//
// Software License for AMDiS
//
// Copyright (c) 2010 Dresden University of Technology 
// All rights reserved.
// Authors: Simon Vey, Thomas Witkowski et al.
//
// This file is part of AMDiS
//
// See also license.opensource.txt in the distribution.


#include "RobinBC.h"
#include "Assembler.h"
#include "DOFVector.h"
#include "DOFMatrix.h"
#include "SurfaceOperator.h"
#include "est/Estimator.h"

#include <math.h>

namespace AMDiS {

  RobinBC::RobinBC(BoundaryType type,
		   AbstractFunction<double, WorldVector<double> > *j,
		   AbstractFunction<double, WorldVector<double> > *alpha,
		   FiniteElemSpace *rowFeSpace_,
		   FiniteElemSpace *colFeSpace_)
    : BoundaryCondition(type, rowFeSpace_, colFeSpace_), 
      neumannOperators(NULL), 
      robinOperators(NULL)
  {
    int dim = rowFeSpace->getMesh()->getDim();

    // create barycentric coords for each vertex of each side
    const Element *refElement = Global::getReferenceElement(dim);
    coords = new VectorOfFixVecs<DimVec<double> >*[dim + 1];

    // for all element sides
    for (int i = 0; i < dim + 1; i++) {
      coords[i] = 
	new VectorOfFixVecs<DimVec<double> >(dim, dim, DEFAULT_VALUE,
					     DimVec<double>(dim, DEFAULT_VALUE, 0.0));
      // for each vertex of the side
      for (int k = 0; k < dim; k++) {
	int index = refElement->getVertexOfPosition(INDEX_OF_DIM(dim - 1, dim), i, k);
	(*coords[i])[k][index] = 1.0;
      }
    }

    if (j) {
      Operator *jOp = new Operator(rowFeSpace);
      jOp->addZeroOrderTerm(new CoordsAtQP_ZOT(j));
      neumannOperators = new DimVec<SurfaceOperator*>(dim, NO_INIT);
    
      for (int i = 0; i < dim + 1; i++)
	(*neumannOperators)[i] = new SurfaceOperator(jOp, *coords[i]);

      delete jOp;
    }

    if (alpha) {
      Operator *alphaOp = new Operator(rowFeSpace, colFeSpace);
      alphaOp->addZeroOrderTerm(new CoordsAtQP_ZOT(alpha));
      robinOperators = new DimVec<SurfaceOperator*>(dim, NO_INIT);

      for (int i = 0; i < dim + 1; i++)
	(*robinOperators)[i] = new SurfaceOperator(alphaOp, *coords[i]);
      
      delete alphaOp;
    }
  }


  RobinBC::RobinBC(BoundaryType type,
		   DOFVectorBase<double> *j,
		   DOFVectorBase<double> *alpha,
		   FiniteElemSpace *rowFeSpace_,
		   FiniteElemSpace *colFeSpace_)
    : BoundaryCondition(type, rowFeSpace_, colFeSpace_), 
      neumannOperators(NULL), 
      robinOperators(NULL)
  {
    int dim = rowFeSpace->getMesh()->getDim();

    // create barycentric coords for each vertex of each side
    const Element *refElement = Global::getReferenceElement(dim);
    coords = new VectorOfFixVecs<DimVec<double> >*[dim+1];

    // for all element sides
    for (int i = 0; i < dim + 1; i++) {
      coords[i] =
	new VectorOfFixVecs<DimVec<double> >(dim, dim, DEFAULT_VALUE, 
					     DimVec<double>(dim, DEFAULT_VALUE, 0.0));
      // for each vertex of the side
      for (int k = 0; k < dim; k++) {
	int index = refElement->getVertexOfPosition(INDEX_OF_DIM(dim - 1, dim), i, k);
	(*coords[i])[k][index] = 1.0;
      }
    }

    if (j) {
      Operator *jOp = new Operator(rowFeSpace);
      jOp->addZeroOrderTerm(new VecAtQP_ZOT(j, NULL));
      neumannOperators = new DimVec<SurfaceOperator*>(dim, NO_INIT);
    
      for (int i = 0; i < dim + 1; i++)
	(*neumannOperators)[i] = new SurfaceOperator(jOp, *coords[i]);    

      delete jOp;
    }

    if (alpha) {
      Operator *alphaOp = new Operator(rowFeSpace, colFeSpace);
      alphaOp->addZeroOrderTerm(new VecAtQP_ZOT(alpha, NULL));
      robinOperators = new DimVec<SurfaceOperator*>(dim, NO_INIT);

      for (int i = 0; i < dim + 1; i++)
	(*robinOperators)[i] = new SurfaceOperator(alphaOp, *coords[i]);     

      delete alphaOp;
    }
  }


  RobinBC::RobinBC(BoundaryType type,
		   Operator* jOp, Operator* alphaOp,
		   FiniteElemSpace *rowFeSpace_,
		   FiniteElemSpace *colFeSpace_) 
    : BoundaryCondition(type, rowFeSpace_, colFeSpace_), 
      neumannOperators(NULL), 
      robinOperators(NULL)
  {
    int dim = rowFeSpace->getMesh()->getDim();

    // create barycentric coords for each vertex of each side
    const Element *refElement = Global::getReferenceElement(dim);
    coords = new VectorOfFixVecs<DimVec<double> >*[dim+1];

    // for all element sides
    for (int i = 0; i < dim + 1; i++) {
      coords[i] = new VectorOfFixVecs<DimVec<double> >(dim, dim, DEFAULT_VALUE,
						       DimVec<double>(dim,
								      DEFAULT_VALUE, 
								      0.0));
      // for each vertex of the side
      for (int k = 0; k < dim; k++) {
	int index = refElement->getVertexOfPosition(INDEX_OF_DIM(dim - 1, dim), i, k);
	(*coords[i])[k][index] = 1.0;
      }
    }

    if (jOp) {
      neumannOperators = new DimVec<SurfaceOperator*>(dim, NO_INIT);
      for (int i = 0; i < dim + 1; i++) 
	(*neumannOperators)[i] = new SurfaceOperator(jOp, *coords[i]);
    }
    if (alphaOp) {
      robinOperators = new DimVec<SurfaceOperator*>(dim, NO_INIT);
      for (int i = 0; i < dim + 1; i++) 
	(*robinOperators)[i] = new SurfaceOperator(alphaOp, *coords[i]);
    }

  }


  void RobinBC::fillBoundaryCondition(DOFVectorBase<double>* vector, 
				      ElInfo* elInfo,
				      const DegreeOfFreedom* dofIndices,
				      const BoundaryType* localBound,
				      int nBasFcts)
  {
    FUNCNAME("RobinBC::fillBoundaryCondition()");
    TEST_EXIT_DBG(vector->getFeSpace() == rowFeSpace)("invalid row fe space\n");

    int dim = elInfo->getMesh()->getDim();

    if (neumannOperators)
      for (int i = 0; i < dim + 1; i++)
	if (elInfo->getBoundary(i) == boundaryType)
	  vector->assemble(1.0, elInfo, localBound, (*neumannOperators)[i]);
  }


  void RobinBC::fillBoundaryCondition(DOFMatrix* matrix,
				      ElInfo* elInfo,
				      const DegreeOfFreedom* dofIndices,
				      const BoundaryType* localBound,
				      int nBasFcts) 
  {
    if (robinOperators) {
      int dim = elInfo->getMesh()->getDim();

      for (int i = 0; i < dim + 1; i++)
	if (elInfo->getBoundary(i) == boundaryType)
	  matrix->assemble(-1.0, elInfo, localBound, (*robinOperators)[i]);
    }
  }
  

  double RobinBC::boundResidual(ElInfo *elInfo,
				DOFMatrix *matrix,
				const DOFVectorBase<double> *dv)
  {
    FUNCNAME("RobinBC::fillBoundaryCondition()");
    TEST_EXIT(matrix->getRowFeSpace() == rowFeSpace)("invalid row fe space\n");
    TEST_EXIT(matrix->getColFeSpace() == colFeSpace)("invalid col fe space\n");

    int dim = elInfo->getMesh()->getDim();
    DimVec<double>  lambda(dim, NO_INIT);
    double n_A_grdUh, val = 0.0;
    WorldVector<double> normal;
    const DimVec<WorldVector<double> > &Lambda = elInfo->getGrdLambda();
    double det = elInfo->getDet();
    bool neumannQuad = false;
    const BasisFunction *basFcts = dv->getFeSpace()->getBasisFcts();

    TEST_EXIT(basFcts == rowFeSpace->getBasisFcts())("invalid basFcts\n");

    ElementVector uhEl(basFcts->getNumber());
    dv->getLocalVector(elInfo->getElement(), uhEl);

    TEST_EXIT(neumannOperators || robinOperators)
      ("neither neumann nor robin operators set!\n");

    if (!robinOperators) {
      neumannQuad = true;
    } else {
      if (neumannOperators) {
	if ((*neumannOperators)[0]->getAssembler()->
	    getZeroOrderAssembler()->getQuadrature()->getNumPoints() > 
	    (*robinOperators)[0]->getAssembler()->
	    getZeroOrderAssembler()->getQuadrature()->getNumPoints()) 
	  neumannQuad = true;
      }
    }

    std::vector<Operator*>::iterator op;
    for (op = matrix->getOperatorsBegin(); op != matrix->getOperatorsEnd(); ++op)
      (*op)->getAssembler()->initElement(elInfo);        

    for (int face = 0; face < dim + 1; face++) {
      elInfo->getNormal(face, normal);

      Quadrature *quadrature = 
	neumannQuad ? 
	(*neumannOperators)[face]->getAssembler()->
	getZeroOrderAssembler()->getQuadrature() :
	(*robinOperators)[face]->getAssembler()->
	getZeroOrderAssembler()->getQuadrature();

      if (elInfo->getBoundary(face) == boundaryType) {
	(*neumannOperators)[face]->getAssembler()->
	  getZeroOrderAssembler()->initElement(elInfo);

	int nPoints = quadrature->getNumPoints();
	mtl::dense_vector<double> uhAtQp(nPoints);
	dv->getVecAtQPs(elInfo, quadrature, NULL, uhAtQp);
	ElementVector f(nPoints);
	f = 0.0;

	if (robinOperators)
	  (*robinOperators)[face]->evalZeroOrder(nPoints, uhAtQp, NULL,  NULL, f, 1.0);
	
	std::vector<WorldVector<double> > grdUh(nPoints);
	std::vector<WorldVector<double> > A_grdUh(nPoints);

	for (int iq = 0; iq < nPoints; iq++) {
	  A_grdUh[iq].set(0.0);	
	  lambda = quadrature->getLambda(iq);
	  basFcts->evalGrdUh(lambda, Lambda, uhEl, &grdUh[iq]);
	}
	
	for (op = matrix->getOperatorsBegin(); op != matrix->getOperatorsEnd(); ++op)
	  (*op)->weakEvalSecondOrder(grdUh, A_grdUh);		

	if (neumannOperators)
	  (*neumannOperators)[face]->getC(elInfo, nPoints, f);

	val = 0.0;
	for (int iq = 0; iq < nPoints; iq++) {
	  n_A_grdUh = (normal * A_grdUh[iq]) - f[iq]; 
	  val += quadrature->getWeight(iq) * sqr(n_A_grdUh);
	}
      }
    }

    return det * val;
  }

}