//##################################################################################################
//
//   Custom Visualization Core library
//
//   This library may be used under the terms of either the GNU General Public License or
//   the GNU Lesser General Public License as follows:
//
//   GNU General Public License Usage
//   This library 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.
//
//   This library 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 at <<http://www.gnu.org/licenses/gpl.html>>
//   for more details.
//
//   GNU Lesser General Public License Usage
//   This library is free software; you can redistribute it and/or modify
//   it under the terms of the GNU Lesser General Public License as published by
//   the Free Software Foundation; either version 2.1 of the License, or
//   (at your option) any later version.
//
//   This library 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 Lesser General Public License at <<http://www.gnu.org/licenses/lgpl-2.1.html>>
//   for more details.
//
//##################################################################################################

#pragma once

#include "cafPdmUiFieldEditorHandle.h"
#include "cafUiTreeItem.h"

#include <QAbstractItemModel>

#include <map>
#include <vector>

namespace caf
{
class PdmOptionItemInfo;
class PdmUiFieldHandle;

//==================================================================================================
///
//==================================================================================================
class PdmUiTreeSelectionQModel : public QAbstractItemModel
{
    Q_OBJECT
public:
    explicit PdmUiTreeSelectionQModel( QObject* parent = nullptr );
    ~PdmUiTreeSelectionQModel() override;

    static int headingRole();
    static int optionItemValueRole();

    void setCheckedStateForItems( const QModelIndexList& indices, bool checked );
    void invertCheckedStateForItems( const QModelIndexList& indices );
    void unselectAllItems();

    void enableSingleSelectionMode( bool enable );
    void showCheckBoxes( bool enable );

    int  optionItemCount() const;
    void setOptions( caf::PdmUiFieldEditorHandle* field, const QList<caf::PdmOptionItemInfo>& options );
    void setUiValueCache( const QVariant* uiValuesCache );
    void resetUiValueCache();
    bool isReadOnly( const QModelIndex& index ) const;
    bool isChecked( const QModelIndex& index ) const;

    bool hasGrandChildren() const;

    Qt::ItemFlags flags( const QModelIndex& index ) const override;
    QModelIndex   index( int row, int column, const QModelIndex& parent = QModelIndex() ) const override;
    int           columnCount( const QModelIndex& parent = QModelIndex() ) const override;
    QModelIndex   parent( const QModelIndex& child ) const override;
    int           rowCount( const QModelIndex& parent = QModelIndex() ) const override;
    QVariant      data( const QModelIndex& index, int role = Qt::DisplayRole ) const override;
    bool          setData( const QModelIndex& index, const QVariant& value, int role = Qt::EditRole ) override;

    QModelIndex indexForLastUncheckedItem() const;
    void        clearIndexForLastUncheckedItem();

    // Consider moving these functions to PdmUiFieldHandle
    static bool isSingleValueField( const QVariant& fieldValue );
    static bool isMultipleValueField( const QVariant& fieldValue );

private:
    typedef caf::UiTreeItem<int> TreeItemType;

    const caf::PdmOptionItemInfo* optionItem( const QModelIndex& index ) const;
    int                           optionIndex( const QModelIndex& index ) const;
    void                          buildOptionItemTree( int optionIndex, TreeItemType* parentNode );

    void notifyChangedForAllModelIndices();
    void recursiveNotifyChildren( const QModelIndex& index );

private:
    QList<caf::PdmOptionItemInfo>         m_options;
    QPointer<caf::PdmUiFieldEditorHandle> m_uiFieldHandle;

    const QVariant* m_uiValueCache;

    TreeItemType* m_tree;

    bool        m_singleSelectionMode;
    QModelIndex m_indexForLastUncheckedItem;
    bool        m_showCheckBoxes;
};

} // end namespace caf