/*
  *  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 <momemta/Math.h>
 #include <momemta/Module.h>
 #include <momemta/ParameterSet.h>
 #include <momemta/Types.h>
 
 class StandardPhaseSpace: public Module {
     public:
 
         StandardPhaseSpace(PoolPtr pool, const ParameterSet& parameters): Module(pool, parameters.getModuleName()) {
             std::vector<InputTag> input_particles_tags = parameters.get<std::vector<InputTag>>("particles");
             for (auto& t: input_particles_tags)
                 input_particles.push_back(get<LorentzVector>(t));
         };
 
         virtual Status work() override {
 
             *phase_space = 1;
             for (const auto& p: input_particles) {
                 *phase_space *= SQ(p->P()) * sin(p->Theta()) / (2.0 * p->E() * CB(2. * M_PI));
             }
 
             return Status::OK;
         }
 
     private:
 
         // Inputs
         std::vector<Value<LorentzVector>> input_particles;
 
         // Outputs
         std::shared_ptr<double> phase_space = produce<double>("phase_space");
 };
 
 REGISTER_MODULE(StandardPhaseSpace)
     .Inputs("particles")
     .Output("phase_space");