/*
 * This file Copyright (C) 2012-2015 Mnemosyne LLC
 *
 * It may be used under the GNU GPL versions 2 or 3
 * or any future license endorsed by Mnemosyne LLC.
 *
 * $Id$
 */

#include <QHBoxLayout>
#include <QLabel>
#include <QStandardItemModel>

#include "Application.h"
#include "FaviconCache.h"
#include "Filters.h"
#include "FilterBar.h"
#include "FilterBarComboBox.h"
#include "FilterBarComboBoxDelegate.h"
#include "FilterBarLineEdit.h"
#include "Prefs.h"
#include "Torrent.h"
#include "TorrentFilter.h"
#include "TorrentModel.h"

enum
{
  ActivityRole = FilterBarComboBox::UserRole,
  TrackerRole
};

namespace
{
  QString
  readableHostName (const QString& host)
  {
    // get the readable name...
    QString name = host;
    const int pos = name.lastIndexOf (QLatin1Char ('.'));
    if (pos >= 0)
      name.truncate (pos);
    if (!name.isEmpty ())
      name[0] = name[0].toUpper ();
    return name;
  }
}

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

FilterBarComboBox *
FilterBar::createActivityCombo ()
{
  FilterBarComboBox * c = new FilterBarComboBox (this);
  FilterBarComboBoxDelegate * delegate = new FilterBarComboBoxDelegate (this, c);
  c->setItemDelegate (delegate);

  QStandardItemModel * model = new QStandardItemModel (this);

  QStandardItem * row = new QStandardItem (tr ("All"));
  row->setData (FilterMode::SHOW_ALL, ActivityRole);
  model->appendRow (row);

  model->appendRow (new QStandardItem); // separator
  delegate->setSeparator (model, model->index (1, 0));

  row = new QStandardItem (QIcon::fromTheme (QLatin1String ("system-run")), tr ("Active"));
  row->setData (FilterMode::SHOW_ACTIVE, ActivityRole);
  model->appendRow (row);

  row = new QStandardItem (QIcon::fromTheme (QLatin1String ("go-down")), tr ("Downloading"));
  row->setData (FilterMode::SHOW_DOWNLOADING, ActivityRole);
  model->appendRow (row);

  row = new QStandardItem (QIcon::fromTheme (QLatin1String ("go-up")), tr ("Seeding"));
  row->setData (FilterMode::SHOW_SEEDING, ActivityRole);
  model->appendRow (row);

  row = new QStandardItem (QIcon::fromTheme (QLatin1String ("media-playback-pause")), tr ("Paused"));
  row->setData (FilterMode::SHOW_PAUSED, ActivityRole);
  model->appendRow (row);

  row = new QStandardItem (QIcon::fromTheme (QLatin1String ("dialog-ok")), tr ("Finished"));
  row->setData (FilterMode::SHOW_FINISHED, ActivityRole);
  model->appendRow (row);

  row = new QStandardItem (QIcon::fromTheme (QLatin1String ("view-refresh")), tr ("Verifying"));
  row->setData (FilterMode::SHOW_VERIFYING, ActivityRole);
  model->appendRow (row);

  row = new QStandardItem (QIcon::fromTheme (QLatin1String ("process-stop")), tr ("Error"));
  row->setData (FilterMode::SHOW_ERROR, ActivityRole);
  model->appendRow (row);

  c->setModel (model);
  return c;
}

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

void
FilterBar::refreshTrackers ()
{
  FaviconCache& favicons = qApp->faviconCache ();
  const int firstTrackerRow = 2; // skip over the "All" and separator...

  // pull info from the tracker model...
  QSet<QString> oldHosts;
  for (int row=firstTrackerRow; ; ++row)
    {
      QModelIndex index = myTrackerModel->index (row, 0);
      if (!index.isValid ())
        break;
      oldHosts << index.data (TrackerRole).toString ();
    }

  // pull the new stats from the torrent model...
  QSet<QString> newHosts;
  QMap<QString,int> torrentsPerHost;
  for (int row=0; ; ++row)
    {
      QModelIndex index = myTorrents.index (row, 0);
      if (!index.isValid ())
        break;
      const Torrent * tor = index.data (TorrentModel::TorrentRole).value<const Torrent*> ();
      QSet<QString> torrentNames;
      for (const QString& host: tor->hosts ())
        {
          newHosts.insert (host);
          torrentNames.insert (readableHostName (host));
        }
      for (const QString& name: torrentNames)
        ++torrentsPerHost[name];
    }

  // update the "All" row
  myTrackerModel->setData (myTrackerModel->index (0,0), myTorrents.rowCount (), FilterBarComboBox::CountRole);
  myTrackerModel->setData (myTrackerModel->index (0,0), getCountString (myTorrents.rowCount ()), FilterBarComboBox::CountStringRole);

  // rows to update
  for (const QString& host: oldHosts & newHosts)
    {
      const QString name = readableHostName (host);
      QStandardItem * row = myTrackerModel->findItems (name).front ();
      const int count = torrentsPerHost[name];
      row->setData (count, FilterBarComboBox::CountRole);
      row->setData (getCountString (count), FilterBarComboBox::CountStringRole);
      row->setData (favicons.findFromHost (host), Qt::DecorationRole);
    }

  // rows to remove
  for (const QString& host: oldHosts - newHosts)
    {
      const QString name = readableHostName (host);
      QStandardItem * item = myTrackerModel->findItems (name).front ();
      if (!item->data (TrackerRole).toString ().isEmpty ()) // don't remove "All"
        myTrackerModel->removeRows (item->row (), 1);
    }

  // rows to add
  bool anyAdded = false;
  for (const QString& host: newHosts - oldHosts)
    {
      const QString name = readableHostName (host);

      if (!myTrackerModel->findItems (name).isEmpty ())
        continue;

      // find the sorted position to add this row
      int i = firstTrackerRow;
      for (int n=myTrackerModel->rowCount (); i<n; ++i)
        {
          const QString rowName = myTrackerModel->index (i,0).data (Qt::DisplayRole).toString ();
          if (rowName >= name)
            break;
        }

      // add the row
      QStandardItem * row = new QStandardItem (favicons.findFromHost (host), name);
      const int count = torrentsPerHost[host];
      row->setData (count, FilterBarComboBox::CountRole);
      row->setData (getCountString (count), FilterBarComboBox::CountStringRole);
      row->setData (favicons.findFromHost (host), Qt::DecorationRole);
      row->setData (host, TrackerRole);
      myTrackerModel->insertRow (i, row);
      anyAdded = true;
    }

  if (anyAdded) // the one added might match our filter...
    refreshPref (Prefs::FILTER_TRACKERS);
}


FilterBarComboBox *
FilterBar::createTrackerCombo (QStandardItemModel * model)
{
  FilterBarComboBox * c = new FilterBarComboBox (this);
  FilterBarComboBoxDelegate * delegate = new FilterBarComboBoxDelegate (this, c);
  c->setItemDelegate (delegate);

  QStandardItem * row = new QStandardItem (tr ("All"));
  row->setData (QString (), TrackerRole);
  const int count = myTorrents.rowCount ();
  row->setData (count, FilterBarComboBox::CountRole);
  row->setData (getCountString (count), FilterBarComboBox::CountStringRole);
  model->appendRow (row);

  model->appendRow (new QStandardItem); // separator
  delegate->setSeparator (model, model->index (1, 0));

  c->setModel (model);
  return c;
}

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

FilterBar::FilterBar (Prefs& prefs, const TorrentModel& torrents, const TorrentFilter& filter, QWidget * parent):
  QWidget (parent),
  myPrefs (prefs),
  myTorrents (torrents),
  myFilter (filter),
  myRecountTimer (new QTimer (this)),
  myIsBootstrapping (true)
{
  QHBoxLayout * h = new QHBoxLayout (this);
  h->setContentsMargins (3, 3, 3, 3);

  myCountLabel = new QLabel (this);
  h->addWidget (myCountLabel);

  myActivityCombo = createActivityCombo ();
  myActivityCombo->setSizePolicy (QSizePolicy (QSizePolicy::Fixed, QSizePolicy::Fixed));
  h->addWidget (myActivityCombo);

  myTrackerModel = new QStandardItemModel (this);
  myTrackerCombo = createTrackerCombo (myTrackerModel);
  h->addWidget (myTrackerCombo);

  myLineEdit = new FilterBarLineEdit (this);
  h->addWidget (myLineEdit);
  connect (myLineEdit, SIGNAL (textChanged (QString)), this, SLOT (onTextChanged (QString)));

  // listen for changes from the other players
  connect (&myPrefs, SIGNAL (changed (int)), this, SLOT (refreshPref (int)));
  connect (myActivityCombo, SIGNAL (currentIndexChanged (int)), this, SLOT (onActivityIndexChanged (int)));
  connect (myTrackerCombo, SIGNAL (currentIndexChanged (int)), this, SLOT (onTrackerIndexChanged (int)));
  connect (&myFilter, SIGNAL (rowsInserted (QModelIndex, int, int)), this, SLOT (refreshCountLabel ()));
  connect (&myFilter, SIGNAL (rowsRemoved (QModelIndex, int, int)), this, SLOT (refreshCountLabel ()));
  connect (&myTorrents, SIGNAL (modelReset ()), this, SLOT (recountSoon ()));
  connect (&myTorrents, SIGNAL (rowsInserted (QModelIndex, int, int)), this, SLOT (recountSoon ()));
  connect (&myTorrents, SIGNAL (rowsRemoved (QModelIndex, int, int)), this, SLOT (recountSoon ()));
  connect (&myTorrents, SIGNAL (dataChanged (QModelIndex, QModelIndex)), this, SLOT (recountSoon ()));
  connect (myRecountTimer, SIGNAL (timeout ()), this, SLOT (recount ()));

  recountSoon ();
  refreshTrackers ();
  refreshCountLabel ();
  myIsBootstrapping = false;

  // initialize our state
  QList<int> initKeys;
  initKeys << Prefs::FILTER_MODE
           << Prefs::FILTER_TRACKERS;
  for (const int key: initKeys)
      refreshPref (key);
}

FilterBar::~FilterBar ()
{
  delete myRecountTimer;
}

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

void
FilterBar::refreshPref (int key)
{
  switch (key)
    {
      case Prefs::FILTER_MODE:
        {
          const FilterMode m = myPrefs.get<FilterMode> (key);
          QAbstractItemModel * model = myActivityCombo->model ();
          QModelIndexList indices = model->match (model->index (0,0), ActivityRole, m.mode ());
          myActivityCombo->setCurrentIndex (indices.isEmpty () ? 0 : indices.first ().row ());
          break;
        }

      case Prefs::FILTER_TRACKERS:
        {
          const QString tracker = myPrefs.getString (key);
          const QString name = readableHostName (tracker);
          QList<QStandardItem*> rows = myTrackerModel->findItems (name);
          if (!rows.isEmpty ())
            {
              myTrackerCombo->setCurrentIndex (rows.front ()->row ());
            }
          else // hm, we don't seem to have this tracker anymore...
            {
              const bool isBootstrapping = myTrackerModel->rowCount () <= 2;
              if (!isBootstrapping)
                myPrefs.set (key, QString ());
            }
          break;
        }
    }
}

void
FilterBar::onTextChanged (const QString& str)
{
  if (!myIsBootstrapping)
    myPrefs.set (Prefs::FILTER_TEXT, str.trimmed ());
}

void
FilterBar::onTrackerIndexChanged (int i)
{
  if (!myIsBootstrapping)
    {
      QString str;
      const bool isTracker = !myTrackerCombo->itemData (i,TrackerRole).toString ().isEmpty ();
      if (!isTracker)
        {
          // show all
        }
      else
        {
          str = myTrackerCombo->itemData (i,TrackerRole).toString ();
          const int pos = str.lastIndexOf (QLatin1Char ('.'));
          if (pos >= 0)
            str.truncate (pos+1);
        }
      myPrefs.set (Prefs::FILTER_TRACKERS, str);
    }
}

void
FilterBar::onActivityIndexChanged (int i)
{
  if (!myIsBootstrapping)
    {
      const FilterMode mode = myActivityCombo->itemData (i, ActivityRole).toInt ();
      myPrefs.set (Prefs::FILTER_MODE, mode);
    }
}

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

void
FilterBar::recountSoon ()
{
  if (!myRecountTimer->isActive ())
    {
      myRecountTimer->setSingleShot (true);
      myRecountTimer->start (800);
    }
}
void
FilterBar::recount ()
{
  QAbstractItemModel * model = myActivityCombo->model ();

  int torrentsPerMode[FilterMode::NUM_MODES] = {};
  myFilter.countTorrentsPerMode (torrentsPerMode);

  for (int row=0, n=model->rowCount (); row<n; ++row)
    {
      QModelIndex index = model->index (row, 0);
      const int mode = index.data (ActivityRole).toInt ();
      const int count = torrentsPerMode [mode];
      model->setData (index, count, FilterBarComboBox::CountRole);
      model->setData (index, getCountString (count), FilterBarComboBox::CountStringRole);
    }

  refreshTrackers ();
  refreshCountLabel ();
}

QString
FilterBar::getCountString (int n) const
{
  return QString::fromLatin1 ("%L1").arg (n);
}

void
FilterBar::refreshCountLabel ()
{
  const int visibleCount = myFilter.rowCount ();
  const int trackerCount = myTrackerCombo->currentCount ();
  const int activityCount = myActivityCombo->currentCount ();

  if ((visibleCount == activityCount) || (visibleCount == trackerCount))
    myCountLabel->setText (tr("Show:"));
  else
    myCountLabel->setText (tr("Show %Ln of:", 0, visibleCount));
}