#include <vector>
#include <algorithm>
#include <boost/numeric/mtl/mtl.hpp>
#include "Assembler.h"
#include "Operator.h"
#include "Element.h"
#include "QPsiPhi.h"
#include "DOFVector.h"
#include "OpenMP.h"

namespace AMDiS {

  Assembler::Assembler(Operator *op,
		       const FiniteElemSpace *row,
		       const FiniteElemSpace *col) 
    : operat(op),
      rowFESpace(row),
      colFESpace(col ? col : row),
      nRow(rowFESpace->getBasisFcts()->getNumber()),
      nCol(colFESpace->getBasisFcts()->getNumber()),
      remember(true),
      rememberElMat(false),
      rememberElVec(false),
      elementMatrix(nRow, nCol),
      elementVector(nRow),
      lastMatEl(NULL),
      lastVecEl(NULL),
      lastTraverseId(-1)
  
  {}

  Assembler::~Assembler()
  {}

  void Assembler::calculateElementMatrix(const ElInfo *elInfo, 
					 ElementMatrix& userMat,
					 double factor)
  {
    FUNCNAME("Assembler::calculateElementMatrix()");

    if (remember && (factor != 1.0 || operat->uhOld)) {     
      rememberElMat = true;
    }

    Element *el = elInfo->getElement();

    if ((el != lastMatEl && el != lastVecEl) || !operat->isOptimized()) {
      initElement(elInfo);
    }

    if (el != lastMatEl || !operat->isOptimized()) {
      if (rememberElMat)
	set_to_zero(elementMatrix);

      lastMatEl = el;
    } else {
      if (rememberElMat) {
	userMat += factor * elementMatrix;
	return;
      }
    }
 
    ElementMatrix& mat = rememberElMat ? elementMatrix : userMat;

    if (secondOrderAssembler)
      secondOrderAssembler->calculateElementMatrix(elInfo, mat);
    if (firstOrderAssemblerGrdPsi)
      firstOrderAssemblerGrdPsi->calculateElementMatrix(elInfo, mat);
    if (firstOrderAssemblerGrdPhi)
      firstOrderAssemblerGrdPhi->calculateElementMatrix(elInfo, mat);
    if (zeroOrderAssembler)
      zeroOrderAssembler->calculateElementMatrix(elInfo, mat);

    if (rememberElMat)
      userMat += factor * elementMatrix;
  }

  void Assembler::calculateElementMatrix(const ElInfo *rowElInfo,
					 const ElInfo *colElInfo,
					 const ElInfo *smallElInfo,
					 const ElInfo *largeElInfo,
					 ElementMatrix& userMat,
					 double factor)
  {
    FUNCNAME("Assembler::calculateElementMatrix()");

    if (remember && ((factor != 1.0) || (operat->uhOld))) {
      rememberElMat = true;
    }
  
    Element *el = smallElInfo->getElement();   
    lastVecEl = lastMatEl = NULL;
   
    if ((el != lastMatEl && el != lastVecEl) || !operat->isOptimized()) {
      initElement(smallElInfo, largeElInfo);
    }

    if (el != lastMatEl || !operat->isOptimized()) {
      if (rememberElMat)
	set_to_zero(elementMatrix);

      lastMatEl = el;
    } else {
      if (rememberElMat) {
	userMat += factor * elementMatrix;
	return;
      }
    }
  
    ElementMatrix& mat = rememberElMat ? elementMatrix : userMat;

    TEST_EXIT(zeroOrderAssembler)("Not yet implemented for not zero order assembler!\n");

    if (secondOrderAssembler)
      secondOrderAssembler->calculateElementMatrix(smallElInfo, mat);
    if (firstOrderAssemblerGrdPsi)
      firstOrderAssemblerGrdPsi->calculateElementMatrix(smallElInfo, mat);
    if (firstOrderAssemblerGrdPhi)
      firstOrderAssemblerGrdPhi->calculateElementMatrix(smallElInfo, mat);
    if (zeroOrderAssembler)
      zeroOrderAssembler->calculateElementMatrix(smallElInfo, mat);

    const mtl::dense2D<double>& m = smallElInfo->getSubElemCoordsMat();
    ElementMatrix tmpMat(nRow, nRow);
    tmpMat = m * mat;
    mat = tmpMat;


    if (rememberElMat)
      userMat += factor * elementMatrix;
  }

  void Assembler::calculateElementVector(const ElInfo *elInfo, 
					 ElementVector& userVec,
					 double factor)
  {
    FUNCNAME("Assembler::calculateElementVector()");

    if (remember && factor != 1.0) {
      rememberElVec = true;
    }

    Element *el = elInfo->getElement();

    if ((el != lastMatEl && el != lastVecEl) || !operat->isOptimized()) {
      initElement(elInfo);
    }
    
    if (el != lastVecEl || !operat->isOptimized()) {
      if (rememberElVec)
	set_to_zero(elementVector);
	
      lastVecEl = el;
    } else {
      if (rememberElVec) {
	userVec += factor * elementVector;
	return;
      }
    }

    ElementVector& vec = rememberElVec ? elementVector : userVec;
    if (operat->uhOld && remember) {
      matVecAssemble(elInfo, vec);
      if (rememberElVec) {
	userVec += factor * elementVector;
      }
      return;
    } 

    if (firstOrderAssemblerGrdPsi)
      firstOrderAssemblerGrdPsi->calculateElementVector(elInfo, vec);
    if (zeroOrderAssembler)
      zeroOrderAssembler->calculateElementVector(elInfo, vec);
    if (rememberElVec)
      userVec += factor * elementVector;
  }

  void Assembler::calculateElementVector(const ElInfo *mainElInfo, 
					 const ElInfo *auxElInfo,
					 const ElInfo *smallElInfo,
					 const ElInfo *largeElInfo,
					 ElementVector& userVec, 
					 double factor)
  {
    FUNCNAME("Assembler::calculateElementVector()");

    if (remember && factor != 1.0) {
      rememberElVec = true;
    }

    Element *el = mainElInfo->getElement();

    if ((el != lastMatEl && el != lastVecEl) || !operat->isOptimized()) {
      initElement(auxElInfo);
    }
    
    if (el != lastVecEl || !operat->isOptimized()) {
      if (rememberElVec)
	set_to_zero(elementVector);

      lastVecEl = el;
    } else {
      if (rememberElVec) {
	userVec += factor * elementVector;
	return;
      }
    }
    ElementVector& vec = rememberElVec ? elementVector : userVec;

    if (operat->uhOld && remember) {

      if (smallElInfo->getLevel() == largeElInfo->getLevel()) {
	matVecAssemble(auxElInfo, vec);
      } else {
	matVecAssemble(mainElInfo, auxElInfo, smallElInfo, largeElInfo, vec);
      }

      if (rememberElVec) {
	userVec += factor * elementVector;
      }

      return;
    } 

    ERROR_EXIT("Not yet implemented!\n");
//     if (firstOrderAssemblerGrdPsi) {
//       firstOrderAssemblerGrdPsi->calculateElementVector(elInfo, vec);
//     }
//     if (zeroOrderAssembler) {
//       zeroOrderAssembler->calculateElementVector(elInfo, vec);
//     }
//     if (rememberElVec) {
//       axpy(factor, *elementVector, *userVec);
//     }      

  }

  void Assembler::matVecAssemble(const ElInfo *elInfo, ElementVector& vec)
  {
    FUNCNAME("Assembler::matVecAssemble()");

    Element *el = elInfo->getElement(); 
    const BasisFunction *basFcts = rowFESpace->getBasisFcts();
    int nBasFcts = basFcts->getNumber();
    double *uhOldLoc = new double[nBasFcts];

    operat->uhOld->getLocalVector(el, uhOldLoc);
    
    if (el != lastMatEl)
      calculateElementMatrix(elInfo, elementMatrix);
    
    for (int i = 0; i < nBasFcts; i++) {
      double val = 0.0;
      for (int j = 0; j < nBasFcts; j++) {
	val += elementMatrix[i][j] * uhOldLoc[j];
      }
      vec[i] += val;
    }
    

    delete [] uhOldLoc;
  }

  void Assembler::matVecAssemble(const ElInfo *mainElInfo, const ElInfo *auxElInfo,
				 const ElInfo *smallElInfo, const ElInfo *largeElInfo,
				 ElementVector& vec)
  {
    FUNCNAME("Assembler::matVecAssemble()");

    TEST_EXIT(rowFESpace->getBasisFcts() == colFESpace->getBasisFcts())
      ("Works only for equal basis functions for different components!\n");

    TEST_EXIT(operat->uhOld->getFESpace()->getMesh() == auxElInfo->getMesh())
      ("Da stimmt was nicht!\n");

    Element *mainEl = mainElInfo->getElement(); 
    Element *auxEl = auxElInfo->getElement();

    const BasisFunction *basFcts = rowFESpace->getBasisFcts();
    int nBasFcts = basFcts->getNumber();
    double *uhOldLoc = new double[nBasFcts];
    double *uhOldLoc2 = new double[nBasFcts];

    operat->uhOld->getLocalVector(auxEl, uhOldLoc);

    const mtl::dense2D<double>& m = smallElInfo->getSubElemCoordsMat();

    for (int i = 0; i < nBasFcts; i++) {
      uhOldLoc2[i] = 0.0;
      for (int j = 0; j < nBasFcts; j++) {
	uhOldLoc2[i] += m[j][i] * uhOldLoc[i];
      }      
    }

    
    if (mainEl != lastMatEl) {
      calculateElementMatrix(mainElInfo, auxElInfo, smallElInfo, largeElInfo, 
			     elementMatrix);
    }
    
    for (int i = 0; i < nBasFcts; i++) {
      double val = 0.0;
      for (int j = 0; j < nBasFcts; j++) {
	val += elementMatrix[i][j] * uhOldLoc2[j];
      }
      vec[i] += val;
    }
    

    delete [] uhOldLoc;
    delete [] uhOldLoc2;
  }

  void Assembler::initElement(const ElInfo *smallElInfo, 
			      const ElInfo *largeElInfo,
			      Quadrature *quad)
  {
    if (secondOrderAssembler) 
      secondOrderAssembler->initElement(smallElInfo, largeElInfo, quad);
    if (firstOrderAssemblerGrdPsi)
      firstOrderAssemblerGrdPsi->initElement(smallElInfo, largeElInfo, quad);
    if (firstOrderAssemblerGrdPhi)
      firstOrderAssemblerGrdPhi->initElement(smallElInfo, largeElInfo, quad);
    if (zeroOrderAssembler)
      zeroOrderAssembler->initElement(smallElInfo, largeElInfo, quad);
  }

  void Assembler::checkQuadratures()
  { 
    if (secondOrderAssembler) {
      // create quadrature
      if (!secondOrderAssembler->getQuadrature()) {
	int dim = rowFESpace->getMesh()->getDim();
	int degree = operat->getQuadratureDegree(2);
	Quadrature *quadrature = Quadrature::provideQuadrature(dim, degree);
	secondOrderAssembler->setQuadrature(quadrature);
      }
    }
    if (firstOrderAssemblerGrdPsi) {
      // create quadrature
      if (!firstOrderAssemblerGrdPsi->getQuadrature()) {
	int dim = rowFESpace->getMesh()->getDim();
	int degree = operat->getQuadratureDegree(1, GRD_PSI);
	Quadrature *quadrature = Quadrature::provideQuadrature(dim, degree);
	firstOrderAssemblerGrdPsi->setQuadrature(quadrature);
      }
    }
    if (firstOrderAssemblerGrdPhi) {
      // create quadrature
      if (!firstOrderAssemblerGrdPhi->getQuadrature()) {
	int dim = rowFESpace->getMesh()->getDim();
	int degree = operat->getQuadratureDegree(1, GRD_PHI);
	Quadrature *quadrature = Quadrature::provideQuadrature(dim, degree);
	firstOrderAssemblerGrdPhi->setQuadrature(quadrature);
      }
    }
    if (zeroOrderAssembler) {
      // create quadrature
      if (!zeroOrderAssembler->getQuadrature()) {
	int dim = rowFESpace->getMesh()->getDim();
	int degree = operat->getQuadratureDegree(0);
	Quadrature *quadrature = Quadrature::provideQuadrature(dim, degree);
	zeroOrderAssembler->setQuadrature(quadrature);
      }
    }
  }

  void Assembler::finishAssembling()
  {
    lastVecEl = NULL;
    lastMatEl = NULL;
  }

  OptimizedAssembler::OptimizedAssembler(Operator  *op,
					 Quadrature *quad2,
					 Quadrature *quad1GrdPsi,
					 Quadrature *quad1GrdPhi,
					 Quadrature *quad0,
					 const FiniteElemSpace *row,
					 const FiniteElemSpace *col) 
    : Assembler(op, row, col)
  {
    bool opt = (row == col);

    // create sub assemblers
    secondOrderAssembler = 
      SecondOrderAssembler::getSubAssembler(op, this, quad2, opt);
    firstOrderAssemblerGrdPsi = 
      FirstOrderAssembler::getSubAssembler(op, this, quad1GrdPsi, GRD_PSI, opt);
    firstOrderAssemblerGrdPhi = 
      FirstOrderAssembler::getSubAssembler(op, this, quad1GrdPhi, GRD_PHI, opt);
    zeroOrderAssembler = 
      ZeroOrderAssembler::getSubAssembler(op, this, quad0, opt);

    checkQuadratures();
  }

  StandardAssembler::StandardAssembler(Operator *op,
				       Quadrature *quad2,
				       Quadrature *quad1GrdPsi,
				       Quadrature *quad1GrdPhi,
				       Quadrature *quad0,
				       const FiniteElemSpace *row,
				       const FiniteElemSpace *col) 
    : Assembler(op, row, col)
  {
    remember = false;

    // create sub assemblers
    secondOrderAssembler = 
      SecondOrderAssembler::getSubAssembler(op, this, quad2, false);
    firstOrderAssemblerGrdPsi = 
      FirstOrderAssembler::getSubAssembler(op, this, quad1GrdPsi, GRD_PSI, false);
    firstOrderAssemblerGrdPhi = 
      FirstOrderAssembler::getSubAssembler(op, this, quad1GrdPhi, GRD_PHI, false);
    zeroOrderAssembler = 
      ZeroOrderAssembler::getSubAssembler(op, this, quad0, false);

    checkQuadratures();
  }

}