/*//////////////////////////////////////////////////////////////////////////////
// CMT Cosmic Muon Tomography project //////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////

  Copyright (c) 2014, Universita' degli Studi di Padova, INFN sez. di Padova
  All rights reserved

  Authors: Andrea Rigoni Garola < andrea.rigoni@pd.infn.it >

  ------------------------------------------------------------------
  This library is free software;  you  can  redistribute  it  and/or
  modify it  under the  terms  of  the  GNU  Lesser  General  Public
  License as published  by  the  Free  Software  Foundation;  either
  version 3.0 of the License, or (at your option) any later version.

  This library 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
  Lesser General Public License for more details.

  You should have received a copy of  the GNU Lesser General  Public
  License along with this library.

//////////////////////////////////////////////////////////////////////////////*/

#include "Vtk/HEP/Detectors/vtkDetectorChamber.h"
#include "Vtk/HEP/Detectors/vtkMuonScatter.h"
#include "Math/Units.h"
#include "Vtk/HEP/Detectors/vtkDetectorChamber.h"
#include "Vtk/HEP/Detectors/vtkMuonScatter.h"
#include "Vtk/uLibVtkViewer.h"

#include <vtkActor.h>
#include <vtkArrowSource.h>
#include <vtkMath.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkTransform.h>

#define BOOST_TEST_MODULE vtkDetectorMuonProjectionTest
#include <boost/test/unit_test.hpp>

using namespace uLib;

// A simple prop3d class to represent an arrow indicative of a projected muon hit
class vtkArrowProp3D : public Vtk::Prop3D {
public:
  vtkArrowProp3D() : m_Actor(vtkActor::New()) {
    vtkNew<vtkArrowSource> arrow;
    vtkNew<vtkPolyDataMapper> mapper;
    mapper->SetInputConnection(arrow->GetOutputPort());
    m_Actor->SetMapper(mapper);
    this->SetProp(m_Actor);
    m_Actor->GetProperty()->SetColor(1, 1, 0); // Yellow color for visibility
  }

  virtual ~vtkArrowProp3D() { m_Actor->Delete(); }

  void SetProjection(const HLine3f &line) {
    HPoint3f p = line.origin;
    HVector3f d = line.direction;
    d.normalize();

    vtkNew<vtkTransform> t;
    t->Translate(p.x(), p.y(), p.z());

    // vtkArrowSource initially points along X+ (1, 0, 0)
    double vtk_x[3] = {1, 0, 0};
    double vtk_d[3] = {d.x(), d.y(), d.z()};

    double axis[3];
    vtkMath::Cross(vtk_x, vtk_d, axis);
    double dot = vtkMath::Dot(vtk_x, vtk_d);
    double angle = vtkMath::DegreesFromRadians(acos(dot));

    // Handle parallel or anti-parallel cases
    if (vtkMath::Norm(axis) < 1e-6) {
      if (dot < 0) {
        t->RotateY(180); // Reverse direction if anti-parallel
      }
    } else {
      t->RotateWXYZ(angle, axis);
    }

    t->Scale(100, 100, 100); // Scale the arrow for visual prominence
    m_Actor->SetUserTransform(t);
  }

private:
  vtkActor *m_Actor;
};

BOOST_AUTO_TEST_CASE(vtkDetectorMuonProjectionTest) {
  using namespace uLib::literals;

  // 1. Prepare a scene with two detector chambers
  DetectorChamber d1, d2;
  d1.Scale(Vector3f(1_m, 1_m, 10_cm));
  d1.Translate(Vector3f(0, 0, -0.5_m));

  
  d2.Scale(Vector3f(1_m, 1_m, 10_cm));
  d2.Translate(Vector3f(0, 0, 0.5_m));

  // 2. Setup a muon event that crosses the detectors
  MuonScatter event;
  // Set an origin slightly offset and point it toward (0,0,0)
  HPoint3f mu_origin(20_cm, 30_cm, -1_m);
  event.LineIn().origin = mu_origin;
  
  // Direction is toward (0,0,0)
  HVector3f mu_dir = (HPoint3f(0,0,0) - mu_origin);
  mu_dir.normalize();
  event.LineIn().direction = mu_dir;
  
  // Let's make the track continue straight for a simple projection test
  event.LineOut().origin = mu_origin - mu_dir * 3_m; 
  event.LineOut().direction = -mu_dir;

  MuonEvent mu_event;
  mu_event.LineIn() = event.LineIn();
  mu_event.LineOut() = event.LineOut();

  // 3. Project the muon on each detector to find the projection points
  MuonEvent mu_proj1 = d1.ProjectMuonEvent(mu_event);
  MuonEvent mu_proj2 = d2.ProjectMuonEvent(mu_event);

  Vtk::DetectorChamber v_d1(&d1);
  Vtk::DetectorChamber v_d2(&d2);
  Vtk::MuonScatter v_event(event);
  v_event.AddPocaPoint(HPoint3f(0, 0, 0));
  v_event.SetColor(1, 0, 0); // Red muon event

  v_d1.SetRepresentation(Vtk::Prop3D::Surface);
  v_d1.SetOpacity(0.3);
  v_d2.SetRepresentation(Vtk::Prop3D::Surface);
  v_d2.SetOpacity(0.3);

  // 5. Add two arrows to mark where the projection is located on the chambers
  vtkArrowProp3D v_p1, v_p2;
  v_p1.SetProjection(mu_proj1.LineIn());
  v_p2.SetProjection(mu_proj2.LineIn());

  if (std::getenv("CTEST_PROJECT_NAME") == nullptr) {
    Vtk::Viewer viewer;
    viewer.SetGridAxis(Vtk::Viewport::Z);
    viewer.AddProp3D(v_d1);
    viewer.AddProp3D(v_d2);
    viewer.AddProp3D(v_event);
    viewer.AddProp3D(v_p1);
    viewer.AddProp3D(v_p2);
    viewer.Start();
  }

  BOOST_CHECK(true);
}