#include <private/linesearchimpl.h>
#include <private/snesimpl.h>

typedef struct {
  LineSearchUserFunc func;
  void               *ctx;
} LineSearch_Shell;

#undef __FUNCT__
#define __FUNCT__ "LineSearchShellSetUserFunc"
PetscErrorCode LineSearchShellSetUserFunc(LineSearch linesearch, LineSearchUserFunc func, void *ctx) {

  PetscErrorCode   ierr;
  PetscBool        flg;
  LineSearch_Shell *shell = (LineSearch_Shell *)linesearch->data;
  PetscFunctionBegin;
  PetscValidHeaderSpecific(linesearch, LineSearch_CLASSID, 1);
  ierr = PetscTypeCompare((PetscObject)linesearch,LINESEARCHSHELL,&flg);CHKERRQ(ierr);
  if (flg) {
    shell->ctx = ctx;
  }
  PetscFunctionReturn(0);
}


#undef __FUNCT__
#define __FUNCT__ "LineSearchShellGetUserFunc"
PetscErrorCode LineSearchShellGetUserFunc(LineSearch linesearch, LineSearchUserFunc *func, void **ctx) {

  PetscErrorCode   ierr;
  PetscBool        flg;
  LineSearch_Shell *shell = (LineSearch_Shell *)linesearch->data;
  PetscFunctionBegin;
  PetscValidHeaderSpecific(linesearch, LineSearch_CLASSID, 1);
  if (func) PetscValidPointer(func,2);
  if (ctx)  PetscValidPointer(ctx,3);
  ierr = PetscTypeCompare((PetscObject)linesearch,LINESEARCHSHELL,&flg);CHKERRQ(ierr);
  if (flg) {
    *ctx  = shell->ctx;
    *func = shell->func;
  }
  PetscFunctionReturn(0);
}


#undef __FUNCT__
#define __FUNCT__ "LineSearchApply_Shell"
PetscErrorCode  LineSearchApply_Shell(LineSearch linesearch)
{
  LineSearch_Shell *shell = (LineSearch_Shell *)linesearch->data;
  PetscErrorCode   ierr;

  PetscFunctionBegin;

  /* apply the user function */
  if (shell->func) {
    ierr = (*shell->func)(linesearch, shell->ctx);CHKERRQ(ierr);
  } else {
    SETERRQ(((PetscObject)linesearch)->comm, PETSC_ERR_USER, "LineSearchShell needs to have a shell function set with LineSearchShellSetUserFunc");
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "LineSearchDestroy_Shell"
PetscErrorCode  LineSearchDestroy_Shell(LineSearch linesearch)
{
  LineSearch_Shell *shell = (LineSearch_Shell *)linesearch->data;
  PetscErrorCode   ierr;

  PetscFunctionBegin;
  ierr = PetscFree(shell);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

EXTERN_C_BEGIN
#undef __FUNCT__
#define __FUNCT__ "LineSearchCreate_Shell"
PetscErrorCode LineSearchCreate_Shell(LineSearch linesearch)
{

  LineSearch_Shell     *shell;
  PetscErrorCode       ierr;

  PetscFunctionBegin;

  linesearch->ops->apply          = LineSearchApply_Shell;
  linesearch->ops->destroy        = LineSearchDestroy_Shell;
  linesearch->ops->setfromoptions = PETSC_NULL;
  linesearch->ops->reset          = PETSC_NULL;
  linesearch->ops->view           = PETSC_NULL;
  linesearch->ops->setup          = PETSC_NULL;

  ierr = PetscNewLog(linesearch, LineSearch_Shell, &shell);CHKERRQ(ierr);
  linesearch->data = (void*) shell;
  PetscFunctionReturn(0);
}
EXTERN_C_END