/****************************************************************************
 *   This file is part of the aGrUM/pyAgrum library.                        *
 *                                                                          *
 *   Copyright (c) 2005-2026 by                                             *
 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
 *                                                                          *
 *   The aGrUM/pyAgrum library is free software; you can redistribute it    *
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 *      the Free Software Foundation, either version 3 of the License,      *
 *      or (at your option) any later version,                              *
 *    - the MIT license (MIT),                                              *
 *    - or both in dual license, as here.                                   *
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 *   (see https://agrum.gitlab.io/articles/dual-licenses-lgplv3mit.html)    *
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 *   See LICENCES for more details.                                         *
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 *   SPDX-FileCopyrightText: Copyright 2005-2026                            *
 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
 *   SPDX-License-Identifier: LGPL-3.0-or-later OR MIT                      *
 *                                                                          *
 *   Contact  : info_at_agrum_dot_org                                       *
 *   homepage : http://agrum.gitlab.io                                      *
 *   gitlab   : https://gitlab.com/agrumery/agrum                           *
 *                                                                          *
 ****************************************************************************/


/**
 * @file
 * @brief Headers of the Operator Strategy interface.
 *
 * @author Pierre-Henri WUILLEMIN(_at_LIP6) and Jean-Christophe MAGNAN and Christophe
 * GONZALES(_at_AMU)
 */


// =========================================================================
#ifndef GUM_SDYNA_OPERATOR_STRATEGY_H
#define GUM_SDYNA_OPERATOR_STRATEGY_H
// =========================================================================
// =========================================================================
#include <agrum/FMDP/planning/actionSet.h>

// =========================================================================
// =========================================================================

namespace gum {

  /**
   * @class IOperatorStrategy IOperatorStrategy.h
   * <agrum/FMDP/SDyna/IOperatorStrategy.h>
   * @brief Interface for manipulating Operator center
   * @ingroup fmdp_group
   *
   */
  template < typename GUM_ELEMENT >
  class IOperatorStrategy {
    // ###################################################################
    /// @name Constructor & destructor.
    // ###################################################################
    /// @{

    public:
    // ==========================================================================
    /// Destructor (virtual and empty since it's an interface)
    // ==========================================================================
    virtual ~IOperatorStrategy() = default;

    /// @}


    // ###################################################################
    /// @name
    // ###################################################################
    /// @{

    virtual MultiDimFunctionGraph< GUM_ELEMENT, ExactTerminalNodePolicy >* getFunctionInstance()
        = 0;
    virtual MultiDimFunctionGraph< ArgMaxSet< GUM_ELEMENT, Idx >, SetTerminalNodePolicy >*
        getArgMaxFunctionInstance()                                                            = 0;
    virtual MultiDimFunctionGraph< ActionSet, SetTerminalNodePolicy >* getAggregatorInstance() = 0;

    /// @}


    // ###################################################################
    /// @name Graph Function Operations Methods
    // ###################################################################
    /// @{

    public:
    // ==========================================================================
    /// Performs a multiplication/projection on given qAction
    /// @return qAction : the computed Q(s,a)
    /// @warning given qAction is deleted, return the new one
    // ==========================================================================
    virtual MultiDimFunctionGraph< GUM_ELEMENT >*
        regress(const MultiDimFunctionGraph< GUM_ELEMENT >* Vold,
                Idx                                         actionId,
                const FMDP< GUM_ELEMENT >*                  fmdp,
                const gum::VariableSet&                     elVarSeq) = 0;

    // ==========================================================================
    /// @warning given vFunction and qAction are deleted, returns the new one
    // ==========================================================================
    virtual MultiDimFunctionGraph< GUM_ELEMENT >*
        maximize(const MultiDimFunctionGraph< GUM_ELEMENT >* f1,
                 const MultiDimFunctionGraph< GUM_ELEMENT >* f2,
                 Idx                                         del = 3) = 0;

    // ==========================================================================
    /// @warning Minimze the two given functions
    // ==========================================================================
    virtual MultiDimFunctionGraph< GUM_ELEMENT >*
        minimize(const MultiDimFunctionGraph< GUM_ELEMENT >* f1,
                 const MultiDimFunctionGraph< GUM_ELEMENT >* f2,
                 Idx                                         del = 3) = 0;

    // ==========================================================================
    /// @warning given f1 and f2 are deleted, returns the new one
    // ==========================================================================
    virtual MultiDimFunctionGraph< GUM_ELEMENT >*
        multiply(const MultiDimFunctionGraph< GUM_ELEMENT >* f1,
                 const MultiDimFunctionGraph< GUM_ELEMENT >* f2,
                 Idx                                         del = 3) = 0;

    // ==========================================================================
    /// @warning given vFunction and qAction are deleted, returns the new one
    // ==========================================================================
    virtual MultiDimFunctionGraph< ArgMaxSet< GUM_ELEMENT, Idx >, SetTerminalNodePolicy >*
        argmaximize(
            const MultiDimFunctionGraph< ArgMaxSet< GUM_ELEMENT, Idx >, SetTerminalNodePolicy >* f1,
            const MultiDimFunctionGraph< ArgMaxSet< GUM_ELEMENT, Idx >, SetTerminalNodePolicy >* f2,
            Idx del = 3) = 0;

    // ==========================================================================
    /// @warning given function is deleted, returns the new one
    // ==========================================================================
    virtual MultiDimFunctionGraph< GUM_ELEMENT >*
        add(const MultiDimFunctionGraph< GUM_ELEMENT >* f1,
            const MultiDimFunctionGraph< GUM_ELEMENT >* f2,
            Idx                                         del = 1) = 0;

    // ==========================================================================
    /// @warning this time, nothing is deleted
    // ==========================================================================
    virtual MultiDimFunctionGraph< GUM_ELEMENT >*
        subtract(const MultiDimFunctionGraph< GUM_ELEMENT >* f1,
                 const MultiDimFunctionGraph< GUM_ELEMENT >* f2,
                 Idx                                         del = 0) = 0;


    /// @}

    protected:
    void deleteFunctionGraph_(const MultiDimFunctionGraph< GUM_ELEMENT >* f1,
                              const MultiDimFunctionGraph< GUM_ELEMENT >* f2,
                              Idx                                         del);

    void deleteFunctionGraph_(
        const MultiDimFunctionGraph< ArgMaxSet< GUM_ELEMENT, Idx >, SetTerminalNodePolicy >* f1,
        const MultiDimFunctionGraph< ArgMaxSet< GUM_ELEMENT, Idx >, SetTerminalNodePolicy >* f2,
        Idx                                                                                  del);
  };
}   // namespace gum

#include <agrum/FMDP/planning/IOperatorStrategy_tpl.h>
#endif   // GUM_SDYNA_OPERATOR_STRATEGY_H
