/*
 * (c) Copyright 2018 CORSIKA Project, corsika-project@lists.kit.edu
 *
 * This software is distributed under the terms of the GNU General Public
 * Licence version 3 (GPL Version 3). See file LICENSE for a full version of
 * the license.
 */

#include <corsika/framework/core/Cascade.hpp>
#include <corsika/framework/process/ProcessSequence.hpp>
#include <corsika/framework/core/PhysicalUnits.hpp>
#include <corsika/framework/random/RNGManager.hpp>
#include <corsika/framework/geometry/Sphere.hpp>
#include <corsika/framework/utility/CorsikaFenv.hpp>
#include <corsika/framework/core/Logging.hpp>

#include <corsika/output/OutputManager.hpp>

#include <corsika/media/Environment.hpp>
#include <corsika/media/HomogeneousMedium.hpp>
#include <corsika/media/NuclearComposition.hpp>
#include <corsika/media/ShowerAxis.hpp>
#include <corsika/media/MediumPropertyModel.hpp>
#include <corsika/media/UniformMagneticField.hpp>

#include <corsika/setup/SetupEnvironment.hpp>
#include <corsika/setup/SetupStack.hpp>
#include <corsika/setup/SetupTrajectory.hpp>

#include <corsika/modules/BetheBlochPDG.hpp>
#include <corsika/modules/StackInspector.hpp>
#include <corsika/modules/Sibyll.hpp>
#include <corsika/modules/ParticleCut.hpp>
#include <corsika/modules/TrackWriter.hpp>
#include <corsika/modules/HadronicElasticModel.hpp>
#include <corsika/modules/Pythia8.hpp>

/*
  NOTE, WARNING, ATTENTION

  The file Random.hpp implements the hooks of external modules to the C8 random
  number generator. It has to occur excatly ONCE per linked
  executable. If you include the header below multiple times and
  link this togehter, it will fail.
 */
#include <corsika/modules/Random.hpp>

#include <iostream>
#include <limits>
#include <typeinfo>

using namespace corsika;
using namespace std;

//
// The example main program for a particle cascade
//
int main() {

  logging::set_level(logging::level::info);

  std::cout << "cascade_proton_example" << std::endl;

  feenableexcept(FE_INVALID);
  // initialize random number sequence(s)
  RNGManager<>::getInstance().registerRandomStream("cascade");

  OutputManager output("cascade_proton_outputs");

  // setup environment, geometry
  using EnvType = setup::Environment;
  EnvType env;
  auto& universe = *(env.getUniverse());
  CoordinateSystemPtr const& rootCS = env.getCoordinateSystem();

  auto world = EnvType::createNode<Sphere>(Point{rootCS, 0_m, 0_m, 0_m}, 150_km);

  using MyHomogeneousModel = MediumPropertyModel<
      UniformMagneticField<HomogeneousMedium<setup::EnvironmentInterface>>>;

  world->setModelProperties<MyHomogeneousModel>(
      Medium::AirDry1Atm, MagneticFieldVector(rootCS, 0_T, 0_T, 1_mT),
      1_kg / (1_m * 1_m * 1_m),
      NuclearComposition(std::vector<Code>{Code::Hydrogen},
                         std::vector<float>{(float)1.}));

  universe.addChild(std::move(world));

  // setup particle stack, and add primary particle
  setup::Stack stack;
  stack.clear();
  const Code beamCode = Code::Proton;
  const HEPMassType mass = Proton::mass;
  const HEPEnergyType E0 = 200_GeV;
  double theta = 0.;
  double phi = 0.;

  Point injectionPos(rootCS, 0_m, 0_m, 0_m);
  {
    auto elab2plab = [](HEPEnergyType Elab, HEPMassType m) {
      return sqrt(Elab * Elab - m * m);
    };
    HEPMomentumType P0 = elab2plab(E0, mass);
    auto momentumComponents = [](double theta, double phi, HEPMomentumType ptot) {
      return std::make_tuple(ptot * sin(theta) * cos(phi), ptot * sin(theta) * sin(phi),
                             -ptot * cos(theta));
    };
    auto const [px, py, pz] =
        momentumComponents(theta / 180. * M_PI, phi / 180. * M_PI, P0);
    auto plab = MomentumVector(rootCS, {px, py, pz});
    cout << "input particle: " << beamCode << endl;
    cout << "input angles: theta=" << theta << " phi=" << phi << endl;
    cout << "input momentum: " << plab.getComponents() / 1_GeV << endl;
    stack.addParticle(std::make_tuple(beamCode, plab, injectionPos, 0_ns));
  }

  // setup processes, decays and interactions
  setup::Tracking tracking;
  StackInspector<setup::Stack> stackInspect(1000, true, E0);

  RNGManager<>::getInstance().registerRandomStream("sibyll");
  RNGManager<>::getInstance().registerRandomStream("pythia");
  corsika::pythia8::Interaction pythia;
  corsika::pythia8::Decay decay;
  ParticleCut cut(60_GeV, true, true);
  cut.printThresholds();

  // RNGManager::getInstance().registerRandomStream("HadronicElasticModel");
  // HadronicElasticModel::HadronicElasticInteraction
  // hadronicElastic(env);

  TrackWriter trackWriter;
  output.add("tracks", trackWriter); // register TrackWriter

  ShowerAxis const showerAxis{injectionPos, Vector{rootCS, 0_m, 0_m, -100_km}, env};
  BetheBlochPDG eLoss{showerAxis};

  // assemble all processes into an ordered process list
  auto sequence = make_sequence(pythia, decay, eLoss, cut, trackWriter, stackInspect);

  // define air shower object, run simulation
  Cascade EAS(env, tracking, sequence, output, stack);
  output.startOfShower();
  EAS.run();
  output.endOfShower();

  cout << "Result: E0=" << E0 / 1_GeV << endl;
  cut.showResults();
  const HEPEnergyType Efinal =
      cut.getCutEnergy() + cut.getInvEnergy() + cut.getEmEnergy();
  cout << "total energy (GeV): " << Efinal / 1_GeV << endl
       << "relative difference (%): " << (Efinal / E0 - 1.) * 100 << endl;

  output.endOfLibrary();
}