/*****************************************************************************
 * 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
// RooNumIntFactory is a factory to instantiate numeric integrators
// from a given function binding and a given configuration. The factory
// searches for a numeric integrator registered with the factory that
// has the ability to perform the numeric integration. The choice of
// method may depend on the number of dimensions integrated,
// the nature of the integration limits (closed or open ended) and
// the preference of the caller as encoded in the configuration object.
// END_HTML
//

#include "TClass.h"
#include "Riostream.h"

#include "RooFit.h"

#include "RooNumIntFactory.h"
#include "RooArgSet.h"
#include "RooAbsFunc.h"
#include "RooNumIntConfig.h"
#include "RooNumber.h"

#include "RooIntegrator1D.h"
#include "RooBinIntegrator.h"
#include "RooIntegrator2D.h"
#include "RooSegmentedIntegrator1D.h"
#include "RooSegmentedIntegrator2D.h"
#include "RooImproperIntegrator1D.h"
#include "RooMCIntegrator.h"
#include "RooGaussKronrodIntegrator1D.h"
#include "RooAdaptiveGaussKronrodIntegrator1D.h"
#include "RooAdaptiveIntegratorND.h"
#include "RooSentinel.h"

#include "RooMsgService.h"

using namespace std ;

ClassImp(RooNumIntFactory)
;

RooNumIntFactory* RooNumIntFactory::_instance = 0 ;



////////////////////////////////////////////////////////////////////////////////
/// Constructor. Register all known integrators by calling
/// their static registration functions

RooNumIntFactory::RooNumIntFactory()
{
  _instance = this ;

  RooBinIntegrator::registerIntegrator(*this) ;
  RooIntegrator1D::registerIntegrator(*this) ;
  RooIntegrator2D::registerIntegrator(*this) ;
  RooSegmentedIntegrator1D::registerIntegrator(*this) ;
  RooSegmentedIntegrator2D::registerIntegrator(*this) ;
  RooImproperIntegrator1D::registerIntegrator(*this) ;
  RooMCIntegrator::registerIntegrator(*this) ;
  RooAdaptiveGaussKronrodIntegrator1D::registerIntegrator(*this) ;
  RooGaussKronrodIntegrator1D::registerIntegrator(*this) ;  
  RooAdaptiveIntegratorND::registerIntegrator(*this) ;

  RooNumIntConfig::defaultConfig().method1D().setLabel("RooIntegrator1D") ;
  RooNumIntConfig::defaultConfig().method1DOpen().setLabel("RooImproperIntegrator1D") ;
  RooNumIntConfig::defaultConfig().method2D().setLabel("RooAdaptiveIntegratorND") ;
  RooNumIntConfig::defaultConfig().methodND().setLabel("RooAdaptiveIntegratorND") ;
  
}



////////////////////////////////////////////////////////////////////////////////
/// Destructor

RooNumIntFactory::~RooNumIntFactory()
{
  std::map<std::string,pair<RooAbsIntegrator*,std::string> >::iterator iter = _map.begin() ;
  while (iter != _map.end()) {
    delete iter->second.first ;
    ++iter ;
  }  
}


////////////////////////////////////////////////////////////////////////////////
/// Copy constructor

RooNumIntFactory::RooNumIntFactory(const RooNumIntFactory& other) : TObject(other)
{
}



////////////////////////////////////////////////////////////////////////////////
/// Static method returning reference to singleton instance of factory

RooNumIntFactory& RooNumIntFactory::instance()
{
  if (_instance==0) {
    new RooNumIntFactory ;
    RooSentinel::activate() ;
  } 
  return *_instance ;
}


////////////////////////////////////////////////////////////////////////////////
/// Cleanup routine called by atexit() handler installed by RooSentinel

void RooNumIntFactory::cleanup()
{
  if (_instance) {
    delete _instance ;
    _instance = 0 ;
  }
}



////////////////////////////////////////////////////////////////////////////////
/// Method accepting registration of a prototype numeric integrator along with a RooArgSet of its
/// default configuration options and an optional list of names of other numeric integrators
/// on which this integrator depends. Returns true if integrator was previously registered

Bool_t RooNumIntFactory::storeProtoIntegrator(RooAbsIntegrator* proto, const RooArgSet& defConfig, const char* depName) 
{
  TString name = proto->IsA()->GetName() ;

  if (getProtoIntegrator(name)) {
    //cout << "RooNumIntFactory::storeIntegrator() ERROR: integrator '" << name << "' already registered" << endl ;
    return kTRUE ;
  }

  // Add to factory 
  _map[name.Data()] = std::pair<RooAbsIntegrator*,std::string>(proto,depName) ;

  // Add default config to master config
  RooNumIntConfig::defaultConfig().addConfigSection(proto,defConfig) ;
  
  return kFALSE ;
}



////////////////////////////////////////////////////////////////////////////////
/// Return prototype integrator with given (class) name

const RooAbsIntegrator* RooNumIntFactory::getProtoIntegrator(const char* name) 
{
  if (_map.count(name)==0) {
    return 0 ;
  } 
  
  return _map[name].first ;
}



////////////////////////////////////////////////////////////////////////////////
/// Get list of class names of integrators needed by integrator named 'name'

const char* RooNumIntFactory::getDepIntegratorName(const char* name) 
{
  if (_map.count(name)==0) {
    return 0 ;
  }

  return _map[name].second.c_str() ;
}



////////////////////////////////////////////////////////////////////////////////
/// Construct a numeric integrator instance that operates on function 'func' and is configured
/// with 'config'. If ndimPreset is greater than zero that number is taken as the dimensionality
/// of the integration, otherwise it is queried from 'func'. This function iterators over list
/// of available prototype integrators and returns an clone attached to the given function of
/// the first class that matches the specifications of the requested integration considering
/// the number of dimensions, the nature of the limits (open ended vs closed) and the user
/// preference stated in 'config'

RooAbsIntegrator* RooNumIntFactory::createIntegrator(RooAbsFunc& func, const RooNumIntConfig& config, Int_t ndimPreset, Bool_t isBinned) 
{
  // First determine dimensionality and domain of integrand  
  Int_t ndim = ndimPreset>0 ? ndimPreset : ((Int_t)func.getDimension()) ;

  Bool_t openEnded = kFALSE ;
  Int_t i ;
  for (i=0 ; i<ndim ; i++) {
    if(RooNumber::isInfinite(func.getMinLimit(i)) ||
       RooNumber::isInfinite(func.getMaxLimit(i))) {
      openEnded = kTRUE ;
    }
  }

  // Find method defined configuration
  TString method ;
  switch(ndim) {
  case 1:
    method = openEnded ? config.method1DOpen().getLabel() : config.method1D().getLabel() ;
    break ;

  case 2:
    method = openEnded ? config.method2DOpen().getLabel() : config.method2D().getLabel() ;
    break ;

  default:
    method = openEnded ? config.methodNDOpen().getLabel() : config.methodND().getLabel() ;
    break ;
  }

  // If distribution is binned and not open-ended override with bin integrator
  if (isBinned & !openEnded) {
    method = "RooBinIntegrator" ;
  }

  // Check that a method was defined for this case
  if (!method.CompareTo("N/A")) {
    oocoutE((TObject*)0,Integration) << "RooNumIntFactory::createIntegrator: No integration method has been defined for " 
				     << (openEnded?"an open ended ":"a ") << ndim << "-dimensional integral" << endl ;
    return 0 ;    
  }

  // Retrieve proto integrator and return clone configured for the requested integration task
  const RooAbsIntegrator* proto = getProtoIntegrator(method) ;  
  RooAbsIntegrator* engine =  proto->clone(func,config) ;
  if (config.printEvalCounter()) {
    engine->setPrintEvalCounter(kTRUE) ;
  }
  return engine ;
}