//                                               -*- C++ -*-
/**
 *  @brief Haar wavelet function implementation
 *
 *  Copyright 2005-2026 Airbus-EDF-IMACS-ONERA-Phimeca
 *
 *  This library 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 library 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 library.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
#ifndef OPENTURNS_HAARWAVELET_HXX
#define OPENTURNS_HAARWAVELET_HXX

#include "openturns/UniVariateFunctionImplementation.hxx"

BEGIN_NAMESPACE_OPENTURNS



/**
 * @class HaarWavelet
 *
 * Haar wavelet function implementation
 */

class OT_API HaarWavelet
  : public UniVariateFunctionImplementation
{
  CLASSNAME
public:

  /** Parameter constructor */
  explicit HaarWavelet(const UnsignedInteger j = 0,
                       const UnsignedInteger k = 0,
                       const Bool isScaling = true);

  /** Virtual constructor */
  HaarWavelet * clone() const override;

  /** String converter */
  String __repr__() const override;
  String __str__(const String & offset = "") const override;

  /** HaarWavelet are evaluated as functors */
  Scalar operator() (const Scalar x) const override;

  /** HaarWavelet gradient */
  Scalar gradient(const Scalar x) const override;

  /** HaarWavelet hessian */
  Scalar hessian(const Scalar x) const override;

  /** Method save() stores the object through the StorageManager */
  void save(Advocate & adv) const override;

  /** Method load() reloads the object from the StorageManager */
  void load(Advocate & adv) override;

protected:
  void initialize();

  /* Wavelet order */
  UnsignedInteger j_;

  /* Wavelet shift */
  UnsignedInteger k_;

  /* Scaling flag */
  Bool isScaling_;

  /* Left bound */
  Scalar a_;

  /* Middle bound */
  Scalar m_;

  /* Right bound */
  Scalar b_;

  /* Value */
  Scalar value_;

} ; /* Class HaarWavelet */

END_NAMESPACE_OPENTURNS

#endif /* OPENTURNS_HAARWAVELET_HXX */
