/*******************************************************************************
 * libretroshare/src/pqi: pqihandler.cc                                        *
 *                                                                             *
 * libretroshare: retroshare core library                                      *
 *                                                                             *
 * Copyright (C) 2004-2006  Robert Fernie                                      *
 *                                                                             *
 * 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 <https://www.gnu.org/licenses/>.       *
 *                                                                             *
 *******************************************************************************/
#include "pqi/pqihandler.h"

#include <stdlib.h>               // for NULL
#include "util/rstime.h"                 // for time, rstime_t
#include <algorithm>              // for sort
#include <iostream>               // for dec
#include <string>                 // for string, char_traits, operator+, bas...
#include <utility>                // for pair

#include "pqi/pqi_base.h"         // for PQInterface, RsBwRates
#include "retroshare/rsconfig.h"  // for RSTrafficClue
#include "retroshare/rsids.h"     // for t_RsGenericIdType
#include "retroshare/rspeers.h"   // for RsPeers, rsPeers
#include "serialiser/rsserial.h"  // for RsItem, RsRawItem
#include "util/rsdebug.h"         // for pqioutput, PQL_DEBUG_BASIC, PQL_ALERT
#include "util/rsstring.h"        // for rs_sprintf_append

using std::dec;

#ifdef WINDOWS_SYS
#include <sys/timeb.h>
#endif

struct RsLog::logInfo pqihandlerzoneInfo = {RsLog::Default, "pqihandler"};
#define pqihandlerzone &pqihandlerzoneInfo

//static const int PQI_HANDLER_NB_PRIORITY_LEVELS = 10 ;
//static const float PQI_HANDLER_NB_PRIORITY_RATIO = 2 ;

//#define UPDATE_RATES_DEBUG 1
// #define DEBUG_TICK 1
// #define RSITEM_DEBUG 1

pqihandler::pqihandler() : coreMtx("pqihandler")
{
    RS_STACK_MUTEX(coreMtx); /**************** LOCKED MUTEX ****************/

    // setup minimal total+individual rates.
    rateIndiv_out = 0.01;
    rateIndiv_in = 0.01;
    rateMax_out = 0.01;
    rateMax_in = 0.01;
    rateTotal_in = 0.0 ;
    rateTotal_out = 0.0 ;
	traffInSum = 0;
	traffOutSum = 0;
    last_m = time(NULL) ;
    nb_ticks = 0 ;
    mLastRateCapUpdate = 0 ;
    ticks_per_sec = 5 ; // initial guess
    return;
}

int	pqihandler::tick()
{
	int moreToTick = 0;

	{
		RS_STACK_MUTEX(coreMtx); /**************** LOCKED MUTEX ****************/

		// tick all interfaces...
		std::map<RsPeerId, SearchModule *>::iterator it;
		for(it = mods.begin(); it != mods.end(); ++it)
		{
			if (0 < ((it -> second) -> pqi) -> tick())
			{
#ifdef DEBUG_TICK
				std::cerr << "pqihandler::tick() moreToTick from mod()" << std::endl;
#endif
				moreToTick = 1;
			}
		}
#ifdef TO_BE_REMOVED
		// get the items, and queue them correctly
		if (0 < locked_GetItems())
		{
#ifdef DEBUG_TICK
			std::cerr << "pqihandler::tick() moreToTick from GetItems()" << std::endl;
#endif
			moreToTick = 1;
		}
#endif
	}

	rstime_t now = time(NULL) ;

	if(now > mLastRateCapUpdate + 5)
	{
        std::map<RsPeerId, RsConfigDataRates> rateMap;
        std::map<RsPeerId, RsConfigDataRates>::iterator it;


		// every 5 secs, update the max rates for all modules

		RS_STACK_MUTEX(coreMtx); /**************** LOCKED MUTEX ****************/
		for(std::map<RsPeerId, SearchModule *>::iterator it = mods.begin(); it != mods.end(); ++it)
		{
			// This is rather inelegant, but pqihandler has searchModules that are dynamically allocated, so the max rates
			// need to be updated from inside.
			uint32_t maxUp = 0,maxDn =0 ;
			if (rsPeers->getPeerMaximumRates(it->first,maxUp,maxDn) )
				it->second->pqi->setRateCap(maxDn,maxUp);// mind the order! Dn first, than Up.
		}

		mLastRateCapUpdate = now ;
	}

	UpdateRates();
	return moreToTick;
}


bool pqihandler::queueOutRsItem(RsItem *item)
{
	RS_STACK_MUTEX(coreMtx); /**************** LOCKED MUTEX ****************/

	uint32_t size ;
    locked_HandleRsItem(item, size);

#ifdef DEBUG_QOS
	if(item->priority_level() == QOS_PRIORITY_UNKNOWN)
		std::cerr << "Caught an unprioritized item !" << std::endl;

	print() ;
#endif
	return true ;
}

int	pqihandler::status()
{
	std::map<RsPeerId, SearchModule *>::iterator it;
	RS_STACK_MUTEX(coreMtx); /**************** LOCKED MUTEX ****************/

	{ // for output
		std::string out = "pqihandler::status() Active Modules:\n";

		// display all interfaces...
		for(it = mods.begin(); it != mods.end(); ++it)
		{
			rs_sprintf_append(out, "\tModule [%s] Pointer <%p>", it -> first.toStdString().c_str(), (void *) ((it -> second) -> pqi));
		}

		pqioutput(PQL_DEBUG_BASIC, pqihandlerzone, out);

	} // end of output.


	// status all interfaces...
	for(it = mods.begin(); it != mods.end(); ++it)
	{
		((it -> second) -> pqi) -> status();
	}
	return 1;
}

bool	pqihandler::AddSearchModule(SearchModule *mod)
{
	RS_STACK_MUTEX(coreMtx); /**************** LOCKED MUTEX ****************/
	// if peerid used -> error.
	//std::map<RsPeerId, SearchModule *>::iterator it;
	if (mod->peerid != mod->pqi->PeerId())
	{
		// ERROR!
		pqioutput(PQL_ALERT, pqihandlerzone, "ERROR peerid != PeerId!");
		return false;
	}

	if (mod->peerid.isNull())
	{
		// ERROR!
		pqioutput(PQL_ALERT, pqihandlerzone, "ERROR peerid == NULL");
		return false;
	}

	if (mods.find(mod->peerid) != mods.end())
	{
		// ERROR!
		pqioutput(PQL_ALERT, pqihandlerzone, "ERROR PeerId Module already exists!");
		return false;
	}

	// store.
	mods[mod->peerid] = mod;
	return true;
}

bool	pqihandler::RemoveSearchModule(SearchModule *mod)
{
	RS_STACK_MUTEX(coreMtx); /**************** LOCKED MUTEX ****************/
	std::map<RsPeerId, SearchModule *>::iterator it;
	for(it = mods.begin(); it != mods.end(); ++it)
	{
		if (mod == it -> second)
		{
			mods.erase(it);
			return true;
		}
	}
	return false;
}

// generalised output
int	pqihandler::locked_HandleRsItem(RsItem *item, uint32_t& computed_size)
{
	computed_size = 0 ;
	std::map<RsPeerId, SearchModule *>::iterator it;
	pqioutput(PQL_DEBUG_BASIC, pqihandlerzone,
	  "pqihandler::HandleRsItem()");

	pqioutput(PQL_DEBUG_BASIC, pqihandlerzone,
	  "pqihandler::HandleRsItem() Sending to One Channel");
#ifdef DEBUG_TICK
        std::cerr << "pqihandler::HandleRsItem() Sending to One Channel" << std::endl;
#endif


	// find module.
	if ((it = mods.find(item->PeerId())) == mods.end())
	{
		std::string out = "pqihandler::HandleRsItem() Invalid chan!";
		pqioutput(PQL_DEBUG_BASIC, pqihandlerzone, out);
#ifdef DEBUG_TICK
		std::cerr << out << std::endl;
#endif

		delete item;
		return -1;
	}

		std::string out = "pqihandler::HandleRsItem() sending to chan: " + it -> first.toStdString();
		pqioutput(PQL_DEBUG_BASIC, pqihandlerzone, out);
#ifdef DEBUG_TICK
		std::cerr << out << std::endl;
#endif

		// if yes send on item.
		((it -> second) -> pqi) -> SendItem(item,computed_size);
		return 1;
}

int     pqihandler::SendRsRawItem(RsRawItem *ns)
{
	pqioutput(PQL_DEBUG_BASIC, pqihandlerzone, "pqihandler::SendRsRawItem()");

	// directly send item to streamers

	return queueOutRsItem(ns) ;
}

int     pqihandler::ExtractTrafficInfo(std::list<RSTrafficClue>& out_lst,std::list<RSTrafficClue>& in_lst)
{
    in_lst.clear() ;
    out_lst.clear() ;

    for( std::map<RsPeerId, SearchModule *>::iterator it = mods.begin(); it != mods.end(); ++it)
    {
        std::list<RSTrafficClue> ilst,olst ;

        (it -> second)->pqi->gatherStatistics(olst,ilst) ;

        for(std::list<RSTrafficClue>::const_iterator it(ilst.begin());it!=ilst.end();++it) in_lst.push_back(*it) ;
        for(std::list<RSTrafficClue>::const_iterator it(olst.begin());it!=olst.end();++it) out_lst.push_back(*it) ;
    }

    return 1 ;
}

// NEW extern fn to extract rates.
int     pqihandler::ExtractRates(std::map<RsPeerId, RsBwRates> &ratemap, RsBwRates &total)
{
	total.mMaxRateIn = getMaxRate(true);
	total.mMaxRateOut = getMaxRate(false);
	total.mRateIn = 0;
	total.mRateOut = 0;
	total.mQueueIn = 0;
	total.mQueueOut = 0;

	/* Lock once rates have been retrieved */
	RS_STACK_MUTEX(coreMtx); /**************** LOCKED MUTEX ****************/

	std::map<RsPeerId, SearchModule *>::iterator it;
	for(it = mods.begin(); it != mods.end(); ++it)
	{
		SearchModule *mod = (it -> second);

		RsBwRates peerRates;
		mod -> pqi -> getRates(peerRates);

		total.mRateIn  += peerRates.mRateIn;
		total.mRateOut += peerRates.mRateOut;
		total.mQueueIn  += peerRates.mQueueIn;
		total.mQueueOut += peerRates.mQueueOut;

		ratemap[it->first] = peerRates;

	}

	return 1;
}



// internal fn to send updates
int     pqihandler::UpdateRates()
{
	std::map<RsPeerId, SearchModule *>::iterator it;

	float avail_in = getMaxRate(true);
	float avail_out = getMaxRate(false);

	float used_bw_in = 0;
	float used_bw_out = 0;

	/* Lock once rates have been retrieved */
	RS_STACK_MUTEX(coreMtx); /**************** LOCKED MUTEX ****************/

	int num_sm = mods.size();
	float used_bw_in_table[num_sm];         /* table of in bandwidth currently used by each module */
	float used_bw_out_table[num_sm];        /* table of out bandwidth currently used by each module */

	// loop through modules to get the used bandwidth
#ifdef UPDATE_RATES_DEBUG
		RsDbg() << "UPDATE_RATES pqihandler::UpdateRates Looping through modules" << std::endl;
#endif

	int index = 0;

	for(it = mods.begin(); it != mods.end(); ++it)
	{
		SearchModule *mod = (it -> second);

		traffInSum += mod -> pqi -> getTraffic(true);
		traffOutSum += mod -> pqi -> getTraffic(false);
        
                float crate_in = mod -> pqi -> getRate(true);
		float crate_out = mod -> pqi -> getRate(false);

		used_bw_in += crate_in;
		used_bw_out += crate_out;

		/* fill the table of used bandwidths */
		used_bw_in_table[index] = crate_in;
		used_bw_out_table[index] = crate_out;

		++index;
	}

#ifdef UPDATE_RATES_DEBUG
	RsDbg() << "UPDATE_RATES pqihandler::UpdateRates Sorting used_bw_out_table: " << num_sm << " entries" << std::endl;
#endif

	/* Sort the used bw in/out table in ascending order */
	std::sort(used_bw_in_table, used_bw_in_table + num_sm);
	std::sort(used_bw_out_table, used_bw_out_table + num_sm);

#ifdef UPDATE_RATES_DEBUG
	RsDbg() << "UPDATE_RATES pqihandler::UpdateRates used_bw_out " << used_bw_out << std::endl;
#endif

	/* Calculate the optimal out_max value, taking into account avail_out and the out bw requested by modules */

	float out_remaining_bw = avail_out;
	float out_max_bw = 0;
	bool keep_going = true;
	int mod_index = 0;

	while (keep_going && (mod_index < num_sm)) {
		float result = (num_sm - mod_index) * (used_bw_out_table[mod_index] - out_max_bw);
		if (result > out_remaining_bw) {
			/* There is not enough remaining out bw to satisfy all modules,
			   distribute the remaining out bw among modules, then exit */
			out_max_bw += out_remaining_bw / (num_sm - mod_index);
			out_remaining_bw = 0;
			keep_going = false;
		} else {
			/* Grant the requested out bandwidth to all modules,
			   then recalculate the remaining out bandwidth */
			out_remaining_bw -= result;
			out_max_bw = used_bw_out_table[mod_index];
			++mod_index;
		}
	}

#ifdef UPDATE_RATES_DEBUG
	RsDbg() << "UPDATE_RATES pqihandler::UpdateRates mod_index " << mod_index << " out_max_bw " << out_max_bw << " remaining out bw " << out_remaining_bw << std::endl;
#endif

	/* Allocate only half the remaining out bw, if any, to make it smoother */
	out_max_bw = out_max_bw + out_remaining_bw / 2;

	/* Calculate the optimal in_max value, taking into account avail_in and the in bw requested by modules */

	float in_remaining_bw = avail_in;
	float in_max_bw = 0;
	keep_going = true;
	mod_index = 0;

	while (keep_going && mod_index < num_sm) {
		float result = (num_sm - mod_index) * (used_bw_in_table[mod_index] - in_max_bw);
		if (result > in_remaining_bw) {
			/* There is not enough remaining in bw to satisfy all modules,
			   distribute the remaining in bw among modules, then exit */
			in_max_bw += in_remaining_bw / (num_sm - mod_index);
			in_remaining_bw = 0;
			keep_going = false;
		} else {
			/* Grant the requested in bandwidth to all modules,
			   then recalculate the remaining in bandwidth */
			in_remaining_bw -= result;
			in_max_bw = used_bw_in_table[mod_index];
			++mod_index;
		}
	}

#ifdef UPDATE_RATES_DEBUG
	RsDbg() << "UPDATE_RATES pqihandler::UpdateRates mod_index " << mod_index << " in_max_bw " << in_max_bw << " remaining in bw " << in_remaining_bw << std::endl;
#endif

	/* Allocate only half the remaining in bw, if any, to make it smoother */
	in_max_bw = in_max_bw + in_remaining_bw / 2;

	// store current total in and ou used bw 
	locked_StoreCurrentRates(used_bw_in, used_bw_out);

#ifdef UPDATE_RATES_DEBUG
	RsDbg() << "UPDATE_RATES pqihandler::UpdateRates setting new out_max " << out_max_bw << " in_max " << in_max_bw << std::endl;
#endif

	// retrieve down (from peer point of view) bandwidth limits set by peers in their own settings
        std::map<RsPeerId, RsConfigDataRates> rateMap;
        rsConfig->getAllBandwidthRates(rateMap);
        std::map<RsPeerId, RsConfigDataRates>::iterator rateMap_it;

#ifdef UPDATE_RATES_DEBUG
	// Dump RsConfigurationDataRates
	RsDbg() << "UPDATE_RATES pqihandler::UpdateRates RsConfigDataRates dump" << std::endl;
	for (rateMap_it = rateMap.begin(); rateMap_it != rateMap.end(); rateMap_it++)
		RsDbg () << "UPDATE_RATES pqihandler::UpdateRates PeerId " << rateMap_it->first.toStdString() << " mAllowedOut " << rateMap_it->second.mAllowedOut << std::endl;
#endif

        // update max rates taking into account the limits set by peers in their own settings
	for(it = mods.begin(); it != mods.end(); ++it)
	{
		SearchModule *mod = (it -> second);

		// for our down bandwidth we set the max to the calculated value without taking into account the max set by peers: they will control their up bw on their side
		mod -> pqi -> setMaxRate(true, in_max_bw);

		// for our up bandwidth we limit to the maximum down bw provided by peers via BwCtrl because we don't want to clog our outqueues, the SSL buffers, and our friends inbound queues
		if ((rateMap_it = rateMap.find(mod->pqi->PeerId())) != rateMap.end())
		{
			if (rateMap_it->second.mAllowedOut > 0)
			{	
				if (out_max_bw > rateMap_it->second.mAllowedOut)
        	                        mod -> pqi -> setMaxRate(false, rateMap_it->second.mAllowedOut);
				else
					mod -> pqi -> setMaxRate(false, out_max_bw);
			}
			else
				mod -> pqi -> setMaxRate(false, out_max_bw);
		}
	}

#ifdef UPDATE_RATES_DEBUG
	// dump maxRates
	for(it = mods.begin(); it != mods.end(); ++it)
	{
		SearchModule *mod = (it -> second);
		RsDbg() << "UPDATE_RATES pqihandler::UpdateRates PeerID " << (mod ->pqi -> PeerId()).toStdString() << " new bandwidth limits up " << mod -> pqi -> getMaxRate(false) << " down " << mod -> pqi -> getMaxRate(true) << std::endl;
	}
#endif

	return 1;
}

void    pqihandler::getCurrentRates(float &in, float &out)
{
	RS_STACK_MUTEX(coreMtx); /**************** LOCKED MUTEX ****************/

	in = rateTotal_in;
	out = rateTotal_out;
}

void    pqihandler::locked_StoreCurrentRates(float in, float out)
{
	rateTotal_in = in;
	rateTotal_out = out;
}

void pqihandler::GetTraffic(uint64_t &in, uint64_t &out)
{
	in = traffInSum;
	out = traffOutSum;
}