/****************************************************************************
 *   This file is part of the aGrUM/pyAgrum library.                        *
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 *   Copyright (c) 2005-2026 by                                             *
 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
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 *   SPDX-FileCopyrightText: Copyright 2005-2026                            *
 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
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/**
 * @file
 * @brief d-separation analysis (as described in Koller & Friedman 2009)
 *
 * @author Christophe GONZALES(_at_AMU) and Pierre-Henri WUILLEMIN(_at_LIP6)
 */

#ifndef GUM_D_SEPARATION_ALGORITHM_H
#define GUM_D_SEPARATION_ALGORITHM_H


#include <agrum/agrum.h>

#include <agrum/BN/IBayesNet.h>

namespace gum {

  /** @class dSeparationAlgorithm
   * @brief the d-separation algorithm as described in Koller & Friedman (2009)
   * @ingroup bn_inference
   */
  class dSeparationAlgorithm {
    public:
    // ############################################################################
    /// @name Constructors / Destructors
    // ############################################################################
    /// @{

    /// default constructor
    dSeparationAlgorithm();

    /// copy constructor
    dSeparationAlgorithm(const dSeparationAlgorithm& from);

    /// move constructor
    dSeparationAlgorithm(dSeparationAlgorithm&& from);

    /// destructor
    ~dSeparationAlgorithm();

    /// @}


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

    /// copy operator
    dSeparationAlgorithm& operator=(const dSeparationAlgorithm& from);

    /// move operator
    dSeparationAlgorithm& operator=(dSeparationAlgorithm&& from);

    /// @}


    // ############################################################################
    /// @name Accessors / Modifiers
    // ############################################################################
    /// @{

    /** @brief Fill the 'requisite' nodeset with the requisite nodes in dag
     * given a query and evidence.
     *
     * Requisite nodes are those that are d-connected to at least one of the
     * query nodes given a set of hard and soft evidence
     */
    void requisiteNodes(const DAG&     dag,
                        const NodeSet& query,
                        const NodeSet& hardEvidence,
                        const NodeSet& softEvidence,
                        NodeSet&       requisite) const;

    /** @brief update a set of tensors, keeping only those d-connected with
     * query variables given evidence */
    template < GUM_Numeric GUM_SCALAR, class TABLE >
    void relevantTensors(const IBayesNet< GUM_SCALAR >& bn,
                         const NodeSet&                 query,
                         const NodeSet&                 hardEvidence,
                         const NodeSet&                 softEvidence,
                         Set< const TABLE* >&           tensors);

    /// @}
  };


} /* namespace gum */


#ifndef GUM_NO_INLINE
#  include <agrum/BN/algorithms/dSeparationAlgorithm_inl.h>
#endif   // GUM_NO_INLINE

#include <agrum/BN/algorithms/dSeparationAlgorithm_tpl.h>


#endif /* GUM_D_SEPARATION_ALGORITHM_H */
