/*
 *  Lattice Boltzmann grid refinement sample, written in C++,
 *  using the OpenLB library
 *
 *  Copyright (C) 2019 Adrian Kummerländer
 *  E-mail contact: info@openlb.net
 *  The most recent release of OpenLB can be downloaded at
 *  <http://www.openlb.net/>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public
 *  License along with this program; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA  02110-1301, USA.
 */

namespace SchaeferTurek {

const T deltaR = cylinderD / N; // coarse lattice spacing

const Vector<T,2> modelOrigin {0.0, 0.0};
const Vector<T,2> modelExtend {22*cylinderD + deltaR, 4.1*cylinderD + deltaR};

const Vector<T,2> cylinderCenter {2*cylinderD, 2*cylinderD};

void prepareGeometry(Grid2D<T,DESCRIPTOR>& grid, Vector<T,2> origin, Vector<T,2> extend)
{
  OstreamManager clout(std::cout,"prepareGeometry");
  clout << "Prepare Geometry ..." << std::endl;

  auto& converter = grid.getConverter();
  auto& sGeometry = grid.getSuperGeometry();

  sGeometry.rename(0,1);

  const T physSpacing = converter.getPhysDeltaX();

  // Set material number for channel walls
  {
    const Vector<T,2> wallExtend { extend[0]+physSpacing/2, physSpacing/2 };
    const Vector<T,2> wallOrigin = origin - physSpacing/4;

    IndicatorCuboid2D<T> lowerWall(wallExtend, wallOrigin);
    sGeometry.rename(1,2,lowerWall);
  }
  {
    const Vector<T,2> wallExtend { extend[0]+physSpacing/2, physSpacing/2 };
    const Vector<T,2> wallOrigin { origin[0]-physSpacing/4, extend[1]-physSpacing/4 };

    IndicatorCuboid2D<T> upperWall(wallExtend, wallOrigin);
    sGeometry.rename(1,2,upperWall);
  }

  // Set material number for inflow and outflow
  {
    const Vector<T,2> inflowExtend { physSpacing/2, extend[1]+physSpacing/4 };
    const Vector<T,2> inflowOrigin = origin - physSpacing/4;

    IndicatorCuboid2D<T> inflow(inflowExtend, inflowOrigin);
    sGeometry.rename(1,3,inflow);
  }
  {
    const Vector<T,2> outflowExtend { physSpacing/2, extend[1]+physSpacing/4 };
    const Vector<T,2> outflowOrigin { extend[0]-physSpacing/4, origin[0]-physSpacing/4 };

    IndicatorCuboid2D<T> outflow(outflowExtend, outflowOrigin);
    sGeometry.rename(1,4,outflow);
  }

  // Set material number for vertically centered cylinder
  {
    const Vector<T,2> cylinderOrigin = origin + Vector<T,2> {cylinderCenter[0], cylinderCenter[1]+physSpacing/2};
    IndicatorCircle2D<T> obstacle(cylinderOrigin, cylinderD/2);
    sGeometry.rename(1,5,obstacle);
  }

  sGeometry.clean();
  sGeometry.innerClean();
  sGeometry.checkForErrors();

  clout << "Prepare Geometry ... OK" << std::endl;
}

void prepareLattice(Grid2D<T,DESCRIPTOR>& grid)
{
  OstreamManager clout(std::cout,"prepareLattice");
  clout << "Prepare lattice ..." << std::endl;

  auto& converter = grid.getConverter();
  auto& sGeometry = grid.getSuperGeometry();
  auto& sLattice  = grid.getSuperLattice();

  const T physSpacing = converter.getPhysDeltaX();

  Dynamics<T,DESCRIPTOR>& bulkDynamics = grid.addDynamics(
      std::unique_ptr<Dynamics<T,DESCRIPTOR>>(
        new BGKdynamics<T,DESCRIPTOR>(
          grid.getConverter().getLatticeRelaxationFrequency(),
          instances::getBulkMomenta<T,DESCRIPTOR>())));

  sOnLatticeBoundaryCondition2D<T,DESCRIPTOR>& sBoundaryCondition = grid.getOnLatticeBoundaryCondition();
  createLocalBoundaryCondition2D<T,DESCRIPTOR>(sBoundaryCondition);

  sOffLatticeBoundaryCondition2D<T,DESCRIPTOR>& sOffBoundaryCondition = grid.getOffLatticeBoundaryCondition();
  createBouzidiBoundaryCondition2D<T,DESCRIPTOR>(sOffBoundaryCondition);

  sLattice.defineDynamics(sGeometry, 0, &instances::getNoDynamics<T,DESCRIPTOR>());
  sLattice.defineDynamics(sGeometry, 1, &bulkDynamics); // bulk
  sLattice.defineDynamics(sGeometry, 2, &bulkDynamics); // walls
  sLattice.defineDynamics(sGeometry, 3, &bulkDynamics); // inflow
  sLattice.defineDynamics(sGeometry, 4, &bulkDynamics); // outflow
  sLattice.defineDynamics(sGeometry, 5, &instances::getNoDynamics<T,DESCRIPTOR>());

  const T omega = converter.getLatticeRelaxationFrequency();

  sBoundaryCondition.addVelocityBoundary(sGeometry, 2, omega);
  sBoundaryCondition.addVelocityBoundary(sGeometry, 3, omega);
  sBoundaryCondition.addPressureBoundary(sGeometry, 4, omega);

  const Vector<T,2> cylinderOrigin {cylinderCenter[0], cylinderCenter[1]+physSpacing/2};
  IndicatorCircle2D<T> obstacle(cylinderOrigin, cylinderD/2);
  sOffBoundaryCondition.addZeroVelocityBoundary(sGeometry, 5, obstacle);

  AnalyticalConst2D<T,T> rho0(1.0);
  AnalyticalConst2D<T,T> u0(0.0, 0.0);

  auto materials = sGeometry.getMaterialIndicator({1, 2, 3, 4});
  sLattice.defineRhoU(materials, rho0, u0);
  sLattice.iniEquilibrium(materials, rho0, u0);

  sLattice.initialize();

  clout << "Prepare lattice ... OK" << std::endl;
  sGeometry.print();
}

void setBoundaryValues(Grid2D<T,DESCRIPTOR>& grid, int iT)
{
  auto& converter = grid.getConverter();
  auto& sGeometry = grid.getSuperGeometry();
  auto& sLattice  = grid.getSuperLattice();

  const int iTmaxStart = converter.getLatticeTime(0.4*16);
  const int iTupdate = 5;

  if ( iT % iTupdate == 0 && iT <= iTmaxStart ) {
    PolynomialStartScale<T,T> StartScale(iTmaxStart, 1);

    T iTvec[1] { T(iT) };
    T frac[1] { };
    StartScale(frac, iTvec);

    const T maxVelocity = converter.getCharLatticeVelocity() * 3./2. * frac[0];
    Poiseuille2D<T> u(sGeometry, 3, maxVelocity, converter.getPhysDeltaX()/2);

    sLattice.defineU(sGeometry, 3, u);
  }
}

void getResults(Grid2D<T,DESCRIPTOR>& grid,
                const std::string& prefix,
                int iT)
{
  auto& converter = grid.getConverter();
  auto& sLattice  = grid.getSuperLattice();
  auto& sGeometry = grid.getSuperGeometry();

  SuperVTMwriter2D<T> vtmWriter(prefix);
  SuperLatticePhysVelocity2D<T,DESCRIPTOR> velocity(sLattice, converter);
  SuperLatticePhysPressure2D<T,DESCRIPTOR> pressure(sLattice, converter);
  SuperLatticeGeometry2D<T,DESCRIPTOR> geometry(sLattice, sGeometry);
  SuperLatticeKnudsen2D<T,DESCRIPTOR> knudsen(sLattice);
  SuperLatticeRefinementMetricKnudsen2D<T,DESCRIPTOR> quality(sLattice, converter);
  vtmWriter.addFunctor(geometry);
  vtmWriter.addFunctor(velocity);
  vtmWriter.addFunctor(pressure);
  vtmWriter.addFunctor(knudsen);
  vtmWriter.addFunctor(quality);

  if (iT==0) {
    vtmWriter.createMasterFile();
  }

  vtmWriter.write(iT);
}

void takeMeasurements(Grid2D<T,DESCRIPTOR>& grid, int iT, bool print=true)
{
  auto& sLattice  = grid.getSuperLattice();
  auto& sGeometry = grid.getSuperGeometry();
  auto& converter = grid.getConverter();

  const T physSpacing = converter.getPhysDeltaX();

  SuperLatticePhysPressure2D<T,DESCRIPTOR> pressure(sLattice, converter);
  AnalyticalFfromSuperF2D<T> intpolatePressure(pressure, true);
  SuperLatticePhysDrag2D<T,DESCRIPTOR> dragF(sLattice, sGeometry, 5, converter);

  const T radiusCylinder  = cylinderD/2;

  const T point1[2] { cylinderCenter[0] - radiusCylinder, cylinderCenter[1]+physSpacing/2 };
  const T point2[2] { cylinderCenter[0] + radiusCylinder, cylinderCenter[1]+physSpacing/2 };

  T pressureInFrontOfCylinder, pressureBehindCylinder;
  intpolatePressure(&pressureInFrontOfCylinder, point1);
  intpolatePressure(&pressureBehindCylinder,    point2);
  const T pressureDrop = pressureInFrontOfCylinder - pressureBehindCylinder;

  const int input[3] {};
  T drag[dragF.getTargetDim()] {};
  dragF(drag, input);

  static Gnuplot<T> gplot("results");
  gplot.setData(converter.getPhysTime(iT), {drag[0], drag[1], pressureDrop}, {"drag", "lift", "deltaP"}, "bottom right", {'l','l'});
  gplot.writePNG();

  if (print) {
    OstreamManager clout(std::cout, "measurement");
    clout << "pressureDrop=" << pressureDrop
          << "; drag=" << drag[0]
          << "; lift=" << drag[1]
          << endl;
  }
}

}