/*
# Copyright (c) 2010,2011 - RZ Uni Freiburg
# Copyright (c) 2010,2011 - OpenSLX Project
#
# This program/file is free software distributed under the GPL version 2.
# See http://openslx.org/COPYING
#
# If you have any feedback please consult http://openslx.org/feedback and
# send your feedback to feedback@openslx.org
#
# General information about OpenSLX can be found under http://openslx.org
#
#
# 	   Class managing download requests:
#		- provides queueing functionality
#		- static info: filename, filesize
#		- dynamic info: download progress, current speed
#
*/

#ifndef DOWNLOADMANAGER_H
#define DOWNLOADMANAGER_H

#include "fbgui.h"

extern bool debug;
extern QUrl baseURL;
extern QString binPath;
extern QString downloadPath;
extern int updateInterval;


class DownloadManager : public QObject
{
	Q_OBJECT

public:
	DownloadManager();

private:
	// checks for valid download directory, ran once in constructor
	void checkDownloadDirectory();
	// private control function for queueing mechanism.
	void processDownloadRequest(const QUrl& url);

	// base objects for downloading
	QNetworkAccessManager* qnam;
	QQueue<QUrl> dlQ;
	QNetworkReply* currentDownload;
	QFile outfile;
	QDir downloadDir;
	// download progress variables
	QTime dltime;
	int currentProgress, lastProgress;
	// download in progress flag
	bool dip;
	// static counter
	static int downloaded;

signals:
	// notify sends a message to the javascript interface to be evaluated there
	void notify(const QString& msg);
	// downloadInfo sends static information (name, size) to the interface.
	void downloadInfo(const QString& filename, const double& filesize);
	// updateProgress sends download progress information to the interface.
	void updateProgress(const int& percent, const double& speed, const QString& unit);
	// signal emitted when download queue is empty.
	void downloadQueueEmpty();

public slots:
	// public slots to receive download requests.
	void downloadFile(const QUrl& fileUrl);
	// convenience function
	void downloadFile(const QString& fileUrl);

private slots:
	// private slots to manage the downloading process
	void startNextDownload();
	void processMetaInfo();
	void downloadReady();
	void downloadProgress(qint64 bytesIn, qint64 bytesTotal);
	void downloadFinished();
};

#endif // DOWNLOADMANAGER_H