// ============================================================================
// ==                                                                        ==
// == AMDiS - Adaptive multidimensional simulations                          ==
// ==                                                                        ==
// ==  http://www.amdis-fem.org                                              ==
// ==                                                                        ==
// ============================================================================
//
// 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.



/** \file Assembler.h */

/**
 * \defgroup Assembler Assembler module
 *
 * \brief
 * Contains the operator and assembler classes:
 * @{ <img src="assembler.png"> @}
 */

#ifndef AMDIS_ASSEMBLER_H
#define AMDIS_ASSEMBLER_H

#include <vector>
#include "AMDiS_fwd.h"
#include "FixVec.h"
#include "ZeroOrderAssembler.h"
#include "FirstOrderAssembler.h"
#include "SecondOrderAssembler.h"
#include "ElInfo.h"

namespace AMDiS {

  /**
   * \ingroup Assembler
   * 
   * \brief
   * Assembles element matrices and vectors for a given Operator. Uses
   * one SubAssembler for all second order terms of the Operator, one for all
   * first order terms, and one for all zero order terms.
   */
  class Assembler
  {
  public:
    /// Constructor
    Assembler(Operator *op,
	      const FiniteElemSpace *rowFeSpace,
	      const FiniteElemSpace *colFeSpace = NULL);

    /// Destructor
    ~Assembler();

    /// Assembles the element matrix for the given ElInfo
    void calculateElementMatrix(const ElInfo *elInfo, 
				ElementMatrix& userMat, 
				double factor = 1.0);

    void calculateElementMatrix(const ElInfo *rowElInfo,
				const ElInfo *colElInfo,
				const ElInfo *smallElInfo,
				const ElInfo *largeElInfo,
				bool rowColFeSpaceEqual,
				ElementMatrix& userMat,
				double factor = 1.0);

    /// Assembles the element vector for the given ElInfo
    void calculateElementVector(const ElInfo *elInfo, 
				ElementVector& userVec, 
				double factor = 1.0);


    void calculateElementVector(const ElInfo *mainElInfo, 
				const ElInfo *auxElInfo,
				const ElInfo *smallElInfo,
				const ElInfo *largeElInfo,
				ElementVector& userVec, 
				double factor = 1.0);

    /// Returns \ref rowFeSpace.
    inline const FiniteElemSpace* getRowFeSpace() 
    { 
      return rowFeSpace; 
    }

    /// Returns \ref colFeSpace.
    inline const FiniteElemSpace* getColFeSpace() 
    { 
      return colFeSpace; 
    }

    /// Returns \ref nRow.
    inline int getNRow() 
    { 
      return nRow; 
    }

    /// Returns \ref nCol.
    inline int getNCol() 
    { 
      return nCol; 
    }

    /// Sets \ref rememberElMat.
    inline void rememberElementMatrix(bool rem) 
    { 
      rememberElMat = rem; 
    }

    /// Sets \ref rememberElVec.
    inline void rememberElementVector(bool rem) 
    { 
      rememberElVec = rem; 
    }

    /// Returns \ref zeroOrderAssembler.
    inline ZeroOrderAssembler* getZeroOrderAssembler() 
    {
      return zeroOrderAssembler;
    }

    /** \brief
     * Returns \ref firstOrderAssemblerGrdPsi or \ref firstOrderAssemblerGrdPhi
     * depending on type.
     */
    inline FirstOrderAssembler* getFirstOrderAssembler(FirstOrderType type = GRD_PSI) 
    {
      return (type == GRD_PSI) ? 
	firstOrderAssemblerGrdPsi : 
	firstOrderAssemblerGrdPhi;
    }

    /// Returns \ref secondOrderAssembler.
    inline SecondOrderAssembler* getSecondOrderAssembler() 
    {
      return secondOrderAssembler;
    }

    /// Returns \ref operat;
    inline Operator* getOperator() 
    { 
      return operat; 
    }

    /// Initialisation for the given ElInfo. The call is deligated to the sub assemblers.
    void initElement(const ElInfo *smallElInfo,
		     const ElInfo *largeElInfo = NULL,
		     Quadrature *quad = NULL);

    /// Sets quadratures of all sub assemblers.
    void setQuadratures(Quadrature *quad2,
			Quadrature *quad1GrdPsi,
			Quadrature *quad1GrdPhi,
			Quadrature *quad0) 
    {
      if (secondOrderAssembler) {
	TEST_EXIT(!secondOrderAssembler->getQuadrature())
	  ("quadrature already existing\n");
	secondOrderAssembler->setQuadrature(quad2);
      }
      if (firstOrderAssemblerGrdPsi) {
	TEST_EXIT(!firstOrderAssemblerGrdPsi->getQuadrature())
	  ("quadrature already existing\n");
	firstOrderAssemblerGrdPsi->setQuadrature(quad1GrdPsi);
      }
      if (firstOrderAssemblerGrdPhi) {
	TEST_EXIT(!firstOrderAssemblerGrdPhi->getQuadrature())
	  ("quadrature already existing\n");
	firstOrderAssemblerGrdPhi->setQuadrature(quad1GrdPhi);
      }
      if (zeroOrderAssembler) {
	TEST_EXIT(!zeroOrderAssembler->getQuadrature())
	  ("quadrature already existing\n");
	zeroOrderAssembler->setQuadrature(quad0);
      }
    }

    /// That function must be called after one assembling cycle has been finished.
    void finishAssembling();

  protected:
    /** \brief
     * Vector assembling by element matrix-vector multiplication. 
     * Usefull if an element matrix was already calculated.
     */
    void matVecAssemble(const ElInfo *elInfo, ElementVector& vec);


    ///
    void matVecAssemble(const ElInfo *mainElInfo, const ElInfo *auxElInfo,
			const ElInfo *smallElInfo, const ElInfo *largeElInfo,
			ElementVector& vec);

    /** \brief
     * Checks whether quadratures for subassemblers are already set.
     * If not they will be created.
     */
    void checkQuadratures();

  protected:
    /// Operator this Assembler belongs to.
    Operator *operat;

    /// Row FiniteElemSpace.
    const FiniteElemSpace *rowFeSpace;

    /// Column FiniteElemSpace.
    const FiniteElemSpace *colFeSpace;

    /// Number of rows.
    int nRow;

    /// Number of columns.
    int nCol;

    /// SubAssembler for the second order terms
    SecondOrderAssembler *secondOrderAssembler;

    /// SubAssembler for the first order terms (grdPsi)
    FirstOrderAssembler *firstOrderAssemblerGrdPsi;

    /// SubAssembler for the first order terms (grdPhi)
    FirstOrderAssembler *firstOrderAssemblerGrdPhi;  

    /// SubAssembler for the zero order terms
    ZeroOrderAssembler *zeroOrderAssembler;

    ///
    bool remember;

    /// Determines whether the element matrix should be stored locally.
    bool rememberElMat;

    /// Determines whether the element vector should be stored locally.
    bool rememberElVec;

    /// Locally stored element matrix
    ElementMatrix elementMatrix;

    /// Locally stored element vector
    ElementVector elementVector;

    ///
    ElementMatrix tmpMat;
  
    /** \brief
     * Used to check whether \ref initElement() must be called, because
     * a new Element is visited.
     */
    Element* lastMatEl;

    /** \brief
     * Used to check whether \ref initElement() must be called, because
     * a new Element is visited.
     */
    Element* lastVecEl;

    /// Used to check for new traverse.
    int lastTraverseId;

    friend class SubAssembler;
    friend class ZeroOrderAssembler;
    friend class FirstOrderAssembler;
    friend class SecondOrderAssembler;
  };

  /**
   * \ingroup Assembler
   *
   * \brief
   * Assembler using non optimized sub assemblers.
   */
  class StandardAssembler : public Assembler
  {
  public:
    /// Constructor
    StandardAssembler(Operator *op,
		      Quadrature *quad2,
		      Quadrature *quad1GrdPsi,
		      Quadrature *quad1GrdPhi,
		      Quadrature *quad0,
		      const FiniteElemSpace *rowFeSpace,
		      const FiniteElemSpace *colFeSpace = NULL);
  };

  /**
   * \ingroup Assembler
   *
   * \brief
   * Assembler using optimized sub assemblers.
   */
  class OptimizedAssembler : public Assembler
  {
  public:
    /// Constructor
    OptimizedAssembler(Operator *op,
		       Quadrature *quad2,
		       Quadrature *quad1GrdPsi,
		       Quadrature *quad1GrdPhi,
		       Quadrature *quad0,
		       const FiniteElemSpace *rowFeSpace,
		       const FiniteElemSpace *colFeSpace = NULL);
  };

}

#endif // AMDIS_ASSEMBLER_H