////////////////////////////////////////////////////////////////////////
//
// 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 (octave_variable_editor_model_h)
#define octave_variable_editor_model_h 1

#include <QAbstractTableModel>
#include <QMap>
#include <QString>

#include "qt-interpreter-events.h"

#include "ov.h"
#include "pr-flt-fmt.h"

namespace octave
{
  class interpreter;

  class base_ve_model
  {
  public:

    base_ve_model (const QString& expr, const octave_value& val);

    virtual ~base_ve_model (void) = default;

    // No copying!

    base_ve_model (const base_ve_model&) = delete;

    base_ve_model& operator = (const base_ve_model&) = delete;

    virtual void maybe_resize_rows (int) { }

    virtual void maybe_resize_columns (int) { }

    std::string name (void) const;

    bool index_ok (const QModelIndex& idx, int& row, int& col) const;

    virtual bool is_editable (void) const { return true; }

    virtual octave_value value_at (const QModelIndex& idx) const;

    int column_width (void) const;

    int rowCount (const QModelIndex& = QModelIndex ()) const;

    int columnCount (const QModelIndex& = QModelIndex ()) const;

    QString edit_display_sub (const octave_value& elt, int role) const;

    virtual QVariant edit_display (const QModelIndex& idx, int role) const;

    QVariant data (const QModelIndex& idx, int role = Qt::DisplayRole) const;

    virtual bool requires_sub_editor (const QModelIndex& idx) const;

    void set_update_pending (const QModelIndex& idx, const QString& str);

    bool update_pending (const QModelIndex& idx) const;

    QString update_pending_data (const QModelIndex& idx) const;

    void clear_update_pending (void);

    virtual char quote_char (const QModelIndex& idx) const;

    virtual QVariant
    header_data (int section, Qt::Orientation orientation, int role) const;

    // Return a subscript expression as a string that can be used to
    // access a sub-element of a data structure.  For example "{1,3}"
    // for cell array element {1,3} or "(2,4)" for array element (2,4).

    virtual QString subscript_expression (const QModelIndex& idx) const;

    bool is_valid (void) const { return m_valid; }

    octave_idx_type data_rows (void) const { return m_data_rows; }

    octave_idx_type data_columns (void) const { return m_data_cols; }

    int display_rows (void) const { return m_display_rows; }

    int display_columns (void) const { return m_display_cols; }

    virtual QString make_description_text (void) const;

    void reset (const octave_value& val);

  protected:

    std::string m_name;

    octave_value m_value;

    octave_idx_type m_data_rows;
    octave_idx_type m_data_cols;

    // Qt table widget limits the size to int.
    int m_display_rows;
    int m_display_cols;

    QMap<QModelIndex, QString> m_update_pending;

    bool m_valid;

    float_display_format m_display_fmt;
  };

  class variable_editor_model : public QAbstractTableModel
  {
    Q_OBJECT

  private:

    static base_ve_model * create (const QString& expr, const octave_value& val);

  public:

    variable_editor_model (const QString& expr, const octave_value& val,
                           QObject *parent = nullptr);

    ~variable_editor_model (void)
    {
      delete rep;
    }

    // No copying!

    variable_editor_model (const variable_editor_model&) = delete;

    variable_editor_model& operator = (const variable_editor_model&) = delete;

    std::string name (void) const
    {
      return rep->name ();
    }

    bool is_editable (void) const
    {
      return rep->is_editable ();
    }

    octave_value value_at (const QModelIndex& idx) const
    {
      return rep->value_at (idx);
    }

    int column_width (void) const
    {
      return rep->column_width ();
    }

    int rowCount (const QModelIndex& idx = QModelIndex ()) const
    {
      return rep->rowCount (idx);
    }

    int columnCount (const QModelIndex& idx = QModelIndex ()) const
    {
      return rep->columnCount (idx);
    }

    QVariant data (const QModelIndex& idx = QModelIndex (),
                   int role = Qt::DisplayRole) const
    {
      return rep->data (idx, role);
    }

    bool setData (const QModelIndex& idx, const QVariant& v,
                  int role = Qt::EditRole);

    bool clear_content (const QModelIndex& idx);

    Qt::ItemFlags flags (const QModelIndex& idx) const;

    bool insertRows (int row, int count,
                     const QModelIndex& parent = QModelIndex());

    bool removeRows (int row, int count,
                     const QModelIndex& parent = QModelIndex());

    bool insertColumns (int column, int count,
                        const QModelIndex& parent = QModelIndex());

    bool removeColumns (int column, int count,
                        const QModelIndex& parent = QModelIndex());

    // Is cell at idx complex enough to require a sub editor?

    bool requires_sub_editor (const QModelIndex& idx) const
    {
      return rep->requires_sub_editor (idx);
    }

    void set_update_pending (const QModelIndex& idx, const QString& str)
    {
      rep->set_update_pending (idx, str);
    }

    bool update_pending (const QModelIndex& idx) const
    {
      return rep->update_pending (idx);
    }

    QString update_pending_data (const QModelIndex& idx) const
    {
      return rep->update_pending_data (idx);
    }

    void clear_update_pending (void)
    {
      rep->clear_update_pending ();
    }

    char quote_char (const QModelIndex& idx) const
    {
      return rep->quote_char (idx);
    }

    QVariant
    headerData (int section, Qt::Orientation orientation, int role) const
    {
      return rep->header_data (section, orientation, role);
    }

    // Return a subscript expression as a string that can be used to
    // access a sub-element of a data structure.  For example "{1,3}"
    // for cell array element {1,3} or "(2,4)" for array element (2,4).

    QString subscript_expression (const QModelIndex& idx) const
    {
      return rep->subscript_expression (idx);
    }

    int display_rows (void) const
    {
      return rep->display_rows ();
    }

    octave_idx_type data_rows (void) const
    {
      return rep->data_rows ();
    }

    int display_columns (void) const
    {
      return rep->display_columns ();
    }

    octave_idx_type data_columns (void) const
    {
      return rep->data_columns ();
    }

    void maybe_resize_rows (int rows);

    void maybe_resize_columns (int cols);

  signals:

    void update_data_signal (const octave_value& val);

    void data_error_signal (const QString& name) const;

    void user_error_signal (const QString& title, const QString& msg) const;

    void set_editable_signal (bool);

    void description_changed (const QString& description);

    void edit_variable_signal (const QString& name, const octave_value& val);

    void interpreter_event (const fcn_callback& fcn);
    void interpreter_event (const meth_callback& meth);

  public slots:

    void update_data (const octave_value& val);

    void update_data_cache (void);

    void double_click (const QModelIndex& idx);

  private slots:

    void data_error (const QString& msg);

    void user_error (const QString& title, const QString& msg);

  private:

    base_ve_model *rep;

    void init_from_oct (interpreter& interp);

    void eval_expr_event (const QString& expr);

    octave_value retrieve_variable (interpreter&, const std::string& name);

    bool is_valid (void) const
    {
      return rep->is_valid ();
    }

    void change_display_size (int old_rows, int old_cols,
                              int new_rows, int new_cols);

    QString make_description_text (void) const
    {
      return rep->make_description_text ();
    }

    void reset (const octave_value& val);

    void invalidate (void);

    void update_description (const QString& description = QString ());

    void evaluation_error (const std::string& expr) const;
  };
}

#endif