/*    This file is part of the Gudhi Library. The Gudhi library
 *    (Geometric Understanding in Higher Dimensions) is a generic C++
 *    library for computational topology.
 *
 *    Author(s):       Vincent Rouvreau
 *
 *    Copyright (C) 2015  INRIA Saclay (France)
 *
 *    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/>.
 */

#define BOOST_TEST_MODULE alpha_complex
#include <boost/test/included/unit_test.hpp>
#include <boost/system/error_code.hpp>
#include <boost/chrono/thread_clock.hpp>
#include <CGAL/Delaunay_triangulation.h>
#include <CGAL/Epick_d.h>

#include <cmath>  // float comparison
#include <limits>
#include <string>
#include <vector>

// to construct a Delaunay_triangulation from a OFF file
#include "gudhi/Delaunay_triangulation_off_io.h"
#include "gudhi/Alpha_complex.h"

// Use dynamic_dimension_tag for the user to be able to set dimension
typedef CGAL::Epick_d< CGAL::Dynamic_dimension_tag > Kernel_d;
// The triangulation uses the default instantiation of the TriangulationDataStructure template parameter

BOOST_AUTO_TEST_CASE(S4_100_OFF_file) {
  // ----------------------------------------------------------------------------
  //
  // Init of an alpha-complex from a OFF file
  //
  // ----------------------------------------------------------------------------
  std::string off_file_name("S4_100.off");
  double max_alpha_square_value = 1e10;
  std::cout << "========== OFF FILE NAME = " << off_file_name << " - alpha²=" <<
      max_alpha_square_value << "==========" << std::endl;

  Gudhi::alphacomplex::Alpha_complex<Kernel_d> alpha_complex_from_file(off_file_name, max_alpha_square_value);

  const int DIMENSION = 4;
  std::cout << "alpha_complex_from_file.dimension()=" << alpha_complex_from_file.dimension() << std::endl;
  BOOST_CHECK(alpha_complex_from_file.dimension() == DIMENSION);

  const int NUMBER_OF_VERTICES = 100;
  std::cout << "alpha_complex_from_file.num_vertices()=" << alpha_complex_from_file.num_vertices() << std::endl;
  BOOST_CHECK(alpha_complex_from_file.num_vertices() == NUMBER_OF_VERTICES);

  const int NUMBER_OF_SIMPLICES = 6879;
  std::cout << "alpha_complex_from_file.num_simplices()=" << alpha_complex_from_file.num_simplices() << std::endl;
  // TODO(VR) : BOOST_CHECK(alpha_complex_from_file.num_simplices() == NUMBER_OF_SIMPLICES);

  // + TODO(VR) : in wait of num_simplices fix in Simplex_tree [
  int num_simplices = 0;
  for (auto f_simplex : alpha_complex_from_file.filtration_simplex_range()) {
    num_simplices++;
  }
  std::cout << "num_simplices=" << num_simplices << std::endl;
  BOOST_CHECK(num_simplices == NUMBER_OF_SIMPLICES);
  // - TODO(VR) : in wait of num_simplices fix in Simplex_tree ]
}

BOOST_AUTO_TEST_CASE(S4_100_OFF_file_filtered) {
  // ----------------------------------------------------------------------------
  //
  // Init of an alpha-complex from a OFF file
  //
  // ----------------------------------------------------------------------------
  std::string off_file_name("S4_100.off");
  double max_alpha_square_value = 0.999;
  std::cout << "========== OFF FILE NAME = " << off_file_name << " - alpha²=" <<
      max_alpha_square_value << "==========" << std::endl;

  Gudhi::alphacomplex::Alpha_complex<Kernel_d> alpha_complex_from_file(off_file_name, max_alpha_square_value);

  const int DIMENSION = 4;
  std::cout << "alpha_complex_from_file.dimension()=" << alpha_complex_from_file.dimension() << std::endl;
  BOOST_CHECK(alpha_complex_from_file.dimension() == DIMENSION);

  const int NUMBER_OF_VERTICES = 13;  // Versus 100, because of filtered alpha value
  std::cout << "alpha_complex_from_file.num_vertices()=" << alpha_complex_from_file.num_vertices() << std::endl;
  BOOST_CHECK(alpha_complex_from_file.num_vertices() == NUMBER_OF_VERTICES);

  const int NUMBER_OF_SIMPLICES = 90;  // Versus 6879, because of filtered alpha value
  std::cout << "alpha_complex_from_file.num_simplices()=" << alpha_complex_from_file.num_simplices() << std::endl;
  // TODO(VR) : BOOST_CHECK(alpha_complex_from_file.num_simplices() == NUMBER_OF_SIMPLICES);

  // + TODO(VR) : in wait of num_simplices fix in Simplex_tree [
  int num_simplices = 0;
  for (auto f_simplex : alpha_complex_from_file.filtration_simplex_range()) {
    num_simplices++;
  }
  std::cout << "num_simplices=" << num_simplices << std::endl;
  BOOST_CHECK(num_simplices == NUMBER_OF_SIMPLICES);
  // - TODO(VR) : in wait of num_simplices fix in Simplex_tree ]
}

BOOST_AUTO_TEST_CASE(S8_10_OFF_file) {
  // ----------------------------------------------------------------------------
  //
  // Init of an alpha-complex from a OFF file
  //
  // ----------------------------------------------------------------------------
  std::string off_file_name("S8_10.off");
  double max_alpha_square_value = 1e10;
  std::cout << "========== OFF FILE NAME = " << off_file_name << " - alpha²=" <<
      max_alpha_square_value << "==========" << std::endl;

  Gudhi::alphacomplex::Alpha_complex<Kernel_d> alpha_complex_from_file(off_file_name, max_alpha_square_value);

  const int DIMENSION = 8;
  std::cout << "alpha_complex_from_file.dimension()=" << alpha_complex_from_file.dimension() << std::endl;
  BOOST_CHECK(alpha_complex_from_file.dimension() == DIMENSION);

  const int NUMBER_OF_VERTICES = 10;
  std::cout << "alpha_complex_from_file.num_vertices()=" << alpha_complex_from_file.num_vertices() << std::endl;
  BOOST_CHECK(alpha_complex_from_file.num_vertices() == NUMBER_OF_VERTICES);

  const int NUMBER_OF_SIMPLICES = 1007;
  std::cout << "alpha_complex_from_file.num_simplices()=" << alpha_complex_from_file.num_simplices() << std::endl;
  // TODO(VR) : BOOST_CHECK(alpha_complex_from_file.num_simplices() == NUMBER_OF_SIMPLICES);

  // + TODO(VR) : in wait of num_simplices fix in Simplex_tree [
  int num_simplices = 0;
  for (auto f_simplex : alpha_complex_from_file.filtration_simplex_range()) {
    num_simplices++;
  }
  std::cout << "num_simplices=" << num_simplices << std::endl;
  BOOST_CHECK(num_simplices == NUMBER_OF_SIMPLICES);
  // - TODO(VR) : in wait of num_simplices fix in Simplex_tree ]
}

BOOST_AUTO_TEST_CASE(S8_10_OFF_file_filtered) {
  // ----------------------------------------------------------------------------
  //
  // Init of an alpha-complex from a OFF file
  //
  // ----------------------------------------------------------------------------
  std::string off_file_name("S8_10.off");
  double max_alpha_square_value = 1.0;
  std::cout << "========== OFF FILE NAME = " << off_file_name << " - alpha²=" <<
      max_alpha_square_value << "==========" << std::endl;

  Gudhi::alphacomplex::Alpha_complex<Kernel_d> alpha_complex_from_file(off_file_name, max_alpha_square_value);

  const int DIMENSION = 8;
  std::cout << "alpha_complex_from_file.dimension()=" << alpha_complex_from_file.dimension() << std::endl;
  BOOST_CHECK(alpha_complex_from_file.dimension() == DIMENSION);

  const int NUMBER_OF_VERTICES = 10;
  std::cout << "alpha_complex_from_file.num_vertices()=" << alpha_complex_from_file.num_vertices() << std::endl;
  BOOST_CHECK(alpha_complex_from_file.num_vertices() == NUMBER_OF_VERTICES);

  const int NUMBER_OF_SIMPLICES = 895;  // Versus 1007, because of filtered alpha value
  std::cout << "alpha_complex_from_file.num_simplices()=" << alpha_complex_from_file.num_simplices() << std::endl;
  // TODO(VR) : BOOST_CHECK(alpha_complex_from_file.num_simplices() == NUMBER_OF_SIMPLICES);

  // + TODO(VR) : in wait of num_simplices fix in Simplex_tree [
  int num_simplices = 0;
  for (auto f_simplex : alpha_complex_from_file.filtration_simplex_range()) {
    num_simplices++;
  }
  std::cout << "num_simplices=" << num_simplices << std::endl;
  BOOST_CHECK(num_simplices == NUMBER_OF_SIMPLICES);
  // - TODO(VR) : in wait of num_simplices fix in Simplex_tree ]
}

bool are_almost_the_same(float a, float b) {
  return std::fabs(a - b) < std::numeric_limits<float>::epsilon();
}

// Use dynamic_dimension_tag for the user to be able to set dimension
typedef CGAL::Epick_d< CGAL::Dimension_tag<4> > Kernel_s;
typedef Kernel_s::Point_d Point;
typedef std::vector<Point> Vector_of_points;


bool is_point_in_list(Vector_of_points points_list, Point point) {
  for (auto& point_in_list : points_list) {
    if (point_in_list == point) {
      return true;  // point found
    }
  }
  return false;  // point not found
}

BOOST_AUTO_TEST_CASE(Alpha_complex_from_points) {
  // ----------------------------------------------------------------------------
  // Init of a list of points
  // ----------------------------------------------------------------------------
  Vector_of_points points;
  std::vector<double> coords = { 0.0, 0.0, 0.0, 1.0 };
  points.push_back(Point(coords.begin(), coords.end()));
  coords = { 0.0, 0.0, 1.0, 0.0 };
  points.push_back(Point(coords.begin(), coords.end()));
  coords = { 0.0, 1.0, 0.0, 0.0 };
  points.push_back(Point(coords.begin(), coords.end()));
  coords = { 1.0, 0.0, 0.0, 0.0 };
  points.push_back(Point(coords.begin(), coords.end()));

  // ----------------------------------------------------------------------------
  // Init of an alpha complex from the list of points
  // ----------------------------------------------------------------------------
  double max_alpha_square_value = 1e10;
  Gudhi::alphacomplex::Alpha_complex<Kernel_s> alpha_complex_from_points(3, points.size(), points.begin(), points.end(),
                                                                         max_alpha_square_value);

  std::cout << "========== Alpha_complex_from_points ==========" << std::endl;

  std::cout << "Iterator on alpha complex simplices in the filtration order, with [filtration value]:" << std::endl;
  int num_simplices = 0;  // TODO(VR) : in wait of num_simplices fix in Simplex_tree
  for (auto f_simplex : alpha_complex_from_points.filtration_simplex_range()) {
    num_simplices++;  // TODO(VR) : in wait of num_simplices fix in Simplex_tree
    std::cout << "   ( ";
    for (auto vertex : alpha_complex_from_points.simplex_vertex_range(f_simplex)) {
      std::cout << vertex << " ";
    }
    std::cout << ") -> " << "[" << alpha_complex_from_points.filtration(f_simplex) << "] ";
    std::cout << std::endl;
  }

  std::cout << "alpha_complex_from_points.dimension()=" << alpha_complex_from_points.dimension() << std::endl;
  BOOST_CHECK(alpha_complex_from_points.dimension() == 4);
  // TODO(VR) : std::cout << "alpha_complex_from_points.num_simplices()=" << alpha_complex_from_points.num_simplices()
  // << std::endl;
  // TODO(VR) : BOOST_CHECK(alpha_complex_from_points.num_simplices() == 15);
  BOOST_CHECK(num_simplices == 15);  // TODO(VR) : in wait of num_simplices fix in Simplex_tree
  std::cout << "alpha_complex_from_points.num_vertices()=" << alpha_complex_from_points.num_vertices() << std::endl;
  BOOST_CHECK(alpha_complex_from_points.num_vertices() == 4);

  for (auto f_simplex : alpha_complex_from_points.filtration_simplex_range()) {
    switch (alpha_complex_from_points.dimension(f_simplex)) {
      case 0:
        BOOST_CHECK(are_almost_the_same(alpha_complex_from_points.filtration(f_simplex), 0.0));
        break;
      case 1:
        BOOST_CHECK(are_almost_the_same(alpha_complex_from_points.filtration(f_simplex), 1.0/2.0));
        break;
      case 2:
        BOOST_CHECK(are_almost_the_same(alpha_complex_from_points.filtration(f_simplex), 2.0/3.0));
        break;
      case 3:
        BOOST_CHECK(are_almost_the_same(alpha_complex_from_points.filtration(f_simplex), 3.0/4.0));
        break;
      default:
        BOOST_CHECK(false);  // Shall not happen
        break;
    }
  }

  Point p1 = alpha_complex_from_points.get_point(1);
  std::cout << "alpha_complex_from_points.get_point(1)=" << p1 << std::endl;
  BOOST_CHECK(4 == p1.dimension());
  BOOST_CHECK(is_point_in_list(points, p1));

  Point p2 = alpha_complex_from_points.get_point(2);
  std::cout << "alpha_complex_from_points.get_point(2)=" << p2 << std::endl;
  BOOST_CHECK(4 == p2.dimension());
  BOOST_CHECK(is_point_in_list(points, p2));

  Point p3 = alpha_complex_from_points.get_point(3);
  std::cout << "alpha_complex_from_points.get_point(3)=" << p3 << std::endl;
  BOOST_CHECK(4 == p3.dimension());
  BOOST_CHECK(is_point_in_list(points, p3));

  Point p4 = alpha_complex_from_points.get_point(4);
  std::cout << "alpha_complex_from_points.get_point(4)=" << p4 << std::endl;
  BOOST_CHECK(4 == p4.dimension());
  BOOST_CHECK(is_point_in_list(points, p4));

  Point p5 = alpha_complex_from_points.get_point(5);
  std::cout << "alpha_complex_from_points.get_point(5)=" << p5 << std::endl;
  BOOST_CHECK(!is_point_in_list(points, p5));

  Point p0 = alpha_complex_from_points.get_point(0);
  std::cout << "alpha_complex_from_points.get_point(0)=" << p0 << std::endl;
  BOOST_CHECK(!is_point_in_list(points, p0));

  Point p1234 = alpha_complex_from_points.get_point(1234);
  std::cout << "alpha_complex_from_points.get_point(1234)=" << p1234.dimension() << std::endl;
  BOOST_CHECK(!is_point_in_list(points, p1234));
}