// This file is distributed under the BSD License.
// See "license.txt" for details.
// Copyright 2009-2012, Jonathan Turner (jonathan@emptycrate.com)
// Copyright 2009-2018, Jason Turner (jason@emptycrate.com)
// http://www.chaiscript.com

#ifndef CHAISCRIPT_CALLABLE_TRAITS_HPP_
#define CHAISCRIPT_CALLABLE_TRAITS_HPP_

#include <memory>

namespace chaiscript {
  namespace dispatch {
    namespace detail {
      template<typename Class, typename... Param>
      struct Constructor {
        template<typename... Inner>
        std::shared_ptr<Class> operator()(Inner &&...inner) const {
          return std::make_shared<Class>(std::forward<Inner>(inner)...);
        }
      };

      template<typename Ret, typename Class, typename... Param>
      struct Const_Caller {
        explicit Const_Caller(Ret (Class::*t_func)(Param...) const)
            : m_func(t_func) {
        }

        template<typename... Inner>
        Ret operator()(const Class &o, Inner &&...inner) const {
          return (o.*m_func)(std::forward<Inner>(inner)...);
        }

        Ret (Class::*m_func)(Param...) const;
      };

      template<typename Ret, typename... Param>
      struct Fun_Caller {
        explicit Fun_Caller(Ret (*t_func)(Param...))
            : m_func(t_func) {
        }

        template<typename... Inner>
        Ret operator()(Inner &&...inner) const {
          return (m_func)(std::forward<Inner>(inner)...);
        }

        Ret (*m_func)(Param...);
      };

      template<typename Ret, typename Class, typename... Param>
      struct Caller {
        explicit Caller(Ret (Class::*t_func)(Param...))
            : m_func(t_func) {
        }

        template<typename... Inner>
        Ret operator()(Class &o, Inner &&...inner) const {
          return (o.*m_func)(std::forward<Inner>(inner)...);
        }

        Ret (Class::*m_func)(Param...);
      };

      template<typename T>
      struct Arity {
      };

      template<typename Ret, typename... Params>
      struct Arity<Ret(Params...)> {
        static const size_t arity = sizeof...(Params);
      };

      template<typename T>
      struct Function_Signature {
      };

      template<typename Ret, typename... Params>
      struct Function_Signature<Ret(Params...)> {
        using Return_Type = Ret;
        using Signature = Ret()(Params...);
      };

      template<typename Ret, typename T, typename... Params>
      struct Function_Signature<Ret (T::*)(Params...) const> {
        using Return_Type = Ret;
        using Signature = Ret()(Params...);
      };

      template<typename T>
      struct Callable_Traits {
        using Signature = typename Function_Signature<decltype(&T::operator())>::Signature;
        using Return_Type = typename Function_Signature<decltype(&T::operator())>::Return_Type;
      };
    } // namespace detail
  } // namespace dispatch
} // namespace chaiscript

#endif