#include <petsc/private/logimpl.h> /*I    "petscsys.h"   I*/

/*@C
  PetscIntStackDestroy - This function destroys a stack.

  Not Collective

  Input Parameter:
. stack - The stack

  Level: developer

.seealso: `PetscIntStackCreate()`, `PetscIntStackEmpty()`, `PetscIntStackPush()`, `PetscIntStackPop()`, `PetscIntStackTop()`
@*/
PetscErrorCode PetscIntStackDestroy(PetscIntStack stack)
{
  PetscFunctionBegin;
  PetscAssertPointer(stack, 1);
  PetscCall(PetscFree(stack->stack));
  PetscCall(PetscFree(stack));
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
  PetscIntStackEmpty - This function determines whether any items have been pushed.

  Not Collective

  Input Parameter:
. stack - The stack

  Output Parameter:
. empty - `PETSC_TRUE` if the stack is empty

  Level: developer

.seealso: `PetscIntStackCreate()`, `PetscIntStackDestroy()`, `PetscIntStackPush()`, `PetscIntStackPop()`, `PetscIntStackTop()`
@*/
PetscErrorCode PetscIntStackEmpty(PetscIntStack stack, PetscBool *empty)
{
  PetscFunctionBegin;
  PetscAssertPointer(stack, 1);
  PetscAssertPointer(empty, 2);
  *empty = stack->top == -1 ? PETSC_TRUE : PETSC_FALSE;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
  PetscIntStackTop - This function returns the top of the stack.

  Not Collective

  Input Parameter:
. stack - The stack

  Output Parameter:
. top - The integer on top of the stack

  Level: developer

.seealso: `PetscIntStackCreate()`, `PetscIntStackDestroy()`, `PetscIntStackEmpty()`, `PetscIntStackPush()`, `PetscIntStackPop()`
@*/
PetscErrorCode PetscIntStackTop(PetscIntStack stack, int *top)
{
  PetscFunctionBegin;
  PetscAssertPointer(stack, 1);
  PetscAssertPointer(top, 2);
  *top = stack->stack[stack->top];
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
  PetscIntStackPush - This function pushes an integer on the stack.

  Not Collective

  Input Parameters:
+ stack - The stack
- item  - The integer to push

  Level: developer

.seealso: `PetscIntStackCreate()`, `PetscIntStackDestroy()`, `PetscIntStackEmpty()`, `PetscIntStackPop()`, `PetscIntStackTop()`
@*/
PetscErrorCode PetscIntStackPush(PetscIntStack stack, int item)
{
  PetscFunctionBegin;
  PetscAssertPointer(stack, 1);
  if (++stack->top >= stack->max) {
    stack->max *= 2;
    PetscCall(PetscRealloc(stack->max * sizeof(*stack->stack), &stack->stack));
  }
  stack->stack[stack->top] = item;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
  PetscIntStackPop - This function pops an integer from the stack.

  Not Collective

  Input Parameter:
. stack - The stack

  Output Parameter:
. item - The integer popped

  Level: developer

.seealso: `PetscIntStackCreate()`, `PetscIntStackDestroy()`, `PetscIntStackEmpty()`, `PetscIntStackPush()`, `PetscIntStackTop()`
@*/
PetscErrorCode PetscIntStackPop(PetscIntStack stack, int *item)
{
  PetscFunctionBegin;
  PetscAssertPointer(stack, 1);
  PetscCheck(stack->top != -1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Stack is empty");
  if (item) {
    PetscAssertPointer(item, 2);
    PetscCall(PetscIntStackTop(stack, item));
  }
  --stack->top;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
  PetscIntStackCreate - This function creates a stack.

  Not Collective

  Output Parameter:
. stack - The stack

  Level: developer

.seealso: `PetscIntStackDestroy()`, `PetscIntStackEmpty()`, `PetscIntStackPush()`, `PetscIntStackPop()`, `PetscIntStackTop()`
@*/
PetscErrorCode PetscIntStackCreate(PetscIntStack *stack)
{
  PetscFunctionBegin;
  PetscAssertPointer(stack, 1);
  PetscCall(PetscNew(stack));

  (*stack)->top = -1;
  (*stack)->max = 128;

  PetscCall(PetscCalloc1((*stack)->max, &(*stack)->stack));
  PetscFunctionReturn(PETSC_SUCCESS);
}
