#include "type_stack.h"

/************************/
/* Fonctions primitives */
/************************/

static void grow_stack(stack *thestack) {
  thestack->array =
      realloc(thestack->array, 2 * thestack->size_array * sizeof(void *));
  if (thestack->array == NULL) {
    ERROR("Erreur d'allocation mémoire");
  }
  thestack->size_array = 2 * thestack->size_array;
}

static void shrink_stack(stack *thestack) {
  thestack->array =
      realloc(thestack->array, thestack->size_array * sizeof(void *) / 2);
  if (thestack->array == NULL) {
    ERROR("Erreur d'allocation mémoire");
  }
  thestack->size_array = thestack->size_array / 2;
}

/* Création */
stack *create_stack(void) {
  stack *thestack = malloc(sizeof(stack));
  thestack->size_array = 1;
  thestack->size_stack = 0;
  thestack->array = malloc(sizeof(void *));
  return thestack;
}

/* Suppression */
void delete_stack(stack *thestack) {
  free(thestack->array);
  free(thestack);
}

/* Test du vide */
bool isempty_stack(stack *thestack) {
  return thestack->size_stack == 0;
}

/* Taille*/
uint size_stack(stack *thestack) { return thestack->size_stack; }

/* Lecture */
void *read_stack(stack *thestack, const uint index) { return thestack->array[index]; }

/*  Dépiler */
void *pop(stack *thestack) {
  if (isempty_stack(thestack)) {
    ERROR("La pile est vide.");
  }
  void *v = thestack->array[(thestack->size_stack) - 1];
  thestack->size_stack -= 1;
  if (thestack->size_stack <= thestack->size_array / 4 &&
      thestack->size_array > 1) {
    shrink_stack(thestack);
  }
  return v;
}

/* Empiler */
void push(void *val, stack *thestack) {
  if (thestack->size_array <= thestack->size_stack) {
    grow_stack(thestack);
  }
  thestack->size_stack += 1;
  thestack->array[thestack->size_stack - 1] = val;
}