///////////////////////////////////////////////////////////////////////////////
//
// File: WallBC.cpp
//
// 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: Slip wall boundary condition
//
///////////////////////////////////////////////////////////////////////////////

#include "WallBC.h"

namespace Nektar
{

std::string WallBC::className = GetCFSBndCondFactory().RegisterCreatorFunction(
    "Wall", WallBC::create, "Slip wall boundary condition.");

WallBC::WallBC(const LibUtilities::SessionReaderSharedPtr &pSession,
               const Array<OneD, MultiRegions::ExpListSharedPtr> &pFields,
               const Array<OneD, Array<OneD, NekDouble>> &pTraceNormals,
               const Array<OneD, Array<OneD, NekDouble>> &pGridVelocity,
               const int pSpaceDim, const int bcRegion, const int cnt)
    : CFSBndCond(pSession, pFields, pTraceNormals, pGridVelocity, pSpaceDim,
                 bcRegion, cnt)
{
    m_diffusionAveWeight = 0.5;
}

void WallBC::v_Apply(Array<OneD, Array<OneD, NekDouble>> &Fwd,
                     Array<OneD, Array<OneD, NekDouble>> &physarray,
                     [[maybe_unused]] const NekDouble &time)
{
    int i;
    int nVariables = physarray.size();

    const Array<OneD, const int> &traceBndMap = m_fields[0]->GetTraceBndMap();

    // Adjust the physical values of the trace to take
    // user defined boundaries into account
    int e, id1, id2, nBCEdgePts, eMax;

    eMax = m_fields[0]->GetBndCondExpansions()[m_bcRegion]->GetExpSize();

    for (e = 0; e < eMax; ++e)
    {
        nBCEdgePts = m_fields[0]
                         ->GetBndCondExpansions()[m_bcRegion]
                         ->GetExp(e)
                         ->GetTotPoints();
        id1 =
            m_fields[0]->GetBndCondExpansions()[m_bcRegion]->GetPhys_Offset(e);
        id2 =
            m_fields[0]->GetTrace()->GetPhys_Offset(traceBndMap[m_offset + e]);

        // Boundary condition for epsilon term.
        if (nVariables == m_spacedim + 3)
        {
            Vmath::Zero(nBCEdgePts, &Fwd[nVariables - 1][id2], 1);
        }

        // @TODO: Look at paper on this
        // https://www.researchgate.net/publication/264044118_A_Guide_to_the_Implementation_of_Boundary_Conditions_in_Compact_High-Order_Methods_for_Compressible_Aerodynamics
        // For 2D/3D, define: v* = v - 2(v.n)n
        Array<OneD, NekDouble> tmp(nBCEdgePts, 0.0);

        // Calculate (v.n)
        for (i = 0; i < m_spacedim; ++i)
        {
            Vmath::Vvtvp(nBCEdgePts, &Fwd[1 + i][id2], 1,
                         &m_traceNormals[i][id2], 1, &tmp[0], 1, &tmp[0], 1);
        }

        // Calculate 2.0(v.n)
        Vmath::Smul(nBCEdgePts, -2.0, &tmp[0], 1, &tmp[0], 1);

        // Calculate v* = v - 2.0(v.n)n
        for (i = 0; i < m_spacedim; ++i)
        {
            Vmath::Vvtvp(nBCEdgePts, &tmp[0], 1, &m_traceNormals[i][id2], 1,
                         &Fwd[1 + i][id2], 1, &Fwd[1 + i][id2], 1);
        }

        // Copy boundary adjusted values into the boundary expansion
        for (i = 0; i < nVariables; ++i)
        {
            Vmath::Vcopy(nBCEdgePts, &Fwd[i][id2], 1,
                         &(m_fields[i]
                               ->GetBndCondExpansions()[m_bcRegion]
                               ->UpdatePhys())[id1],
                         1);
        }
    }
}

} // namespace Nektar
