#pragma once

#include "tl/detail/prologue.h"
#include "tl/hash_map.h"
#include <compare>

namespace tl
{

template<typename T, T invalid_value, typename Tag>
struct identifier
{
	using underlying_type = T;

	constexpr identifier() noexcept = default;
	explicit constexpr identifier(T value) noexcept : m_value(std::move(value)) {}

	constexpr T value() const noexcept { return m_value; }
	constexpr bool is_valid() const noexcept { return m_value != invalid_value; }
	//inline static identifier<T, invalid_value, Tag> invalid() noexcept { return identifier<T, invalid_value, Tag>(); }

	auto operator<=>(const identifier<T, invalid_value, Tag>& other) const noexcept { return m_value <=> other.value(); }
	auto operator<=>(const T& other) const noexcept { return m_value <=> other; }
	bool operator==(const identifier<T, invalid_value, Tag>& other) const noexcept { return m_value == other.value(); }
	bool operator==(const T& other) const noexcept { return m_value == other; }

private:
	T m_value = invalid_value;
};
}

#define TL_DECLARE_INTEGRAL_ID(NAME, TYPE, INVALID_VALUE) \
struct NAME##_tag {};\
using NAME = tl::identifier<TYPE, INVALID_VALUE, NAME##_tag>;

template <typename T, T invalid_value, typename Tag>
struct std::formatter<tl::identifier<T, invalid_value, Tag>>
{
	constexpr auto parse(format_parse_context& ctx) noexcept { return ctx.begin(); }
	auto format(const tl::identifier<T, invalid_value, Tag>& id, std::format_context& ctx) const
	{
		return format_to(ctx.out(), "{}", id.value());
	}
};

template<typename T, T invalid_value, typename Tag>
struct eastl::hash<tl::identifier<T, invalid_value, Tag>>
{
	size_t operator()(tl::identifier<T, invalid_value, Tag> const& id) const
	{
		return hash<T>()(id.value());
	}
};