///////////////////////////////////////////////////////////////////////////////
//
// File: ScaledMatrix.hpp
//
// For more information, please see: http://www.nektar.info
//
// The MIT License
//
// Copyright (c) 2006 Division of Applied Mathematics, Brown University (USA),
// Department of Aeronautics, Imperial College London (UK), and Scientific
// Computing and Imaging Institute, University of Utah (USA).
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
// Description:
//
///////////////////////////////////////////////////////////////////////////////

#ifndef NEKTAR_LIB_UTILITIES_LINEAR_ALGEBRA_SCALED_MATRIX_HPP
#define NEKTAR_LIB_UTILITIES_LINEAR_ALGEBRA_SCALED_MATRIX_HPP

#include <LibUtilities/LibUtilitiesDeclspec.h>

#include <LibUtilities/LinearAlgebra/MatrixBase.hpp>
#include <LibUtilities/LinearAlgebra/NekVector.hpp>

namespace Nektar
{
template <typename DataType, typename InnerMatrixType>
class NekMatrix<NekMatrix<DataType, InnerMatrixType>, ScaledMatrixTag>
    : public ConstMatrix<DataType>
{
public:
    typedef ConstMatrix<DataType> BaseType;
    typedef NekMatrix<DataType, InnerMatrixType> InnerType;
    typedef NekMatrix<InnerType, ScaledMatrixTag> ThisType;
    typedef typename std::remove_const<typename InnerType::NumberType>::type
        NumberType;

    typedef NumberType GetValueType;
    typedef NumberType ConstGetValueType;

public:
    /// \internal
    /// \brief Iterator through elements of the matrix.
    /// Not quite a real iterator in the C++ sense.
    class const_iterator
    {
    public:
        const_iterator(typename InnerType::const_iterator iter,
                       const NumberType &scale)
            : m_iter(iter), m_scale(scale)
        {
        }

        const_iterator operator++(int)
        {
            const_iterator out = *this;
            ++m_iter;
            return out;
        }

        const_iterator &operator++()
        {
            ++m_iter;
            return *this;
        }

        NumberType operator*()
        {
            return m_scale * (*m_iter);
        }

        bool operator==(const const_iterator &rhs)
        {
            return m_iter == rhs.m_iter;
        }

        bool operator!=(const const_iterator &rhs)
        {
            return !(*this == rhs);
        }

    private:
        typename InnerType::const_iterator m_iter;
        NumberType m_scale;
    };

public:
    LIB_UTILITIES_EXPORT NekMatrix();

    LIB_UTILITIES_EXPORT NekMatrix(
        typename boost::call_traits<NumberType>::const_reference scale,
        std::shared_ptr<const InnerType> m);

    LIB_UTILITIES_EXPORT NekMatrix(const ThisType &rhs);

    LIB_UTILITIES_EXPORT NekMatrix(
        typename boost::call_traits<NumberType>::const_reference scale,
        const ThisType &rhs);

    LIB_UTILITIES_EXPORT ThisType &operator=(const ThisType &) = default;

    LIB_UTILITIES_EXPORT ConstGetValueType operator()(unsigned int row,
                                                      unsigned int col) const;

    LIB_UTILITIES_EXPORT unsigned int GetStorageSize() const;

    LIB_UTILITIES_EXPORT NumberType Scale() const;
    LIB_UTILITIES_EXPORT void SetScale(const NumberType &);

    LIB_UTILITIES_EXPORT const NumberType *GetRawPtr() const;

    LIB_UTILITIES_EXPORT std::shared_ptr<const InnerType> GetOwnedMatrix()
        const;

    LIB_UTILITIES_EXPORT unsigned int GetNumberOfSubDiagonals() const;
    LIB_UTILITIES_EXPORT unsigned int GetNumberOfSuperDiagonals() const;

    LIB_UTILITIES_EXPORT const_iterator begin() const;
    LIB_UTILITIES_EXPORT const_iterator end() const;

    LIB_UTILITIES_EXPORT static ThisType CreateWrapper(const ThisType &rhs);

    LIB_UTILITIES_EXPORT static std::shared_ptr<ThisType> CreateWrapper(
        const std::shared_ptr<ThisType> &rhs);

protected:
    LIB_UTILITIES_EXPORT
    typename boost::call_traits<NumberType>::value_type v_GetValue(
        unsigned int row, unsigned int column) const override;

    LIB_UTILITIES_EXPORT unsigned int v_GetStorageSize() const override;

    LIB_UTILITIES_EXPORT char v_GetTransposeFlag() const override;

private:
    std::shared_ptr<const InnerType> m_matrix;
    NumberType m_scale;
};

template <typename DataType>
LIB_UTILITIES_EXPORT void NegateInPlace(
    NekMatrix<DataType, ScaledMatrixTag> &v);

template <typename DataType>
LIB_UTILITIES_EXPORT NekMatrix<DataType, ScaledMatrixTag> Transpose(
    NekMatrix<DataType, ScaledMatrixTag> &rhs);

} // namespace Nektar

#endif // NEKTAR_LIB_UTILITIES_LINEAR_ALGEBRA_SCALED_MATRIX_HPP
