// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief Add a short analysis description here
  class BELLE_2009_I809630 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2009_I809630);


    /// @name Analysis methods
    /// @{

    /// Book histograms and initialise projections before the run
    void init() {

      // Initialise and register projections
      declare(FinalState(), "FS");
      declare(UnstableParticles(), "UFS");
      book(_cphipippim, "TMP/phipippim");
      book(_cphif0 ,    "TMP/phif0");
    }

    void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
      for(const Particle &child : p.children()) {
	if(child.children().empty()) {
	  nRes[child.pid()]-=1;
	  --ncount;
	}
	else
	  findChildren(child,nRes,ncount);
      }
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {

      const FinalState& fs = apply<FinalState>(event, "FS");

      map<long,int> nCount;
      int ntotal(0);
      for (const Particle& p : fs.particles()) {
	nCount[p.pid()] += 1;
	++ntotal;
      }
      const FinalState& ufs = apply<FinalState>(event, "UFS");
      for (const Particle& p : ufs.particles()) {
	if(p.children().empty()) continue;
	// phi
	if(p.pid()!=333) continue;
	map<long,int> nRes=nCount;
	int ncount = ntotal;
	findChildren(p,nRes,ncount);
	// phi pi+pi-
	if(ncount==2) {
	  bool matched = true;
	  for(auto const & val : nRes) {
	    if(abs(val.first)==211) {
	      if(val.second!=1) {
		matched = false;
		break;
	      }
	    }
	    else if(val.second!=0) {
	      matched = false;
	      break;
	    }
	  }
	  if(matched)
	    _cphipippim->fill();
	}
	for (const Particle& p2 : ufs.particles()) {
	  if(p2.pid()!=9010221) continue;
	  if(p2.parents()[0].isSame(p)) continue;
	  map<long,int> nResB = nRes;
	  int ncountB = ncount;
	  findChildren(p2,nResB,ncountB);
	  if(ncountB!=0) continue;
	  bool matched2 = true;
	  for(auto const & val : nResB) {
	    if(val.second!=0) {
	      matched2 = false;
	      break;
	    }
	  }
	  if(matched2) {
	    _cphif0  ->fill();
	  }
	}
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix=1;ix<3;++ix) {
        double sigma,error;
        if(ix==1) {
          sigma = _cphipippim->val();
          error = _cphipippim->err();
        }
        else {
          sigma = _cphif0->val();
          error = _cphif0->err();
        }
        sigma *= crossSection()/ sumOfWeights() /nanobarn;
        error *= crossSection()/ sumOfWeights() /nanobarn;
        Estimate1DPtr  mult;
        book(mult, ix, 1, 1);
        for (auto& b : mult->bins()) {
          if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
            b.set(sigma, error);
          }
        }
      }
    }
    /// @}


    /// @name Histograms
    /// @{
    CounterPtr _cphipippim;
    CounterPtr _cphif0;
    /// @}


  };


  RIVET_DECLARE_PLUGIN(BELLE_2009_I809630);


}
