#pragma once

#include <array>
#include <cstddef>
#include <string_view>
#include <utility>

namespace ovdl::detail {

	template<std::size_t... Idxs>
	constexpr auto substring_as_array(std::string_view str, std::index_sequence<Idxs...>) {
		return std::array { str[Idxs]... };
	}

	template<typename T>
	constexpr auto type_name_array() {
#if defined(__clang__)
		constexpr auto prefix = std::string_view { "[T = " };
		constexpr auto suffix = std::string_view { "]" };
		constexpr auto function = std::string_view { __PRETTY_FUNCTION__ };
#elif defined(__GNUC__)
		constexpr auto prefix = std::string_view { "with T = " };
		constexpr auto suffix = std::string_view { "]" };
		constexpr auto function = std::string_view { __PRETTY_FUNCTION__ };
#elif defined(_MSC_VER)
		constexpr auto prefix = std::string_view { "type_name_array<" };
		constexpr auto suffix = std::string_view { ">(void)" };
		constexpr auto function = std::string_view { __FUNCSIG__ };
#else
#error Unsupported compiler
#endif

		constexpr auto start = function.find(prefix) + prefix.size();
		constexpr auto end = function.rfind(suffix);

		static_assert(start < end);

		constexpr auto name = function.substr(start, (end - start));
		return substring_as_array(name, std::make_index_sequence<name.size()> {});
	}

	template<typename T>
	struct type_name_holder {
		static inline constexpr auto value = type_name_array<T>();
	};

	template<typename T>
	constexpr auto type_name() -> std::string_view {
		constexpr auto& value = type_name_holder<T>::value;
		return std::string_view { value.data(), value.size() };
	}
}