// https://github.com/kunitoki/LuaBridge3
// Copyright 2023, kunitoki
// SPDX-License-Identifier: MIT

#pragma once

#include "Config.h"
#include "Errors.h"
#include "LuaHelpers.h"
#include "Stack.h"

#include <type_traits>

namespace luabridge {

//=================================================================================================
/**
 * @brief LuaBridge enum wrapper for enums as integers.
 *
 * An enum exposed with this class will just be decayed to lua as integer. It's responsibility of
 * the developer to make sure that a lua integer could be converted back to C++. Failing to validate a lua
 * integer before converting to the corresponding C++ enum value could lead to a C++ enum that has no defined value.
 *
 * For improved security, specify which values the enum will have, so runtime validation could be performed.
 */
template <class T, T... Values>
struct Enum
{
    static_assert(std::is_enum_v<T>);

    using Type = std::underlying_type_t<T>;

    [[nodiscard]] static Result push(lua_State* L, T value)
    {
        return Stack<Type>::push(L, static_cast<Type>(value));
    }

    [[nodiscard]] static TypeResult<T> get(lua_State* L, int index)
    {
        const auto result = Stack<Type>::get(L, index);
        if (! result)
            return result.error();

        if constexpr (sizeof...(Values) > 0)
        {
            constexpr Type values[] = { static_cast<Type>(Values)... };
            for (std::size_t i = 0; i < sizeof...(Values); ++i)
            {
                if (values[i] == *result)
                    return static_cast<T>(*result);
            }

            return makeErrorCode(ErrorCode::InvalidTypeCast);
        }
        else
        {
            return static_cast<T>(*result);
        }
    }

    [[nodiscard]] static bool isInstance(lua_State* L, int index)
    {
        return lua_type(L, index) == LUA_TNUMBER;
    }
};

} // namespace luabridge