// Copyright (c) 2004-2022 Tomáš Oberhuber et al.
//
// This file is part of TNL - Template Numerical Library (https://tnl-project.org/)
//
// SPDX-License-Identifier: MIT

#pragma once

#include <sstream>
#include <TNL/Assert.h>
#include <TNL/Matrices/TridiagonalMatrix.h>
#include <TNL/Exceptions/NotImplementedError.h>

namespace TNL {
namespace Matrices {

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::TridiagonalMatrix() = default;

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::TridiagonalMatrix( const IndexType rows,
                                                                                          const IndexType columns )
{
   this->setDimensions( rows, columns );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename ListReal >
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::TridiagonalMatrix(
   const IndexType columns,
   const std::initializer_list< std::initializer_list< ListReal > >& data )
{
   this->setDimensions( data.size(), columns );
   this->setElements( data );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
auto
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getView() const -> ViewType
{
   // TODO: fix when getConstView works
   return ViewType( const_cast< TridiagonalMatrix* >( this )->values.getView(), indexer );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
std::string
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getSerializationType()
{
   return "Matrices::TridiagonalMatrix< " + TNL::getSerializationType< RealType >() + ", [any_device], "
        + TNL::getSerializationType< IndexType >() + ", " + TNL::getSerializationType( Organization ) + ", [any_allocator] >";
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
std::string
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getSerializationTypeVirtual() const
{
   return this->getSerializationType();
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::setDimensions( const IndexType rows,
                                                                                      const IndexType columns )
{
   Matrix< Real, Device, Index >::setDimensions( rows, columns );
   this->indexer.setDimensions( rows, columns );
   this->values.setSize( this->indexer.getStorageSize() );
   this->values = 0.0;
   this->view = this->getView();
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename RowCapacitiesVector >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::setRowCapacities(
   const RowCapacitiesVector& rowCapacities )
{
   if( max( rowCapacities ) > 3 )
      throw std::logic_error( "Too many non-zero elements per row in a tri-diagonal matrix." );
   if( rowCapacities.getElement( 0 ) > 2 )
      throw std::logic_error( "Too many non-zero elements per row in a tri-diagonal matrix." );
   const IndexType diagonalLength = min( this->getRows(), this->getColumns() );
   if( this->getRows() > this->getColumns() )
      if( rowCapacities.getElement( this->getRows() - 1 ) > 1 )
         throw std::logic_error( "Too many non-zero elements per row in a tri-diagonal matrix." );
   if( this->getRows() == this->getColumns() )
      if( rowCapacities.getElement( this->getRows() - 1 ) > 2 )
         throw std::logic_error( "Too many non-zero elements per row in a tri-diagonal matrix." );
   if( this->getRows() < this->getColumns() )
      if( rowCapacities.getElement( this->getRows() - 1 ) > 3 )
         throw std::logic_error( "Too many non-zero elements per row in a tri-diagonal matrix." );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Vector >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getRowCapacities( Vector& rowCapacities ) const
{
   return this->view.getRowCapacities( rowCapacities );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename ListReal >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::setElements(
   const std::initializer_list< std::initializer_list< ListReal > >& data )
{
   if( std::is_same< DeviceType, Devices::Host >::value ) {
      this->getValues() = 0.0;
      auto row_it = data.begin();
      for( size_t rowIdx = 0; rowIdx < data.size(); rowIdx++ ) {
         auto data_it = row_it->begin();
         IndexType i = 0;
         while( data_it != row_it->end() )
            this->getRow( rowIdx ).setElement( i++, *data_it++ );
         row_it++;
      }
   }
   else {
      TridiagonalMatrix< Real, Devices::Host, Index, Organization > hostMatrix( this->getRows(), this->getColumns() );
      hostMatrix.setElements( data );
      *this = hostMatrix;
   }
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Vector >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getCompressedRowLengths( Vector& rowLengths ) const
{
   return this->view.getCompressedRowLengths( rowLengths );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Real_, typename Device_, typename Index_, ElementsOrganization Organization_, typename RealAllocator_ >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::setLike(
   const TridiagonalMatrix< Real_, Device_, Index_, Organization_, RealAllocator_ >& m )
{
   this->setDimensions( m.getRows(), m.getColumns() );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
Index
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getNonzeroElementsCount() const
{
   return this->view.getNonzeroElementsCount();
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::reset()
{
   Matrix< Real, Device, Index >::reset();
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Real_, typename Device_, typename Index_, ElementsOrganization Organization_, typename RealAllocator_ >
bool
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::operator==(
   const TridiagonalMatrix< Real_, Device_, Index_, Organization_, RealAllocator_ >& matrix ) const
{
   if( Organization == Organization_ )
      return this->values == matrix.values;
   else {
      TNL_ASSERT_TRUE( false, "TODO" );
   }
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Real_, typename Device_, typename Index_, ElementsOrganization Organization_, typename RealAllocator_ >
bool
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::operator!=(
   const TridiagonalMatrix< Real_, Device_, Index_, Organization_, RealAllocator_ >& matrix ) const
{
   return ! this->operator==( matrix );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::setValue( const RealType& v )
{
   this->view.setValue( v );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
__cuda_callable__
auto
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getRow( const IndexType& rowIdx ) const
   -> const ConstRowView
{
   return this->view.getRow( rowIdx );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
__cuda_callable__
auto
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getRow( const IndexType& rowIdx ) -> RowView
{
   return this->view.getRow( rowIdx );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::setElement( const IndexType row,
                                                                                   const IndexType column,
                                                                                   const RealType& value )
{
   this->view.setElement( row, column, value );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::addElement( const IndexType row,
                                                                                   const IndexType column,
                                                                                   const RealType& value,
                                                                                   const RealType& thisElementMultiplicator )
{
   this->view.addElement( row, column, value, thisElementMultiplicator );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
Real
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getElement( const IndexType row,
                                                                                   const IndexType column ) const
{
   return this->view.getElement( row, column );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Fetch, typename Reduce, typename Keep, typename FetchReal >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::reduceRows( IndexType first,
                                                                                   IndexType last,
                                                                                   Fetch& fetch,
                                                                                   Reduce& reduce,
                                                                                   Keep& keep,
                                                                                   const FetchReal& identity ) const
{
   this->view.reduceRows( first, last, fetch, reduce, keep, identity );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Fetch, typename Reduce, typename Keep, typename FetchReal >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::reduceRows( IndexType first,
                                                                                   IndexType last,
                                                                                   Fetch& fetch,
                                                                                   Reduce& reduce,
                                                                                   Keep& keep,
                                                                                   const FetchReal& identity )
{
   this->view.reduceRows( first, last, fetch, reduce, keep, identity );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Fetch, typename Reduce, typename Keep, typename FetchReal >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::reduceAllRows( Fetch& fetch,
                                                                                      Reduce& reduce,
                                                                                      Keep& keep,
                                                                                      const FetchReal& identity ) const
{
   this->view.reduceRows( (IndexType) 0, this->getRows(), fetch, reduce, keep, identity );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Fetch, typename Reduce, typename Keep, typename FetchReal >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::reduceAllRows( Fetch& fetch,
                                                                                      Reduce& reduce,
                                                                                      Keep& keep,
                                                                                      const FetchReal& identity )
{
   this->view.reduceRows( (IndexType) 0, this->getRows(), fetch, reduce, keep, identity );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::forElements( IndexType first,
                                                                                    IndexType last,
                                                                                    Function& function ) const
{
   this->view.forElements( first, last, function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::forElements( IndexType first,
                                                                                    IndexType last,
                                                                                    Function& function )
{
   this->view.forElements( first, last, function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::forAllElements( Function& function ) const
{
   this->view.forElements( (IndexType) 0, this->getRows(), function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::forAllElements( Function& function )
{
   this->view.forElements( (IndexType) 0, this->getRows(), function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::forRows( IndexType begin,
                                                                                IndexType end,
                                                                                Function&& function )
{
   this->getView().forRows( begin, end, function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::forRows( IndexType begin,
                                                                                IndexType end,
                                                                                Function&& function ) const
{
   this->getConstView().forRows( begin, end, function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::forAllRows( Function&& function )
{
   this->getView().forAllRows( function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::forAllRows( Function&& function ) const
{
   this->getConsView().forAllRows( function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::sequentialForRows( IndexType begin,
                                                                                          IndexType end,
                                                                                          Function& function ) const
{
   this->view.sequentialForRows( begin, end, function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::sequentialForRows( IndexType first,
                                                                                          IndexType last,
                                                                                          Function& function )
{
   this->view.sequentialForRows( first, last, function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::sequentialForAllRows( Function& function ) const
{
   this->sequentialForRows( (IndexType) 0, this->getRows(), function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Function >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::sequentialForAllRows( Function& function )
{
   this->sequentialForRows( (IndexType) 0, this->getRows(), function );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename InVector, typename OutVector >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::vectorProduct( const InVector& inVector,
                                                                                      OutVector& outVector,
                                                                                      RealType matrixMultiplicator,
                                                                                      RealType outVectorMultiplicator,
                                                                                      IndexType begin,
                                                                                      IndexType end ) const
{
   this->view.vectorProduct( inVector, outVector, matrixMultiplicator, outVectorMultiplicator, begin, end );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Real_, typename Device_, typename Index_, ElementsOrganization Organization_, typename RealAllocator_ >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::addMatrix(
   const TridiagonalMatrix< Real_, Device_, Index_, Organization_, RealAllocator_ >& matrix,
   const RealType& matrixMultiplicator,
   const RealType& thisMatrixMultiplicator )
{
   this->view.addMatrix( matrix.getView(), matrixMultiplicator, thisMatrixMultiplicator );
}

#ifdef HAVE_CUDA
template< typename Real, typename Real2, typename Index, typename Index2 >
__global__
void
TridiagonalMatrixTranspositionCudaKernel( const TridiagonalMatrix< Real2, Devices::Cuda, Index2 >* inMatrix,
                                          TridiagonalMatrix< Real, Devices::Cuda, Index >* outMatrix,
                                          const Real matrixMultiplicator,
                                          const Index gridIdx )
{
   const Index rowIdx = ( gridIdx * Cuda::getMaxGridSize() + blockIdx.x ) * blockDim.x + threadIdx.x;
   if( rowIdx < inMatrix->getRows() ) {
      if( rowIdx > 0 )
         outMatrix->setElementFast( rowIdx - 1, rowIdx, matrixMultiplicator * inMatrix->getElementFast( rowIdx, rowIdx - 1 ) );
      outMatrix->setElementFast( rowIdx, rowIdx, matrixMultiplicator * inMatrix->getElementFast( rowIdx, rowIdx ) );
      if( rowIdx < inMatrix->getRows() - 1 )
         outMatrix->setElementFast( rowIdx + 1, rowIdx, matrixMultiplicator * inMatrix->getElementFast( rowIdx, rowIdx + 1 ) );
   }
}
#endif

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Real2, typename Index2 >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getTransposition(
   const TridiagonalMatrix< Real2, Device, Index2 >& matrix,
   const RealType& matrixMultiplicator )
{
   TNL_ASSERT( this->getRows() == matrix.getRows(),
               std::cerr << "This matrix rows: " << this->getRows() << std::endl
                         << "That matrix rows: " << matrix.getRows() << std::endl );
   if( std::is_same< Device, Devices::Host >::value ) {
      const IndexType& rows = matrix.getRows();
      for( IndexType i = 1; i < rows; i++ ) {
         RealType aux = matrix.getElement( i, i - 1 );
         this->setElement( i, i - 1, matrix.getElement( i - 1, i ) );
         this->setElement( i, i, matrix.getElement( i, i ) );
         this->setElement( i - 1, i, aux );
      }
   }
   if( std::is_same< Device, Devices::Cuda >::value ) {
#ifdef HAVE_CUDA
      TridiagonalMatrix* kernel_this = Cuda::passToDevice( *this );
      typedef TridiagonalMatrix< Real2, Device, Index2 > InMatrixType;
      InMatrixType* kernel_inMatrix = Cuda::passToDevice( matrix );
      dim3 cudaBlockSize( 256 ), cudaGridSize( Cuda::getMaxGridSize() );
      const IndexType cudaBlocks = roundUpDivision( matrix.getRows(), cudaBlockSize.x );
      const IndexType cudaGrids = roundUpDivision( cudaBlocks, Cuda::getMaxGridSize() );
      for( IndexType gridIdx = 0; gridIdx < cudaGrids; gridIdx++ ) {
         if( gridIdx == cudaGrids - 1 )
            cudaGridSize.x = cudaBlocks % Cuda::getMaxGridSize();
         TridiagonalMatrixTranspositionCudaKernel<<< cudaGridSize,
            cudaBlockSize >>>( kernel_inMatrix, kernel_this, matrixMultiplicator, gridIdx );
      }
      Cuda::freeFromDevice( kernel_this );
      Cuda::freeFromDevice( kernel_inMatrix );
      TNL_CHECK_CUDA_DEVICE;
#endif
   }
}

// copy assignment
template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >&
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::operator=( const TridiagonalMatrix& matrix )
{
   this->setLike( matrix );
   this->values = matrix.values;
   return *this;
}

// cross-device copy assignment
template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
template< typename Real_, typename Device_, typename Index_, ElementsOrganization Organization_, typename RealAllocator_ >
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >&
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::operator=(
   const TridiagonalMatrix< Real_, Device_, Index_, Organization_, RealAllocator_ >& matrix )
{
   static_assert( std::is_same< Device, Devices::Host >::value || std::is_same< Device, Devices::Cuda >::value,
                  "unknown device" );
   static_assert( std::is_same< Device_, Devices::Host >::value || std::is_same< Device_, Devices::Cuda >::value,
                  "unknown device" );

   this->setLike( matrix );
   if( Organization == Organization_ )
      this->values = matrix.getValues();
   else {
      if( std::is_same< Device, Device_ >::value ) {
         const auto matrix_view = matrix.getView();
         auto f = [ = ] __cuda_callable__(
                     const IndexType& rowIdx, const IndexType& localIdx, const IndexType& column, Real& value ) mutable
         {
            value = matrix_view.getValues()[ matrix_view.getIndexer().getGlobalIndex( rowIdx, localIdx ) ];
         };
         this->forAllElements( f );
      }
      else {
         TridiagonalMatrix< Real, Device, Index, Organization_ > auxMatrix;
         auxMatrix = matrix;
         const auto matrix_view = auxMatrix.getView();
         auto f = [ = ] __cuda_callable__(
                     const IndexType& rowIdx, const IndexType& localIdx, const IndexType& column, Real& value ) mutable
         {
            value = matrix_view.getValues()[ matrix_view.getIndexer().getGlobalIndex( rowIdx, localIdx ) ];
         };
         this->forAllElements( f );
      }
   }
   return *this;
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::save( File& file ) const
{
   Matrix< Real, Device, Index >::save( file );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::load( File& file )
{
   Matrix< Real, Device, Index >::load( file );
   this->indexer.setDimensions( this->getRows(), this->getColumns() );
   this->view = this->getView();
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::save( const String& fileName ) const
{
   Object::save( fileName );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::load( const String& fileName )
{
   Object::load( fileName );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
void
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::print( std::ostream& str ) const
{
   this->view.print( str );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
auto
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getIndexer() const -> const IndexerType&
{
   return this->indexer;
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
auto
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getIndexer() -> IndexerType&
{
   return this->indexer;
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
__cuda_callable__
Index
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getElementIndex( const IndexType row,
                                                                                        const IndexType column ) const
{
   IndexType localIdx = column - row + 1;

   TNL_ASSERT_GE( localIdx, 0, "" );
   TNL_ASSERT_LT( localIdx, 3, "" );

   return this->indexer.getGlobalIndex( row, localIdx );
}

template< typename Real, typename Device, typename Index, ElementsOrganization Organization, typename RealAllocator >
__cuda_callable__
Index
TridiagonalMatrix< Real, Device, Index, Organization, RealAllocator >::getPaddingIndex() const
{
   return this->view.getPaddingIndex();
}

}  // namespace Matrices
}  // namespace TNL
