// --------------------------------------------------------------------------
//                   OpenMS -- Open-Source Mass Spectrometry
// --------------------------------------------------------------------------
// Copyright The OpenMS Team -- Eberhard Karls University Tuebingen,
// ETH Zurich, and Freie Universitaet Berlin 2002-2023.
//
// This software is released under a three-clause BSD license:
//  * Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//  * Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//  * Neither the name of any author or any participating institution
//    may be used to endorse or promote products derived from this software
//    without specific prior written permission.
// For a full list of authors, refer to the file AUTHORS.
// --------------------------------------------------------------------------
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL ANY OF THE AUTHORS OR THE CONTRIBUTING
// INSTITUTIONS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// --------------------------------------------------------------------------
// $Maintainer: Chris Bielow $
// $Authors: Chris Bielow $
// --------------------------------------------------------------------------

#pragma once

#include <OpenMS/DATASTRUCTURES/Matrix.h>

namespace OpenMS
{
  /**
      @brief Wrapper for a non-negative least squares (NNLS) solver.

      It solves Ax=b, where x>0 in the least squares sense (i.e. minimum residual)
  */
  class OPENMS_DLLAPI NonNegativeLeastSquaresSolver
  {
public:

    enum RETURN_STATUS
    {
      SOLVED,
      ITERATION_EXCEEDED
    };

    /**
        @brief This is a wrapper for the external nnls library for the non-negative least square problem Ax=b, where x>0

        @param A Input matrix A of size mxn
        @param b Input vector (matrix with one column) b of size mx1
        @param x Output vector with non-negative least square solution of size mx1
        @return status of solution (either NonNegativeLeastSquaresSolver::SOLVED, NonNegativeLeastSquaresSolver::ITERATION_EXCEEDED)

        @throws Exception::InvalidParameters if Matrix dimensions do not fit
    */
    static Int solve(const Matrix<double> & A, const Matrix<double> & b, Matrix<double> & x);
  };

} // namespace OpenMS

