/*
 * Copyright 2013 (c) Anna Schumaker.
 */
#include <callback.h>
#include <library.h>
#include <queue.h>

#include <stdlib.h>
#include <algorithm>
#include <sstream>

#define O_MINUTES (60)
#define O_HOURS   (60 * O_MINUTES)
#define O_DAYS    (24 * O_HOURS)

Queue :: Queue()
	 : flags(0), cur(-1), length(0)
{
}

Queue :: Queue(queue_flags f)
	 : flags(f), cur(-1), length(0)
{
}

Queue :: ~Queue()
{
}

void Queue :: write(File &f)
{
	f << flags << " " << tracks.size();
	for (unsigned int i = 0; i < tracks.size(); i++)
		f << " " << tracks[i];
}

void Queue :: read(File &f)
{
	unsigned int n;
	f >> flags >> n;
	tracks.resize(n);
	for (unsigned int i = 0; i < n; i++)
		f >> tracks[i];
}

void Queue :: set_flag(queue_flags f)
{
	flags |= f;
	get_callbacks()->on_queue_changed();
}

void Queue :: unset_flag(queue_flags f)
{
	flags &= ~f;
	get_callbacks()->on_queue_changed();
}

const unsigned int Queue :: get_flags()
{
	return flags;
}

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

static inline void add_duration(std::stringstream &ss, unsigned int dur,
				unsigned int remaining, const std::string &field)
{
	if (dur > 0) {
		ss << dur << " " << field;
		if (dur > 1)
			ss << "s";
		if (remaining > 0)
			ss << ", ";
	}
}

std::string Queue :: get_length_str()
{
	std::stringstream ss;
	unsigned int len = length;

	unsigned int days = len / O_DAYS;
	len -= days * O_DAYS;
	add_duration(ss, days, len, "day");

	unsigned int hours = len / O_HOURS;
	len -= hours *O_HOURS;
	add_duration(ss, hours, len, "hour");
	unsigned int mins = len / O_MINUTES;
	add_duration(ss, mins, len, "minute");
	unsigned int secs = len - (mins * O_MINUTES);
	add_duration(ss, secs, 0, "second");

	return ss.str();
}

/*
 * std::string.compare() returns
 *	  0: Strings are equal
 *	< 0: a < b
 *	> 0: a > b
 */
static inline int track_compare(Track *lhs, Track *rhs, sort_t field)
{
	int ret = lhs->less_than(rhs, field);
	if (field == SORT_YEAR && ret == 0)
		ret = lhs->less_than(rhs, SORT_ALBUM);
	return ret;
}

static bool track_less_than(Track *lhs, Track *rhs, std::list<sort_info> &order)
{
	std::list<sort_info>::iterator it;
	int res;

	for (it = order.begin(); it != order.end(); it++) {
		if (it->ascending == true)
			res = track_compare(lhs, rhs, it->field);
		else
			res = track_compare(rhs, lhs, it->field);
		if (res != 0)
			return res < 0;
	}
	return res;
}

unsigned int Queue :: find_sorted_id(Track *rhs)
{
	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 = tagdb :: lookup(tracks[mid]);
		if (track_less_than(lhs, rhs, sort_order))
			begin = mid + 1;
		else {
			if (mid == begin)
				return begin;
			else
				end = mid - 1;
		}
	}

	lhs = tagdb :: lookup(tracks[begin]);
	if (track_less_than(lhs, rhs, sort_order))
		return begin + 1;
	return begin;
}

unsigned int Queue :: add(unsigned int track_id)
{
	unsigned int id = tracks.size();
	Track *track = tagdb :: lookup(track_id);

	if (sort_order.size() > 0)
		id = find_sorted_id(track);

	tracks.insert(tracks.begin() + id, track_id);
	length += track->length;
	get_callbacks()->on_queue_track_add(this, id);
	if (!(flags & Q_DISABLE_CHANGED_SIZE))
		get_callbacks()->on_queue_changed();
	return id;
}

unsigned int Queue :: add_front(unsigned int track_id)
{
	Track *track;
	tracks.insert(tracks.begin(), track_id);

	track = tagdb :: lookup(track_id);
	length += track->length;
	get_callbacks()->on_queue_track_add(this, 0);
	if (!(flags & Q_DISABLE_CHANGED_SIZE))
		get_callbacks()->on_queue_changed();
	return 0;
}

void Queue :: del(unsigned int plist_id)
{
	Track *track;
	unsigned int track_id = tracks[plist_id];

	tracks.erase(tracks.begin() + plist_id);
	track = tagdb :: lookup(track_id);
	length -= track->length;
	get_callbacks()->on_queue_track_del(this, plist_id);
	if (!(flags & Q_DISABLE_CHANGED_SIZE))
		get_callbacks()->on_queue_changed();
}

void Queue :: del_track(unsigned int track_id)
{
	unsigned int i = 0;
	while (i < tracks.size()) {
		if (tracks[i] == track_id)
			del(i);
		else
			i++;
	}
}

void Queue :: track_updated(unsigned int track_id)
{
	for (unsigned int i = 0; i < tracks.size(); i++) {
		if (tracks[i] == track_id)
			get_callbacks()->on_queue_track_changed(this, i);
	}
}

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


/* Sorting function */
class SortTracks {
private:
	std::list<sort_info> fields;
public:
	SortTracks(std::list<sort_info> f) : fields(f) {}
	bool operator()(unsigned int a, unsigned int b)
	{
		Track *lhs = tagdb :: lookup(a);
		Track *rhs = tagdb :: lookup(b);
		return track_less_than(lhs, rhs, fields);
	}
};

void Queue :: _add_sort(sort_t field, bool ascending)
{
	struct sort_info info;
	std::list<sort_info>::iterator it;

	/* Is field already in the sort_order? */
	for (it = sort_order.begin(); it != sort_order.end(); it++) {
		if (it->field == field) {
			it->ascending = !it->ascending;
			return;
		}
	}

	info.field = field;
	info.ascending = ascending;
	sort_order.push_back(info);
	if (sort_order.size() >= 4)
		sort_order.erase(sort_order.begin());
}

void Queue :: add_sort(sort_t field, bool ascending)
{
	if (flags & Q_NEVER_SORT)
		return;

	_add_sort(field, ascending);
	std::stable_sort(tracks.begin(), tracks.end(), SortTracks(sort_order));

	for (unsigned int i = 0; i < tracks.size(); i++)
		get_callbacks()->on_queue_track_changed(this, i);
	get_callbacks()->on_queue_changed();
}

void Queue :: reset_sort(sort_t field, bool ascending)
{
	if (flags & Q_NEVER_SORT)
		return;
	if (sort_order.front().field != field)
		sort_order.clear();
	add_sort(field, ascending);
}

void Queue :: force_clear_sort()
{
	sort_order.clear();
}

std::list<sort_info> &Queue :: get_sort_order()
{
	return sort_order;
}

unsigned int Queue :: operator[](unsigned int i)
{
	return tracks[i];
}

unsigned int Queue :: next()
{
	unsigned int res;

	if (tracks.size() == 0)
		throw -E_EXIST;
	else if (tracks.size() == 1)
		cur = 0;
	else if (flags & Q_RANDOM)
		cur += rand() % (tracks.size() / 2) + 1;
	else
		cur++;

	if (cur >= tracks.size())
		cur -= tracks.size();

	res = tracks[cur];
	if (!(flags & Q_REPEAT)) {
		del(cur);
		cur--;
	}
	return res;
}

void Queue :: set_cur(unsigned int c)
{
	cur = c;
}

void Queue :: path_selected(unsigned int id)
{
	cur = id;
	if (!(flags &Q_REPEAT)) {
		del(cur);
		cur--;
	}
}

#ifdef CONFIG_TEST
void Queue :: reset()
{
	tracks.clear();
	set_cur(0);
}
#endif /* CONFIG_TEST */