/*! \file pidiagnostics.h
 * \ingroup IO
 * \~\brief
 * \~english Connection quality diagnostics
 * \~russian Диагностика качества связи
 */
/*
    PIP - Platform Independent Primitives
    Speed and quality in/out diagnostics
    Andrey Bychkov work.a.b@yandex.ru, Ivan Pelipenko peri4ko@yandex.ru

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef PIDIAGNOSTICS_H
#define PIDIAGNOSTICS_H

#include "piqueue.h"
#include "pitimer.h"


class PIP_EXPORT PIDiagnostics: public PITimer {
	PIOBJECT_SUBCLASS(PIDiagnostics, PITimer);
	friend class PIConnection;

public:
	NO_COPY_CLASS(PIDiagnostics);

	//! Constructs an empty diagnostics and if "start_" start it
	PIDiagnostics(bool start_ = true);

	virtual ~PIDiagnostics();

	//! Connection quality
	enum Quality {
		Unknown /** Unknown, no one packet received yet */                           = 1,
		Failure /** No connection, no one correct packet received for last period */ = 2,
		Bad /** Bad connection, correct packets received <= 20% */                   = 3,
		Average /** Average connection, correct packets received > 20% and <= 80% */ = 4,
		Good /** Good connection, correct packets received > 80% */                  = 5
	};

	//! Information about current diagnostics state
	struct PIP_EXPORT State {
		State();
		float immediate_freq;
		float integral_freq;
		ullong received_packets_per_sec;
		ullong received_packets;
		ullong received_packets_wrong;
		ullong received_bytes_per_sec;
		ullong received_bytes;
		ullong received_bytes_wrong;
		ullong sended_packets_per_sec;
		ullong sended_packets;
		ullong sended_bytes_per_sec;
		ullong sended_bytes;
		PIString receive_speed;
		PIString send_speed;
		PIDiagnostics::Quality quality;
	};


	//! Returns current state
	PIDiagnostics::State state() const;

	//! Returns period of full disconnect in seconds and period of averaging frequency
	float disconnectTimeout() const { return disconn_; }

	//! Returns period of full disconnect in seconds and period of averaging frequency
	void setDisconnectTimeout(float s) { setProperty("disconnectTimeout", s); }

	//! Returns connection quality
	PIDiagnostics::Quality quality() const;

	//! Returns receive speed in format "n {B|kB|MB|GB|TB}/s"
	PIString receiveSpeed() const;

	//! Returns send speed in format "n {B|kB|MB|GB|TB}/s"
	PIString sendSpeed() const;


	EVENT_HANDLER0(void, start) {
		PITimer::start(100.);
		changeDisconnectTimeout(disconn_);
	}
	EVENT_HANDLER1(void, start, double, msecs) {
		if (msecs > 0.) {
			PITimer::start(msecs);
			changeDisconnectTimeout(disconn_);
		}
	}
	EVENT_HANDLER0(void, reset);

	EVENT_HANDLER1(void, received, int, size) { received(size, true); }
	EVENT_HANDLER2(void, received, int, size, bool, correct);
	EVENT_HANDLER1(void, sended, int, size);

	EVENT2(qualityChanged, PIDiagnostics::Quality, new_quality, PIDiagnostics::Quality, old_quality);

	//! \handlers
	//! \{

	//! \fn void start(double msecs = 1000.)
	//! \brief Start diagnostics evaluations with period "msecs" milliseconds

	//! \fn void reset()
	//! \brief Reset diagnostics counters

	//! \fn void received(int size, bool correct = true)
	//! \brief Notify diagnostics about "correct" corected received packet

	//! \fn void sended(int size)
	//! \brief Notify diagnostics about sended packet

	//! \}
	//! \events
	//! \{

	//! \fn void qualityChanged(PIDiagnostics::Quality new_quality, PIDiagnostics::Quality old_quality)
	//! \brief Raise on change receive quality from "old_quality" to "new_quality"

	//! \}

private:
	struct PIP_EXPORT Entry {
		Entry() {
			bytes_ok = bytes_fail = 0;
			cnt_ok = cnt_fail = 0;
			empty             = true;
		}
		ullong bytes_ok;
		ullong bytes_fail;
		uint cnt_ok;
		uint cnt_fail;
		bool empty;
	};
	friend bool operator==(const PIDiagnostics::Entry & f, const PIDiagnostics::Entry & s);
	friend bool operator!=(const PIDiagnostics::Entry & f, const PIDiagnostics::Entry & s);
	friend bool operator<(const PIDiagnostics::Entry & f, const PIDiagnostics::Entry & s);

	void tick(void *, int) override;
	Entry calcHistory(PIQueue<Entry> & hist, int & cnt);
	void propertyChanged(const char *) override;
	void changeDisconnectTimeout(float disct);

	PIQueue<Entry> history_rec, history_send;
	float disconn_;
	State cur_state;
	mutable PIMutex mutex_state;
};

inline bool operator==(const PIDiagnostics::Entry & f, const PIDiagnostics::Entry & s) {
	return f.bytes_ok == s.bytes_ok && f.bytes_fail == s.bytes_fail && f.cnt_ok == s.cnt_ok && f.cnt_fail == s.cnt_fail &&
	       f.empty == s.empty;
}
inline bool operator!=(const PIDiagnostics::Entry & f, const PIDiagnostics::Entry & s) {
	return !(f == s);
}
inline bool operator<(const PIDiagnostics::Entry & f, const PIDiagnostics::Entry & s) {
	return f.bytes_ok < s.bytes_ok;
}

#endif // PIDIAGNOSTICS_H