#ifndef RFL_PARSING_IS_REQUIRED_HPP_
#define RFL_PARSING_IS_REQUIRED_HPP_

#include <memory>
#include <optional>
#include <type_traits>

#include "../Rename.hpp"
#include "../internal/StringLiteral.hpp"
#include "../internal/is_rename.hpp"
#include "is_map_like.hpp"
#include "is_vector_like.hpp"

namespace rfl {
  namespace parsing {

    /// Determines whether a field in a named tuple is required.
    /// General case - most fields are required.
    template <class T>
    class is_never_required;

    template <class T>
    class is_never_required : public std::false_type {};

    template <class T>
    class is_never_required<std::optional<T>> : public std::true_type {};

    template <class T>
    class is_never_required<std::shared_ptr<T>> : public std::true_type {};

    template <class T>
    class is_never_required<std::unique_ptr<T>> : public std::true_type {};

    template <class T>
    constexpr bool is_never_required_v = is_never_required<T>::value;

    template <class T, bool _ignore_empty_containers>
    consteval bool is_required() {
      using Type = std::remove_cvref_t<std::remove_pointer_t<T>>;
      if constexpr (internal::has_reflection_type_v<Type>) {
        return is_required<typename Type::ReflectionType, _ignore_empty_containers>();
      } else if constexpr (internal::is_rename_v<Type>) {
        return is_required<typename Type::Type, _ignore_empty_containers>();
      } else {
        return !(
          is_never_required_v<Type> ||
          (_ignore_empty_containers && (is_vector_like_v<Type> || is_map_like_v<Type>))
        );
      }
    }

  } // namespace parsing
} // namespace rfl

#endif