/*
 * 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);

	if (queue_has_flag(queue, Q_REPEAT) == false)
		__queue_remove(queue, &queue->q_cur);
	else
		__queue_updated(queue, pos);
	return track;
}

void queue_init(struct queue *queue, unsigned int flags,
		const struct queue_ops *ops, void *data)
{
	queue->q_flags  = flags;
	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;
}

void queue_save_flags(struct queue *queue, struct file *file, bool iter)
{
	GSList *cur = queue->q_sort;
	int field;

	if (iter)
		file_writef(file, "%u ", queue->q_cur.it_pos);

	file_writef(file, "%u %u", queue->q_flags, g_slist_length(cur));
	while (cur) {
		field = GPOINTER_TO_INT(cur->data);
		file_writef(file, " %u %d", abs(field) - 1, field > 0);
		cur = g_slist_next(cur);
	}
	file_writef(file, "\n");
}

void queue_save_tracks(struct queue *queue, struct file *file)
{
	struct queue_iter it;

	file_writef(file, "%u", queue_size(queue));
	queue_for_each(queue, &it)
		file_writef(file, " %u", track_index(queue_iter_val(&it)));
	file_writef(file, "\n");
}

void queue_load_flags(struct queue *queue, struct file *file, bool iter)
{
	unsigned int flags, n, i;
	int field, ascending;
	unsigned int it = 0;
	gchar *line;

	if (iter)
		file_readf(file, "%u", &it);

	file_readf(file, "%u %u", &flags, &n);
	for (i = 0; i < n; i++) {
		file_readf(file, "%u %d", &field, &ascending);
		queue_sort(queue, field + 1, (i == 0) ? true : false);
		if (ascending == false)
			queue_sort(queue, field + 1, false);
	}

	flags &= Q_UNUSED_MASK;
	queue->q_flags |= flags;
	queue->q_cur.it_pos = it;

	if (file_readf(file, "%m\n", &line))
		g_free(line);
}

void queue_load_tracks(struct queue *queue, struct file *file)
{
	unsigned int i, n, t;
	gchar *line;

	file_readf(file, "%u ", &n);
	for (i = 0; i < n; i++) {
		file_readf(file, "%u", &t);
		queue_add(queue, track_get(t));
	}

	if (file_readf(file, "%m\n", &line))
		g_free(line);
}

void queue_set_flag(struct queue *queue, enum queue_flags flag)
{
	queue->q_flags |= flag;
}

void queue_unset_flag(struct queue *queue, enum queue_flags flag)
{
	if (!queue_has_flag(queue, flag))
		return;
	queue->q_flags &= ~flag;
}

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);
}

struct track *queue_next(struct queue *queue)
{
	unsigned int pos, size = queue_size(queue);

	if (size == 0)
		return NULL;
	else if (size == 1)
		queue_iter_set(queue, &queue->q_cur, 0);
	else if (queue_has_flag(queue, Q_RANDOM)) {
		pos = g_random_int_range(1, (size < 15) ? size : size / 3);
		pos += queue->q_cur.it_pos;
		queue_iter_set(queue, &queue->q_cur, pos % size);
	} else {
		queue_iter_next(&queue->q_cur);
		if (!queue->q_cur.it_iter)
			queue_iter_set(queue, &queue->q_cur, 0);
	}

	return __queue_selected(queue, queue->q_cur.it_pos);
}

void queue_resort(struct queue *queue)
{
	g_queue_sort(&queue->q_tracks, track_less_than, queue->q_sort);

	queue_iter_set(queue, &queue->q_cur, queue->q_cur.it_pos);
	for (unsigned int i = 0; i < queue_size(queue); i++)
		__queue_updated(queue, i);
}

void queue_sort(struct queue *queue, enum compare_t sort, bool reset)
{
	GSList *cur = NULL;
	int field;

	if (reset) {
		g_slist_free(queue->q_sort);
		queue->q_sort = NULL;
	}

	cur = queue->q_sort;
	while (cur) {
		field = GPOINTER_TO_INT(cur->data);
		if (abs(field) == sort) {
			cur->data = GINT_TO_POINTER(-field);
			goto out_sort;
		}
		cur = g_slist_next(cur);
	}

	queue->q_sort = g_slist_append(queue->q_sort, GINT_TO_POINTER(sort));

out_sort:
	queue_resort(queue);
}