/*
 * Cantata
 *
 * Copyright (c) 2011-2022 Craig Drummond <craig.p.drummond@gmail.com>
 *
 */
/*
 * Copyright (c) 2008 Sander Knopper (sander AT knopper DOT tk) and
 *                    Roeland Douma (roeland AT rullzer DOT com)
 *
 * This file is part of QtMPC.
 *
 * QtMPC is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * QtMPC is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with QtMPC.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "song.h"
#include "config.h"
#include <cmath>
#if !defined CANTATA_NO_UI_FUNCTIONS
#include "online/onlineservice.h"
#include "online/podcastservice.h"
#include "support/utils.h"
#endif
#include <QChar>
#include <QLatin1Char>
#include <QMutex>
#include <QMutexLocker>
#include <QSet>
#include <QStringList>
#include <QUrl>
#include <QtAlgorithms>
#include <algorithm>

#if defined CANTATA_NO_UI_FUNCTIONS
#define COMPARE(A, B) A.localeAwareCompare(B)
#else
#define COMPARE(A, B) Utils::compare(A, B)
#endif

//static const quint8 constOnlineDiscId=0xEE;
static const QString constMpdQueue = QLatin1String(".cue/track");// .cue.track0123

const QString Song::constCddaProtocol = QLatin1String("/[cantata-cdda]/");
const QString Song::constMopidyLocal = QLatin1String("local:track:");
const QString Song::constForkedDaapdLocal = QLatin1String("file:");

static QString unknownStr;
static QString variousArtistsStr;
static QString singleTracksStr;
static bool useOrigYear = false;

const QString& Song::unknown()
{
	return unknownStr;
}

const QString& Song::variousArtists()
{
	return variousArtistsStr;
}

const QString& Song::singleTracks()
{
	return singleTracksStr;
}

void Song::initTranslations()
{
	unknownStr = QObject::tr("Unknown");
	variousArtistsStr = QObject::tr("Various Artists");
	singleTracksStr = QObject::tr("Single Tracks");
}

// When displaying albums, we use the 1st track's year as the year of the album.
// The map below stores the mapping from artist+album to year.
// This way the grouped view can find this quickly...
static QHash<QString, quint16> albumYears;

void Song::storeAlbumYear(const Song& s)
{
	albumYears.insert(s.albumKey(), s.displayYear());
}

int Song::albumYear(const Song& s)
{
	QHash<QString, quint16>::ConstIterator it = albumYears.find(s.albumKey());
	return it == albumYears.end() ? s.displayYear() : it.value();
}

static int songType(const Song& s)
{
	static QStringList extensions = QStringList() << QLatin1String(".flac")
												  << QLatin1String(".wav")
												  << QLatin1String(".dff")
												  << QLatin1String(".dsf")
												  << QLatin1String(".aac")
												  << QLatin1String(".m4a")
												  << QLatin1String(".m4b")
												  << QLatin1String(".m4p")
												  << QLatin1String(".mp4")
												  << QLatin1String(".ogg")
												  << QLatin1String(".opus")
												  << QLatin1String(".mp3")
												  << QLatin1String(".wma");

	for (int i = 0; i < extensions.count(); ++i) {
		if (s.file.endsWith(extensions.at(i), Qt::CaseInsensitive)) {
			return i;
		}
	}

	if (s.isCdda()) {
		return extensions.count() + 2;
	}
	if (s.isStream()) {
		return extensions.count() + 3;
	}
	return extensions.count() + 1;
}

static bool songTypeSort(const Song& s1, const Song& s2)
{
	int t1 = songType(s1);
	int t2 = songType(s2);
	return t1 < t2 || (t1 == t2 && s1.id < s2.id);
}

void Song::sortViaType(QList<Song>& songs)
{
	std::sort(songs.begin(), songs.end(), songTypeSort);
}

QString Song::decodePath(const QString& file, bool cdda)
{
	if (cdda) {
		return QString(file).replace("/", "_").replace(":", "_");
	}
	if (file.startsWith(constMopidyLocal)) {
		return QUrl::fromPercentEncoding(file.mid(constMopidyLocal.length()).toLatin1());
	}
	if (file.startsWith(constForkedDaapdLocal)) {
		return file.mid(constForkedDaapdLocal.length());
	}
	return file;
}

QString Song::encodePath(const QString& file)
{
	return constMopidyLocal + QString(QUrl::toPercentEncoding(file, "/"));
}

static QSet<QString> compGenres;

const QSet<QString>& Song::composerGenres()
{
	return compGenres;
}

void Song::setComposerGenres(const QSet<QString>& g)
{
	compGenres = g;
}

Song::Song()
	: extraFields(0), priority(0), disc(0), blank(0), time(0), track(0), origYear(0), year(0), type(Standard), guessed(false), id(-1), size(0), rating(Rating_Null), lastModified(0), key(Null_Key)
{
}

Song& Song::operator=(const Song& s)
{
	id = s.id;
	file = s.file;
	time = s.time;
	album = s.album;
	artist = s.artist;
	albumartist = s.albumartist;
	title = s.title;
	track = s.track;
	//     pos = s.pos;
	disc = s.disc;
	blank = s.blank;
	priority = s.priority;
	origYear = s.origYear;
	year = s.year;
	for (int i = 0; i < constNumGenres; ++i) {
		genres[i] = s.genres[i];
	}
	size = s.size;
	rating = s.rating;
	key = s.key;
	type = s.type;
	guessed = s.guessed;
	extra = s.extra;
	extraFields = s.extraFields;
	lastModified = s.lastModified;
	return *this;
}

bool Song::operator==(const Song& o) const
{
	return 0 == compareTo(o);
}

bool Song::operator<(const Song& o) const
{
	return compareTo(o) < 0;
}

int Song::compareTo(const Song& o) const
{
	//
	// NOTE: This compare DOES NOT use XXXSORT tags
	//

	if (type != o.type) {
		return type < o.type ? -1 : 1;
	}

	// For playlists, we only need to compare filename...
	if (Playlist != type) {
		if (SingleTracks == type) {
			int compare = COMPARE(artistSong(), o.artistSong());
			if (0 != compare) {
				return compare < 0;
			}
		}

		int compare = COMPARE(albumArtistOrComposer(), o.albumArtistOrComposer());
		if (0 != compare) {
			return compare;
		}
		compare = COMPARE(album, o.album);
		if (0 != compare) {
			return compare;
		}
		compare = COMPARE(mbAlbumId(), o.mbAlbumId());
		if (0 != compare) {
			return compare;
		}
		if (disc != o.disc) {
			return disc < o.disc ? -1 : 1;
		}
		if (track != o.track) {
			return track < o.track ? -1 : 1;
		}
		if (useOrigYear) {
			if (origYear != o.origYear) {
				return origYear < o.origYear ? -1 : 1;
			}
			if (year != o.year) {
				return year < o.year ? -1 : 1;
			}
		}
		else {
			if (year != o.year) {
				return year < o.year ? -1 : 1;
			}
			if (origYear != o.origYear) {
				return origYear < o.origYear ? -1 : 1;
			}
		}
		compare = COMPARE(title, o.title);
		if (0 != compare) {
			return compare;
		}
		compare = COMPARE(name(), o.name());
		if (0 != compare) {
			return compare;
		}
		compare = compareGenres(o);
		if (0 != compare) {
			return compare;
		}
		if (time != o.time) {
			return time < o.time ? -1 : 1;
		}
	}
	return file.compare(o.file);
}

bool Song::isEmpty() const
{
	return (artist.isEmpty() && album.isEmpty() && title.isEmpty() && name().isEmpty()) || file.isEmpty();
}

bool Song::sameMetadata(const Song& o) const
{
	return disc == o.disc && track == o.track && time == o.time && year == o.year && origYear == o.origYear && artist == o.artist && albumartist == o.albumartist && album == o.album && title == o.title;
}

void Song::guessTags()
{
	if (!isStream()) {
		QString newtitle = title;
		QString newalbum = album;
		QString newartist = artist;

		static const QLatin1String constAlbumArtistSep(" - ");
		guessed = true;
		QStringList parts = file.split("/", CANTATA_SKIP_EMPTY);
		if (3 == parts.length()) {
			newtitle = parts.at(2);
			newalbum = parts.at(1);
			newartist = parts.at(0);
		}
		else if (2 == parts.length() && parts.at(0).contains(constAlbumArtistSep)) {
			newtitle = parts.at(1);
			QStringList albumArtistParts = parts.at(0).split(constAlbumArtistSep, CANTATA_SKIP_EMPTY);
			if (2 == albumArtistParts.length()) {
				newalbum = albumArtistParts.at(1);
				newartist = albumArtistParts.at(0);
			}
		}
		else if (!parts.isEmpty()) {
			newtitle = parts.at(parts.length() - 1);
		}

		if (!newtitle.isEmpty()) {
			int dot = newtitle.lastIndexOf('.');
			if (dot > 0 && dot < newtitle.length() - 2) {
				newtitle = newtitle.left(dot);
			}
			static const QSet<QChar> constSeparators = QSet<QChar>() << QLatin1Char(' ') << QLatin1Char('-') << QLatin1Char('_') << QLatin1Char('.');
			int separator = 0;

			for (const QChar& sep : constSeparators) {
				separator = newtitle.indexOf(sep);
				if (1 == separator || 2 == separator) {
					break;
				}
			}

			if ((1 == separator && newtitle[separator - 1].isDigit()) || (2 == separator && newtitle[separator - 2].isDigit() && newtitle[separator - 1].isDigit())) {
				if (0 == track) {
					track = newtitle.left(separator).toInt();
				}
				newtitle = newtitle.mid(separator + 1);

				while (!newtitle.isEmpty() && constSeparators.contains(newtitle[0])) {
					newtitle = newtitle.mid(1);
				}
			}
		}
		title = !title.isEmpty() ? title : newtitle;
		album = !album.isEmpty() ? album : newalbum;
		artist = !artist.isEmpty() ? artist : newartist;
	}
}

void Song::revertGuessedTags()
{
	title = artist = album = unknownStr;
}

void Song::fillEmptyFields()
{
	if (artist.isEmpty()) {
		artist = unknownStr;
		blank |= BlankArtist;
	}
	if (album.isEmpty()) {
		album = unknownStr;
		blank |= BlankAlbum;
	}
	if (title.isEmpty()) {
		title = unknownStr;
		blank |= BlankTitle;
	}
	if (genres[0].isEmpty()) {
		genres[0] = unknownStr;
	}
}

struct KeyStore {
	KeyStore() : currentKey(0) {}
	quint16 currentKey;
	QHash<QString, quint16> keys;
};

static QHash<int, KeyStore> storeMap;
static QMutex storeMapMutex;

void Song::clearKeyStore(int location)
{
	QMutexLocker locker(&storeMapMutex);
	storeMap.remove(location);
}

QString Song::displayAlbum(const QString& albumName, quint16 albumYear)
{
	return albumYear > 0 ? albumName + QLatin1String(" (") + QString::number(albumYear) + QLatin1Char(')') : albumName;
}

static QSet<QString> prefixesToIngore = QSet<QString>() << QLatin1String("The");

QSet<QString> Song::ignorePrefixes()
{
	return prefixesToIngore;
}

void Song::setIgnorePrefixes(const QSet<QString>& prefixes)
{
	prefixesToIngore = prefixes;
}

static QString ignorePrefix(const QString& str)
{
	for (const QString& p : prefixesToIngore) {
		if (str.startsWith(p + QLatin1Char(' '))) {
			return str.mid(p.length() + 1) + QLatin1String(", ") + p;
		}
	}
	return QString();
}

QString Song::sortString(const QString& str)
{
	QString sort = ignorePrefix(str);

	if (sort.isEmpty()) {
		sort = str;
	}
	sort = sort.remove('.');
	return sort == str ? QString() : sort;
}

bool Song::useOriginalYear()
{
	return useOrigYear;
}

void Song::setUseOriginalYear(bool u)
{
	useOrigYear = u;
}

quint16 Song::setKey(int location)
{
	if (isStandardStream()) {
		key = 0;
		return 0;
	}

	QString songKey(albumKey());
	QMutexLocker locker(&storeMapMutex);
	KeyStore& store = storeMap[location];
	QHash<QString, quint16>::ConstIterator it = store.keys.find(songKey);

	if (it != store.keys.end()) {
		key = it.value();
	}
	else {
		store.currentKey++;// Key 0 is for streams, so we need to increment before setting...
		store.keys.insert(songKey, store.currentKey);
		key = store.currentKey;
	}
	return key;
}

bool Song::isUnknownAlbum() const
{
	return (album.isEmpty() || album == unknownStr) && (albumArtist().isEmpty() || albumArtist() == unknownStr);
}

bool Song::isInvalid() const
{
	return 0 == time && guessed && !file.contains("://") && (genres[0].isEmpty() || genres[0] == unknownStr) && name().isEmpty();
}

void Song::clear()
{
	id = -1;
	file.clear();
	time = 0;
	album.clear();
	artist.clear();
	title.clear();
	track = 0;
	//     pos = 0;
	disc = 0;
	blank = 0;
	year = 0;
	origYear = 0;
	for (int i = 0; i < constNumGenres; ++i) {
		genres[i] = QString();
	}
	size = 0;
	extra.clear();
	type = Standard;
}

const QLatin1Char Song::constFieldSep('\001');
const QString Song::constSep = QString::fromUtf8(" \u2022 ");

void Song::addGenre(const QString& g)
{
	for (int i = 0; i < constNumGenres; ++i) {
		if (genres[i].isEmpty()) {
			genres[i] = g;
			break;
		}
	}
}

quint16 Song::displayYear() const
{
	return useOrigYear && origYear > 0 ? origYear : year;
}

QString Song::entryName() const
{
	if (title.isEmpty()) {
		return file;
	}

	return title + constFieldSep + artist + constFieldSep + album;
}

QString Song::albumArtistOrComposer() const
{
	if (useComposer()) {
		QString c = composer();
		if (!c.isEmpty()) {
			return c;
		}
	}
	return albumArtist();
}

QString Song::trackArtistOrComposer() const
{
	if (useComposer()) {
		QString c = composer();
		if (!c.isEmpty()) {
			return c;
		}
	}
	return artist;
}

QString Song::albumName() const
{
	if (useComposer()) {
		QString c = composer();
		if (!c.isEmpty() && c != albumArtist()) {
			return album + QLatin1String(" (") + albumArtist() + QLatin1Char(')');
		}
	}
	return album;
}

QString Song::albumId() const
{
	QString mb = mbAlbumId();
	return mb.isEmpty() ? album : mb;
}

QString Song::artistSong() const
{
	//return artist+constSep+title;
	return title + constSep + artist;
}

QString Song::trackAndTitleStr(bool showArtistIfDifferent) const
{
#if !defined CANTATA_NO_UI_FUNCTIONS
	if ((OnlineSvrTrack == type || CantataStream == type) && OnlineService::showLogoAsCover(*this)) {
		return artistSong();
	}
#endif
	//    if (isFromOnlineService()) {
	//        return (disc>0 && disc!=constOnlineDiscId ? (QString::number(disc)+QLatin1Char('.')) : QString())+
	//               (track>0 ? (track>9 ? QString::number(track) : (QLatin1Char('0')+QString::number(track))) : QString())+
	//               QLatin1Char(' ')+(addArtist ? artistSong() : title);
	//    }
	return//(disc>0 ? (QString::number(disc)+QLatin1Char('.')) : QString())+
			(track > 0 && SingleTracks != type ? (track > 9 ? QString::number(track) + QLatin1Char(' ') : (QLatin1Char('0') + QString::number(track) + QLatin1Char(' '))) : QString()) + (showArtistIfDifferent && diffArtist() ? artistSong() : title) + (origYear > 0 && origYear != year ? QLatin1String(" (") + QString::number(origYear) + QLatin1Char(')') : QString());
}

#ifndef CANTATA_NO_UI_FUNCTIONS
static void addField(const QString& name, const QString& val, QString& tt)
{
	if (!val.isEmpty()) {
		tt += QString("<tr><td align=\"right\"><b>%1:&nbsp;&nbsp;</b></td><td>%2</td></tr>").arg(name).arg(val);
	}
}
#endif

QString Song::toolTip() const
{
#ifdef CANTATA_NO_UI_FUNCTIONS
	return QString();
#else
	QString toolTip = QLatin1String("<table>");
	addField(QObject::tr("Title"), title, toolTip);
	addField(QObject::tr("Artist"), artist, toolTip);
	if (albumartist != artist) {
		addField(QObject::tr("Album artist"), albumartist, toolTip);
	}
	addField(QObject::tr("Composer"), composer(), toolTip);
	addField(QObject::tr("Performer"), performer(), toolTip);
	addField(QObject::tr("Album"), albumName(), toolTip);
	if (track > 0) {
		addField(QObject::tr("Track number"), QString::number(track), toolTip);
	}
	if (disc > 0) {
		addField(QObject::tr("Disc number"), QString::number(disc), toolTip);
	}
	addField(QObject::tr("Genre"), displayGenre(), toolTip);
	if (year > 0) {
		addField(QObject::tr("Year"), QString::number(year), toolTip);
	}
	if (origYear > 0) {
		addField(QObject::tr("Original Year"), QString::number(origYear), toolTip);
	}
	addField(QObject::tr("Grouping"), grouping(), toolTip);
	if (time > 0) {
		addField(QObject::tr("Length"), Utils::formatTime(time, true), toolTip);
	}
	toolTip += QLatin1String("</table>");

	if (isNonMPD()) {
		return toolTip;
	}
	return toolTip + QLatin1String("<br/><br/><small><i>") + filePath() + QLatin1String("</i></small>");
#endif
}

QString Song::displayGenre() const
{
	QString g = genres[0];
	for (int i = 1; i < constNumGenres && !genres[i].isEmpty(); ++i) {
		g += QLatin1String(", ") + genres[i];
	}
	return g;
}

int Song::compareGenres(const Song& o) const
{
	for (int i = 0; i < constNumGenres; ++i) {
		int compare = genres[i].compare(o.genres[i]);
		if (0 != compare) {
			return compare;
		}
	}
	return 0;
}

void Song::setExtraField(quint32 f, const QString& v)
{
	if (v.isEmpty()) {
		extra.remove(f);
		extraFields &= ~f;
	}
	else {
		extra[f] = v;
		extraFields |= f;
	}
}

bool Song::isVariousArtists(const QString& str)
{
	return QLatin1String("Various Artists") == str || variousArtistsStr == str;
}

bool Song::diffArtist() const
{
	return /*isVariousArtists() || */ (!albumartist.isEmpty() && !artist.isEmpty() && albumartist != artist);
}

bool Song::fixVariousArtists()
{
	if (isVariousArtists()) {
		artist.replace(" - ", ", ");
		title = artistSong();
		artist = albumartist;
		return true;
	}
	return false;
}

bool Song::revertVariousArtists()
{
	if (artist == albumartist) {// Then real artist is embedded in track title...
		int sepPos = title.indexOf(QLatin1String(" - "));
		if (sepPos > 0 && sepPos < title.length() - 3) {
			artist = title.left(sepPos);
			title = title.mid(sepPos + 3);
			return true;
		}
	}

	return false;
}

bool Song::setAlbumArtist()
{
	if (!artist.isEmpty() && albumartist.isEmpty()) {
		albumartist = artist;
		return true;
	}
	return false;
}

QString Song::capitalize(const QString& s)
{
	if (s.isEmpty()) {
		return s;
	}

	QStringList words = s.split(' ', CANTATA_SKIP_EMPTY);
	for (int i = 0; i < words.count(); i++) {
		QString word = words[i];//.toLower();
		int j = 0;
		while (j < word.length() && ('(' == word[j] || '[' == word[j] || '{' == word[j])) {
			j++;
		}
		if (j < word.length()) {
			word[j] = word[j].toUpper();
		}
		words[i] = word;
	}
	return words.join(" ");
}

bool Song::capitalise()
{
	QString origArtist = artist;
	QString origAlbumArtist = albumartist;
	QString origAlbum = album;
	QString origTitle = title;

	artist = capitalize(artist);
	albumartist = capitalize(albumartist);
	album = capitalize(album);
	title = capitalize(title);
	QString c = composer();
	if (!c.isEmpty()) {
		setComposer(capitalize(c));
	}
	/* Performer is not currently in tag editor...
    QString p=performer();
    if (!p.isEmpty()) {
        setPerformer(capitalize(p));
    }
    */

	return artist != origArtist || albumartist != origAlbumArtist || album != origAlbum || title != origTitle || (!c.isEmpty() && c != composer()) /*|| (!p.isEmpty() && p!=performer())*/;
}

QString Song::albumKey() const
{
#if !defined CANTATA_NO_UI_FUNCTIONS
	if ((OnlineSvrTrack == type || CantataStream == type) && OnlineService::showLogoAsCover(*this)) {
		return onlineService();
	}
#endif
	return albumArtistOrComposer() + QLatin1Char(':') + albumId();//+QLatin1Char(':')+QString::number(disc);
}

static QString basic(const QString& str, const QStringList& extraToStrip = QStringList())
{
	QStringList toStrip = QStringList() << QLatin1String("ft. ") << QLatin1String("feat. ") << QLatin1String("featuring ") << QLatin1String("f. ")
										<< extraToStrip;
	QStringList prefixes = QStringList() << QLatin1String(" ") << QLatin1String(" (") << QLatin1String(" [");

	for (const QString& s : toStrip) {
		for (const QString& p : prefixes) {
			int strip = str.toLower().indexOf(p + s);
			if (-1 != strip) {
				return str.mid(0, strip);
			}
		}
	}
	return str;
}

QString Song::basicArtist(bool orComposer) const
{
	if (orComposer && useComposer()) {
		QString c = composer();
		if (!c.isEmpty()) {
			return c;
		}
	}

	if (!albumartist.isEmpty() && (artist.isEmpty() || albumartist == artist || (albumartist.length() < artist.length() && artist.startsWith(albumartist)))) {
		return albumartist;
	}

	return basic(artist);
}

QString Song::basicTitle() const
{
	return basic(title, QStringList() << QLatin1String("prod. ") << QLatin1String("prod ") << QLatin1String("producer ") << QLatin1String("produced by "));
}

QString Song::filePath(const QString& base) const
{
	if (isCantataStream()) {
		QString p = localPath();
		return p.isEmpty() ? QUrl(file).path() : p;
	}
	if (isLocalFile()) {
		return file;
	}
	QString fileName = decodePath(file, isCdda());
	int mpdCueIdx = fileName.indexOf(constMpdQueue);
	if (mpdCueIdx == fileName.length() - (constMpdQueue.length() + 4)) {
		fileName = fileName.mid(0, mpdCueIdx + 4);
	}
	if (!base.isEmpty() && !fileName.isEmpty() && !isNonMPD()) {
		bool haveAbsPath = fileName.startsWith("/") || fileName.contains(":/");
		if (!haveAbsPath) {
			return QString(base + fileName);
		}
	}
	return fileName;
}

bool Song::isMpdCueTrack() const
{
	return file.indexOf(constMpdQueue) == file.length() - (constMpdQueue.length() + 4);
}

QString Song::getDir() const
{
#ifdef CANTATA_NO_UI_FUNCTIONS
	return QString();
#else
	QString dir = Utils::getDir(file);
	if (isMpdCueTrack() && dir.endsWith(".cue/")) {
		dir = Utils::getDir(dir.left(dir.length() - 1));
	}
	return dir;
#endif
}

QString Song::describe() const
{
#if !defined CANTATA_NO_UI_FUNCTIONS
	if (OnlineSvrTrack == type && PodcastService::constName == onlineService()) {
		return title;
	}
#endif

	QString albumText = album.isEmpty() ? name() : displayAlbum(album, Song::albumYear(*this));

	if (title.isEmpty()) {
		return QLatin1String("<b>") + albumText + QLatin1String("</b>");
	}
	return artist.isEmpty()
			? QObject::tr("<b>%1</b> on <b>%2</b>", "Song on Album").arg(title).arg(albumText)
			: QObject::tr("<b>%1</b> by <b>%2</b> on <b>%3</b>", "Song by Artist on Album").arg(title).arg(artist).arg(albumText);
}

QString Song::mainText() const
{
	if (isEmpty()) {
		return QString();
	}

	QString n = name();
	if (isStream() && !isCantataStream() && !isCdda() && !isDlnaStream()) {
		return n.isEmpty() ? Song::unknown() : n;
	}
	else if (title.isEmpty() && artist.isEmpty() && (!n.isEmpty() || !file.isEmpty())) {
		return n.isEmpty() ? file : n;
	}
	else {
		return title + (origYear > 0 && !Song::useOriginalYear() && origYear != year ? QLatin1String(" (") + QString::number(origYear) + QLatin1Char(')') : QString());
	}
}

QString Song::subText() const
{
	if (isEmpty()) {
		return QString();
	}

	if (isStream() && !isCantataStream() && !isCdda() && !isDlnaStream()) {
		if (artist.isEmpty() && title.isEmpty() && !name().isEmpty()) {
			return QObject::tr("(Stream)");
		}
		else {
			return artist.isEmpty() ? title : artistSong();
		}
	}
	else if (album.isEmpty() && artist.isEmpty() && (!useComposer() || composer().isEmpty())) {
		return mainText().isEmpty() ? QString() : Song::unknown();
	}
	else {
		QString comp = useComposer() ? composer() : QString();
		if (album.isEmpty()) {
			return artist.isEmpty() ? comp : comp.isEmpty() ? artist
															: (comp + constSep + artist);
		}
		else {
			// Artist here is always artist (or 'composer - artist'), and not album artist
			return (artist.isEmpty() ? comp : comp.isEmpty() ? artist
			                                                 : (comp + constSep + artist))
					+ constSep + displayAlbum(!comp.isEmpty());
		}
	}
}

bool Song::useComposer() const
{
	if (compGenres.isEmpty()) {
		return false;
	}

	for (int i = 0; i < constNumGenres && !genres[i].isEmpty(); ++i) {
		if (compGenres.contains(genres[i])) {
			return true;
		}
	}
	return false;
}

void Song::populateSorts()
{
	if (!hasArtistSort()) {
		QString val = sortString(artist);
		if (val != artist) {
			setArtistSort(val);
		}
	}
	if (!albumartist.isEmpty() && !hasAlbumArtistSort()) {
		QString val = sortString(albumartist);
		if (val != albumartist) {
			setAlbumArtistSort(val);
		}
	}
	if (!hasAlbumSort()) {
		QString val = sortString(album);
		if (val != album) {
			setAlbumSort(val);
		}
	}
}

void Song::setFromSingleTracks()
{
	albumartist = variousArtists();
	album = singleTracks();
	type = SingleTracks;
	setAlbumArtistSort(QString());
	setAlbumSort(QString());
	setMbAlbumId(QString());
}

//QString Song::basicDescription() const
//{
//    return isStandardStream()
//            ? name
//            : title.isEmpty()
//                ? QString()
//                : artist.isEmpty()
//                    ? title
//                    : trc("track – artist", "%1 – %2", title, artist);
//}

QDataStream& operator<<(QDataStream& stream, const Song& song)
{
	stream << song.id << song.file << song.album << song.artist << song.albumartist << song.title
		   << song.disc << song.priority << song.time << song.track << (quint16)song.year// << song.origYear
		   << (quint16)song.type << (bool)song.guessed << song.size << song.extra << song.extraFields;
	for (int i = 0; i < Song::constNumGenres; ++i) {
		stream << song.genres[i];
	}
	return stream;
}

QDataStream& operator>>(QDataStream& stream, Song& song)
{
	quint16 type;
	quint16 year;
	quint8 disc;
	bool guessed;
	stream >> song.id >> song.file >> song.album >> song.artist >> song.albumartist >> song.title
			>> disc >> song.priority >> song.time >> song.track >> year// >> song.origYear
			>> type >> guessed >> song.size >> song.extra >> song.extraFields;
	song.type = (Song::Type)type;
	song.year = year;
	song.guessed = guessed;
	song.disc = disc;
	for (int i = 0; i < Song::constNumGenres; ++i) {
		stream >> song.genres[i];
	}

	return stream;
}