/*****************************************************************************
 * Project: RooFit                                                           *
 * Package: RooFitCore                                                       *
 * @(#)root/roofitcore:$Id$
 * Authors:                                                                  *
 *   WV, Wouter Verkerke, UC Santa Barbara, verkerke@slac.stanford.edu       *
 *   DK, David Kirkby,    UC Irvine,         dkirkby@uci.edu                 *
 *                                                                           *
 * Copyright (c) 2000-2005, Regents of the University of California          *
 *                          and Stanford University. All rights reserved.    *
 *                                                                           *
 * Redistribution and use in source and binary forms,                        *
 * with or without modification, are permitted according to the terms        *
 * listed in LICENSE (http://roofit.sourceforge.net/license.txt)             *
 *****************************************************************************/

//////////////////////////////////////////////////////////////////////////////
//
// BEGIN_HTML
//
// RooGenProdProj is an auxiliary class for RooProdPdf that calculates
// a general normalized projection of a product of non-factorizing PDFs, e.g.
//
//            Int ( P1 * P2 * ....) dx
//  P_x_xy = -------------------------------
//            Int (P1 * P2 * ... ) dx dy
//
// Partial integrals that factorize that can be calculated are calculated
// analytically. Remaining non-factorizing observables are integrated numerically.
// END_HTML
//


#include "RooFit.h"

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

#include "RooGenProdProj.h"
#include "RooAbsReal.h"
#include "RooAbsPdf.h"
#include "RooErrorHandler.h"
#include "RooProduct.h"

using namespace std;

ClassImp(RooGenProdProj)
;


//_____________________________________________________________________________
RooGenProdProj::RooGenProdProj() :
  _compSetOwnedN(0), 
  _compSetOwnedD(0),
  _haveD(kFALSE)
{
  // Default constructor
}


//_____________________________________________________________________________
RooGenProdProj::RooGenProdProj(const char *name, const char *title, const RooArgSet& _prodSet, const RooArgSet& _intSet, 
			       const RooArgSet& _normSet, const char* isetRangeName, const char* normRangeName, Bool_t doFactorize) :
  RooAbsReal(name, title),
  _compSetOwnedN(0), 
  _compSetOwnedD(0),
  _compSetN("compSetN","Set of integral components owned by numerator",this,kFALSE),
  _compSetD("compSetD","Set of integral components owned by denominator",this,kFALSE),
  _intList("intList","List of integrals",this,kTRUE),
  _haveD(kFALSE)
{
  // Constructor for a normalization projection of the product of p.d.f.s _prodSet
  // integrated over _intSet in range isetRangeName while normalized over _normSet

  // Set expensive object cache to that of first item in prodSet
  setExpensiveObjectCache(_prodSet.first()->expensiveObjectCache()) ;

  // Create owners of components created in ctor
  _compSetOwnedN = new RooArgSet ;
  _compSetOwnedD = new RooArgSet ;

  RooAbsReal* numerator = makeIntegral("numerator",_prodSet,_intSet,*_compSetOwnedN,isetRangeName,doFactorize) ;
  RooAbsReal* denominator = makeIntegral("denominator",_prodSet,_normSet,*_compSetOwnedD,normRangeName,doFactorize) ;

//   cout << "RooGenProdPdf::ctor(" << GetName() << ") numerator = " << numerator->GetName() << endl ;
//   numerator->printComponentTree() ;
//   cout << "RooGenProdPdf::ctor(" << GetName() << ") denominator = " << denominator->GetName() << endl ;
//   denominator->printComponentTree() ;

  // Copy all components in (non-owning) set proxy
  _compSetN.add(*_compSetOwnedN) ;
  _compSetD.add(*_compSetOwnedD) ;
  
  _intList.add(*numerator) ;
  if (denominator) {
    _intList.add(*denominator) ;
    _haveD = kTRUE ;
  }
}



//_____________________________________________________________________________
RooGenProdProj::RooGenProdProj(const RooGenProdProj& other, const char* name) :
  RooAbsReal(other, name), 
  _compSetOwnedN(0), 
  _compSetOwnedD(0),
  _compSetN("compSetN","Set of integral components owned by numerator",this),
  _compSetD("compSetD","Set of integral components owned by denominator",this),
  _intList("intList","List of integrals",this)
{
  // Copy constructor

  // Explicitly remove all server links at this point
  TIterator* iter = serverIterator() ;
  RooAbsArg* server ;
  while((server=(RooAbsArg*)iter->Next())) {
    removeServer(*server,kTRUE) ;
  }
  delete iter ;

  // Copy constructor
  _compSetOwnedN = (RooArgSet*) other._compSetN.snapshot() ;
  _compSetN.add(*_compSetOwnedN) ;

  _compSetOwnedD = (RooArgSet*) other._compSetD.snapshot() ;
  _compSetD.add(*_compSetOwnedD) ;

  RooAbsArg* arg ;
  TIterator* nIter = _compSetOwnedN->createIterator() ;  
  while((arg=(RooAbsArg*)nIter->Next())) {
//     cout << "ownedN elem " << arg->GetName() << "(" << arg << ")" << endl ;
    arg->setOperMode(_operMode) ;
  }
  delete nIter ;
  TIterator* dIter = _compSetOwnedD->createIterator() ;
  while((arg=(RooAbsArg*)dIter->Next())) {
//     cout << "ownedD elem " << arg->GetName() << "(" << arg << ")" << endl ;
    arg->setOperMode(_operMode) ;
  }
  delete dIter ;

  // Fill _intList
  _haveD = other._haveD ;
  _intList.add(*_compSetN.find(other._intList.at(0)->GetName())) ;
  if (other._haveD) {
    _intList.add(*_compSetD.find(other._intList.at(1)->GetName())) ;
  }
}



//_____________________________________________________________________________
RooGenProdProj::~RooGenProdProj()
{
  // Destructor

  if (_compSetOwnedN) delete _compSetOwnedN ;
  if (_compSetOwnedD) delete _compSetOwnedD ;
}



//_____________________________________________________________________________
RooAbsReal* RooGenProdProj::makeIntegral(const char* name, const RooArgSet& compSet, const RooArgSet& intSet, 
					 RooArgSet& saveSet, const char* isetRangeName, Bool_t doFactorize) 
{
  // Utility function to create integral over observables intSet in range isetRangeName over product of p.d.fs in compSet.
  // The integration is factorized into components as much as possible and done analytically as far as possible.
  // All component object needed to represent product integral are added as owned members to saveSet.
  // The return value is a RooAbsReal object representing the requested integral

  RooArgSet anaIntSet, numIntSet ;

  // First determine subset of observables in intSet that are factorizable
  TIterator* compIter = compSet.createIterator() ;
  TIterator* intIter = intSet.createIterator() ;
  RooAbsPdf* pdf ;
  RooAbsArg* arg ;
  while((arg=(RooAbsArg*)intIter->Next())) {
    Int_t count(0) ;
    compIter->Reset() ;
    while((pdf=(RooAbsPdf*)compIter->Next())) {
      if (pdf->dependsOn(*arg)) count++ ;
    }

    if (count==0) {
    } else if (count==1) {
      anaIntSet.add(*arg) ;
    } else {
    }    
  }

  // Determine which of the factorizable integrals can be done analytically
  RooArgSet prodSet ;
  numIntSet.add(intSet) ;
  
  compIter->Reset() ;
  while((pdf=(RooAbsPdf*)compIter->Next())) {
    if (doFactorize && pdf->dependsOn(anaIntSet)) {
      RooArgSet anaSet ;
      Int_t code = pdf->getAnalyticalIntegralWN(anaIntSet,anaSet,0,isetRangeName) ;
      if (code!=0) {
	// Analytical integral, create integral object
	RooAbsReal* pai = pdf->createIntegral(anaSet,isetRangeName) ;
	pai->setOperMode(_operMode) ;
	
	// Add to integral to product
	prodSet.add(*pai) ;
	
	// Remove analytically integratable observables from numeric integration list
	numIntSet.remove(anaSet) ;
	
	// Declare ownership of integral
	saveSet.addOwned(*pai) ;
      } else {
	// Analytic integration of factorizable observable not possible, add straight pdf to product
	prodSet.add(*pdf) ;
      }      
    } else {
      // Non-factorizable observables, add straight pdf to product
      prodSet.add(*pdf) ;
    }
  }

  //cout << "RooGenProdProj::makeIntegral(" << GetName() << ") prodset = " << prodSet << endl ;

  // Create product of (partial) analytical integrals
  TString prodName ;
  if (isetRangeName) {
    prodName = Form("%s_%s_Range[%s]",GetName(),name,isetRangeName) ;
  } else {
    prodName = Form("%s_%s",GetName(),name) ;
  }
  RooProduct* prod = new RooProduct(prodName,"product",prodSet) ;
  prod->setExpensiveObjectCache(expensiveObjectCache()) ;
  prod->setOperMode(_operMode) ;

  // Declare owndership of product
  saveSet.addOwned(*prod) ;

  // Create integral performing remaining numeric integration over (partial) analytic product
  RooAbsReal* ret = prod->createIntegral(numIntSet,isetRangeName) ;
//   cout << "verbose print of integral object" << endl ;
//   ret->Print("v") ;
  ret->setOperMode(_operMode) ;
  saveSet.addOwned(*ret) ;

  delete compIter ;
  delete intIter ;

  // Caller owners returned master integral object
  return ret ;
}



//_____________________________________________________________________________
Double_t RooGenProdProj::evaluate() const 
{  
  // Calculate and return value of normalization projection

  Double_t nom = ((RooAbsReal*)_intList.at(0))->getVal() ;

  if (!_haveD) return nom ;

  Double_t den = ((RooAbsReal*)_intList.at(1))->getVal() ;

  //cout << "RooGenProdProj::eval(" << GetName() << ") nom = " << nom << " den = " << den << endl ;

  return nom / den ;
}



//_____________________________________________________________________________
void RooGenProdProj::operModeHook() 
{
  // Intercept cache mode operation changes and propagate them to the components

  // WVE use cache manager here!

  RooAbsArg* arg ;
  TIterator* nIter = _compSetOwnedN->createIterator() ;  
  while((arg=(RooAbsArg*)nIter->Next())) {
    arg->setOperMode(_operMode) ;
  }
  delete nIter ;

  TIterator* dIter = _compSetOwnedD->createIterator() ;
  while((arg=(RooAbsArg*)dIter->Next())) {
    arg->setOperMode(_operMode) ;
  }
  delete dIter ;

  _intList.at(0)->setOperMode(_operMode) ;
  if (_haveD) _intList.at(1)->setOperMode(Auto) ; // Denominator always stays in Auto mode (normalization integral)
}