#include "vieter_tree.h"
#include "vieter_tree_internal.h"

vieter_tree_iterator *vieter_tree_iterator_from(vieter_tree *tree) {
  vieter_tree_iterator *iter = calloc(1, sizeof(vieter_tree_iterator));

  // An empty tree's iterator will be done immediately
  if (tree->size == 0) {
    iter->started = true;
    iter->done = true;

    return iter;
  }

  iter->current_node = tree->root;

  return iter;
}

vieter_tree_error vieter_tree_iterator_next(void **out,
                                            vieter_tree_iterator *iter) {
  if (iter->done) {
    return vieter_tree_iterator_done;
  }

  if (!iter->started) {
    while (iter->current_node->children[0] != NULL) {
      iter->current_node = iter->current_node->children[0];
    }

    iter->started = true;
  }

  *out = iter->current_node->data;

  iter->current_node = vieter_tree_node_next(iter->current_node);

  if (iter->current_node == NULL) {
    iter->done = true;
  }

  return vieter_tree_ok;
}

void vieter_tree_iterator_free(vieter_tree_iterator **ptp) {
  free(*ptp);

  *ptp = NULL;
}