/*****************************************************************************

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//////////////////////////////////////////////////////////////////////////////
// 
// BEGIN_HTML
// PiecewiseInterpolation 
// END_HTML
//

#include <exception>
#include "RooFit.h"

#include "Riostream.h"
#include "Riostream.h"
#include <math.h>

#include "RooStats/HistFactory/PiecewiseInterpolation.h"
#include "RooAbsReal.h"
#include "RooAbsPdf.h"
#include "RooErrorHandler.h"
#include "RooArgSet.h"
#include "RooNLLVar.h"
#include "RooChi2Var.h"
#include "RooRealVar.h"
#include "RooMsgService.h"
#include "RooNumIntConfig.h"

using namespace std;

ClassImp(PiecewiseInterpolation)
;


//_____________________________________________________________________________
PiecewiseInterpolation::PiecewiseInterpolation()
{
  _positiveDefinite=false;
}



//_____________________________________________________________________________
PiecewiseInterpolation::PiecewiseInterpolation(const char* name, const char* title, const RooAbsReal& nominal,
					       const RooArgList& lowSet, 
					       const RooArgList& highSet,
					       const RooArgList& paramSet,
					       Bool_t takeOwnership) :
  RooAbsReal(name, title),
  _nominal("!nominal","nominal value", this, (RooAbsReal&)nominal),
  _lowSet("!lowSet","low-side variation",this),
  _highSet("!highSet","high-side variation",this),
  _paramSet("!paramSet","high-side variation",this),
  _positiveDefinite(false)

{
  // Constructor with two set of RooAbsReals. The value of the function will be
  //
  //  A = sum_i lowSet(i)*highSet(i) 
  //
  // If takeOwnership is true the PiecewiseInterpolation object will take ownership of the arguments in sumSet

  // KC: check both sizes
  if (lowSet.getSize() != highSet.getSize()) {
    coutE(InputArguments) << "PiecewiseInterpolation::ctor(" << GetName() << ") ERROR: input lists should be of equal length" << endl ;
    RooErrorHandler::softAbort() ;    
  }

  RooFIter inputIter1 = lowSet.fwdIterator() ;
  RooAbsArg* comp ;
  while((comp = inputIter1.next())) {
    if (!dynamic_cast<RooAbsReal*>(comp)) {
      coutE(InputArguments) << "PiecewiseInterpolation::ctor(" << GetName() << ") ERROR: component " << comp->GetName() 
			    << " in first list is not of type RooAbsReal" << endl ;
      RooErrorHandler::softAbort() ;
    }
    _lowSet.add(*comp) ;
    if (takeOwnership) {
      _ownedList.addOwned(*comp) ;
    }
  }


  RooFIter inputIter2 = highSet.fwdIterator() ;
  while((comp = inputIter2.next())) {
    if (!dynamic_cast<RooAbsReal*>(comp)) {
      coutE(InputArguments) << "PiecewiseInterpolation::ctor(" << GetName() << ") ERROR: component " << comp->GetName() 
			    << " in first list is not of type RooAbsReal" << endl ;
      RooErrorHandler::softAbort() ;
    }
    _highSet.add(*comp) ;
    if (takeOwnership) {
      _ownedList.addOwned(*comp) ;
    }
  }


  RooFIter inputIter3 = paramSet.fwdIterator() ;
  while((comp = inputIter3.next())) {
    if (!dynamic_cast<RooAbsReal*>(comp)) {
      coutE(InputArguments) << "PiecewiseInterpolation::ctor(" << GetName() << ") ERROR: component " << comp->GetName() 
			    << " in first list is not of type RooAbsReal" << endl ;
      RooErrorHandler::softAbort() ;
    }
    _paramSet.add(*comp) ;
    if (takeOwnership) {
      _ownedList.addOwned(*comp) ;
    }
    _interpCode.push_back(0); // default code: linear interpolation
  }

  
  // Choose special integrator by default 
  specialIntegratorConfig(kTRUE)->method1D().setLabel("RooBinIntegrator") ;
}



//_____________________________________________________________________________
PiecewiseInterpolation::PiecewiseInterpolation(const PiecewiseInterpolation& other, const char* name) :
  RooAbsReal(other, name), 
  _nominal("!nominal",this,other._nominal),
  _lowSet("!lowSet",this,other._lowSet),
  _highSet("!highSet",this,other._highSet),
  _paramSet("!paramSet",this,other._paramSet),
  _positiveDefinite(other._positiveDefinite),
  _interpCode(other._interpCode)
{
  // Copy constructor

  // Member _ownedList is intentionally not copy-constructed -- ownership is not transferred
}



//_____________________________________________________________________________
PiecewiseInterpolation::~PiecewiseInterpolation() 
{
  // Destructor
}




//_____________________________________________________________________________
Double_t PiecewiseInterpolation::evaluate() const 
{
  // Calculate and return current value of self

  ///////////////////
  Double_t nominal = _nominal;
  Double_t sum(nominal) ;

  RooAbsReal* param ;
  RooAbsReal* high ;
  RooAbsReal* low ;
  int i=0;

  RooFIter lowIter(_lowSet.fwdIterator()) ;
  RooFIter highIter(_highSet.fwdIterator()) ;
  RooFIter paramIter(_paramSet.fwdIterator()) ;

  while((param=(RooAbsReal*)paramIter.next())) {
    low = (RooAbsReal*)lowIter.next() ;
    high = (RooAbsReal*)highIter.next() ;

    Int_t icode = _interpCode[i] ;

    switch(icode) {
    case 0: {
      // piece-wise linear
      if(param->getVal()>0)
	sum +=  param->getVal()*(high->getVal() - nominal );
      else
	sum += param->getVal()*(nominal - low->getVal());
      break ;
    }
    case 1: {
      // pice-wise log
      if(param->getVal()>=0)
	sum *= pow(high->getVal()/nominal, +param->getVal());
      else
	sum *= pow(low->getVal()/nominal,  -param->getVal());
      break ;
    }
    case 2: {
      // parabolic with linear
      double a = 0.5*(high->getVal()+low->getVal())-nominal;
      double b = 0.5*(high->getVal()-low->getVal());
      double c = 0;
      if(param->getVal()>1 ){
	sum += (2*a+b)*(param->getVal()-1)+high->getVal()-nominal;
      } else if(param->getVal()<-1 ) {
	sum += -1*(2*a-b)*(param->getVal()+1)+low->getVal()-nominal;
      } else {
	sum +=  a*pow(param->getVal(),2) + b*param->getVal()+c;
      }
      break ;
    }
    case 3: {
      //parabolic version of log-normal
      double a = 0.5*(high->getVal()+low->getVal())-nominal;
      double b = 0.5*(high->getVal()-low->getVal());
      double c = 0;
      if(param->getVal()>1 ){
	sum += (2*a+b)*(param->getVal()-1)+high->getVal()-nominal;
      } else if(param->getVal()<-1 ) {
	sum += -1*(2*a-b)*(param->getVal()+1)+low->getVal()-nominal;
      } else {
	sum +=  a*pow(param->getVal(),2) + b*param->getVal()+c;
      }
      break ;
    }
    case 4: {
      
      // WVE ****************************************************************
      // WVE *** THIS CODE IS CRITICAL TO HISTFACTORY FIT CPU PERFORMANCE ***
      // WVE *** Do not modify unless you know what you are doing...      ***
      // WVE ****************************************************************

      double x  = param->getVal();      
      if (x>1) {
	sum += x*(high->getVal() - nominal );
      } else if (x<-1) {
	sum += x*(nominal - low->getVal());
      } else {
	double eps_plus = high->getVal() - nominal;
	double eps_minus = nominal - low->getVal();
	double S = (eps_plus + eps_minus)/2;
	double A = (eps_plus - eps_minus)/16;
	
	//fcns+der+2nd_der are eq at bd
	double xx = x*x ;
	double xxxx = xx*xx ;
	double val = nominal + S*x + A*(15*xx - 10*xxxx + 3*xxxx*xx);
	if (val < 0) val = 0;
	sum += val-nominal;
      }
      break ;

      // WVE ****************************************************************
    }
    case 5: {
      
      double x0 = 1.0;//boundary;
      double x  = param->getVal();

      if (x > x0 || x < -x0)
      {
	if(x>0)
	  sum += x*(high->getVal() - nominal );
	else
	  sum += x*(nominal - low->getVal());
      }
      else if (nominal != 0)
      {
	double eps_plus = high->getVal() - nominal;
	double eps_minus = nominal - low->getVal();
	double S = (eps_plus + eps_minus)/2;
	double A = (eps_plus - eps_minus)/2;

	//fcns+der are eq at bd
	double a = S;
	double b = 3*A/(2*x0);
	//double c = 0;
	double d = -A/(2*x0*x0*x0);

	double val = nominal + a*x + b*pow(x, 2) + 0/*c*pow(x, 3)*/ + d*pow(x, 4);
	if (val < 0) val = 0;

	//cout << "Using interp code 5, val = " << val << endl;

	sum += val-nominal;
      }
      break ;
    }
    default: {
      coutE(InputArguments) << "PiecewiseInterpolation::evaluate ERROR:  " << param->GetName() 
			    << " with unknown interpolation code" << icode << endl ;
      break ;
    }
    }
    ++i;
  }
  
  if(_positiveDefinite && (sum<0)){
    sum = 1e-6;
    sum = 0;
    //     cout <<"sum < 0 forcing  positive definite"<<endl;
     //     int code = 1;
     //     RooArgSet* myset = new RooArgSet();
     //     cout << "integral = " << analyticalIntegralWN(code, myset) << endl;
  } else if(sum<0){
     cout <<"sum < 0, not forcing positive definite"<<endl;
  }
  return sum;

}

//_____________________________________________________________________________
Bool_t PiecewiseInterpolation::setBinIntegrator(RooArgSet& allVars) 
{

  if(allVars.getSize()==1){
    RooAbsReal* temp = const_cast<PiecewiseInterpolation*>(this);
    temp->specialIntegratorConfig(kTRUE)->method1D().setLabel("RooBinIntegrator")  ;
    int nbins = ((RooRealVar*) allVars.first())->numBins();
    temp->specialIntegratorConfig(kTRUE)->getConfigSection("RooBinIntegrator").setRealValue("numBins",nbins);
    return true;
  }else{
    cout << "Currently BinIntegrator only knows how to deal with 1-d "<<endl;
    return false;
  }
  return false;
}

//_____________________________________________________________________________
Int_t PiecewiseInterpolation::getAnalyticalIntegralWN(RooArgSet& allVars, RooArgSet& analVars, 
						      const RooArgSet* normSet, const char* /*rangeName*/) const 
{
  // Advertise that all integrals can be handled internally.

  /*
  cout << "---------------------------\nin PiecewiseInterpolation get analytic integral " <<endl;
  cout << "all vars = "<<endl;
  allVars.Print("v");
  cout << "anal vars = "<<endl;
  analVars.Print("v");
  cout << "normset vars = "<<endl;
  if(normSet2)
    normSet2->Print("v");
  */


  // Handle trivial no-integration scenario
  if (allVars.getSize()==0) return 0 ;
  if (_forceNumInt) return 0 ;


  // Force using numeric integration
  // use special numeric integrator  
  return 0;
  

  // KC: check if interCode=0 for all 
  RooFIter paramIterExtra(_paramSet.fwdIterator()) ;
  int i=0;
  while( paramIterExtra.next() ) {
    if(!_interpCode.empty() && _interpCode[i]!=0){
      // can't factorize integral
      cout <<"can't factorize integral"<<endl;
      return 0;
    }
    ++i;
  }

  // Select subset of allVars that are actual dependents
  analVars.add(allVars) ;
  //  RooArgSet* normSet = normSet2 ? getObservables(normSet2) : 0 ;
  //  RooArgSet* normSet = getObservables();
  //  RooArgSet* normSet = 0;


  // Check if this configuration was created before
  Int_t sterileIdx(-1) ;
  CacheElem* cache = (CacheElem*) _normIntMgr.getObj(normSet,&analVars,&sterileIdx) ;
  if (cache) {
    return _normIntMgr.lastIndex()+1 ;
  }
  
  // Create new cache element
  cache = new CacheElem ;

  // Make list of function projection and normalization integrals 
  RooAbsReal *func ;
  //  const RooArgSet* nset = _paramList.nset() ;

  // do nominal
  func = (RooAbsReal*)(&_nominal.arg()) ;
  RooAbsReal* funcInt = func->createIntegral(analVars) ;
  cache->_funcIntList.addOwned(*funcInt) ;

  // do variations
  RooFIter lowIter(_lowSet.fwdIterator()) ;
  RooFIter highIter(_highSet.fwdIterator()) ;
  RooFIter paramIter(_paramSet.fwdIterator()) ;

  //  int i=0;
  i=0;
  while(paramIter.next() ) {
    func = (RooAbsReal*)lowIter.next() ;
    funcInt = func->createIntegral(analVars) ;
    cache->_lowIntList.addOwned(*funcInt) ;

    func = (RooAbsReal*)highIter.next() ;
    funcInt = func->createIntegral(analVars) ;
    cache->_highIntList.addOwned(*funcInt) ;
    ++i;
  }

  // Store cache element
  Int_t code = _normIntMgr.setObj(normSet,&analVars,(RooAbsCacheElement*)cache,0) ;

  return code+1 ; 
}




//_____________________________________________________________________________
Double_t PiecewiseInterpolation::analyticalIntegralWN(Int_t code, const RooArgSet* /*normSet2*/,const char* /*rangeName*/) const 
{
  // Implement analytical integrations by doing appropriate weighting from  component integrals
  // functions to integrators of components

  /*
  cout <<"Enter analytic Integral"<<endl;
  printDirty(true);
  //  _nominal.arg().setDirtyInhibit(kTRUE) ;
  _nominal.arg().setShapeDirty() ;
  RooAbsReal* temp ;
  RooFIter lowIter(_lowSet.fwdIterator()) ;
  while((temp=(RooAbsReal*)lowIter.next())) {
    //    temp->setDirtyInhibit(kTRUE) ;
    temp->setShapeDirty() ;
  }
  RooFIter highIter(_highSet.fwdIterator()) ;
  while((temp=(RooAbsReal*)highIter.next())) {
    //    temp->setDirtyInhibit(kTRUE) ;
    temp->setShapeDirty() ;
  }
  */

  /*
  RooAbsArg::setDirtyInhibit(kTRUE);
  printDirty(true);
  cout <<"done setting dirty inhibit = true"<<endl;

  // old integral, only works for linear and not positive definite
  CacheElem* cache = (CacheElem*) _normIntMgr.getObjByIndex(code-1) ;

  
 std::auto_ptr<RooArgSet> vars2( getParameters(RooArgSet()) );
 std::auto_ptr<RooArgSet> iset(  _normIntMgr.nameSet2ByIndex(code-1)->select(*vars2) );            
 cout <<"iset = "<<endl;
 iset->Print("v");

  double sum = 0;
  RooArgSet* vars = getVariables();
  vars->remove(_paramSet);
  _paramSet.Print("v");
  vars->Print("v");
  if(vars->getSize()==1){
    RooRealVar* obs = (RooRealVar*) vars->first();
    for(int i=0; i<obs->numBins(); ++i){
      obs->setVal( obs->getMin() + (.5+i)*(obs->getMax()-obs->getMin())/obs->numBins());
      sum+=evaluate()*(obs->getMax()-obs->getMin())/obs->numBins();
      cout << "obs = " << obs->getVal() << " sum = " << sum << endl;
    }
  } else{
    cout <<"only know how to deal with 1 observable right now"<<endl;
  }
  */

  /*
  _nominal.arg().setDirtyInhibit(kFALSE) ;
  RooFIter lowIter2(_lowSet.fwdIterator()) ;
  while((temp=(RooAbsReal*)lowIter2.next())) {
    temp->setDirtyInhibit(kFALSE) ;
  }
  RooFIter highIter2(_highSet.fwdIterator()) ;
  while((temp=(RooAbsReal*)highIter2.next())) {
    temp->setDirtyInhibit(kFALSE) ;
  }
  */
  
  /*
  RooAbsArg::setDirtyInhibit(kFALSE);
  printDirty(true);
  cout <<"done"<<endl;
  cout << "sum = " <<sum<<endl;
  //return sum;
  */  

  // old integral, only works for linear and not positive definite
  CacheElem* cache = (CacheElem*) _normIntMgr.getObjByIndex(code-1) ;
  if( cache==NULL ) {
    std::cout << "Error: Cache Element is NULL" << std::endl;
    throw std::exception();
  }

  // old integral, only works for linear and not positive definite
  RooFIter funcIntIter = cache->_funcIntList.fwdIterator() ;
  RooFIter lowIntIter = cache->_lowIntList.fwdIterator() ;
  RooFIter highIntIter = cache->_highIntList.fwdIterator() ;
  RooAbsReal *funcInt(0), *low(0), *high(0), *param(0) ;
  Double_t value(0) ;
  Double_t nominal(0);

  // get nominal 
  int i=0;
  while(( funcInt = (RooAbsReal*)funcIntIter.next())) {
    value += funcInt->getVal() ;
    nominal = value;
    i++;
  }
  if(i==0 || i>1) { cout << "problem, wrong number of nominal functions"<<endl; }

  // now get low/high variations
  i = 0;
  RooFIter paramIter(_paramSet.fwdIterator()) ;

  // KC: old interp code with new iterator
  while( (param=(RooAbsReal*)paramIter.next()) ) {
    low = (RooAbsReal*)lowIntIter.next() ;
    high = (RooAbsReal*)highIntIter.next() ;
    
    if(param->getVal()>0) {
      value += param->getVal()*(high->getVal() - nominal );
    } else {
      value += param->getVal()*(nominal - low->getVal());
    }
    ++i;
  }

  /* // MB : old bit of interpolation code
  while( (param=(RooAbsReal*)_paramIter->Next()) ) {
    low = (RooAbsReal*)lowIntIter->Next() ;
    high = (RooAbsReal*)highIntIter->Next() ;
    
    if(param->getVal()>0) {
      value += param->getVal()*(high->getVal() - nominal );
    } else {
      value += param->getVal()*(nominal - low->getVal());
    }
    ++i;
  }
  */

  /* KC: the code below is wrong.  Can't pull out a constant change to a non-linear shape deformation.
  while( (param=(RooAbsReal*)paramIter.next()) ) {
    low = (RooAbsReal*)lowIntIter.next() ;
    high = (RooAbsReal*)highIntIter.next() ;

    if(_interpCode.empty() || _interpCode.at(i)==0){
      // piece-wise linear
      if(param->getVal()>0)
	value +=  param->getVal()*(high->getVal() - nominal );
      else
	value += param->getVal()*(nominal - low->getVal());
    } else if(_interpCode.at(i)==1){
      // pice-wise log
      if(param->getVal()>=0)
	value *= pow(high->getVal()/nominal, +param->getVal());
      else
	value *= pow(low->getVal()/nominal,  -param->getVal());
    } else if(_interpCode.at(i)==2){
      // parabolic with linear
      double a = 0.5*(high->getVal()+low->getVal())-nominal;
      double b = 0.5*(high->getVal()-low->getVal());
      double c = 0;
      if(param->getVal()>1 ){
	value += (2*a+b)*(param->getVal()-1)+high->getVal()-nominal;
      } else if(param->getVal()<-1 ) {
	value += -1*(2*a-b)*(param->getVal()+1)+low->getVal()-nominal;
      } else {
	value +=  a*pow(param->getVal(),2) + b*param->getVal()+c;
      }
    } else if(_interpCode.at(i)==3){
      //parabolic version of log-normal
      double a = 0.5*(high->getVal()+low->getVal())-nominal;
      double b = 0.5*(high->getVal()-low->getVal());
      double c = 0;
      if(param->getVal()>1 ){
	value += (2*a+b)*(param->getVal()-1)+high->getVal()-nominal;
      } else if(param->getVal()<-1 ) {
	value += -1*(2*a-b)*(param->getVal()+1)+low->getVal()-nominal;
      } else {
	value +=  a*pow(param->getVal(),2) + b*param->getVal()+c;
      }
	
    } else {
      coutE(InputArguments) << "PiecewiseInterpolation::analyticalIntegralWN ERROR:  " << param->GetName() 
			    << " with unknown interpolation code" << endl ;
    }
    ++i;
  }
  */

  //  cout << "value = " << value <<endl;
  return value;
}


//_____________________________________________________________________________
void PiecewiseInterpolation::setInterpCode(RooAbsReal& param, int code){

  int index = _paramSet.index(&param);
  if(index<0){
      coutE(InputArguments) << "PiecewiseInterpolation::setInterpCode ERROR:  " << param.GetName() 
			    << " is not in list" << endl ;
  } else {
      coutW(InputArguments) << "PiecewiseInterpolation::setInterpCode :  " << param.GetName() 
			    << " is now " << code << endl ;
    _interpCode.at(index) = code;
  }
}


//_____________________________________________________________________________
void PiecewiseInterpolation::setAllInterpCodes(int code){

  for(unsigned int i=0; i<_interpCode.size(); ++i){
    _interpCode.at(i) = code;
  }
}


//_____________________________________________________________________________
void PiecewiseInterpolation::printAllInterpCodes(){

  for(unsigned int i=0; i<_interpCode.size(); ++i){
    coutI(InputArguments) <<"interp code for " << _paramSet.at(i)->GetName() << " = " << _interpCode.at(i) <<endl;
  }
}


//_____________________________________________________________________________
std::list<Double_t>* PiecewiseInterpolation::binBoundaries(RooAbsRealLValue& obs, Double_t xlo, Double_t xhi) const 
{
  // WVE note: assumes nominal and alternates have identical structure, must add explicit check
  return _nominal.arg().binBoundaries(obs,xlo,xhi) ;  
}


//_____________________________________________________________________________
Bool_t PiecewiseInterpolation::isBinnedDistribution(const RooArgSet& obs) const 
{
  // WVE note: assumes nominal and alternates have identical structure, must add explicit check
  return _nominal.arg().isBinnedDistribution(obs) ;
}



//_____________________________________________________________________________
std::list<Double_t>* PiecewiseInterpolation::plotSamplingHint(RooAbsRealLValue& obs, Double_t xlo, Double_t xhi) const 
{
  return _nominal.arg().plotSamplingHint(obs,xlo,xhi) ;  
}

//______________________________________________________________________________
void PiecewiseInterpolation::Streamer(TBuffer &R__b)
{
   // Stream an object of class PiecewiseInterpolation.

   if (R__b.IsReading()) {
      R__b.ReadClassBuffer(PiecewiseInterpolation::Class(),this);
      specialIntegratorConfig(kTRUE)->method1D().setLabel("RooBinIntegrator") ;      
      if (_interpCode.empty()) _interpCode.resize(_paramSet.getSize());
   } else {
      R__b.WriteClassBuffer(PiecewiseInterpolation::Class(),this);
   }
}


/*
//_____________________________________________________________________________
void PiecewiseInterpolation::printMetaArgs(ostream& os) const 
{
  // Customized printing of arguments of a PiecewiseInterpolation to more intuitively reflect the contents of the
  // product operator construction

  _lowIter->Reset() ;
  if (_highIter) {
    _highIter->Reset() ;
  }

  Bool_t first(kTRUE) ;
    
  RooAbsArg* arg1, *arg2 ;
  if (_highSet.getSize()!=0) { 

    while((arg1=(RooAbsArg*)_lowIter->Next())) {
      if (!first) {
	os << " + " ;
      } else {
	first = kFALSE ;
      }
      arg2=(RooAbsArg*)_highIter->Next() ;
      os << arg1->GetName() << " * " << arg2->GetName() ;
    }

  } else {
    
    while((arg1=(RooAbsArg*)_lowIter->Next())) {
      if (!first) {
	os << " + " ;
      } else {
	first = kFALSE ;
      }
      os << arg1->GetName() ; 
    }  

  }

  os << " " ;    
}

*/