///////////////////////////////////////////////////////////////////////////////
// LameXP - Audio Encoder Front-End
// Copyright (C) 2004-2011 LoRd_MuldeR <MuldeR2@GMX.de>
//
// This program 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.
//
// This program 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 this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
// http://www.gnu.org/licenses/gpl-2.0.txt
///////////////////////////////////////////////////////////////////////////////

#include "PlaylistImporter.h"

#include <QString>
#include <QStringList>
#include <QDir>
#include <QFileInfo>
#include <QProcess>
#include <QDate>
#include <QTime>
#include <QDebug>
#include <QTextCodec>

//Un-escape XML characters
static const struct
{
	char *escape;
	char *output;
}
g_xmlEscapeSequence[] =
{
	{"&amp;", "&"},
	{"&lt;", "<"},
	{"&gt;", ">"},
	{"&apos;", "'"},
	{"&nbsp;", " "},
	{"&quot;", "\""},
	{NULL, NULL}
};

const char *PlaylistImporter::supportedExtensions = "*.m3u *.m3u8 *.pls *.asx *.wpl";


////////////////////////////////////////////////////////////
// Public Functions
////////////////////////////////////////////////////////////

bool PlaylistImporter::importPlaylist(QStringList &fileList, const QString &playlistFile)
{
	QFileInfo file(playlistFile);
	QDir baseDir(file.canonicalPath());

	QDir rootDir(baseDir);
	while(rootDir.cdUp());

	//Sanity check
	if(file.size() < 3 || file.size() > 512000)
	{
		return false;
	}
	
	//Detect playlist type
	playlist_t playlistType = isPlaylist(file.canonicalFilePath());

	//Exit if not a playlist
	if(playlistType == notPlaylist)
	{
		return false;
	}
	
	QFile data(playlistFile);

	//Open file for reading
	if(!data.open(QIODevice::ReadOnly))
	{
		return false;
	}

	//Skip very large files (parsing could take very long)
	if(data.size() >= 10485760i64)
	{
		qWarning("File is very big. Probably not a Playlist. Rejecting...");
		return false;
	}

	//Parse playlist depending on type
	switch(playlistType)
	{
	case m3uPlaylist:
		return parsePlaylist_m3u(data, fileList, baseDir, rootDir);
		break;
	case plsPlaylist:
		return parsePlaylist_pls(data, fileList, baseDir, rootDir);
		break;
	case wplPlaylist:
		return parsePlaylist_wpl(data, fileList, baseDir, rootDir);
		break;
	default:
		return false;
		break;
	}
}

////////////////////////////////////////////////////////////
// Private Functions
////////////////////////////////////////////////////////////

PlaylistImporter::playlist_t PlaylistImporter::isPlaylist(const QString &fileName)
{
	QFileInfo file (fileName);
	
	if(file.suffix().compare("m3u", Qt::CaseInsensitive) == 0 || file.suffix().compare("m3u8", Qt::CaseInsensitive) == 0)
	{
		return m3uPlaylist;
	}
	else if(file.suffix().compare("pls", Qt::CaseInsensitive) == 0)
	{
		return  plsPlaylist;
	}
	else if(file.suffix().compare("asx", Qt::CaseInsensitive) == 0 || file.suffix().compare("wpl", Qt::CaseInsensitive) == 0)
	{
		return  wplPlaylist;
	}
	else
	{
		return notPlaylist;
	}
}

bool PlaylistImporter::parsePlaylist_m3u(QFile &data, QStringList &fileList, const QDir &baseDir, const QDir &rootDir)
{
	const QTextCodec *codec = QTextCodec::codecForName("System");
	const bool preferUTF8 = data.fileName().endsWith(".m3u8", Qt::CaseInsensitive);
	bool foundAtLeastOneFile = false;
	
	data.reset();

	while(!data.atEnd())
	{
		QString filePath[3];
		QByteArray line = data.readLine();

		if(preferUTF8)
		{
			filePath[0] = QString(QDir::fromNativeSeparators(QString::fromUtf8(line.constData(), line.size()).trimmed()));
			filePath[1] = QString(QDir::fromNativeSeparators(codec->toUnicode(line.constData(), line.size()).trimmed()));
			filePath[2] = QString(QDir::fromNativeSeparators(QString::fromLatin1(line.constData(), line.size()).trimmed()));
		}
		else
		{
			filePath[0] = QString(QDir::fromNativeSeparators(codec->toUnicode(line.constData(), line.size()).trimmed()));
			filePath[1] = QString(QDir::fromNativeSeparators(QString::fromLatin1(line.constData(), line.size()).trimmed()));
			filePath[2] = QString(QDir::fromNativeSeparators(QString::fromUtf8(line.constData(), line.size()).trimmed()));
		}

		for(size_t i = 0; i < 3; i++)
		{
			if(!(filePath[i].isEmpty() || filePath[i].startsWith("#") || filePath[i].contains(QChar(QChar::ReplacementCharacter))))
			{
				QFileInfo filename(filePath[i]);
				filename.setCaching(false);
				fixFilePath(filename, baseDir, rootDir);

				if(filename.exists() && filename.isFile())
				{
					qDebug("Found: \"%s\"", filePath[i].toUtf8().constData());
					if(isPlaylist(filename.canonicalFilePath()) == notPlaylist)
					{
						fileList << filename.canonicalFilePath();
					}
					foundAtLeastOneFile = true;
					break;
				}
			}
		}
	}

	//If we did not find any files yet, try UTF-16 now
	if(!foundAtLeastOneFile)
	{
		const char* codecs[2] = {"UTF-16LE", "UTF-16BE"};

		for(size_t i = 0; i < 2; i++)
		{
			QTextStream stream(&data);
			stream.setAutoDetectUnicode(false);
			stream.setCodec(codecs[i]);
			stream.seek(0i64);

			while(!stream.atEnd())
			{
				QString filePath = stream.readLine().trimmed();

				if(!(filePath.isEmpty() || filePath.startsWith("#") || filePath.contains(QChar(QChar::ReplacementCharacter))))
				{
					QFileInfo filename(filePath);
					filename.setCaching(false);
					fixFilePath(filename, baseDir, rootDir);

					if(filename.exists() && filename.isFile())
					{
						if(isPlaylist(filename.canonicalFilePath()) == notPlaylist)
						{
							fileList << filename.canonicalFilePath();
						}
						foundAtLeastOneFile = true;
					}
				}
			}

			if(foundAtLeastOneFile) break;
		}
	}

	return true;
}

bool PlaylistImporter::parsePlaylist_pls(QFile &data, QStringList &fileList, const QDir &baseDir, const QDir &rootDir)
{
	QRegExp plsEntry("File(\\d+)=(.+)", Qt::CaseInsensitive);
	const QTextCodec *codec = QTextCodec::codecForName("System");
	bool foundAtLeastOneFile = false;

	data.reset();

	while(!data.atEnd())
	{
		QString filePath[3];
		QByteArray line = data.readLine();

		filePath[0] = QString(QDir::fromNativeSeparators(codec->toUnicode(line.constData(), line.size()).trimmed()));
		filePath[1] = QString(QDir::fromNativeSeparators(QString::fromLatin1(line.constData(), line.size()).trimmed()));
		filePath[2] = QString(QDir::fromNativeSeparators(QString::fromUtf8(line.constData(), line.size()).trimmed()));
		
		for(size_t i = 0; i < 3; i++)
		{
			if(!filePath[i].contains(QChar(QChar::ReplacementCharacter)))
			{
				if(plsEntry.indexIn(filePath[i]) >= 0)
				{
					QFileInfo filename(QDir::fromNativeSeparators(plsEntry.cap(2)).trimmed());
					filename.setCaching(false);
					fixFilePath(filename, baseDir, rootDir);

					if(filename.exists() && filename.isFile())
					{
						if(isPlaylist(filename.canonicalFilePath()) == notPlaylist)
						{
							fileList << filename.canonicalFilePath();
						}
						foundAtLeastOneFile = true;
						break;
					}
				}
			}
		}
	}

	//If we did not find any files yet, try UTF-16 now
	if(!foundAtLeastOneFile)
	{
		const char* codecs[2] = {"UTF-16LE", "UTF-16BE"};

		for(size_t i = 0; i < 2; i++)
		{
			QTextStream stream(&data);
			stream.setAutoDetectUnicode(false);
			stream.setCodec(codecs[i]);
			stream.seek(0i64);

			while(!stream.atEnd())
			{
				QString filePath = stream.readLine().trimmed();

				if(!filePath.contains(QChar(QChar::ReplacementCharacter)))
				{
					if(plsEntry.indexIn(filePath) >= 0)
					{
						QFileInfo filename(QDir::fromNativeSeparators(plsEntry.cap(2)).trimmed());
						filename.setCaching(false);
						fixFilePath(filename, baseDir, rootDir);

						if(filename.exists() && filename.isFile())
						{
							if(isPlaylist(filename.canonicalFilePath()) == notPlaylist)
							{
								fileList << filename.canonicalFilePath();
							}
							foundAtLeastOneFile = true;
						}
					}
				}
			}

			if(foundAtLeastOneFile) break;
		}
	}

	return true;
}

bool PlaylistImporter::parsePlaylist_wpl(QFile &data, QStringList &fileList, const QDir &baseDir, const QDir &rootDir)
{
	QRegExp skipData("<!--(.+)-->", Qt::CaseInsensitive);
	QRegExp wplEntry("<(media|ref)[^<>]*(src|href)=\"([^\"]+)\"[^<>]*>", Qt::CaseInsensitive);
	
	skipData.setMinimal(true);

	QByteArray buffer = data.readAll();
	QString line = QString::fromUtf8(buffer.constData(), buffer.size()).simplified();
	buffer.clear();

	int index = 0;

	while((index = skipData.indexIn(line)) >= 0)
	{
		line.remove(index, skipData.matchedLength());
	}

	int offset = 0;

	while((offset = wplEntry.indexIn(line, offset) + 1) > 0)
	{
		QFileInfo filename(QDir::fromNativeSeparators(unescapeXml(wplEntry.cap(3)).trimmed()));
		filename.setCaching(false);
		fixFilePath(filename, baseDir, rootDir);

		if(filename.exists() && filename.isFile())
		{
			if(isPlaylist(filename.canonicalFilePath()) == notPlaylist)
			{
				fileList << filename.canonicalFilePath();
			}
		}
	}

	return true;
}

void PlaylistImporter::fixFilePath(QFileInfo &filename, const QDir &baseDir, const QDir &rootDir)
{
	if(filename.filePath().startsWith("/"))
	{
		while(filename.filePath().startsWith("/"))
		{
			filename.setFile(filename.filePath().mid(1));
		}
		filename.setFile(rootDir.filePath(filename.filePath()));
	}
	
	if(!filename.isAbsolute())
	{
		filename.setFile(baseDir.filePath(filename.filePath()));
	}
}

QString &PlaylistImporter::unescapeXml(QString &str)
{
	for(int i = 0; (g_xmlEscapeSequence[i].escape && g_xmlEscapeSequence[i].output); i++)
	{
		str.replace(g_xmlEscapeSequence[i].escape, g_xmlEscapeSequence[i].output);
	}
	
	return str;
}
