/*
 * This file Copyright (C) 2009-2015 Mnemosyne LLC
 *
 * It may be used under the GNU GPL versions 2 or 3
 * or any future license endorsed by Mnemosyne LLC.
 *
 */

#include <algorithm>

#include "Filters.h"
#include "Prefs.h"
#include "Torrent.h"
#include "TorrentFilter.h"
#include "TorrentModel.h"
#include "Utils.h"

TorrentFilter::TorrentFilter (const Prefs& prefs):
  myPrefs (prefs)
{
  // listen for changes to the preferences to know when to refilter / resort
  connect (&myPrefs, SIGNAL(changed(int)), this, SLOT(refreshPref(int)));

  setDynamicSortFilter (true);

  // initialize our state from the current prefs
  QList<int> initKeys;
  initKeys << Prefs::SORT_MODE
           << Prefs::FILTER_MODE
           << Prefs::FILTER_TRACKERS
           << Prefs::FILTER_TEXT;
  for (const int key: initKeys)
    refreshPref (key);
}

TorrentFilter::~TorrentFilter ()
{
}

void
TorrentFilter::refreshPref (int key)
{
  switch (key)
    {
      case Prefs::FILTER_TEXT:
      case Prefs::FILTER_MODE:
      case Prefs::FILTER_TRACKERS:
        invalidateFilter ();
        /* force a re-sort */
        sort (0, !myPrefs.getBool(Prefs::SORT_REVERSED) ? Qt::AscendingOrder : Qt::DescendingOrder);

      case Prefs::SORT_MODE:
      case Prefs::SORT_REVERSED:
        sort (0, myPrefs.getBool(Prefs::SORT_REVERSED) ? Qt::AscendingOrder : Qt::DescendingOrder);
        invalidate ();
        break;
    }
}

/***
****
***/

namespace
{
  template <typename T> int compare (const T a, const T b)
    {
      if (a < b)
        return -1;

      if (b < a)
        return 1;

      return 0;
    }
}

bool
TorrentFilter::lessThan (const QModelIndex& left, const QModelIndex& right) const
{
  int val = 0;
  const Torrent * a = sourceModel()->data (left, TorrentModel::TorrentRole).value<const Torrent*>();
  const Torrent * b = sourceModel()->data (right, TorrentModel::TorrentRole).value<const Torrent*>();

  switch (myPrefs.get<SortMode>(Prefs::SORT_MODE).mode())
    {
      case SortMode::SORT_BY_QUEUE:
        if (!val)
          val = -compare (a->queuePosition(), b->queuePosition());
        break;

      case SortMode::SORT_BY_SIZE:
        if (!val)
          val = compare (a->sizeWhenDone(), b->sizeWhenDone());
        break;

      case SortMode::SORT_BY_AGE:
        val = compare (a->dateAdded().toTime_t(), b->dateAdded().toTime_t());
        break;

      case SortMode::SORT_BY_ID:
        if (!val)
          val = compare (a->id(), b->id());
        break;

      case SortMode::SORT_BY_ACTIVITY:
        if (!val)
          val = compare (a->downloadSpeed() + a->uploadSpeed(), b->downloadSpeed() + b->uploadSpeed());
        if (!val)
          val = compare (a->peersWeAreUploadingTo() + a->webseedsWeAreDownloadingFrom(),
                         b->peersWeAreUploadingTo() + b->webseedsWeAreDownloadingFrom());
        // fall through

      case SortMode::SORT_BY_STATE:
        if (!val)
          val = -compare (a->isPaused(), b->isPaused());
        if (!val)
          val = compare (a->getActivity(), b->getActivity());
        if (!val)
          val = -compare (a->queuePosition(), b->queuePosition());
        if (!val)
          val = compare (a->hasError(), b->hasError());
        // fall through

      case SortMode::SORT_BY_PROGRESS:
        if (!val)
          val = compare (a->percentComplete(), b->percentComplete());
        if (!val)
          val = a->compareSeedRatio (*b);
        if (!val)
          val = -compare (a->queuePosition(), b->queuePosition());
        // fall through

      case SortMode::SORT_BY_RATIO:
        if (!val)
          val = a->compareRatio (*b);
        break;

      case SortMode::SORT_BY_ETA:
        if (!val)
          val = a->compareETA (*b);
        break;

      default:
        break;
    }

  if (val == 0)
    val = -a->name().compare (b->name(), Qt::CaseInsensitive);

  if (val == 0)
    val = compare (a->hashString(), b->hashString());

  return val < 0;
}


/***
****
***/

bool
TorrentFilter::trackerFilterAcceptsTorrent (const Torrent * tor, const QString& tracker) const
{
  return tracker.isEmpty() || tor->hasTrackerSubstring (tracker);
}

bool
TorrentFilter::activityFilterAcceptsTorrent (const Torrent * tor, const FilterMode& m) const
{
  bool accepts;

  switch (m.mode ())
    {
      case FilterMode::SHOW_ACTIVE:
        accepts = tor->peersWeAreUploadingTo () > 0 || tor->peersWeAreDownloadingFrom () > 0 || tor->isVerifying ();
        break;

      case FilterMode::SHOW_DOWNLOADING:
        accepts = tor->isDownloading () || tor->isWaitingToDownload ();
        break;

      case FilterMode::SHOW_SEEDING:
        accepts = tor->isSeeding () || tor->isWaitingToSeed ();
        break;

      case FilterMode::SHOW_PAUSED:
        accepts = tor->isPaused ();
        break;

      case FilterMode::SHOW_FINISHED:
        accepts = tor->isFinished ();
        break;

      case FilterMode::SHOW_VERIFYING:
        accepts = tor->isVerifying () || tor->isWaitingToVerify ();
        break;

      case FilterMode::SHOW_ERROR:
        accepts = tor->hasError ();
        break;

      default: // FilterMode::SHOW_ALL
        accepts = true;
        break;
    }

  return accepts;
}

bool
TorrentFilter::filterAcceptsRow (int sourceRow, const QModelIndex& sourceParent) const
{
  QModelIndex childIndex = sourceModel()->index (sourceRow, 0, sourceParent);
  const Torrent * tor = childIndex.model()->data (childIndex, TorrentModel::TorrentRole).value<const Torrent*>();
  bool accepts = true;

  if (accepts)
    {
      const FilterMode m = myPrefs.get<FilterMode>(Prefs::FILTER_MODE);
      accepts = activityFilterAcceptsTorrent (tor, m);
    }

  if (accepts)
    {
      const QString trackers = myPrefs.getString(Prefs::FILTER_TRACKERS);
      accepts = trackerFilterAcceptsTorrent (tor, trackers);
    }

  if (accepts)
    {
      const QString text = myPrefs.getString (Prefs::FILTER_TEXT);
      if (!text.isEmpty ())
        accepts = tor->name().contains (text, Qt::CaseInsensitive);
    }

  return accepts;
}

int
TorrentFilter::hiddenRowCount () const
{
  return sourceModel()->rowCount () - rowCount ();
}

void
TorrentFilter::countTorrentsPerMode (int * setmeCounts) const
{
  std::fill_n (setmeCounts, static_cast<std::size_t>(FilterMode::NUM_MODES), 0);

  for (int row(0); ; ++row)
    {
      QModelIndex index (sourceModel()->index(row, 0));
      if (!index.isValid())
        break;

      const Torrent * tor (index.data (TorrentModel::TorrentRole).value<const Torrent*>());
      for (int mode(0); mode<FilterMode::NUM_MODES; ++mode)
        if (activityFilterAcceptsTorrent (tor, mode))
          ++setmeCounts[mode];
    }
}