/*
  *  MoMEMta: a modular implementation of the Matrix Element Method
  *  Copyright (C) 2016  Universite catholique de Louvain (UCL), Belgium
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation, either version 3 of the License, or
  *  (at your option) any later version.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <TH1D.h>
 
 #include <momemta/ParameterSet.h>
 #include <momemta/Module.h>
 #include <momemta/Types.h>
 
 /*
  * \brief Module implementing the Differential MEM
  *
  * \ingroup modules
  */
 
 class DMEM: public Module {
     public:
 
         DMEM(PoolPtr pool, const ParameterSet& parameters): Module(pool, parameters.getModuleName()) {
             x_start = parameters.get<double>("x_start");
             x_end = parameters.get<double>("x_end");
             n_bins = parameters.get<int64_t>("n_bins");
 
             m_hist = produce<TH1D>("hist", (name() + "_DMEM").c_str(), (name() + "_DMEM").c_str(), n_bins, x_start, x_end);
             m_hist->SetDirectory(0);
 
             auto particle_tags = parameters.get<std::vector<InputTag>>("particles");
             for (auto& t: particle_tags)
               m_particles.push_back(get<LorentzVector>(t));
 
             psWeight = get<double>(parameters.get<InputTag>("ps_weight"));
             meOutput = get<double>(parameters.get<InputTag>("me_output"));
         }
 
         virtual void beginIntegration() override {
             m_hist->Reset();
         }
 
         virtual Status work() override {
 
             LorentzVector tot;
             for (const auto& v: m_particles)
                 tot += *v;
 
             // Fill histogram
             m_hist->Fill(tot.M(), *meOutput * (*psWeight));
 
             return Status::OK;
         }
 
     private:
 
         double x_start, x_end;
         int64_t n_bins;
 
         // Inputs
         std::vector<Value<LorentzVector>> m_particles;
         Value<double> psWeight;
         Value<double> meOutput;
 
         // Outputs
         std::shared_ptr<TH1D> m_hist;
 };
 
 REGISTER_MODULE(DMEM)
         .Inputs("particles")
         .Input("ps_weight")
         .Input("me_output")
         .Output("hist")
         .Attr("x_start:double")
         .Attr("x_end:double")
         .Attr("n_bins:int")
         .Sticky();