/*************************************************************************
*  Copyright (C) 2004 by Olivier Galizzi                                 *
*  olivier.galizzi@imag.fr                                               *
*  Copyright (C) 2004 by Janek Kozicki                                   *
*  cosurgi@berlios.de                                                    *
*                                                                        *
*  This program is free software; it is licensed under the terms of the  *
*  GNU General Public License v2 or later. See file LICENSE for details. *
*************************************************************************/

#include"Scene.hpp"

#include <lib/base/Math.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/algorithm/string.hpp>

#include <core/BodyContainer.hpp>
#include <core/InteractionContainer.hpp>
#include <core/TimeStepper.hpp>
#include <lib/base/AliasNamespaces.hpp>

#include <pwd.h>
#include <unistd.h>
#include <time.h>

namespace yade { // Cannot have #include directive inside.

YADE_PLUGIN((Scene));
CREATE_LOGGER(Scene);
// should be elsewhere, probably
bool TimingInfo::enabled=false;

void Scene::fillDefaultTags(){
	// fill default tags
	struct passwd* pw;
	char hostname[hostNameMax];
	gethostname(hostname,hostNameMax);
	pw=getpwuid(geteuid()); //if(!pw) throw runtime_error("getpwuid(geteuid()) failed!"); // FIXME: Does it really justify an exception??
	// a few default tags
	// real name: will have all non-ASCII characters replaced by ? since serialization doesn't handle that
	// the standard GECOS format is Real Name,,, - first comma and after will be discarded

	if(pw) { // May fail in some clusters
		string gecos(pw->pw_gecos), gecos2;
		size_t p=gecos.find(",");
		if(p!=string::npos) boost::algorithm::erase_tail(gecos,gecos.size()-p);
		for(size_t i=0;i<gecos.size();i++){gecos2.push_back(((unsigned char)gecos[i])<128 ? gecos[i] : '?'); }
		tags.push_back(boost::algorithm::replace_all_copy(string("author=")+gecos2+" ("+string(pw->pw_name)+"@"+hostname+")"," ","~"));
	} else {
		tags.push_back(boost::algorithm::replace_all_copy(string("author=FakeReal Name (FakeReal@")+hostname+")"," ","~"));
	}
	
	tags.push_back(string("isoTime="+boost::posix_time::to_iso_string(boost::posix_time::second_clock::local_time())));
	string id=boost::posix_time::to_iso_string(boost::posix_time::second_clock::local_time())+"p"+boost::lexical_cast<string>(getpid());
	tags.push_back("id="+id);
	tags.push_back("d.id="+id);
	tags.push_back("id.d="+id);
	// tags.push_back("revision="+py::extract<string>(py::import("yade.config").attr("revision"))());;
}

void Scene::postLoad(Scene&){
	// update the interaction container; must be done in Scene ctor as well; important!
	interactions->postLoad__calledFromScene(bodies);

	// this might be removed at some point, since it is checked by regression tests now
	for (const auto & b : *bodies){
		if(!b || !b->material || b->material->id<0) continue; // not a shared material
		if(b->material!=materials[b->material->id]) throw std::logic_error("Scene::postLoad: Internal inconsistency, shared materials not preserved when loaded; please report bug.");
	}
}

void Scene::moveToNextTimeStep(){
	if(runInternalConsistencyChecks){
		runInternalConsistencyChecks=false;
		checkStateTypes();
	}
	// substepping or not, update engines from _nextEngines, if defined, at the beginning of step
	// subStep can be 0, which happens if simulations is saved in the middle of step (without substepping)
	// this assumes that prologue will not set _nextEngines, which is safe hopefully
	if(!_nextEngines.empty() && (subStep<0 || (subStep<=0 && !subStepping))){
		engines=_nextEngines;
		_nextEngines.clear();
		// hopefully this will not break in some margin cases (subStepping with setting _nextEngines and such)
		subStep=-1;
	}
	if(!subStepping && subStep<0){
		/* set substep to 0 during the loop, so that engines/nextEngines handler know whether we are inside the loop currently */
		subStep=0;
		// ** 1. ** prologue
		if(isPeriodic) cell->integrateAndUpdate(dt);
		//forces.reset(); // uncomment if ForceResetter is removed
		const bool TimingInfo_enabled=TimingInfo::enabled; // cache the value, so that when it is changed inside the step, the engine that was just running doesn't get bogus values
		TimingInfo::delta last=TimingInfo::getNow(); // actually does something only if TimingInfo::enabled, no need to put the condition here
		// ** 2. ** engines
		for (const auto & e : engines){
			e->scene=this;
			if(e->dead || !e->isActivated()) continue;
			e->action();
			if(TimingInfo_enabled) {TimingInfo::delta now=TimingInfo::getNow(); e->timingInfo.nsec+=now-last; e->timingInfo.nExec+=1; last=now;}
		}
		// ** 3. ** epilogue
				// Calculation speed
		if (iter==0) {				//For the first time
			prevTime = boost::posix_time::microsec_clock::local_time();
		} else {
			boost::posix_time::ptime timeNow = boost::posix_time::microsec_clock::local_time();
			boost::posix_time::time_duration duration = timeNow - prevTime;
			long dif = duration.total_microseconds();
			SpeedElements(iter%nSpeedIter,0)=1000000.0 / dif;
			
			speed = SpeedElements.mean();
			
			prevTime = timeNow;
		}
		
		iter++;
		time+=dt;
		subStep=-1;
	} else {
		/* IMPORTANT: take care to copy EXACTLY the same sequence as is in the block above !! */
		if(TimingInfo::enabled){ TimingInfo::enabled=false; LOG_INFO("O.timingEnabled disabled, since O.subStepping is used."); }
		if(subStep<-1 || subStep>(int)engines.size()){ LOG_ERROR("Invalid value of Scene::subStep ("<<subStep<<"), setting to -1 (prologue will be run)."); subStep=-1; }
		// if subStepping is disabled, it means we have not yet finished last step completely; in that case, do that here by running all remaining substeps at once
		// if subStepping is enabled, just run the step we need (the loop is traversed only once, with subs==subStep)
		int maxSubStep=subStep;
		if(!subStepping){ maxSubStep=engines.size(); LOG_INFO("Running remaining sub-steps ("<<subStep<<"…"<<maxSubStep<<") before disabling sub-stepping."); }
		for(int subs=subStep; subs<=maxSubStep; subs++){
			assert(subs>=-1 && subs<=(int)engines.size());
			// ** 1. ** prologue
			if(subs==-1){ if(isPeriodic) cell->integrateAndUpdate(dt); }
			// ** 2. ** engines
			else if(subs>=0 && subs<(int)engines.size()){ const shared_ptr<Engine>& e(engines[subs]); e->scene=this; if(!e->dead && e->isActivated()) e->action(); }
			// ** 3. ** epilogue
			else if(subs==(int)engines.size()){ iter++; time+=dt; /* gives -1 along with the increment afterwards */ subStep=-2; }
			// (?!)
			else { /* never reached */ assert(false); }
		}
		subStep++; // if not substepping, this will make subStep=-2+1=-1, which is what we want
	}
}

shared_ptr<Engine> Scene::engineByName(const string& s){
	for (const auto & e : engines){
		if(e->getClassName()==s) return e;
	}
	return shared_ptr<Engine>();
}

bool Scene::timeStepperPresent(){
	int n=0;
	for(const auto &e : engines){ if(dynamic_cast<TimeStepper*>(e.get())) n++; }
	if(n>1) throw std::runtime_error(string("Multiple ("+boost::lexical_cast<string>(n)+") TimeSteppers in the simulation?!").c_str());
	return n>0;
}

bool Scene::timeStepperActive(){
	int n=0; bool ret=false;
	for(const auto &e : engines){
		TimeStepper* ts=dynamic_cast<TimeStepper*>(e.get()); if(ts) { ret=ts->active; n++; }
	}
	if(n>1) throw std::runtime_error(string("Multiple ("+boost::lexical_cast<string>(n)+") TimeSteppers in the simulation?!").c_str());
	return ret;
}

bool Scene::timeStepperActivate(bool a){
	int n=0;
	for (const auto & e : engines){
		TimeStepper* ts=dynamic_cast<TimeStepper*>(e.get());
		if(ts) { ts->setActive(a); n++; }
	}
	if(n>1) throw std::runtime_error(string("Multiple ("+boost::lexical_cast<string>(n)+") TimeSteppers in the simulation?!").c_str());
	return n>0;
}

void Scene::checkStateTypes(){
	for (const auto & b : *bodies){
		if(!b || !b->material) continue;
		if(b->material && !b->state) throw std::runtime_error("Body #"+boost::lexical_cast<string>(b->getId())+": has Body::material, but NULL Body::state.");
		if(!b->material->stateTypeOk(b->state.get())){
			throw std::runtime_error("Body #"+boost::lexical_cast<string>(b->getId())+": Body::material type "+b->material->getClassName()+" doesn't correspond to Body::state type "+b->state->getClassName()+" (should be "+b->material->newAssocState()->getClassName()+" instead).");
		}
	}
}

void Scene::updateBound(){
	if(!bound) bound=shared_ptr<Bound>(new Bound);
	const Real& inf=std::numeric_limits<Real>::infinity();
	Vector3r mx(-inf,-inf,-inf);
	Vector3r mn(inf,inf,inf);
	for (const auto & b : *bodies){
		if(!b) continue;
		if(b->bound){
			for(int i=0; i<3; i++){
				if(!std::isinf(b->bound->max[i])) mx[i]=max(mx[i],b->bound->max[i]);
				if(!std::isinf(b->bound->min[i])) mn[i]=min(mn[i],b->bound->min[i]);
			}
		} else {
	 		mx=mx.cwiseMax(b->state->pos);
 			mn=mn.cwiseMin(b->state->pos);
		}
	}
	bound->min=mn; 
	bound->max=mx;
}

} // namespace yade

