/*
  MetaCmd  -  actual proc command scripts for internal meta and control activities

  Copyright (C)         Lumiera.org
    2018,               Hermann Vosseler <Ichthyostega@web.de>

  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.

  This program 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 this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

* *****************************************************/


/** @file meta-cmd.cpp
 ** Actual definition of Proc-Layer command scripts for meta/ctrl actions.
 ** Any actions issued by the UI-Layer to control internal application state
 ** @todo WIP 8/2018 early draft
 ** 
 ** @see cmd.hpp
 ** @see command.hpp
 ** @see command-def.hpp
 ** @see cmd-context.hpp
 ** @see SessionCommandFunction_test
 **
 */


#include "proc/cmd.hpp"
#include "proc/control/command-def.hpp"
//#include "proc/mobject/session.hpp"
//#include "lib/symbol.hpp"
#include "lib/idi/entry-id.hpp"
//#include "lib/format-string.hpp"

//#include <string>

using lib::hash::LuidH;
//using std::string;
//using util::cStr;
//using util::_Fmt;


namespace proc {
namespace cmd {
  namespace error = lumiera::error;
  
  //using mobject::Session;
  
  namespace { // implementation helper...
  }//(End) implementation helper
  
  
  
  
  /** instruct the session to start keeping the UI up-to-date through diff messages.
   * @remarks we assume the UI is _empty_ when issuing this command. Thus the session
   *    will commence by sending a _population diff_, to reflect all the UI relevant
   *    structures currently present within the session data. Moreover, from that point
   *    on, any changes within the session structure and contents will be reflected by
   *    pushing appropriate diff messages upwards through the GuiNotification façade.
   * @note to UNDO this action means to waive the live-update state. In addition,
   *    the session will push up a status change to mark the session-root as defunct.
   */
COMMAND_DEFINITION (meta_activateContentDiff)
  {
    def.operation ([]()
                      {
                        TODO ("send a population diff starting from scratch");
                        TODO ("activate life-update service within the session");
                      })
       .captureUndo ([]() -> bool
                      {
                        return false;
                      })
       .undoOperation ([](bool wasActive)
                      {
                        if (not wasActive)
                          {
                            UNIMPLEMENTED ("send a status update diff into the root node, to mark it as defunct");
                          }
                      });
  };
  
  
  
  
  /** more to come here...*/
  
  
  
}} // namespace proc::cmd