// ============================================================================
// ==                                                                        ==
// == 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 PetscSolverGlobalMatrix.h */

#ifndef AMDIS_PETSC_SOLVER_GLOBAL_MATRIX_H
#define AMDIS_PETSC_SOLVER_GLOBAL_MATRIX_H

#include "AMDiS_fwd.h"
#include "parallel/PetscSolver.h"

namespace AMDiS {

  using namespace std;


  class PetscSolverGlobalMatrix : public PetscSolver
  {
  public:
    PetscSolverGlobalMatrix()
      : PetscSolver(),
	d_nnz(NULL),
	o_nnz(NULL),
	lastMeshNnz(0),
	zeroStartVector(false),
	alwaysCreateNnzStructure(false)
    {
      Parameters::get("parallel->use zero start vector", zeroStartVector);
      Parameters::get("parallel->always create nnz structure", 
		      alwaysCreateNnzStructure);
    }

    void fillPetscMatrix(Matrix<DOFMatrix*> *mat);

    void fillPetscRhs(SystemVector *vec);

    void solvePetscMatrix(SystemVector &vec, AdaptInfo *adaptInfo);    

    void destroyMatrixData();

  protected:
    /// Creates a new non zero pattern structure for the PETSc matrix. 
    void createPetscNnzStructure(Matrix<DOFMatrix*> *mat);
    
    /// Takes a DOF matrix and sends the values to the global PETSc matrix.
    void setDofMatrix(DOFMatrix* mat, int dispMult = 1, 
		      int dispAddRow = 0, int dispAddCol = 0);

    /// Takes a DOF vector and sends its values to a given PETSc vector.
    void setDofVector(Vec& petscVec, DOFVector<double>* vec, 
		      int disMult = 1, int dispAdd = 0, bool rankOnly = false);

    void createGlobalDofMapping(vector<const FiniteElemSpace*> &feSpaces);

  protected:
    /// Arrays definig the non zero pattern of Petsc's matrix.
    int *d_nnz, *o_nnz;

    /** \brief
     * Stores the mesh change index of the mesh the nnz structure was created for.
     * Therefore, if the mesh change index is higher than this value, we have to create
     * a new nnz structure for PETSc matrices, because the mesh has been changed and
     * therefore also the assembled matrix structure.
     */
    int lastMeshNnz;

    bool zeroStartVector;

    /// If this variable is set to true, the non-zero matrix structure is
    /// created each time from scratch by calling \ref createPetscNnzStrcuture.
    /// This can be necessary if the number of non-zeros in the matrix varies
    /// though the mesh does not change. This may happen if there are many
    /// operators using DOFVectors from old timestep containing many zeros due to
    /// some phase fields.
    bool alwaysCreateNnzStructure;

    map<pair<DegreeOfFreedom, int>, int> dofToGlobalIndex;
  };


}

#endif