//************************************************************************//
//									  //
//  Copyright 2013 Bertram Kopf (bertram@ep1.rub.de)			  //
//  	      	   Julian Pychy (julian@ep1.rub.de)			  //
//          	   - Ruhr-Universität Bochum 				  //
//									  //
//  This file is part of Pawian.					  //
//									  //
//  Pawian is free software: you can redistribute it and/or modify	  //
//  it under the terms of the GNU General Public License as published by  //
//  the Free Software Foundation, either version 3 of the License, or 	  //
//  (at your option) any later version.	 	      	  	   	  //
//									  //
//  Pawian 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 General Public License for more details.	      		  //
//									  //
//  You should have received a copy of the GNU General Public License     //
//  along with Pawian.  If not, see <http://www.gnu.org/licenses/>.	  //
//									  //
//************************************************************************//

// EventReaderDefault class definition file. -*- C++ -*-
// Copyright 2012 Bertram Kopf

#include "Event/EventReaderDefault.hh"

#include "Event/EventList.hh"
#include "Event/Event.hh"
#include "ErrLogger/ErrLogger.hh"

EventReaderDefault::EventReaderDefault() :
  EventReader(false),
  numParticles(0),
  linesToSkip(0),
  _unit("GEV"),
  _order("Px Py Pz E"),
  _unitScaleFactor(1.),
  _energyFirst(false)
{}

EventReaderDefault::EventReaderDefault(const std::vector<std::string>& files, int particles, int skip, bool useWeight):
  EventReader(useWeight),
  numParticles(particles),
  linesToSkip(skip),
  _unit("GEV"),
  _order("Px Py Pz E"),
  _unitScaleFactor(1.),
  _energyFirst(false)
{
  if (0 == files.size()) {
    Alert << "empty list of event files" ;  // << endmsg;
    exit(1);
  }
  std::vector<std::string>::const_iterator iter = files.begin();
  for (; iter != files.end(); ++iter)
    fileNames.push_back(*iter);
  currentFile = fileNames.begin();
}

EventReaderDefault::~EventReaderDefault()
{}

bool EventReaderDefault::fill(EventList& evtList, int evtStart, int evtStop)
{
  int currentEvtNo=-1;

  while (currentFile != fileNames.end()) {
    currentStream.open(currentFile->c_str());
    if (!currentStream) {
      Alert << "can not open " << *currentFile ;  // << endmsg;
      exit(1);
    }

    while (!currentStream.eof()) {
      currentEvtNo++;
      double e,px,py,pz;
      Event* newEvent = new Event();
      int parts;
      
      if(_useWeight)
	{
	  double weight;
	  currentStream >> weight;
	  newEvent->addWeight(weight);
	}      
      Vector4<double> fvX(0,0,0,0); //X four-vector
      for (parts = 0; parts < numParticles; parts++) {
	if(_energyFirst) currentStream >> e >> px >> py >> pz; 
	else currentStream >> px >> py >> pz >> e;
        newEvent->addParticle(e/_unitScaleFactor, px/_unitScaleFactor, py/_unitScaleFactor, pz/_unitScaleFactor);
	Vector4<double> tmp = newEvent->p4(parts);
      }

      bool acceptEvt=true;
      if(_useMassRange){
	std::vector< std::shared_ptr<MassRangeCut> >::iterator itMassRangeCut;
	for (itMassRangeCut=_massRangeCuts.begin(); itMassRangeCut!=_massRangeCuts.end(); ++itMassRangeCut){
	  Vector4<float> particleSystem4Vec;
	  std::vector<unsigned int> particleIndices=(*itMassRangeCut)->particleIds();
	  for(auto it = particleIndices.begin(); it!=particleIndices.end(); ++it){
	    particleSystem4Vec += *(newEvent->p4(*it));
	  }
	  double invMass = particleSystem4Vec.Mass();
	  if(invMass < (*itMassRangeCut)->massMin() || invMass > (*itMassRangeCut)->massMax()){
           acceptEvt=false;
           break;
	  } 
	}
      }

      if( !acceptEvt || currentEvtNo<evtStart || currentEvtNo>evtStop){
	if (!acceptEvt) currentEvtNo--;
	delete newEvent;
	continue;
      }
 
      if (!currentStream.fail()) {
	evtList.add(newEvent);
	for (parts = 0; parts < linesToSkip; parts++)
	  if(_energyFirst) currentStream >> e >> px >> py >> pz; 
	  else currentStream >> px >> py >> pz >> e;
      }
    }
    if (currentEvtNo == 0){
      Alert << "No events have been read in from File: " << *currentFile << " ! \nNo events in massRange? Wrong order of particles? currentEvtNo = " << currentEvtNo;
      exit(1);
    }
    currentStream.close();
    ++currentFile;
  }
  evtList.rewind();

  return true; // success
}

void EventReaderDefault::setUnit(const std::string& theUnit){
  _unit=theUnit;
  if(_unit=="GEV"){
    _unitScaleFactor=1.;
  }
  else if(_unit=="MEV"){
    _unitScaleFactor=1000.;
    }
  else{
    Alert << "unit " << _unit << " does not exist!!!" <<endmsg;
    exit(0);
  }
}

void EventReaderDefault::setOrder(const std::string& theOrder){
  _order=theOrder;
  if(_order=="E Px Py Pz"){
    _energyFirst=true;
  }
  else if(_order=="Px Py Pz E"){
    _energyFirst=false;
  }
  else{
    Alert << "order " << _order << " does not exist!!!" <<endmsg;
    exit(0);
  }
}