#include <stdlib.h>
#include "queue.h"
#include "dllist.h"

typedef struct {
  Dllist *data;
  int size;
} Queue;

void *new_queue() {
  Queue *new_q;
  
  new_q = (Queue *)malloc(sizeof(Queue));
  new_q->data = new_dllist();
  new_q->size = 0;
  return new_q;
}

void free_queue(void *queue) {
  Queue *q = (Queue *)queue;
  free_dllist(q->data);
  free(q);
}

void queue_enqueue(void *queue, void *value) {
  Queue *q = (Queue *)queue;
  dll_append(q->data, value);
  q->size++;
}

void *queue_dequeue(void *queue) {
  Queue *q = (Queue *)queue;
  if (queue_empty(q)) 
    return NULL;
  Dllist_Node *first_node = dll_first(q->data);
  void *save_val = dll_val(first_node);
  dll_delete_node(first_node);
  q->size--;
  return save_val;
}

void *queue_peek(void *queue) {
  Queue *q = (Queue *)queue;
  void *first_node = dll_first(q->data);
  return dll_val(first_node);
}

int queue_empty(void *queue) {
  return (queue_size(queue) == 0);
}

int queue_size(void *queue) {
  Queue *q = (Queue *)queue;
  return q->size;
}