/**
 * Copyright 2013 (c) Anna Schumaker.
 */
#include <core/queue.h>
extern "C" {
#include <core/random.h>
}
#include <core/string.h>

#include <algorithm>
#include <sstream>


static class DefaultNotifier : public QNotifier {
public:
	DefaultNotifier() {};
	void on_track_added(unsigned int pos)   {};
	void on_track_removed(unsigned int pos) {};
	void on_track_updated(unsigned int pos) {};
} def_notify;


static bool track_less_than(struct track *lhs, struct track *rhs,
			    std::vector<struct sort_info> &order)
{
	int res;

	for (unsigned int i = 0; i < order.size(); i++) {
		if (order[i].ascending == true)
			res = track_compare(lhs, rhs, order[i].field);
		else
			res = track_compare(rhs, lhs, order[i].field);
		if (res == 0)
			continue;
		break;
	}
	return res < 0;
}


static inline void __queue_save(struct queue *queue, enum queue_flags flag)
{
	if (queue->q_ops && queue_has_flag(queue, flag))
		queue->q_ops->qop_save(queue, flag);
}

static unsigned int __queue_find_sorted_id(struct queue *queue, struct track *rhs)
{
	struct track *lhs;
	unsigned int mid, begin = 0, end = queue_size(queue) - 1;

	if (queue_size(queue) == 0)
		return 0;

	while (end > begin) {
		mid = begin + ((end - begin) / 2);
		lhs = queue->q_tracks[mid];
		if (track_less_than(lhs, rhs, queue->q_sort))
			begin = mid + 1;
		else {
			if (mid == begin)
				return begin;
			else
				end = mid - 1;
		}
	}

	lhs = queue->q_tracks[begin];
	if (track_less_than(lhs, rhs, queue->q_sort))
		return begin + 1;
	return begin;
}


void queue_init(struct queue *queue, unsigned int flags,
		const struct queue_ops *ops)
{
	queue->q_cur    = -1;
	queue->q_flags  = flags;
	queue->q_length = 0;
	queue->q_notify = &def_notify;
	queue->q_ops    = ops;
}

queue :: ~queue()
{}

void queue :: write(file &file)
{
	file_writef(&file, "%u %zu", q_flags, q_tracks.size());
	for (unsigned int i = 0; i < q_tracks.size(); i++)
		file_writef(&file, " %u", q_tracks[i]->tr_dbe.dbe_index);
}

void queue :: read(file &file)
{
	unsigned int n, id;
	file_readf(&file, "%u %u", &q_flags, &n);
	q_tracks.resize(n);
	for (unsigned int i = 0; i < n; i++) {
		file_readf(&file, "%u", &id);
		q_tracks[i] = track_get(id);
		q_length += q_tracks[i]->tr_length;
	}
}

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

void queue_unset_flag(struct queue *queue, enum queue_flags flag)
{
	queue->q_flags &= ~flag;
	__queue_save(queue, Q_SAVE_FLAGS);
}

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

	if (queue_has_flag(queue, Q_ADD_FRONT))
		pos = 0;
	else if (queue->q_sort.size() > 0)
		pos = __queue_find_sorted_id(queue, track);

	queue->q_tracks.insert(queue->q_tracks.begin() + pos, track);
	queue->q_length += track->tr_length;
	queue->q_notify->on_track_added(pos);
	return pos;
}

void queue :: del(unsigned int index)
{
	q_length -= q_tracks[index]->tr_length;
	q_tracks.erase(q_tracks.begin() + index);
	q_notify->on_track_removed(index);

	if (q_cur == index)
		q_cur--;
}

void queue :: del(struct track *track)
{
	for (unsigned int i = 0; i < q_tracks.size(); i++) {
		while ((i < q_tracks.size()) && (q_tracks[i] == track))
			del(i);
	}
}

void queue_updated(struct queue *queue, struct track *track)
{
	for (unsigned int i = 0; i < queue_size(queue); i++) {
		if (queue->q_tracks[i] == track)
			queue->q_notify->on_track_updated(i);
	}
}

void queue_selected(struct queue *queue, unsigned int index)
{
	queue->q_cur = index;
	if (queue_has_flag(queue, Q_REPEAT) == false)
		queue->del(index);
}

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

	if (!queue_has_flag(queue, Q_ENABLED))
		return NULL;
	else if (size == 0)
		return NULL;
	else if (size == 1)
		queue->q_cur = 0;
	else if (queue_has_flag(queue, Q_RANDOM))
		queue->q_cur += random_range(1, size / 2);
	else
		queue->q_cur++;

	queue->q_cur %= size;
	res = queue->q_tracks[queue->q_cur];
	queue_selected(queue, queue->q_cur);
	return res;
}

class SortTracks {
public:
	std::vector<struct sort_info> fields;
	SortTracks(std::vector<sort_info> f) : fields(f) {}
	bool operator()(struct track *lhs, struct track *rhs)
	{
		return track_less_than(lhs, rhs, fields);
	}
};

void queue_sort(struct queue *queue, enum compare_t field, bool reset)
{
	bool found = false;
	struct sort_info info = { field, true };

	if (queue_has_flag(queue, Q_NO_SORT))
		return;
	if (reset)
		queue->q_sort.clear();

	for (unsigned int i = 0; i < queue->q_sort.size(); i++) {
		if (queue->q_sort[i].field == info.field) {
			queue->q_sort[i].ascending = !queue->q_sort[i].ascending;
			found = true;
			break;
		}
	}

	if (!found)
		queue->q_sort.push_back(info);

	std::stable_sort(queue->q_tracks.begin(),
			 queue->q_tracks.end(),
			 SortTracks(queue->q_sort));

	for (unsigned int i = 0; i < queue->q_tracks.size(); i++)
		queue->q_notify->on_track_updated(i);
	__queue_save(queue, Q_SAVE_SORT);
}