/*
 * Copyright (C) 2001-2017 Jacek Sieka, arnetheduck on gmail point com
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef DCPLUSPLUS_DCPP_DOWNLOAD_MANAGER_H
#define DCPLUSPLUS_DCPP_DOWNLOAD_MANAGER_H

#include "forward.h"

#include "DownloadManagerListener.h"
#include "UserConnectionListener.h"
#include "QueueItem.h"
#include "TimerManager.h"
#include "Singleton.h"
#include "MerkleTree.h"
#include "Speaker.h"

namespace dcpp {

/**
 * Singleton. Use its listener interface to update the download list
 * in the user interface.
 */
class DownloadManager : public Speaker<DownloadManagerListener>,
	private UserConnectionListener, private TimerManagerListener,
	public Singleton<DownloadManager>
{
private:
	using UserConnectionListener::on;
	using TimerManagerListener::on;	
public:

	/** @internal */
	void addConnection(UserConnectionPtr conn);
	void checkIdle(const HintedUser& user);

	/** @return Running average download speed in Bytes/s */
	int64_t getRunningAverage();

	/** @return Number of downloads. */
	size_t getDownloadCount() {
		Lock l(cs);
		return downloads.size();
	}

	bool startDownload(QueueItem::Priority prio);
	
private:
	
	CriticalSection cs;
	DownloadList downloads;
	UserConnectionList idlers;

	void removeConnection(UserConnectionPtr aConn);
	void removeDownload(Download* aDown);
	void fileNotAvailable(UserConnection* aSource);
	void noSlots(UserConnection* aSource, string param = Util::emptyString );

	void logDownload(UserConnection* aSource, Download* d);
	int64_t getResumePos(const string& file, const TigerTree& tt, int64_t startPos);

	void failDownload(UserConnection* aSource, const string& reason);

	friend class Singleton<DownloadManager>;

	DownloadManager();
	virtual ~DownloadManager();

	void checkDownloads(UserConnection* aConn);
	void revive(UserConnection* uc);
	void startData(UserConnection* aSource, int64_t start, int64_t newSize, bool z);
	void endData(UserConnection* aSource);

	void onFailed(UserConnection* aSource, const string& aError);

	// UserConnectionListener
	virtual void on(Data, UserConnection*, const uint8_t*, size_t) noexcept;
	virtual void on(Failed, UserConnection* aSource, const string& aError) noexcept { onFailed(aSource, aError); }
	virtual void on(ProtocolError, UserConnection* aSource, const string& aError) noexcept { onFailed(aSource, aError); }
	virtual void on(MaxedOut, UserConnection*, string param = "") noexcept;
	virtual	void on(FileNotAvailable, UserConnection*) noexcept;
	virtual void on(Updated, UserConnection*) noexcept;
	virtual void on(UserConnectionListener::ListLength, UserConnection* aSource, const string& aListLength) noexcept;

	virtual void on(AdcCommand::SND, UserConnection*, const AdcCommand&) noexcept;
	virtual void on(AdcCommand::STA, UserConnection*, const AdcCommand&) noexcept;

	// TimerManagerListener
	virtual void on(TimerManagerListener::Second, uint64_t aTick) noexcept;
};

} // namespace dcpp

#endif // !defined(DOWNLOAD_MANAGER_H)
