/*
 * Copyright 2013 (c) Anna Schumaker.
 */
#include <core/queue.h>
#include <core/string.h>
#include <stdlib.h>


static int track_less_than(const void *a, const void *b, void *data)
{
	struct track *lhs   = (struct track *)a;
	struct track *rhs   = (struct track *)b;
	GSList *cur = (GSList *)data;
	int res, field;

	while (cur) {
		field = GPOINTER_TO_INT(cur->data);
		if (field > 0)
			res = track_compare(lhs, rhs, field);
		else
			res = track_compare(rhs, lhs, abs(field));
		if (res == 0) {
			cur = g_slist_next(cur);
			continue;
		}
		break;
	};
	return res;
}

static inline void *__queue_init(struct queue *queue, void *data)
{
	if (queue->q_ops)
		return queue->q_ops->qop_init(queue, data);
	return NULL;
}

static inline void __queue_deinit(struct queue *queue)
{
	if (queue->q_ops)
		queue->q_ops->qop_deinit(queue);
}

static inline unsigned int __queue_added(struct queue *queue,
					 struct track *track,
					 unsigned int pos)
{
	queue->q_length += track->tr_length;
	if (queue->q_ops)
		queue->q_ops->qop_added(queue, pos);
	return pos;
}

static inline unsigned int __queue_add_head(struct queue *queue,
					    struct track *track)
{
	g_queue_push_head(&queue->q_tracks, track);
	return __queue_added(queue, track, 0);
}

static inline unsigned int __queue_add_tail(struct queue *queue,
					    struct track *track)
{
	g_queue_push_tail(&queue->q_tracks, track);
	return __queue_added(queue, track, queue_size(queue) - 1);
}

static inline unsigned int __queue_add_sorted(struct queue *queue,
					      struct track *track)
{
	struct queue_iter it;

	queue_for_each(queue, &it) {
		if (track_less_than(queue_iter_val(&it), track, queue->q_sort) > 0) {
			g_queue_insert_before(&queue->q_tracks, it.it_iter, track);
			return __queue_added(queue, track, it.it_pos);
		}
	}
	return __queue_add_tail(queue, track);
}

static inline void __queue_remove(struct queue *queue, struct queue_iter *it)
{
	struct track *track = queue_iter_val(it);
	unsigned int pos = it->it_pos;
	GList *link = it->it_iter;

	queue_iter_prev(it);
	g_queue_delete_link(&queue->q_tracks, link);

	queue->q_length -= track->tr_length;
	if (queue->q_ops)
		queue->q_ops->qop_removed(queue, pos);
}

static inline void __queue_clear(struct queue *queue, unsigned int n)
{
	queue->q_length = 0;
	if (queue->q_ops)
		queue->q_ops->qop_cleared(queue, n);
}

static inline void __queue_updated(struct queue *queue, unsigned int pos)
{
	if (queue->q_ops)
		queue->q_ops->qop_updated(queue, pos);
}

static inline struct track *__queue_selected(struct queue *queue, unsigned int pos)
{
	struct track *track = queue_iter_val(&queue->q_cur);

	__queue_updated(queue, pos);
	return track;
}

void queue_init(struct queue *queue, const struct queue_ops *ops, void *data)
{
	queue->q_length = 0;
	queue->q_sort   = NULL;
	queue->q_ops    = ops;

	g_queue_init(&queue->q_tracks);
	queue_iter_init(queue, &queue->q_cur);

	queue->q_private = __queue_init(queue, data);
}

void queue_deinit(struct queue *queue)
{
	queue_clear(queue);
	__queue_deinit(queue);
	g_slist_free(queue->q_sort);
	queue->q_sort   = NULL;
}

unsigned int queue_add(struct queue *queue, struct track *track)
{
	if (queue->q_sort)
		return __queue_add_sorted(queue, track);
	return __queue_add_tail(queue, track);
}

unsigned int queue_add_front(struct queue *queue, struct track *track)
{
	return __queue_add_head(queue, track);
}

void queue_remove(struct queue *queue, unsigned int index)
{
	struct queue_iter it;

	queue_iter_set(queue, &it, index);
	__queue_remove(queue, &it);
}

unsigned int queue_remove_all(struct queue *queue, struct track *track)
{
	unsigned int count = 0;
	struct queue_iter it;

	while (queue_at(queue, 0) == track) {
		queue_remove(queue, 0);
		count++;
	}

	queue_for_each(queue, &it) {
		if (queue_iter_val(&it) == track) {
			__queue_remove(queue, &it);
			count++;
		}
	}

	return count;
}

void queue_clear(struct queue *queue)
{
	unsigned int n = queue_size(queue);

	g_queue_clear(&queue->q_tracks);
	__queue_clear(queue, n);
}

bool queue_has(struct queue *queue, struct track *track)
{
	struct queue_iter it;

	queue_for_each(queue, &it) {
		if (queue_iter_val(&it) == track)
			return true;
	}
	return false;
}

void queue_updated(struct queue *queue, struct track *track)
{
	struct queue_iter it;

	queue_for_each(queue, &it) {
		if (queue_iter_val(&it) == track)
			__queue_updated(queue, it.it_pos);
	}
}

struct track *queue_selected(struct queue *queue, unsigned int index)
{
	if (index > queue_size(queue))
		return NULL;
	if (queue->q_cur.it_pos != index)
		queue_iter_set(queue, &queue->q_cur, index);
	return __queue_selected(queue, index);
}