/*
 * Copyright 2015 (c) Anna Schumaker.
 */
#ifndef OCARINA_CORE_CONTAINERS_QUEUE_H
#define OCARINA_CORE_CONTAINERS_QUEUE_H

#include <glib.h>

struct _queue {
	GQueue _queue;
};

struct _q_iter {
	guint  it_pos;
	GList *it_iter;
};


/* Called to initialize a queue iterator. */
static inline void _q_iter_init(const struct _queue *queue, struct _q_iter *it)
{
	it->it_iter = g_list_first(queue->_queue.head);
	it->it_pos  = 0;
}

/* Called to advance a queue iterator by one step. */
static inline void _q_iter_next(struct _q_iter *it)
{
	it->it_iter = g_list_next(it->it_iter);
	it->it_pos++;
}

/* Called to rewind a queue iterator by one step. */
static inline void _q_iter_prev(struct _q_iter *it)
{
	it->it_iter = g_list_previous(it->it_iter);
	it->it_pos--;
}

/* Called to set a queue iterator to a specific position. */
static inline void _q_iter_set(struct _queue *queue, struct _q_iter *it,
			       unsigned int pos)
{
	it->it_iter = g_queue_peek_nth_link(&queue->_queue, pos);
	it->it_pos  = pos;
}

/* Called to access the value of a queue iterator. */
static inline gpointer _q_iter_val(struct _q_iter *it)
{
	return (it->it_iter) ? it->it_iter->data : NULL;
}

#define _q_for_each(queue, it) \
	for (_q_iter_init(queue, it); (it)->it_iter; _q_iter_next(it))


#define _Q_INIT()				\
	{					\
		._queue = G_QUEUE_INIT,	\
	}

/* Called to initialize a queue. */
static inline void _q_init(struct _queue *queue)
{
	g_queue_init(&queue->_queue);
}

/* Called to find the size of a queue. */
static inline guint _q_size(struct _queue *queue)
{
	return g_queue_get_length(&queue->_queue);
}

/* Called to add an item to the head of a queue. */
static inline guint _q_add_head(struct _queue *queue, gpointer data)
{
	g_queue_push_head(&queue->_queue, data);
	return 0;
}

/* Called to add an item to the tail of a queue. */
static inline guint _q_add_tail(struct _queue *queue, gpointer data)
{
	g_queue_push_tail(&queue->_queue, data);
	return _q_size(queue) - 1;
}

/* Called to add an item to a sorted queue. */
guint _q_add_sorted(struct _queue *, gpointer, GCompareDataFunc, gpointer);

/* Called to remove all items from a queue */
static inline void _q_clear(struct _queue *queue)
{
	g_queue_clear(&queue->_queue);
}

/* Called to remove an item by iterator. */
gpointer _q_remove_it(struct _queue *, struct _q_iter *);

/* Called to sort the queue. */
static inline void _q_sort(struct _queue *queue, GCompareDataFunc func,
			   gpointer user_data)
{
	g_queue_sort(&queue->_queue, func, user_data);
}

#endif /* OCARINA_CORE_CONTAINERS_QUEUE_H */