#ifdef PETSC_RCS_HEADER
static char vcid[] = "$Id: mpiaijpc.c,v 1.33 1997/10/19 03:25:26 bsmith Exp bsmith $";
#endif
/*
   Defines a block Jacobi preconditioner for the SeqAIJ/MPIAIJ format.
   Handles special case of  single block per processor.
   This file knows about storage formats for SeqMPI/MPIAIJ matrices.
   The general case is handled in aijpc.c
*/
#include "src/mat/impls/aij/mpi/mpiaij.h"
#include "src/pc/pcimpl.h"
#include "src/vec/vecimpl.h"
#include "src/pc/impls/bjacobi/bjacobi.h"
#include "sles.h"

typedef struct {
  Vec  x, y;
} PC_BJacobi_MPIAIJ;

#undef __FUNC__  
#define __FUNC__ "PCDestroy_BJacobi_MPIAIJ"
int PCDestroy_BJacobi_MPIAIJ(PetscObject obj)
{
  PC                pc = (PC) obj;
  PC_BJacobi        *jac = (PC_BJacobi *) pc->data;
  PC_BJacobi_MPIAIJ *bjac = (PC_BJacobi_MPIAIJ *) jac->data;
  int               ierr;

  PetscFunctionBegin;
  ierr = SLESDestroy(jac->sles[0]); CHKERRQ(ierr);
  PetscFree(jac->sles);
  ierr = VecDestroy(bjac->x); CHKERRQ(ierr);
  ierr = VecDestroy(bjac->y); CHKERRQ(ierr);
  if (jac->l_lens) PetscFree(jac->l_lens);
  if (jac->g_lens) PetscFree(jac->g_lens);
  PetscFree(bjac); PetscFree(jac); 
  PetscFunctionReturn(0);
}


#undef __FUNC__  
#define __FUNC__ "PCSetUpOnBlocks_BJacobi_MPIAIJ"
int PCSetUpOnBlocks_BJacobi_MPIAIJ(PC pc)
{
  int               ierr;
  PC_BJacobi        *jac = (PC_BJacobi *) pc->data;
  PC_BJacobi_MPIAIJ *bjac = (PC_BJacobi_MPIAIJ *) jac->data;

  PetscFunctionBegin;
  ierr = SLESSetUp(jac->sles[0],bjac->x,bjac->y); CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNC__  
#define __FUNC__ "PCApply_BJacobi_MPIAIJ"
int PCApply_BJacobi_MPIAIJ(PC pc,Vec x, Vec y)
{
  int               ierr,its;
  PC_BJacobi        *jac = (PC_BJacobi *) pc->data;
  PC_BJacobi_MPIAIJ *bjac = (PC_BJacobi_MPIAIJ *) jac->data;
  Scalar            *x_array,*x_true_array, *y_array,*y_true_array;

  PetscFunctionBegin;
  /* 
      The VecPlaceArray() is to avoid having to copy the 
    y vector into the bjac->x vector. The reason for 
    the bjac->x vector is that we need a sequential vector
    for the sequential solve.
  */
  VecGetArray_Fast(x,x_array); 
  VecGetArray_Fast(y,y_array); 
  VecGetArray_Fast(bjac->x,x_true_array); 
  VecGetArray_Fast(bjac->y,y_true_array);  
  VecPlaceArray_Fast(bjac->x,x_array); 
  VecPlaceArray_Fast(bjac->y,y_array); 
  ierr = SLESSolve(jac->sles[0],bjac->x,bjac->y,&its); 
  VecPlaceArray_Fast(bjac->x,x_true_array); 
  VecPlaceArray_Fast(bjac->y,y_true_array); 
  PetscFunctionReturn(0);
}

#undef __FUNC__  
#define __FUNC__ "PCSetUp_BJacobi_MPIAIJ"
int PCSetUp_BJacobi_MPIAIJ(PC pc)
{
  PC_BJacobi        *jac = (PC_BJacobi *) pc->data;
  Mat               mat = pc->mat, pmat = pc->pmat;
  Mat_MPIAIJ        *pmatin = (Mat_MPIAIJ *) pmat->data;
  Mat_MPIAIJ        *matin = 0;
  int               ierr, m;
  SLES              sles;
  Vec               x,y;
  PC_BJacobi_MPIAIJ *bjac;
  KSP               subksp;
  PC                subpc;
  MatType           type;

  PetscFunctionBegin;
  if (jac->use_true_local) {
    ierr = MatGetType(pc->mat,&type,PETSC_NULL);CHKERRQ(ierr);
    if (type != MATMPIAIJ) SETERRQ(PETSC_ERR_ARG_INCOMP,0,"Incompatible matrix type.");
    matin = (Mat_MPIAIJ *) mat->data;
  }

  /* set default direct solver with no Krylov method */
  if (!pc->setupcalled) {
    char *prefix;
    ierr = SLESCreate(PETSC_COMM_SELF,&sles); CHKERRQ(ierr);
    PLogObjectParent(pc,sles);
    ierr = SLESGetKSP(sles,&subksp); CHKERRQ(ierr);
    ierr = KSPSetType(subksp,KSPPREONLY); CHKERRQ(ierr);
    ierr = SLESGetPC(sles,&subpc); CHKERRQ(ierr);
    ierr = PCSetType(subpc,PCILU); CHKERRQ(ierr);
    ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr);
    ierr = SLESSetOptionsPrefix(sles,prefix); CHKERRQ(ierr);
    ierr = SLESAppendOptionsPrefix(sles,"sub_"); CHKERRQ(ierr);
    ierr = SLESSetFromOptions(sles); CHKERRQ(ierr);
/*
   This is not so good. The only reason we need to generate this vector
  is so KSP may generate seq vectors for the local solves
*/
    ierr = MatGetSize(pmatin->A,&m,&m); CHKERRQ(ierr);
    ierr = VecCreateSeq(PETSC_COMM_SELF,m,&x); CHKERRQ(ierr);
    ierr = VecCreateSeq(PETSC_COMM_SELF,m,&y); CHKERRQ(ierr);
    PLogObjectParent(pc,x);
    PLogObjectParent(pc,y);

    pc->destroy       = PCDestroy_BJacobi_MPIAIJ;
    pc->apply         = PCApply_BJacobi_MPIAIJ;
    pc->setuponblocks = PCSetUpOnBlocks_BJacobi_MPIAIJ;

    bjac         = (PC_BJacobi_MPIAIJ *) PetscMalloc(sizeof(PC_BJacobi_MPIAIJ));CHKPTRQ(bjac);
    PLogObjectMemory(pc,sizeof(PC_BJacobi_MPIAIJ));
    bjac->x      = x;
    bjac->y      = y;

    jac->sles    = (SLES*) PetscMalloc( sizeof(SLES) ); CHKPTRQ(jac->sles);
    jac->sles[0] = sles;
    jac->data    = (void *) bjac;
  } else {
    sles = jac->sles[0];
    bjac = (PC_BJacobi_MPIAIJ *)jac->data;
  }
  if (jac->use_true_local) {
    ierr = SLESSetOperators(sles,matin->A,pmatin->A,pc->flag); CHKERRQ(ierr);
  }  else {
    ierr = SLESSetOperators(sles,pmatin->A,pmatin->A,pc->flag); CHKERRQ(ierr);
  }   
  PetscFunctionReturn(0);
}

#undef __FUNC__  
#define __FUNC__ "PCSetUp_BJacobi_SeqAIJ"
int PCSetUp_BJacobi_SeqAIJ(PC pc)
{
  PC_BJacobi        *jac = (PC_BJacobi *) pc->data;
  Mat               mat = pc->mat, pmat = pc->pmat;
  int               ierr, m;
  SLES              sles;
  Vec               x,y;
  PC_BJacobi_MPIAIJ *bjac;
  KSP               subksp;
  PC                subpc;
  MatType           type;

  PetscFunctionBegin;
  if (jac->use_true_local) {
    MatGetType(mat,&type,PETSC_NULL);
    if (type != MATSEQAIJ) SETERRQ(PETSC_ERR_ARG_INCOMP,0,"Incompatible matrix type.");
  }

  /* set default direct solver with no Krylov method */
  if (!pc->setupcalled) {
    char *prefix;
    ierr = SLESCreate(PETSC_COMM_SELF,&sles); CHKERRQ(ierr);
    PLogObjectParent(pc,sles);
    ierr = SLESGetKSP(sles,&subksp); CHKERRQ(ierr);
    ierr = KSPSetType(subksp,KSPPREONLY); CHKERRQ(ierr);
    ierr = SLESGetPC(sles,&subpc); CHKERRQ(ierr);
    ierr = PCSetType(subpc,PCILU); CHKERRQ(ierr);
    ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr);
    ierr = SLESSetOptionsPrefix(sles,prefix); CHKERRQ(ierr);
    ierr = SLESAppendOptionsPrefix(sles,"sub_"); CHKERRQ(ierr);
    ierr = SLESSetFromOptions(sles); CHKERRQ(ierr);
/*
   This is not so good. The only reason we need to generate this vector
  is so KSP may generate seq vectors for the local solves
*/
    ierr = MatGetSize(pmat,&m,&m); CHKERRQ(ierr);
    ierr = VecCreateSeq(PETSC_COMM_SELF,m,&x); CHKERRQ(ierr);
    ierr = VecCreateSeq(PETSC_COMM_SELF,m,&y); CHKERRQ(ierr);
    PLogObjectParent(pc,x);
    PLogObjectParent(pc,y);

    pc->destroy       = PCDestroy_BJacobi_MPIAIJ;
    pc->apply         = PCApply_BJacobi_MPIAIJ;
    pc->setuponblocks = PCSetUpOnBlocks_BJacobi_MPIAIJ;

    bjac         = (PC_BJacobi_MPIAIJ *) PetscMalloc(sizeof(PC_BJacobi_MPIAIJ));CHKPTRQ(bjac);
    PLogObjectMemory(pc,sizeof(PC_BJacobi_MPIAIJ));
    bjac->x      = x;
    bjac->y      = y;

    jac->sles    = (SLES*) PetscMalloc( sizeof(SLES) ); CHKPTRQ(jac->sles);
    jac->sles[0] = sles;
    jac->data    = (void *) bjac;
  } else {
    sles = jac->sles[0];
    bjac = (PC_BJacobi_MPIAIJ *)jac->data;
  }
  if (jac->use_true_local) {
    ierr = SLESSetOperators(sles,mat,pmat,pc->flag); CHKERRQ(ierr);
  }  else {
    ierr = SLESSetOperators(sles,pmat,pmat,pc->flag); CHKERRQ(ierr);
  }   
  PetscFunctionReturn(0);
}