#include <iostream>
#include <fstream>

#include <CGAL/Simple_cartesian.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/Surface_mesh_simplification/edge_collapse.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Count_ratio_stop_predicate.h>

typedef CGAL::Simple_cartesian<double> Kernel;
typedef Kernel::Point_3 Point_3;
typedef CGAL::Surface_mesh<Point_3> Surface_mesh; 

namespace SMS = CGAL::Surface_mesh_simplification;


int main( int argc, char** argv ) 
{
  Surface_mesh surface_mesh; 
  
  std::ifstream is(argv[1]);
  is >> surface_mesh;
  if (!CGAL::is_triangle_mesh(surface_mesh)){
    std::cerr << "Input geometry is not triangulated." << std::endl;
    return EXIT_FAILURE;
  }

  // In this example, the simplification stops when the number of undirected edges
  // drops below 10% of the initial count
  SMS::Count_ratio_stop_predicate<Surface_mesh> stop(0.1);
 
  int r = SMS::edge_collapse(surface_mesh, stop);

  std::cout << "\nFinished...\n" << r << " edges removed.\n" 
            << surface_mesh.number_of_edges() << " final edges.\n";
 
  std::ofstream os( argc > 2 ? argv[2] : "out.off" );
  os.precision(17);
  os << surface_mesh;
  
  return EXIT_SUCCESS;      
}
