QDir torrentBackup(misc::qBittorrentPath() + "BT_backup");
  fs::path saveDir = h.save_path_boost();
  QString fileName = h.name();
  QString hash = h.hash();
  boost::intrusive_ptr<torrent_info> t(new torrent_info(h.get_torrent_info()));
  qDebug("Reloading torrent: %s", fileName.toUtf8().data());
  entry resumeData;
    // Checking if torrentBackup Dir exists
  // create it if it is not
  if(! torrentBackup.exists()) {
    torrentBackup.mkpath(torrentBackup.path());
  }
  // Extracting resume data
  if (h.has_metadata()) {
    // get fast resume data
    resumeData = h.write_resume_data();
  }
  // Remove torrent
  s->remove_torrent(h.get_torrent_handle());
  // Add torrent again to session
  unsigned int timeout = 0;
  while(h.is_valid() && timeout < 6) {
    qDebug("Waiting for the torrent to be removed...");
    SleeperThread::msleep(1000);
    ++timeout;
  }
  QTorrentHandle new_h;
  if(full_alloc) {
    new_h = s->add_torrent(t, saveDir, resumeData, storage_mode_allocate);
    qDebug("Using full allocation mode");
  } else {
    new_h = s->add_torrent(t, saveDir, resumeData, storage_mode_sparse);
    qDebug("Using sparse mode");
  }
  // Connections limit per torrent
  new_h.set_max_connections(maxConnecsPerTorrent);
  // Uploads limit per torrent
  new_h.set_max_uploads(maxUploadsPerTorrent);
  // Load filtered Files
  loadFilesPriorities(new_h);
  // Load speed limit from hard drive
  loadTorrentSpeedLimits(hash);
  // Load custom url seeds
  loadWebSeeds(hash);
  // Load ratio data
  loadDownloadUploadForTorrent(hash);
  // Pause torrent if it was paused last time
  if(QFile::exists(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".paused")) {
    new_h.pause();
  }
  // Incremental download
  if(QFile::exists(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".incremental")) {
    qDebug("Incremental download enabled for %s", fileName.toUtf8().data());
    new_h.set_sequenced_download_threshold(1);
  }
}



int bittorrent::getListenPort() const{
  return s->listen_port();
}

session_status bittorrent::getSessionStatus() const{
  return s->status();
}

QString bittorrent::getSavePath(QString hash) {
  QFile savepath_file(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".savepath");
  QByteArray line;
  QString savePath;
  if(savepath_file.open(QIODevice::ReadOnly | QIODevice::Text)) {
    line = savepath_file.readAll();
    savepath_file.close();
    qDebug(" -> Save path: %s", line.data());
    savePath = QString::fromUtf8(line.data());
  }else{
    // use default save path
    qDebug("Using default save path because none was set");
    savePath = defaultSavePath;
  }
  // Checking if savePath Dir exists
  // create it if it is not
  QDir saveDir(savePath);
  if(!saveDir.exists()) {
    if(!saveDir.mkpath(saveDir.path())) {
      std::cerr << "Couldn't create the save directory: " << saveDir.path().toUtf8().data() << "\n";
      // XXX: handle this better
      return QDir::homePath();
    }
  }
  return savePath;
}

// Take an url string to a torrent file,
// download the torrent file to a tmp location, then
// add it to download list
void bittorrent::downloadFromUrl(QString url) {
  emit aboutToDownloadFromUrl(url);
  // Launch downloader thread
  downloader->downloadUrl(url);
}

// Add to bittorrent session the downloaded torrent file
void bittorrent::processDownloadedFile(QString url, QString file_path) {
  // Add file to torrent download list
  emit newDownloadedTorrent(file_path, url);
}

void bittorrent::downloadFromURLList(const QStringList& url_list) {
  QString url;
  qDebug("DownloadFromUrlList");
  foreach(url, url_list) {
    downloadFromUrl(url);
  }
}

// Return current download rate for the BT
// session. Payload means that it only take into
// account "useful" part of the rate
float bittorrent::getPayloadDownloadRate() const{
  session_status sessionStatus = s->status();
  return sessionStatus.payload_download_rate;
}

// Return current upload rate for the BT
// session. Payload means that it only take into
// account "useful" part of the rate
float bittorrent::getPayloadUploadRate() const{
  session_status sessionStatus = s->status();
  return sessionStatus.payload_upload_rate;
}

// Save DHT entry to hard drive
void bittorrent::saveDHTEntry() {
  // Save DHT entry
  if(DHTEnabled) {
    try{
      entry dht_state = s->dht_state();
      boost::filesystem::ofstream out((misc::qBittorrentPath()+QString::fromUtf8("dht_state")).toUtf8().data(), std::ios_base::binary);
      out.unsetf(std::ios_base::skipws);
      bencode(std::ostream_iterator<char>(out), dht_state);
      qDebug("DHT entry saved");
    }catch (std::exception& e) {
      std::cerr << e.what() << "\n";
    }
  }
}

void bittorrent::applyEncryptionSettings(pe_settings se) {
  qDebug("Applying encryption settings");
  s->set_pe_settings(se);
}

// Will fast resume torrents in
// backup directory
void bittorrent::resumeUnfinishedTorrents() {
  qDebug("Resuming unfinished torrents");
  QDir torrentBackup(misc::qBittorrentPath() + "BT_backup");
  QStringList fileNames, filePaths;
  // Scan torrentBackup directory
  QStringList filters;
  filters << "*.torrent";
  fileNames = torrentBackup.entryList(filters, QDir::Files, QDir::Unsorted);
  QString fileName;
  foreach(fileName, fileNames) {
    filePaths.append(torrentBackup.path()+QDir::separator()+fileName);
  }
  // Resume downloads
  foreach(fileName, filePaths) {
    addTorrent(fileName, false, QString(), true);
  }
  qDebug("Unfinished torrents resumed");
}