/*
  Defines matrix-matrix-matrix product routines for SeqAIJ matrices
          D = A * B * C
*/
#include <../src/mat/impls/aij/seq/aij.h> /*I "petscmat.h" I*/

PetscErrorCode MatDestroy_SeqAIJ_MatMatMatMult(void* data)
{
  Mat_MatMatMatMult *matmatmatmult = (Mat_MatMatMatMult*)data;

  PetscFunctionBegin;
  PetscCall(MatDestroy(&matmatmatmult->BC));
  PetscCall(PetscFree(matmatmatmult));
  PetscFunctionReturn(0);
}

PetscErrorCode MatMatMatMultSymbolic_SeqAIJ_SeqAIJ_SeqAIJ(Mat A,Mat B,Mat C,PetscReal fill,Mat D)
{
  Mat               BC;
  Mat_MatMatMatMult *matmatmatmult;
  char              *alg;

  PetscFunctionBegin;
  MatCheckProduct(D,5);
  PetscCheck(!D->product->data,PetscObjectComm((PetscObject)D),PETSC_ERR_PLIB,"Product data not empty");
  PetscCall(MatCreate(PETSC_COMM_SELF,&BC));
  PetscCall(MatMatMultSymbolic_SeqAIJ_SeqAIJ(B,C,fill,BC));

  PetscCall(PetscStrallocpy(D->product->alg,&alg));
  PetscCall(MatProductSetAlgorithm(D,"sorted")); /* set alg for D = A*BC */
  PetscCall(MatMatMultSymbolic_SeqAIJ_SeqAIJ(A,BC,fill,D));
  PetscCall(MatProductSetAlgorithm(D,alg)); /* resume original algorithm */
  PetscCall(PetscFree(alg));

  /* create struct Mat_MatMatMatMult and attached it to D */
  PetscCheck(!D->product->data,PETSC_COMM_SELF,PETSC_ERR_PLIB,"Not yet coded");
  PetscCall(PetscNew(&matmatmatmult));
  matmatmatmult->BC   = BC;
  D->product->data    = matmatmatmult;
  D->product->destroy = MatDestroy_SeqAIJ_MatMatMatMult;

  D->ops->matmatmultnumeric = MatMatMatMultNumeric_SeqAIJ_SeqAIJ_SeqAIJ;
  PetscFunctionReturn(0);
}

PetscErrorCode MatMatMatMultNumeric_SeqAIJ_SeqAIJ_SeqAIJ(Mat A,Mat B,Mat C,Mat D)
{
  Mat_MatMatMatMult *matmatmatmult;
  Mat               BC;

  PetscFunctionBegin;
  MatCheckProduct(D,4);
  PetscCheck(D->product->data,PetscObjectComm((PetscObject)D),PETSC_ERR_PLIB,"Product data empty");
  matmatmatmult = (Mat_MatMatMatMult*)D->product->data;
  BC = matmatmatmult->BC;
  PetscCheck(BC,PetscObjectComm((PetscObject)D),PETSC_ERR_PLIB,"Missing BC mat");
  PetscCheck(BC->ops->matmultnumeric,PetscObjectComm((PetscObject)BC),PETSC_ERR_PLIB,"Missing numeric operation");
  PetscCall((*BC->ops->matmultnumeric)(B,C,BC));
  PetscCheck(D->ops->matmultnumeric,PetscObjectComm((PetscObject)D),PETSC_ERR_PLIB,"Missing numeric operation");
  PetscCall((*D->ops->matmultnumeric)(A,BC,D));
  PetscFunctionReturn(0);
}