/*
 * Bittorrent Client using Qt4 and libtorrent.
 * Copyright (C) 2010  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.
 *
 * In addition, as a special exception, the copyright holders give permission to
 * link this program with the OpenSSL project's "OpenSSL" library (or with
 * modified versions of it that use the same license as the "OpenSSL" library),
 * and distribute the linked executables. 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), 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.
 *
 * Contact : chris@qbittorrent.org
 */

#include <QDebug>

#include "torrentmodel.h"
#include "torrentpersistentdata.h"
#include "qbtsession.h"
#include "fs_utils.h"

using namespace libtorrent;

namespace {
QIcon get_paused_icon() {
    static QIcon cached = QIcon(":/Icons/skin/paused.png");
    return cached;
  }

QIcon get_queued_icon() {
    static QIcon cached = QIcon(":/Icons/skin/queued.png");
    return cached;
  }

QIcon get_downloading_icon() {
    static QIcon cached = QIcon(":/Icons/skin/downloading.png");
    return cached;
  }

QIcon get_stalled_downloading_icon() {
    static QIcon cached = QIcon(":/Icons/skin/stalledDL.png");
    return cached;
  }

QIcon get_uploading_icon() {
    static QIcon cached = QIcon(":/Icons/skin/uploading.png");
    return cached;
  }

QIcon get_stalled_uploading_icon() {
    static QIcon cached = QIcon(":/Icons/skin/stalledUP.png");
    return cached;
  }

QIcon get_checking_icon() {
    static QIcon cached = QIcon(":/Icons/skin/checking.png");
    return cached;
  }

QIcon get_error_icon() {
    static QIcon cached = QIcon(":/Icons/skin/error.png");
    return cached;
  }
}

TorrentModelItem::TorrentModelItem(const QTorrentHandle &h)
  : m_torrent(h)
  , m_lastStatus(h.status(torrent_handle::query_accurate_download_counters))
  , m_addedTime(TorrentPersistentData::getAddedDate(h.hash()))
  , m_label(TorrentPersistentData::getLabel(h.hash()))
  , m_name(TorrentPersistentData::getName(h.hash()))
  , m_hash(h.hash())
{
  if (m_name.isEmpty())
    m_name = h.name();
}

void TorrentModelItem::refreshStatus(libtorrent::torrent_status const& status) {
  m_lastStatus = status;
}

TorrentModelItem::State TorrentModelItem::state() const {
  try {
    // Pause or Queued
    if (m_torrent.is_paused(m_lastStatus)) {
      m_icon = get_paused_icon();
      m_fgColor = QColor("red");
      return m_torrent.is_seed(m_lastStatus) ? STATE_PAUSED_UP : STATE_PAUSED_DL;
    }
    if (m_torrent.is_queued(m_lastStatus)) {
      if (m_lastStatus.state != torrent_status::queued_for_checking
          && m_lastStatus.state != torrent_status::checking_resume_data
          && m_lastStatus.state != torrent_status::checking_files) {
        m_icon = get_queued_icon();
        m_fgColor = QColor("grey");
        return m_torrent.is_seed(m_lastStatus) ? STATE_QUEUED_UP : STATE_QUEUED_DL;
      }
    }
    // Other states
    switch(m_lastStatus.state) {
    case torrent_status::allocating:
      m_icon = get_stalled_downloading_icon();
      m_fgColor = QColor("grey");
      return STATE_ALLOCATING;
    case torrent_status::downloading_metadata:
      m_icon = get_downloading_icon();
      m_fgColor = QColor("green");
      return STATE_DOWNLOADING_META;
    case torrent_status::downloading: {
      if (m_lastStatus.download_payload_rate > 0) {
        m_icon = get_downloading_icon();
        m_fgColor = QColor("green");
        return STATE_DOWNLOADING;
      } else {
        m_icon = get_stalled_downloading_icon();
        m_fgColor = QColor("grey");
        return STATE_STALLED_DL;
      }
    }
    case torrent_status::finished:
    case torrent_status::seeding:
      if (m_lastStatus.upload_payload_rate > 0) {
        m_icon = get_uploading_icon();
        m_fgColor = QColor("orange");
        return STATE_SEEDING;
      } else {
        m_icon = get_stalled_uploading_icon();
        m_fgColor = QColor("grey");
        return STATE_STALLED_UP;
      }
    case torrent_status::queued_for_checking:
      m_icon = get_checking_icon();
      m_fgColor = QColor("grey");
      return STATE_QUEUED_CHECK;
    case torrent_status::checking_resume_data:
      m_icon = get_checking_icon();
      m_fgColor = QColor("grey");
      return STATE_QUEUED_FASTCHECK;
    case torrent_status::checking_files:
      m_icon = get_checking_icon();
      m_fgColor = QColor("grey");
      return m_torrent.is_seed(m_lastStatus) ? STATE_CHECKING_UP : STATE_CHECKING_DL;
    default:
      m_icon = get_error_icon();
      m_fgColor = QColor("red");
      return STATE_INVALID;
    }
  } catch(invalid_handle&) {
    m_icon = get_error_icon();
    m_fgColor = QColor("red");
    return STATE_INVALID;
  }
}

bool TorrentModelItem::setData(int column, const QVariant &value, int role)
{
  qDebug() << Q_FUNC_INFO << column << value;
  if (role != Qt::DisplayRole) return false;
  // Label, seed date and Name columns can be edited
  switch(column) {
  case TR_NAME:
    m_name = value.toString();
    TorrentPersistentData::saveName(m_torrent.hash(), m_name);
    return true;
  case TR_LABEL: {
    QString new_label = value.toString();
    if (m_label != new_label) {
      QString old_label = m_label;
      m_label = new_label;
      TorrentPersistentData::saveLabel(m_torrent.hash(), new_label);
      emit labelChanged(old_label, new_label);
    }
    return true;
  }
  default:
    break;
  }
  return false;
}

QVariant TorrentModelItem::data(int column, int role) const
{
  if (role == Qt::DecorationRole && column == TR_NAME) {
    return m_icon;
  }
  if (role == Qt::ForegroundRole) {
    return m_fgColor;
  }
  if (role != Qt::DisplayRole && role != Qt::UserRole) return QVariant();
  switch(column) {
  case TR_NAME:
    return m_name.isEmpty() ? m_torrent.name() : m_name;
  case TR_PRIORITY: {
    int pos = m_torrent.queue_position(m_lastStatus);;
    if (pos > -1)
      return pos - HiddenData::getSize();
    else
      return pos;
  }
  case TR_SIZE:
    return m_lastStatus.has_metadata ? static_cast<qlonglong>(m_lastStatus.total_wanted) : -1;
  case TR_PROGRESS:
    return m_torrent.progress(m_lastStatus);
  case TR_STATUS:
    return state();
  case TR_SEEDS: {
    return (role == Qt::DisplayRole) ? m_lastStatus.num_seeds : m_lastStatus.num_complete;
  }
  case TR_PEERS: {
    return (role == Qt::DisplayRole) ? (m_lastStatus.num_peers-m_lastStatus.num_seeds) : m_lastStatus.num_incomplete;
  }
  case TR_DLSPEED:
    return m_lastStatus.download_payload_rate;
  case TR_UPSPEED:
    return m_lastStatus.upload_payload_rate;
  case TR_ETA: {
    // XXX: Is this correct?
    if (m_torrent.is_paused(m_lastStatus) || m_torrent.is_queued(m_lastStatus)) return MAX_ETA;
    return QBtSession::instance()->getETA(m_hash, m_lastStatus);
  }
  case TR_RATIO:
    return QBtSession::instance()->getRealRatio(m_lastStatus);
  case TR_LABEL:
    return m_label;
  case TR_ADD_DATE:
    return m_addedTime;
  case TR_SEED_DATE:
    return m_lastStatus.completed_time ? QDateTime::fromTime_t(m_lastStatus.completed_time) : QDateTime();
  case TR_TRACKER:
    return misc::toQString(m_lastStatus.current_tracker);
  case TR_DLLIMIT:
    return m_torrent.download_limit();
  case TR_UPLIMIT:
    return m_torrent.upload_limit();
  case TR_AMOUNT_DOWNLOADED:
    return static_cast<qlonglong>(m_lastStatus.all_time_download);
  case TR_AMOUNT_UPLOADED:
    return static_cast<qlonglong>(m_lastStatus.all_time_upload);
  case TR_AMOUNT_LEFT:
    return static_cast<qlonglong>(m_lastStatus.total_wanted - m_lastStatus.total_wanted_done);
  case TR_TIME_ELAPSED:
    return (role == Qt::DisplayRole) ? m_lastStatus.active_time : m_lastStatus.seeding_time;
  case TR_SAVE_PATH:
    return fsutils::toNativePath(m_torrent.save_path_parsed());
  case TR_COMPLETED:
    return static_cast<qlonglong>(m_lastStatus.total_wanted_done);
  case TR_RATIO_LIMIT: {
    QString hash = misc::toQString(m_lastStatus.info_hash);
    return QBtSession::instance()->getMaxRatioPerTorrent(hash, NULL);
  }
  default:
    return QVariant();
  }
}

// TORRENT MODEL

TorrentModel::TorrentModel(QObject *parent) :
  QAbstractListModel(parent), m_refreshInterval(2000)
{
}

void TorrentModel::populate() {
  // Load the torrents
  std::vector<torrent_handle> torrents = QBtSession::instance()->getSession()->get_torrents();
  
  std::vector<torrent_handle>::const_iterator it = torrents.begin();
  std::vector<torrent_handle>::const_iterator itend = torrents.end();
  for ( ; it != itend; ++it) {
    const QTorrentHandle h(*it);
    if (HiddenData::hasData(h.hash()))
      continue;
    addTorrent(h);
  }
  // Refresh timer
  connect(&m_refreshTimer, SIGNAL(timeout()), SLOT(forceModelRefresh()));
  m_refreshTimer.start(m_refreshInterval);
  // Listen for torrent changes
  connect(QBtSession::instance(), SIGNAL(addedTorrent(QTorrentHandle)), SLOT(addTorrent(QTorrentHandle)));
  connect(QBtSession::instance(), SIGNAL(torrentAboutToBeRemoved(QTorrentHandle)), SLOT(handleTorrentAboutToBeRemoved(QTorrentHandle)));
  connect(QBtSession::instance(), SIGNAL(deletedTorrent(QString)), SLOT(removeTorrent(QString)));
  connect(QBtSession::instance(), SIGNAL(finishedTorrent(QTorrentHandle)), SLOT(handleFinishedTorrent(QTorrentHandle)));
  connect(QBtSession::instance(), SIGNAL(metadataReceived(QTorrentHandle)), SLOT(handleTorrentUpdate(QTorrentHandle)));
  connect(QBtSession::instance(), SIGNAL(resumedTorrent(QTorrentHandle)), SLOT(handleTorrentUpdate(QTorrentHandle)));
  connect(QBtSession::instance(), SIGNAL(pausedTorrent(QTorrentHandle)), SLOT(handleTorrentUpdate(QTorrentHandle)));
  connect(QBtSession::instance(), SIGNAL(torrentFinishedChecking(QTorrentHandle)), SLOT(handleTorrentUpdate(QTorrentHandle)));
  connect(QBtSession::instance(), SIGNAL(stateUpdate(std::vector<libtorrent::torrent_status>)), SLOT(stateUpdated(std::vector<libtorrent::torrent_status>)));
}

TorrentModel::~TorrentModel() {
  qDebug() << Q_FUNC_INFO << "ENTER";
  qDeleteAll(m_torrents);
  m_torrents.clear();
  qDebug() << Q_FUNC_INFO << "EXIT";
}

QVariant TorrentModel::headerData(int section, Qt::Orientation orientation,
                                  int role) const
{
  if (orientation == Qt::Horizontal) {
    if (role == Qt::DisplayRole) {
      switch(section) {
      case TorrentModelItem::TR_NAME: return tr("Name", "i.e: torrent name");
      case TorrentModelItem::TR_PRIORITY: return "#";
      case TorrentModelItem::TR_SIZE: return tr("Size", "i.e: torrent size");
      case TorrentModelItem::TR_PROGRESS: return tr("Done", "% Done");
      case TorrentModelItem::TR_STATUS: return tr("Status", "Torrent status (e.g. downloading, seeding, paused)");
      case TorrentModelItem::TR_SEEDS: return tr("Seeds", "i.e. full sources (often untranslated)");
      case TorrentModelItem::TR_PEERS: return tr("Peers", "i.e. partial sources (often untranslated)");
      case TorrentModelItem::TR_DLSPEED: return tr("Down Speed", "i.e: Download speed");
      case TorrentModelItem::TR_UPSPEED: return tr("Up Speed", "i.e: Upload speed");
      case TorrentModelItem::TR_RATIO: return tr("Ratio", "Share ratio");
      case TorrentModelItem::TR_ETA: return tr("ETA", "i.e: Estimated Time of Arrival / Time left");
      case TorrentModelItem::TR_LABEL: return tr("Label");
      case TorrentModelItem::TR_ADD_DATE: return tr("Added On", "Torrent was added to transfer list on 01/01/2010 08:00");
      case TorrentModelItem::TR_SEED_DATE: return tr("Completed On", "Torrent was completed on 01/01/2010 08:00");
      case TorrentModelItem::TR_TRACKER: return tr("Tracker");
      case TorrentModelItem::TR_DLLIMIT: return tr("Down Limit", "i.e: Download limit");
      case TorrentModelItem::TR_UPLIMIT: return tr("Up Limit", "i.e: Upload limit");
      case TorrentModelItem::TR_AMOUNT_DOWNLOADED: return tr("Downloaded", "Amount of data downloaded (e.g. in MB)");
      case TorrentModelItem::TR_AMOUNT_UPLOADED: return tr("Uploaded", "Amount of data uploaded (e.g. in MB)");
      case TorrentModelItem::TR_AMOUNT_LEFT: return tr("Remaining", "Amount of data left to download (e.g. in MB)");
      case TorrentModelItem::TR_TIME_ELAPSED: return tr("Time Active", "Time (duration) the torrent is active (not paused)");
      case TorrentModelItem::TR_SAVE_PATH: return tr("Save path", "Torrent save path");
      case TorrentModelItem::TR_COMPLETED: return tr("Completed", "Amount of data completed (e.g. in MB)");
      case TorrentModelItem::TR_RATIO_LIMIT: return tr("Ratio Limit", "Upload share ratio limit");
      default:
        return QVariant();
      }
    }
  }

  return QVariant();
}

QVariant TorrentModel::data(const QModelIndex &index, int role) const
{
  if (!index.isValid()) return QVariant();
  try {
    if (index.row() >= 0 && index.row() < rowCount() && index.column() >= 0 && index.column() < columnCount())
      return m_torrents[index.row()]->data(index.column(), role);
  } catch(invalid_handle&) {}
  return QVariant();
}

bool TorrentModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
  qDebug() << Q_FUNC_INFO << value;
  if (!index.isValid() || role != Qt::DisplayRole) return false;
  qDebug("Index is valid and role is DisplayRole");
  try {
    if (index.row() >= 0 && index.row() < rowCount() && index.column() >= 0 && index.column() < columnCount()) {
      bool change = m_torrents[index.row()]->setData(index.column(), value, role);
      if (change)
        notifyTorrentChanged(index.row());
      return change;
    }
  } catch(invalid_handle&) {}
  return false;
}

int TorrentModel::torrentRow(const QString &hash) const
{
  int row = 0;

  QList<TorrentModelItem*>::const_iterator it = m_torrents.constBegin();
  QList<TorrentModelItem*>::const_iterator itend = m_torrents.constEnd();
  for ( ; it != itend; ++it) {
    if ((*it)->hash() == hash) return row;
    ++row;
  }
  return -1;
}

void TorrentModel::addTorrent(const QTorrentHandle &h)
{
  if (torrentRow(h.hash()) < 0) {
    beginInsertTorrent(m_torrents.size());
    TorrentModelItem *item = new TorrentModelItem(h);
    connect(item, SIGNAL(labelChanged(QString,QString)), SLOT(handleTorrentLabelChange(QString,QString)));
    m_torrents << item;
    emit torrentAdded(item);
    endInsertTorrent();
  }
}

void TorrentModel::removeTorrent(const QString &hash)
{
  const int row = torrentRow(hash);
  qDebug() << Q_FUNC_INFO << hash << row;
  if (row >= 0) {
    beginRemoveTorrent(row);
    m_torrents.removeAt(row);
    endRemoveTorrent();
  }
}

void TorrentModel::beginInsertTorrent(int row)
{
  beginInsertRows(QModelIndex(), row, row);
}

void TorrentModel::endInsertTorrent()
{
  endInsertRows();
}

void TorrentModel::beginRemoveTorrent(int row)
{
  beginRemoveRows(QModelIndex(), row, row);
}

void TorrentModel::endRemoveTorrent()
{
  endRemoveRows();
}

void TorrentModel::handleTorrentUpdate(const QTorrentHandle &h)
{
  const int row = torrentRow(h.hash());
  if (row >= 0) {
    m_torrents[row]->refreshStatus(h.status(torrent_handle::query_accurate_download_counters));
    notifyTorrentChanged(row);
  }
}

void TorrentModel::handleFinishedTorrent(const QTorrentHandle& h)
{
  const int row = torrentRow(h.hash());
  if (row < 0)
    return;

  // Update completion date
  m_torrents[row]->refreshStatus(h.status(torrent_handle::query_accurate_download_counters));
  notifyTorrentChanged(row);
}

void TorrentModel::notifyTorrentChanged(int row)
{
  emit dataChanged(index(row, 0), index(row, columnCount()-1));
}

void TorrentModel::setRefreshInterval(int refreshInterval)
{
  if (m_refreshInterval != refreshInterval) {
    m_refreshInterval = refreshInterval;
    m_refreshTimer.stop();
    m_refreshTimer.start(m_refreshInterval);
  }
}

void TorrentModel::forceModelRefresh()
{
  emit dataChanged(index(0, 0), index(rowCount()-1, columnCount()-1));
  QBtSession::instance()->postTorrentUpdate();
}

TorrentStatusReport TorrentModel::getTorrentStatusReport() const
{
  TorrentStatusReport report;

  QList<TorrentModelItem*>::const_iterator it = m_torrents.constBegin();
  QList<TorrentModelItem*>::const_iterator itend = m_torrents.constEnd();
  for ( ; it != itend; ++it) {
    switch((*it)->data(TorrentModelItem::TR_STATUS).toInt()) {
    case TorrentModelItem::STATE_DOWNLOADING:
      ++report.nb_active;
      ++report.nb_downloading;
      break;
    case TorrentModelItem::STATE_DOWNLOADING_META:
      ++report.nb_downloading;
      break;
    case TorrentModelItem::STATE_PAUSED_DL:
      ++report.nb_paused;
    case TorrentModelItem::STATE_STALLED_DL:
    case TorrentModelItem::STATE_CHECKING_DL:
    case TorrentModelItem::STATE_QUEUED_DL: {
      ++report.nb_inactive;
      ++report.nb_downloading;
      break;
    }
    case TorrentModelItem::STATE_SEEDING:
      ++report.nb_active;
      ++report.nb_seeding;
      break;
    case TorrentModelItem::STATE_PAUSED_UP:
      ++report.nb_paused;
    case TorrentModelItem::STATE_STALLED_UP:
    case TorrentModelItem::STATE_CHECKING_UP:
    case TorrentModelItem::STATE_QUEUED_UP: {
      ++report.nb_seeding;
      ++report.nb_inactive;
      break;
    }
    default:
      break;
    }
  }
  return report;
}

Qt::ItemFlags TorrentModel::flags(const QModelIndex &index) const
{
  if (!index.isValid())
    return 0;
  // Explicitely mark as editable
  return QAbstractListModel::flags(index) | Qt::ItemIsEditable;
}

void TorrentModel::handleTorrentLabelChange(QString previous, QString current)
{
  emit torrentChangedLabel(static_cast<TorrentModelItem*>(sender()), previous, current);
}

QString TorrentModel::torrentHash(int row) const
{
  if (row >= 0 && row < rowCount())
    return m_torrents.at(row)->hash();
  return QString();
}

void TorrentModel::handleTorrentAboutToBeRemoved(const QTorrentHandle &h)
{
  const int row = torrentRow(h.hash());
  if (row >= 0) {
    emit torrentAboutToBeRemoved(m_torrents.at(row));
  }
}

void TorrentModel::stateUpdated(const std::vector<libtorrent::torrent_status> &statuses) {
  typedef std::vector<libtorrent::torrent_status> statuses_t;

  for (statuses_t::const_iterator i = statuses.begin(), end = statuses.end(); i != end; ++i) {
    libtorrent::torrent_status const& status = *i;

    const int row = torrentRow(misc::toQString(status.info_hash));
    if (row >= 0)
      m_torrents[row]->refreshStatus(status);
  }
}

bool TorrentModel::inhibitSystem()
{
  QList<TorrentModelItem*>::const_iterator it = m_torrents.constBegin();
  QList<TorrentModelItem*>::const_iterator itend = m_torrents.constEnd();
  for ( ; it != itend; ++it) {
    switch((*it)->data(TorrentModelItem::TR_STATUS).toInt()) {
    case TorrentModelItem::STATE_DOWNLOADING:
    case TorrentModelItem::STATE_DOWNLOADING_META:
    case TorrentModelItem::STATE_STALLED_DL:
    case TorrentModelItem::STATE_SEEDING:
    case TorrentModelItem::STATE_STALLED_UP:
      return true;
    default:
      break;
    }
  }
  return false;
}