#include <igl/guess_extension.h>
#include <igl/read_triangle_mesh.h>
#include <igl/viewer/Viewer.h>
#include <Eigen/Core>
#include <iostream>
#include <string>
#include <cstdio>
#include <unistd.h>

int main(int argc, char * argv[])
{
  Eigen::MatrixXd V;
  Eigen::MatrixXi F;
  if(argc >= 2)
  {
    igl::read_triangle_mesh(argv[1],V,F);
  }else if(isatty(fileno(stdin)))
  {
    std::cerr<<R"(Usage:

    ./viewmesh input.obj
    ./viewmesh < input.obj
    cat input.obj | ./viewmesh

)";
    return EXIT_FAILURE;
  }else{
    FILE * fp = tmpfile();
    while(std::cin.good())
    {
      std::vector<char> buf(1024);
      std::cin.read(&buf[0],buf.size());
      fwrite(&buf[0],sizeof(char),std::cin.gcount(),fp);
    }
    fp = freopen(NULL,"r",fp);
    std::string ext = igl::guess_extension(fp);
    std::cout<<"[treating stdin as ."<<ext<<" file]"<<std::endl;
    igl::read_triangle_mesh(ext,fp,V,F);
  }
  igl::viewer::Viewer v;
  v.data.set_mesh(V,F);
  v.launch();
  return EXIT_SUCCESS;
}