#ifndef WC3RE_RENDER_PROGRAMPROVIDER_HH__
#define WC3RE_RENDER_PROGRAMPROVIDER_HH__

#include <unordered_map>

#include "Singleton.hh"
#include "GlResource.hh"
namespace render {
  using ProgramProviderKeyType = std::tuple<std::string, std::string>;
}

namespace std
{
  template<>
  struct hash<render::ProgramProviderKeyType> {
    typedef render::ProgramProviderKeyType argument_type;
    typedef std::size_t result_type;
 
    result_type operator()(argument_type const& s) const {
      const result_type h1{std::hash<std::string>()(std::get<0>(s))};
      const result_type h2{std::hash<std::string>()(std::get<1>(s))};
      return h1 ^ h2;
    }
  };
}

namespace render {
  class ProgramProvider : public Singleton<ProgramProvider> {
  private:
    ProgramProvider();
    friend class Singleton<ProgramProvider>;

  public:
    gl::GLuint getProgram(std::string const& vertexShader, std::string const& fragShader);

  private:
    std::unordered_map<ProgramProviderKeyType, ProgramResource> programCache_;
  };
}

#endif