/* -*-	Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) 2001 University of Mannheim, Praktische Informatik IV
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Praktische Informatik IV,
 *      University of Mannheim.
 * 4. Neither the name of Praktische Informatik IV nor of University of 
 *    Mannheim may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY U. MANNHEIM AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL U. MANNHEIM OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "agent.h"
#include "packet.h"
#include "ip.h"
#include "timer-handler.h"
#include "random.h"

#define SMALLFLOAT 0.0000001

#define DEC_NO_REPORT 24

struct hdr_pcc {
	int seqno;		//data sequence number
	double timestamp; 	// time this message was sent
	double timestamp_echo; 	// echo timestamp from last receiver report
	double timestamp_offset; // offset since sender received report
	int psize;		//packet size	
	int round_id ; 		//round id.
	double sendrate;        //current send rate

	static int offset_;	// offset for this header
	inline static int& offset() { return offset_; }
	inline static hdr_pcc* access(const Packet* p) {
		return (hdr_pcc*) p->access(offset_);
	}
};

struct hdr_pcc_ack {
	double timestamp;	//time this nack was sent
	double rate;            //expected sending rate (eqn)
	double rtt;	 	//smoothed RTT estimate of receiver
	int discard_after_seqno; //if >= 0, packets after this seqno are discarded by the receiver

	static int offset_;     // offset for this header
	inline static int& offset() { return offset_; }
	inline static hdr_pcc_ack* access(const Packet* p) {
		return (hdr_pcc_ack*) p->access(offset_);
	}
};

class PccAgent; 

class PccSendTimer : public TimerHandler {
public:
		PccSendTimer(PccAgent *a) : TimerHandler() { a_ = a; }
		virtual void expire(Event *e);
protected:
		PccAgent *a_;
};	

class PccNoFeedbackTimer : public TimerHandler {
public:
		PccNoFeedbackTimer(PccAgent *a) : TimerHandler() { a_ = a; }
		virtual void expire(Event *e);
protected:
		PccAgent *a_;
}; 

class PccAgent : public Agent {
	friend PccSendTimer;
	friend PccNoFeedbackTimer;
public:
	PccAgent();
	void recv(Packet*, Handler*);
	void sendpkt();
	void nextpkt();
	int command(int argc, const char*const* argv);
	void start();
	void stop();
	void reduce_rate_on_no_feedback();

protected:
	PccSendTimer send_timer_;
	PccNoFeedbackTimer NoFeedbacktimer_;
	int seqno_; 
	int psize_;
	double rate_;		// send rate
	double rcvrate  ; 	// TCP friendly rate from receiver
 	int printStatus_;	// to print status reports
	double inter_packet;    // inter packet gap

	/* "accurate" estimates for formula */
	double rtt_; /*EWMA version*/

	double last_timestamp_, last_arrival_;

	int AppRate_;		// constant send rate of the Application
	double overhead_;	// if > 0, dither outgoing packets 
	int ndatapack_;	        // number of packets sent
	int active_;		// have we shut down? 
	int round_id ;		// round id

	int flowID;
};