////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2013-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave 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 3 of the License, or
// (at your option) any later version.
//
// Octave 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 Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <algorithm>

#include <QFileIconProvider>
#include <QtAlgorithms>

#include "find-files-model.h"

namespace octave
{
  class find_file_less_than
  {
  public:

    find_file_less_than (int ord) { m_sortorder = ord; }

    QVariant getValue (const QFileInfo& f) const
    {
      QVariant val;

      int col = (m_sortorder > 0) ? m_sortorder : -m_sortorder;

      switch (col-1)
        {
        case 0:
          val = QVariant (f.fileName ());
          break;

        case 1:
          val = QVariant (f.absolutePath ());
          break;

        default:
          break;
        }

      return val;
    }

    bool lessThan (const QVariant& left, const QVariant& right) const
    {
      return
        left.toString ().compare (right.toString (), Qt::CaseInsensitive) < 0;
    }

    bool operator () (const QFileInfo& left, const QFileInfo& right) const
    {
      QVariant leftval = getValue (left);
      QVariant rightval = getValue (right);

      if (m_sortorder > 0)
        return lessThan (leftval, rightval);
      else
        return ! lessThan (leftval, rightval);
    }

  private:

    int m_sortorder;
  };

  find_files_model::find_files_model (QObject *p)
    : QAbstractListModel (p)
  {
    m_columnNames.append (tr ("Filename"));
    m_columnNames.append (tr ("Directory"));
    m_sortorder = 0;
  }

  void find_files_model::clear (void)
  {
    beginResetModel ();

    m_files.clear ();

    endResetModel ();
  }

  void find_files_model::addFile (const QFileInfo& info)
  {
    beginInsertRows (QModelIndex (), m_files.size (), m_files.size ());

    QList<QFileInfo>::Iterator it;
    find_file_less_than less_than (m_sortorder);

    for (it = m_files.begin (); it != m_files.end (); it++)
      {
        if (less_than (info, *it))
          break;
      }

    m_files.insert (it, info);

    endInsertRows ();
  }

  int find_files_model::rowCount (const QModelIndex &) const
  {
    return m_files.size ();
  }

  int find_files_model::columnCount (const QModelIndex &) const
  {
    return m_columnNames.size ();
  }

  QVariant find_files_model::data (const QModelIndex& idx, int role) const
  {
    QVariant retval;

    if (idx.isValid ())
      {
        if (role == Qt::DisplayRole)
          {
            switch (idx.column ())
              {
              case 0:
                retval = QVariant (m_files[idx.row ()].fileName ());
                break;

              case 1:
                retval = QVariant (m_files[idx.row ()].absolutePath ());
                break;

              default:
                break;
              }
          }
        else if (role == Qt::DecorationRole)
          {
            switch (idx.column ())
              {
              case 0:
                retval = fileIcon (idx);

              default:
                break;
              }
          }
      }

    return retval;
  }

  QVariant find_files_model::headerData (int section,
                                         Qt::Orientation orientation,
                                         int role) const
  {
    return ((orientation == Qt::Horizontal && role == Qt::DisplayRole)
            ? m_columnNames[section] : QVariant ());
  }

  void find_files_model::sort (int column, Qt::SortOrder order)
  {
    if (column >= 0)
      {
        if (order == Qt::DescendingOrder)
          m_sortorder = -(column+1);
        else
          m_sortorder = column+1;
      }
    else
      m_sortorder = 0;

    if (m_sortorder != 0)
      {
        beginResetModel ();

        std::sort (m_files.begin (), m_files.end (),
                   find_file_less_than (m_sortorder));

        endResetModel ();
      }
  }

  QFileInfo find_files_model::fileInfo (const QModelIndex & p) const
  {
    return p.isValid () ? m_files[p.row ()] : QFileInfo ();
  }

  QIcon find_files_model::fileIcon (const QModelIndex& p) const
  {
    QFileIconProvider icon_provider;

    return p.isValid () ? icon_provider.icon (m_files[p.row ()]) : QIcon ();
  }
}
