// Copyright 2010-2021 The Mumble Developers. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file at the root of the
// Mumble source tree or at <https://www.mumble.info/LICENSE>.

#ifndef MUMBLE_MURMUR_SERVERUSER_H_
#define MUMBLE_MURMUR_SERVERUSER_H_

#include <QtCore/QtGlobal>

#ifdef Q_OS_WIN
#	include "win.h"
#endif

#include "Connection.h"
#include "HostAddress.h"
#include "Timer.h"
#include "User.h"

#include <QtCore/QElapsedTimer>
#include <QtCore/QStringList>

#ifdef Q_OS_WIN
#	include <winsock2.h>
#else
#	include <sys/socket.h>
#endif

// Unfortunately, this needs to be "large enough" to hold
// enough frames to account for both short-term and
// long-term "maladjustments".

#define N_BANDWIDTH_SLOTS 360

struct BandwidthRecord {
	int iRecNum;
	int iSum;
	Timer tFirst;
	Timer tIdleControl;
	unsigned short a_iBW[N_BANDWIDTH_SLOTS];
	Timer a_qtWhen[N_BANDWIDTH_SLOTS];
	mutable QMutex qmMutex;

	BandwidthRecord();
	bool addFrame(int size, int maxpersec);
	int onlineSeconds() const;
	int idleSeconds() const;
	void resetIdleSeconds();
	int bandwidth() const;
};

struct WhisperTarget {
	struct Channel {
		int iId;
		bool bChildren;
		bool bLinks;
		QString qsGroup;
	};
	QList< unsigned int > qlSessions;
	QList< WhisperTarget::Channel > qlChannels;
};

class ServerUser;

struct WhisperTargetCache {
	QSet< ServerUser * > channelTargets;
	QSet< ServerUser * > directTargets;
	QSet< ServerUser * > listeningTargets;
};

class Server;

/// A simple implementation for rate-limiting.
/// See https://en.wikipedia.org/wiki/Leaky_bucket
class LeakyBucket {
private:
	/// The amount of tokens that are drained per second.
	/// (The sze of the whole in the bucket)
	unsigned int m_tokensPerSec;
	/// The maximum amount of tokens that may be encountered.
	/// (The capacity of the bucket)
	unsigned int m_maxTokens;
	/// The amount of tokens currently stored
	/// (The amount of whater currently in the bucket)
	long m_currentTokens;
	/// A timer that is used to measure time intervals. It is essential
	/// that this timer uses a monotonic clock (which is why QElapsedTimer is
	/// used instead of QTime or QDateTime).
	QElapsedTimer m_timer;

public:
	/// @param tokens The amount of tokens that should be added.
	/// @returns Whether adding this amount of tokens triggers rate
	/// 	limiting (true means the corresponding packet has to be
	/// 	discared and false means the packet may be processed)
	bool ratelimit(int tokens);

	LeakyBucket(unsigned int tokensPerSec, unsigned int maxTokens);
};

class ServerUser : public Connection, public User {
private:
	Q_OBJECT
	Q_DISABLE_COPY(ServerUser)
protected:
	Server *s;

public:
	enum State { Connected, Authenticated };
	State sState;
	operator QString() const;

	float dUDPPingAvg, dUDPPingVar;
	float dTCPPingAvg, dTCPPingVar;
	quint32 uiUDPPackets, uiTCPPackets;

	unsigned int uiVersion;
	QString qsRelease;
	QString qsOS;
	QString qsOSVersion;

	std::string ssContext;
	QString qsIdentity;

	bool bVerified;
	QStringList qslEmail;

	HostAddress haAddress;

	/// Holds whether the user is using TCP
	/// or UDP for voice packets.
	///
	/// If the flag is 0, the user is using
	/// TCP.
	///
	/// If the flag is 1, the user is using
	/// UDP.
	QAtomicInt aiUdpFlag;

	QList< int > qlCodecs;
	bool bOpus;

	QStringList qslAccessTokens;

	QMap< int, WhisperTarget > qmTargets;
	QMap< int, WhisperTargetCache > qmTargetCache;
	QMap< QString, QString > qmWhisperRedirect;

	LeakyBucket leakyBucket;
	LeakyBucket m_pluginMessageBucket;

	int iLastPermissionCheck;
	QMap< int, unsigned int > qmPermissionSent;
#ifdef Q_OS_UNIX
	int sUdpSocket;
#else
	SOCKET sUdpSocket;
#endif
	BandwidthRecord bwr;
	struct sockaddr_storage saiUdpAddress;
	struct sockaddr_storage saiTcpLocalAddress;
	ServerUser(Server *parent, QSslSocket *socket);
};

#endif