///////////////////////////////////////////////////////////////////////////////
//
// File: HDGHelmholtz2D.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:
//
///////////////////////////////////////////////////////////////////////////////

#include <cstdio>
#include <cstdlib>

#include <LibUtilities/BasicUtils/SessionReader.h>
#include <LibUtilities/Communication/Comm.h>
#include <LibUtilities/Memory/NekMemoryManager.hpp>
#include <MultiRegions/DisContField.h>
#include <SpatialDomains/MeshGraphIO.h>

// #define TIMING
#ifdef TIMING
#include <time.h>
#define Timing(s)                                                              \
    fprintf(stdout, "%s Took %g seconds\n", s,                                 \
            (clock() - st) / (double)CLOCKS_PER_SEC);                          \
    st = clock();
#else
#define Timing(s) /* Nothing */
#endif

using namespace std;
using namespace Nektar;

int main(int argc, char *argv[])
{
    LibUtilities::SessionReaderSharedPtr vSession =
        LibUtilities::SessionReader::CreateInstance(argc, argv);

    LibUtilities::CommSharedPtr vComm = vSession->GetComm();

    MultiRegions::DisContFieldSharedPtr Exp, Fce;
    MultiRegions::ExpListSharedPtr DerExp1, DerExp2;
    int i, nq, coordim;
    Array<OneD, NekDouble> fce;
    Array<OneD, NekDouble> xc0, xc1, xc2;
    StdRegions::ConstFactorMap factors;

    if (argc < 2)
    {
        fprintf(stderr, "Usage: HDGHelmholtz2D  meshfile [solntype]\n");
        exit(1);
    }

    LibUtilities::FieldIOSharedPtr fld =
        LibUtilities::FieldIO::CreateDefault(vSession);

    //----------------------------------------------
    // Read in mesh from input file
    SpatialDomains::MeshGraphSharedPtr graph2D =
        SpatialDomains::MeshGraphIO::Read(vSession);
    //----------------------------------------------

    //----------------------------------------------
    // Print summary of solution details
    factors[StdRegions::eFactorLambda] = vSession->GetParameter("Lambda");
    factors[StdRegions::eFactorTau]    = 1.0;
    const SpatialDomains::ExpansionInfoMap &expansions =
        graph2D->GetExpansionInfo();
    LibUtilities::BasisKey bkey0 =
        expansions.begin()->second->m_basisKeyVector[0];

    if (vComm->GetRank() == 0)
    {
        cout << "Solving 2D Helmholtz: " << endl;
        cout << "         Communication: " << vSession->GetComm()->GetType()
             << endl;
        cout << "         Solver type  : "
             << vSession->GetSolverInfo("GlobalSysSoln") << endl;
        cout << "         Lambda       : " << factors[StdRegions::eFactorLambda]
             << endl;
        cout << "         No. modes    : " << bkey0.GetNumModes() << endl;
        cout << endl;
    }

    //----------------------------------------------

    //----------------------------------------------
    // Define Expansion
    Exp = MemoryManager<MultiRegions::DisContField>::AllocateSharedPtr(
        vSession, graph2D, vSession->GetVariable(0));
    //----------------------------------------------
    Timing("Read files and define exp ..");

    //----------------------------------------------
    // Set up coordinates of mesh for Forcing function evaluation
    coordim = Exp->GetCoordim(0);
    nq      = Exp->GetTotPoints();

    xc0 = Array<OneD, NekDouble>(nq, 0.0);
    xc1 = Array<OneD, NekDouble>(nq, 0.0);
    xc2 = Array<OneD, NekDouble>(nq, 0.0);

    switch (coordim)
    {
        case 1:
            Exp->GetCoords(xc0);
            break;
        case 2:
            Exp->GetCoords(xc0, xc1);
            break;
        case 3:
            Exp->GetCoords(xc0, xc1, xc2);
            break;
    }
    //----------------------------------------------

    //----------------------------------------------
    // Define forcing function for first variable defined in file
    fce                                   = Array<OneD, NekDouble>(nq);
    LibUtilities::EquationSharedPtr ffunc = vSession->GetFunction("Forcing", 0);

    ffunc->Evaluate(xc0, xc1, xc2, fce);

    //----------------------------------------------

    //----------------------------------------------
    // Setup expansion containing the  forcing function
    Fce = MemoryManager<MultiRegions::DisContField>::AllocateSharedPtr(*Exp);
    Fce->SetPhys(fce);
    //----------------------------------------------
    Timing("Define forcing ..");

    //----------------------------------------------
    // Helmholtz solution taking physical forcing
    Exp->HelmSolve(Fce->GetPhys(), Exp->UpdateCoeffs(), factors);
    //----------------------------------------------

    Timing("Helmholtz Solve ..");

#ifdef TIMING
    for (i = 0; i < 100; ++i)
    {
        Exp->HelmSolve(Fce->GetPhys(), Exp->UpdateCoeffs(), factors);
    }

    Timing("100 Helmholtz Solves:... ");
#endif

    //-----------------------------------------------
    // Backward Transform Solution to get solved values at
    Exp->BwdTrans(Exp->GetCoeffs(), Exp->UpdatePhys());
    //-----------------------------------------------
    Timing("Backard Transform ..");

    //-----------------------------------------------
    // Write solution to file
    string out = vSession->GetSessionName() + ".fld";
    std::vector<LibUtilities::FieldDefinitionsSharedPtr> FieldDef =
        Exp->GetFieldDefinitions();
    std::vector<std::vector<NekDouble>> FieldData(FieldDef.size());

    for (i = 0; i < FieldDef.size(); ++i)
    {
        FieldDef[i]->m_fields.push_back("u");
        Exp->AppendFieldData(FieldDef[i], FieldData[i]);
    }
    fld->Write(out, FieldDef, FieldData);

    //-----------------------------------------------

    //-----------------------------------------------
    // See if there is an exact solution, if so
    // evaluate and plot errors
    LibUtilities::EquationSharedPtr ex_sol =
        vSession->GetFunction("ExactSolution", 0);

    if (ex_sol)
    {
        //----------------------------------------------
        // evaluate exact solution
        ex_sol->Evaluate(xc0, xc1, xc2, fce);

        //----------------------------------------------

        //--------------------------------------------
        // Calculate error
        Fce->SetPhys(fce);
        Fce->SetPhysState(true);

        NekDouble vLinfError = Exp->Linf(Exp->GetPhys(), Fce->GetPhys());
        NekDouble vL2Error   = Exp->L2(Exp->GetPhys(), Fce->GetPhys());
        NekDouble vH1Error   = Exp->H1(Exp->GetPhys(), Fce->GetPhys());
        vector<NekDouble> vQError(coordim);

        for (i = 0; i < coordim; ++i)
        {
            Fce->PhysDeriv(i, Fce->GetPhys(), fce);
            vQError[i] = Exp->L2_DGDeriv(i, Exp->GetCoeffs(), fce);
        }

        if (vSession->GetComm()->GetRank() == 0)
        {
            cout << "L infinity error : " << vLinfError << endl;
            cout << "L 2 error        : " << vL2Error << endl;
            cout << "H 1 error        : " << vH1Error << endl;

            for (i = 0; i < coordim; ++i)
            {
                cout << "Q" << i << " L2 error      : " << vQError[i] << endl;
            }
        }

        //--------------------------------------------
    }

    Timing("Output ..");
    //----------------------------------------------

    vSession->Finalise();

    return 0;
}
