/**
 * 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;


Queue :: Queue(unsigned int flags)
       : _cur(-1), _flags(flags), _length(0), _notify(&def_notify)
{}

Queue :: Queue()
       : _cur(-1), _flags(0), _length(0), _notify(&def_notify)
{}

Queue :: ~Queue()
{}

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

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

void Queue :: set_flag(queue_flags flag)
{
	_flags |= flag;
}

void Queue :: unset_flag(queue_flags flag)
{
	_flags &= ~flag;
}

bool Queue :: has_flag(queue_flags flag)
{
	return (_flags & flag) == (unsigned int)flag;
}

void Queue :: set_notifier(QNotifier *notify)
{
	_notify = 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;
}

unsigned int Queue :: find_sorted_id(struct track *rhs)
{
	struct track *lhs;
	unsigned int begin = 0, end = (_tracks.size() - 1), mid;

	if (_tracks.size() == 0)
		return 0;

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

	lhs = _tracks[begin];
	if (track_less_than(lhs, rhs, _sort_order))
		return begin + 1;
	return begin;
}

unsigned int Queue :: _add_at(struct track *track, unsigned int pos)
{
	_tracks.insert(_tracks.begin() + pos, track);
	_length += track->tr_length;
	_notify->on_track_added(pos);
	return pos;
}

unsigned int Queue :: add(struct track *track)
{
	unsigned int id = _tracks.size();
	if (_sort_order.size() > 0)
		id = find_sorted_id(track);
	return _add_at(track, id);
}

void Queue :: del(unsigned int index)
{
	_length -= _tracks[index]->tr_length;
	_tracks.erase(_tracks.begin() + index);
	_notify->on_track_removed(index);
}

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

void Queue :: updated(struct track *track)
{
	for (unsigned int i = 0; i < _tracks.size(); i++) {
		if (_tracks[i] == track)
			_notify->on_track_updated(i);
	}
}

struct track *Queue :: next()
{
	struct track *res;

	if (_tracks.size() == 0)
		return NULL;
	else if (_tracks.size() == 1)
		_cur = 0;
	else if (_flags & Q_RANDOM)
		_cur += random_range(1, _tracks.size() / 2);
	else
		_cur++;

	_cur %= _tracks.size();
	res = _tracks[_cur];
	if (!(_flags & Q_REPEAT)) {
		del(_cur);
		_cur--;
	}
	return res;
}

unsigned int Queue :: size()
{
	return _tracks.size();
}

unsigned int Queue :: length()
{
	return _length;
}

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(compare_t field, bool reset)
{
	bool found = false;
	struct sort_info info = { field, true };

	if (_flags & Q_NO_SORT)
		return;
	if (reset)
		_sort_order.clear();

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

	if (!found)
		_sort_order.push_back(info);

	std::stable_sort(_tracks.begin(), _tracks.end(), SortTracks(_sort_order));

	for (unsigned int i = 0; i < _tracks.size(); i++)
		_notify->on_track_updated(i);
}

struct track *Queue :: operator[](unsigned int index)
{
	return _tracks[index];
}

void Queue :: track_selected(unsigned int index)
{
	_cur = index;
	if (has_flag(Q_REPEAT) == false) {
		del(_cur);
		_cur--;
	}
}