/*****************************************************************************
 * Project: RooFit                                                           *
 * Package: RooFitCore                                                       *
 *    File: $Id$
 * 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)             *
 *****************************************************************************/
#ifndef ROO_BIN_INTEGRATOR
#define ROO_BIN_INTEGRATOR

#include "RooAbsIntegrator.h"
#include "RooNumIntConfig.h"
#include <vector>
#include <list>

class RooBinIntegrator : public RooAbsIntegrator {
public:

  // Constructors, assignment etc

  RooBinIntegrator(const RooAbsFunc& function, int numBins=100) ;
  RooBinIntegrator(const RooAbsFunc& function, const RooNumIntConfig& config) ;

  ~RooBinIntegrator() override;

  bool checkLimits() const override;
  double integral(const double *yvec=nullptr) override ;

  using RooAbsIntegrator::setLimits ;
  bool setLimits(double* xmin, double* xmax) override;
  bool setUseIntegrandLimits(bool flag) override {_useIntegrandLimits = flag ; return true ; }

protected:

  friend class RooNumIntFactory ;
  static void registerIntegrator(RooNumIntFactory& fact) ;
  RooBinIntegrator(const RooBinIntegrator&) ;

  // Numerical integrator workspace
  mutable std::vector<double> _xmin;      ///<! Lower integration bound
  mutable std::vector<double> _xmax;      ///<! Upper integration bound
  std::vector<std::vector<double>> _binb; ///<! list of bin boundaries
  mutable Int_t _numBins = 0;             ///<! Size of integration range

  bool _useIntegrandLimits = false;       ///< If true limits of function binding are ued

  double* xvec(double xx) { _x[0] = xx ; return _x.data(); }
  double* xvec(double xx, double yy) { _x[0] = xx ; _x[1] = yy ; return _x.data(); }
  double* xvec(double xx, double yy, double zz) { _x[0] = xx ; _x[1] = yy ; _x[2] = zz ; return _x.data(); }

  std::vector<double> _x ; ///<! do not persist

  ClassDefOverride(RooBinIntegrator,0) // 1-dimensional numerical integration engine
};

#endif