Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Once per turn, this card cannot be destroyed by battle. When this face-up card is selected as an attack target, inflict 500 damage to your opponent.
--ナチュル・ビーンズ
--Naturia Beans
local s,id=GetID()
function s.initial_effect(c)
	--battle indes
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCode(EFFECT_INDESTRUCTABLE_COUNT)
	e1:SetCountLimit(1)
	e1:SetValue(s.valcon)
	c:RegisterEffect(e1)
	--damage
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetCategory(CATEGORY_DAMAGE)
	e2:SetProperty(EFFECT_FLAG_PLAYER_TARGET)
	e2:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
	e2:SetCode(EVENT_BE_BATTLE_TARGET)
	e2:SetTarget(s.damtg)
	e2:SetOperation(s.damop)
	c:RegisterEffect(e2)
end
function s.valcon(e,re,r,rp)
	return (r&REASON_BATTLE)~=0
end
function s.damtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetTargetPlayer(1-tp)
	Duel.SetTargetParam(500)
	Duel.SetOperationInfo(0,CATEGORY_DAMAGE,nil,0,1-tp,500)
end
function s.damop(e,tp,eg,ep,ev,re,r,rp)
	local p,d=Duel.GetChainInfo(0,CHAININFO_TARGET_PLAYER,CHAININFO_TARGET_PARAM)
	Duel.Damage(p,d,REASON_EFFECT)
end