////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2019-2023 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 (octave_gui_settings_h)
#define octave_gui_settings_h 1

#include "octave-config.h"

#include <QColor>
#include <QSettings>
#include <QString>
#if defined (HAVE_QSCINTILLA)
#  include <Qsci/qscilexer.h>
#endif

class QByteArray;
class QComboBox;
class QDateTime;
class QIcon;
class QShortcut;
class QTranslator;

#include "gui-preferences.h"

OCTAVE_BEGIN_NAMESPACE(octave)

class gui_settings : public QSettings
{
  Q_OBJECT

public:

  // Location, name, and format of settings file determined by
  // settings in qt_application class construtor.

  gui_settings (QObject *parent = nullptr)
    : QSettings (parent)
  { }

  gui_settings (const QString& file_name, QSettings::Format format,
                QObject *parent = nullptr)
    : QSettings (file_name, format, parent)
  { }

  gui_settings (QSettings::Format format, QSettings::Scope scope,
                const QString& organization,
                const QString& application = QString (),
                QObject *parent = nullptr)
    : QSettings (format, scope, organization, application, parent)
  { }

  OCTAVE_DISABLE_COPY_MOVE (gui_settings)

  ~gui_settings () = default;

  QString file_name () const;

  QString directory_name () const;

  using QSettings::value;

  QVariant value (const gui_pref& pref) const
  {
    if (pref.ignore ())
      return pref.def ();  // ignore the current pref and always use default

    return value (pref.settings_key (), pref.def ());
  }

  // Convenience functions to (slightly) reduce clutter by allowing us
  // to write
  //
  //   settings.bool_value (gui_pref_name)
  //
  // instead of
  //
  //   settings.value (gui_pref_name).toBool ()

  bool bool_value (const gui_pref& pref) const;

  QByteArray byte_array_value (const gui_pref& pref) const;

  QColor color_value (const gui_pref& pref) const;

  QDateTime date_time_value (const gui_pref& pref) const;

  int int_value (const gui_pref& pref) const;

  QString string_value (const gui_pref& pref) const;

  QStringList string_list_value (const gui_pref& pref) const;

  uint uint_value (const gui_pref& pref) const;

  /*!
    Reading a color from the given QVaraitn @p def taking different
    color modes into account. The default value for a second color mode
    @p mode=1 is deterimined from the standard default value @p mode=0
    by inverting the lightness
      \f{eqnarray*}{
         H_1 &=& H_0\\
         S_1 &=& S_0\\
         L_1 &=& 1.0 - 0.85 L_0    L_0 > 0.3
         L_1 &=& 1.0 - 0.70 L_0    L_0 < 0.3
      \f}

    @param def  Color default value given by a QVariant of QColor
                or QPalette::ColorRole
    @param mode Color mode (currently 0 or 1, default is 0)

    @return Color as QColor
  */
  QColor get_color_value (const QVariant& def, int mode) const;

  /*!
    Reading a color from the gui_settings taking possible color modes
    into account. The default value for a second color mode @p mode=1 is
    deterimined from the standard default value @p mode=0 by inverting
    the lightness (see get_color_value())

    @param pref gui preference (key string, default value); the default
                value can be given by QColor or QPalette::ColorRole
    @param mode Color mode (currently 0 or 1, default is 0)

    @return Color as QColor
  */
  QColor color_value (const gui_pref& pref, int mode) const;

  /*!
    Writing a color to the gui_settings taking possible color modes
    into account. When @p mode is not zero (standard mode), the
    extension related to the mode is appended to the settings key string

    @param pref gui preference where the color should be written
    @param color QColor to write to the settings
    @param mode Color mode (currently 0 or 1, default is 0)

  */
  void set_color_value (const gui_pref& pref, const QColor& color,
                        int mode);

  QString sc_value (const sc_pref& pref) const;

  QKeySequence sc_def_value (const sc_pref& pref) const;

  void set_shortcut (QAction *action, const sc_pref& scpref,
                     bool enable = true);

  void shortcut (QShortcut *sc, const sc_pref& scpref);

  // config_icon_theme, icon, get_default_font_family,
  // get_default_font, and possibly reload and check could be global
  // functions instead of member functions.  But at least for the icon
  // function, defining it as a member function means that we can
  // create a single gui_settings object and access multiple icon
  // objects rather than having to create a separate settings object
  // each time that an icon is needed.  OTOH, creating the base
  // QSettings object is supposed to be fast, so that may not matter.
  // Hmm.

  void config_icon_theme ();

  QIcon icon (const QString& icon_name, bool octave_only = false,
              const QString& icon_alt_name = QString ());

  QString get_default_font_family ();

  QStringList get_default_font ();

  QString get_gui_translation_dir ();

  void config_translators (QTranslator *qt_tr, QTranslator *qsci_tr,
                           QTranslator *gui_tr);

#if defined (HAVE_QSCINTILLA)
  int get_valid_lexer_styles (QsciLexer *lexer, int *styles);
  void read_lexer_settings (QsciLexer *lexer, int mode = 0, int def = 0);
#endif

  bool update_settings_key (const QString& new_key, const QString& old_key);

  void update_network_settings ();

  void combo_encoding (QComboBox *combo, const QString& current = QString ());

  void reload ();

private:

  void check ();
};

OCTAVE_END_NAMESPACE(octave)

// Some constants used in the preferences of several widgets and therefore
// defined globally here

// Constants for handling different color schemes
const QColor settings_color_no_change (255, 0, 255);
const QStringList settings_color_modes_ext (QStringList () << "" << "_2");
const int settings_reload_default_colors_flag = -1;

#endif