#include "ll.h"
#include <stdlib.h>

void ll_init(ll* ll) {
  ll->head = NULL;
  ll->tail = NULL;
}
void ll_free(ll* ll) {
  ll_node* head = ll->head;
  while (head) {
    ll_node* to_free = head;
    head = head->next;
    free(to_free);
  }
  ll->tail = NULL;
  ll->head = NULL;
}

libds_result ll_append(ll* ll, void* data) {
  libds_result result = LIBDS_SUCCESS;
  ll_node** to_set = ll->head ? &ll->tail->next : &ll->head;
  ll_node* new_node = malloc(sizeof(*new_node));
  if (new_node) {
    new_node->next = NULL;
    new_node->prev = ll->tail;
    new_node->data = data;

    *to_set = new_node;
    ll->tail = new_node;
  } else {
    result = LIBDS_MALLOC;
  }
  return result;
}
libds_result ll_prepend(ll* ll, void* data) {
  libds_result result = LIBDS_SUCCESS;
  ll_node** to_set = ll->tail ? &ll->head->prev : &ll->tail;
  ll_node* new_node = malloc(sizeof(*new_node));
  if (new_node) {
    new_node->next = ll->head;
    new_node->prev = NULL;
    new_node->data = data;

    *to_set = new_node;
    ll->head = new_node;
  }
  return result;
}
void ll_remove(ll* ll, void* data) {
  ll_node* head = ll->head;
  while (head) {
    if (head->data == data) {
      ll_node* to_delete = head;

      head = head->next;
      *(to_delete->prev ? &to_delete->prev->next : &ll->head) = to_delete->next;
      *(to_delete->next ? &to_delete->next->prev : &ll->tail) = to_delete->prev;
      free(to_delete);
    } else {
      head = head->next;
    }
  }
}

void* ll_find(ll* ll, void* data, compare_func compare) {
  void* to_return = NULL;
  ll_node* head = ll->head;
  while (head && to_return == NULL) {
    if (compare(data, head->data)) {
      to_return = head->data;
    }
    head = head->next;
  }
  return to_return;
}
int ll_foreach(ll* ll, void* data, compare_func compare, foreach_func foreach,
               ...) {
  int return_code = 0;
  ll_node* head = ll->head;
  va_list args;
  while (head && return_code == 0) {
    if (compare(data, head->data)) {
      va_start(args, foreach);
      return_code = foreach (head->data, args);
      va_end(args);
    }
    head = head->next;
  }
  return return_code;
}

void* ll_head(ll* ll) { return ll->head ? ll->head->data : NULL; }
void* ll_tail(ll* ll) { return ll->tail ? ll->tail->data : NULL; }
void* ll_pophead(ll* ll) {
  void* to_return = NULL;
  if (ll->head) {
    ll_node* to_delete = ll->head;
    to_return = to_delete->data;
    *(to_delete->next ? &to_delete->next->prev : &ll->tail) = NULL;
    ll->head = to_delete->next;
    free(to_delete);
  }
  return to_return;
}
void* ll_poptail(ll* ll) {
  void* to_return = NULL;
  if (ll->tail) {
    ll_node* to_delete = ll->tail;
    to_return = to_delete->data;
    *(to_delete->prev ? &to_delete->prev->next : &ll->head) = NULL;
    ll->tail = to_delete->prev;
    free(to_delete);
  }
  return to_return;
}

void ll_clear(ll* ll){
  ll_node* head = ll->head;
  while(head){
    ll_node* to_free = head;
    head = head->next;
    free(to_free);
  }
  ll->head = NULL;
  ll->tail = NULL;
}