#include "agent.h"

#ifdef Q_OS_UNIX
#include <sys/time.h>
#include <utime.h>
#endif

Agent::Agent(QSslSocket *socket, const QDir& dir, SyncFlags flags, QObject *parent) :
    QObject(parent), _dir(dir), _subPath("/"), _flags(flags), _socket(socket)
{
	connect(_socket, SIGNAL(readyRead()), SLOT(handleDataAvailable()));
	connect(_socket, SIGNAL(sslErrors(QList<QSslError>)), SLOT(handleSslErrors(QList<QSslError>)));
	connect(_socket, SIGNAL(disconnected()), SLOT(handleDisconnected()));
}

Agent::RemoteFileInfo::RemoteFileInfo() :
    _name(), _type(FILE_TYPE_NONE), _mtime(), _size(0)
{
}

Agent::RemoteFileInfo::RemoteFileInfo(const QString &name, FileType type, const QDateTime &mtime, qint64 size) :
    _name(name), _type(type), _mtime(mtime), _size(size)
{
}

Agent::ActionInfo::ActionInfo(FileAction action, const QFileInfo &fileInfo) :
    _action(action), _info(fileInfo)
{
}

Agent::RemoteActionInfo::RemoteActionInfo(FileAction action, const QString &name, FileType type, const QDateTime &mtime, qint64 size) :
    _action(action), _info(name, type, mtime, size)
{

}

void Agent::sendMessage(MessageType msg, const QByteArray &content)
{
	const int header_len = sizeof(MessageHeader);
	QByteArray ba(header_len + content.size(), '\0');

	MessageHeader *h = reinterpret_cast<MessageHeader*>(ba.data());
	h->msg = msg;
	h->len = content.size();
	if (h->len > 0) {
		ba.replace(header_len, content.size(), content);
	}
	Q_ASSERT(ba.size() == header_len + content.size());

	qDebug() << "Sending " << msg << content.size();

	_socket->write(ba);
}

int Agent::inBufRequiredData() const
{
	const int header_len = sizeof(MessageHeader);
	if (_inBuf.size() < header_len) {
		return header_len;
	} else {
		const MessageHeader *h;
		h = reinterpret_cast<const MessageHeader*>(_inBuf.data());
		return header_len + h->len;
	}
}

bool Agent::equalDateTime(const QDateTime& dt1, const QDateTime& dt2)
{
	const qint64 threshold = 5 * 1000;
	qint64 msecs = dt1.msecsTo(dt2);
	return msecs > -threshold && msecs < threshold;
}

void Agent::setLocalFileDateTime(const QString &path, const QDateTime &dt)
{
#ifdef Q_OS_UNIX
	const char *filename = path.toLocal8Bit().constData();
	struct utimbuf times;
	times.actime = dt.toTime_t();
	times.modtime = dt.toTime_t();
	int rc = utime(filename, &times);
	if (rc != 0) {
		qWarning() << "Could not set local mtime of" << path;
	}
#endif
}

QString Agent::wireToLocalPath(const QString &path)
{
	return _dir.absolutePath() + _subPath + path;
}

QString Agent::localToWirePath(const QString& path)
{
	const QString& basePath = _dir.absolutePath() + _subPath;
	Q_ASSERT(_subPath.endsWith('/'));
	QString wire_path(path);
	if (path.startsWith(basePath)) {
		wire_path.remove(0, basePath.size());
	} else if (path + '/' == basePath) {
		wire_path = QString(); // This is the root dir.
	} else {
		qWarning() << "Where does this come from?" << path;
	}
	return wire_path;
}

QString Agent::wireParentPath(const QString &path)
{
	int index = path.lastIndexOf('/');
	if (index == -1) return QString("");
	else return path.left(index);
}

QString Agent::findExistingCommonAncestor(const QString& path,
                                          const QHash<QString, QFileInfo>& local_files,
                                          const QHash<QString, RemoteFileInfo>& remote_files)
{
	QString ancestor = path;
	do {
		ancestor = wireParentPath(ancestor);
	} while (!local_files.contains(ancestor) || !remote_files.contains(ancestor));
	return ancestor;
}

bool Agent::lessPathDepthThan(const QString& s1, const QString& s2)
{
	int d1 = s1.count('/'), d2 = s2.count('/');
	return d1 < d2;
}

bool Agent::morePathDepthThan(const QString& s1, const QString& s2)
{
	int d1 = s1.count('/'), d2 = s2.count('/');
	return d1 > d2;
}

QFileInfoList Agent::scanFiles(const QDir& dir)
{
	QFileInfoList all;
	QFileInfoList sub = dir.entryInfoList(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot);

	all << QFileInfo(dir, ".");

	foreach (const QFileInfo &info, sub) {
		if (info.isDir()) {
			all << scanFiles(QDir(info.absoluteFilePath()));
		} else {
			all << info;
		}
	}

	return all;
}

QByteArray Agent::encodeFileInfoList(const QFileInfoList& list)
{
	QByteArray ba;
	if (list.empty()) return ba;

	ba.reserve(list.size() * (sizeof(FileListItem) + 10));

	foreach (const QFileInfo& info, list) {
		QString path = localToWirePath(info.absoluteFilePath());
		FileListItem item;
		item.size = info.size();

		if (info.isDir() && _flags & SYNC_PULL) {
			// If we are pulling, then simulate all of our local directories being old,
			// so that we get all the new file creations
			// Existing files should be compared with the proper mtimes though.
			item.mtime = 0;
		} else {
			item.mtime = info.lastModified().toTime_t();
		}

		if (info.isDir()) {
			item.type = FILE_TYPE_DIR;
		} else if (info.isFile()) {
			item.type = FILE_TYPE_FILE;
		} else {
			qWarning() << "What is this?" << path;
			continue;
		}
		QByteArray utfPath = encodeFileName(path);

		item.name_len = utfPath.size();
		ba.append(reinterpret_cast<char*>(&item), sizeof(FileListItem));
		ba.append(utfPath.constData());
	}

	return ba;
}

Agent::RemoteFileInfoList Agent::decodeFileInfoList(const QByteArray& ba)
{
	RemoteFileInfoList list;

	int pos = 0;
	while (pos < ba.size()) {
		const FileListItem *item;
		item = reinterpret_cast<const FileListItem*>(&(ba.data()[pos]));

		list.append(RemoteFileInfo(QString::fromUtf8(&item->name[0],
		                                             item->name_len),
		                           static_cast<FileType>(item->type),
		                           QDateTime::fromTime_t(item->mtime),
		                           item->size));

		pos += sizeof(FileListItem) + item->name_len;
	}

	return list;
}

QByteArray Agent::encodeActionInfoList(const ActionInfoList &list)
{
	QByteArray ba;

	ba.reserve(list.size() * (sizeof(ActionItem) + 10));

	foreach (const ActionInfo& info, list) {
		const QFileInfo fileInfo = info.fileInfo();
		QString path = localToWirePath(fileInfo.absoluteFilePath());
		ActionItem item;
		item.action = info.action();
		item.size = fileInfo.size();
		item.mtime = fileInfo.lastModified().toTime_t();

		if (fileInfo.isDir()) {
			item.type = FILE_TYPE_DIR;
		} else if (fileInfo.isFile()) {
			item.type = FILE_TYPE_FILE;
		} else {
			item.type = FILE_TYPE_NONE; // Actions might refer to no-longer existing files
		}

		QByteArray utfPath = path.toUtf8();

		item.name_len = utfPath.size();
		ba.append(reinterpret_cast<char*>(&item), sizeof(item));
		ba.append(utfPath.constData());
	}

	return ba;
}

Agent::RemoteActionInfoList Agent::decodeActionInfoList(const QByteArray& ba)
{
	RemoteActionInfoList list;

	int pos = 0;
	while (pos < ba.size()) {
		const ActionItem *item;
		item = reinterpret_cast<const ActionItem*>(&(ba.data()[pos]));

		list.append(RemoteActionInfo(static_cast<FileAction>(item->action),
		                             QString::fromUtf8(&item->name[0],
		                                               item->name_len),
		                             static_cast<FileType>(item->type),
		                             QDateTime::fromTime_t(item->mtime),
		                             item->size));

		pos += sizeof(ActionItem) + item->name_len;
	}

	return list;
}

bool Agent::lessPathDepthThan(const ActionInfo& a1, const ActionInfo& a2)
{
	return lessPathDepthThan(a1.fileInfo().absoluteFilePath(),
	                         a2.fileInfo().absoluteFilePath());
}

bool Agent::morePathDepthThan(const ActionInfo& a1, const ActionInfo& a2)
{
	return morePathDepthThan(a1.fileInfo().absoluteFilePath(),
	                         a2.fileInfo().absoluteFilePath());
}

QByteArray Agent::encodeFileName(const QString& wire_path)
{
	return wire_path.toUtf8();
}

QString Agent::decodeFileName(const QByteArray& ba)
{
	return QString::fromUtf8(ba);
}

QByteArray Agent::encodeFileNameItem(const QString& wire_path)
{
	QByteArray utf8 = encodeFileName(wire_path);
	QByteArray ba(sizeof(FileNameItem), 0);
	FileNameItem *item = reinterpret_cast<FileNameItem*>(ba.data());
	item->name_len = utf8.length();
	ba.append(utf8);
	return ba;
}

QString Agent::decodeFileNameItem(const QByteArray& ba, int* length)
{
	const FileNameItem *item = reinterpret_cast<const FileNameItem*>(ba.data());
	*length = sizeof(FileNameItem) + item->name_len;
	QString wire_path = decodeFileName(ba.mid(sizeof(FileNameItem), item->name_len));
	return wire_path;
}

void Agent::handleDataAvailable()
{
	do {
		_inBuf.append(_socket->readAll());

		while (_inBuf.size() >= inBufRequiredData()) {
			MessageHeader *h = reinterpret_cast<MessageHeader*>(_inBuf.data());
			QByteArray data;
			if (h->len > 0) {
				data = _inBuf.mid(sizeof(MessageHeader), h->len);
			}
			handleMessage(static_cast<MessageType>(h->msg), data);
			_inBuf.remove(0, inBufRequiredData());
		}
	} while (_socket->bytesAvailable() > 0);
}

void Agent::handleSslErrors(const QList<QSslError> &errors)
{
	qDebug() << "SSL errors:" << errors;
	_socket->ignoreSslErrors(); // TODO For now
}

void Agent::handleDisconnected()
{
	qDebug() << "Disconnected at" << QDateTime::currentDateTime();
	deleteLater();
}