/***************************************************************************
                          qgslayoutundostack.h
                          ----------------------
    begin                : July 2017
    copyright            : (C) 2017 by Nyall Dawson
    email                : nyall dot dawson at gmail dot com
***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program 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 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSLAYOUTUNDOSTACK_H
#define QGSLAYOUTUNDOSTACK_H

#include "qgis.h"
#include "qgis_core.h"
#include "qgslayoutundocommand.h"
#include <memory>

class QgsLayout;
class QUndoStack;

/**
 * \ingroup core
 * An undo stack for QgsLayouts.
 * \since QGIS 3.0
*/
class CORE_EXPORT QgsLayoutUndoStack
{
  public:

    /**
     * Constructor for QgsLayoutUndoStack, for the specified parent \a layout.
     */
    QgsLayoutUndoStack( QgsLayout *layout );

    /**
     * Starts a macro command, with the given descriptive \a commandText.
     *
     * Any commands added to the stack (either via direct manipulation of
     * stack() or via beginCommand()/endCommand() calls) between a
     * beginMacro() and endMacro() block are collapsed into a single
     * undo command, which will be applied or rolled back in a single step.
     *
     * \see endMacro()
     */
    void beginMacro( const QString &commandText );

    /**
     * Ends a macro command. This must be called after beginMacro(), when
     * all child undo commands which form part of the macro have been completed.
     *
     * Any commands added to the stack (either via direct manipulation of
     * stack() or via beginCommand()/endCommand() calls) between a
     * beginMacro() and endMacro() block are collapsed into a single
     * undo command, which will be applied or rolled back in a single step.
     *
     * \see beginMacro()
     */
    void endMacro();

    /**
     * Begins a new undo command for the specified \a object.
     *
     * This must be followed by a call to endCommand() or cancelCommand() after the desired changes
     * have been made to \a object.
     *
     * The \a id argument can be used to specify an id number for the source event - this is used to determine whether QUndoCommand
     * command compression can apply to the command.
     *
     * \see endCommand()
     * \see cancelCommand()
     */
    void beginCommand( QgsLayoutUndoObjectInterface *object, const QString &commandText, int id = 0 );

    /**
     * Saves final state of an object and pushes the active command to the undo history.
     * \see beginCommand()
     * \see cancelCommand()
     */
    void endCommand();

    /**
     * Cancels the active command, discarding it without pushing to the undo history.
     * \see endCommand()
     * \see cancelCommand()
     */
    void cancelCommand();

    /**
     * Returns a pointer to the internal QUndoStack.
     */
    QUndoStack *stack();

  private:

    QgsLayout *mLayout = nullptr;

    std::unique_ptr< QUndoStack > mUndoStack;

    std::vector< std::unique_ptr< QgsAbstractLayoutUndoCommand > > mActiveCommands;

#ifdef SIP_RUN
    QgsLayoutUndoStack( const QgsLayoutUndoStack &other );
#endif
};

#endif // QGSLAYOUTUNDOCOMMAND_H