/*---------------------------------------------------------------------------------*/
/*  NOMAD - Nonlinear Optimization by Mesh Adaptive Direct Search -                */
/*                                                                                 */
/*  NOMAD - Version 4 has been created and developed by                            */
/*                 Viviane Rochon Montplaisir  - Polytechnique Montreal            */
/*                 Christophe Tribes           - Polytechnique Montreal            */
/*                                                                                 */
/*  The copyright of NOMAD - version 4 is owned by                                 */
/*                 Charles Audet               - Polytechnique Montreal            */
/*                 Sebastien Le Digabel        - Polytechnique Montreal            */
/*                 Viviane Rochon Montplaisir  - Polytechnique Montreal            */
/*                 Christophe Tribes           - Polytechnique Montreal            */
/*                                                                                 */
/*  NOMAD 4 has been funded by Rio Tinto, Hydro-Québec, Huawei-Canada,             */
/*  NSERC (Natural Sciences and Engineering Research Council of Canada),           */
/*  InnovÉÉ (Innovation en Énergie Électrique) and IVADO (The Institute            */
/*  for Data Valorization)                                                         */
/*                                                                                 */
/*  NOMAD v3 was created and developed by Charles Audet, Sebastien Le Digabel,     */
/*  Christophe Tribes and Viviane Rochon Montplaisir and was funded by AFOSR       */
/*  and Exxon Mobil.                                                               */
/*                                                                                 */
/*  NOMAD v1 and v2 were created and developed by Mark Abramson, Charles Audet,    */
/*  Gilles Couture, and John E. Dennis Jr., and were funded by AFOSR and           */
/*  Exxon Mobil.                                                                   */
/*                                                                                 */
/*  Contact information:                                                           */
/*    Polytechnique Montreal - GERAD                                               */
/*    C.P. 6079, Succ. Centre-ville, Montreal (Quebec) H3C 3A7 Canada              */
/*    e-mail: nomad@gerad.ca                                                       */
/*                                                                                 */
/*  This program 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 3 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 Lesser General Public License    */
/*  for more details.                                                              */
/*                                                                                 */
/*  You should have received a copy of the GNU Lesser General Public License       */
/*  along with this program. If not, see <http://www.gnu.org/licenses/>.           */
/*                                                                                 */
/*  You can find information on the NOMAD software at www.gerad.ca/nomad           */
/*---------------------------------------------------------------------------------*/

#ifndef __NOMAD_4_5_CSUPDATE__
#define __NOMAD_4_5_CSUPDATE__

#include "../../Algos/Step.hpp"

#include "../../nomad_nsbegin.hpp"

/// Class for Step 1. of CS algorithm: parameter update.
/**
 The update is performed when calling the CSUpdate::run function.
 The update is very similar to MadsUpdate except for the mesh update.
 
  Note: refactoring of MegaIteration could be done to handle the mesh (can be null or not). Than we could use MadsUpdate instead of having a CS update. Issue #642.
 */
class CSUpdate: public Step
{
public:
    // Constructor
    explicit CSUpdate(const Step* parentStep)
      : Step(parentStep)
    {
        init();
    }

    std::string getName() const override;

private:

    /// Helper for constructor to check for valid ancestor.
    void init();

    /// No implementation is required for start.
    virtual void    startImp() override {}

    /// Implementation of the run tasks.
    /**
     Gets the best feasible point (xFeas) and best infeasible point (xInf)
     from the cache, and updates the MegaIteration's Barrier member with it.
     Compares new values of xFeas and xInf with previous ones
     - i.e., compute success or failure.
     Enlarges or shrinks the delta (mesh size)  ( to remove) and Delta (frame size)
     accordingly.
     */
    virtual bool    runImp()   override;

    /// No implementation is required for end.
    virtual void    endImp()   override {}

};

#include "../../nomad_nsend.hpp"

#endif // __NOMAD_4_5_CSUPDATE__

