Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Target 1 Level 7 or lower Dragon monster in your GY; Special Summon it. If you Special Summoned a "Gaia the Dragon Champion" by this effect, your opponent cannot target it with card effects, and it cannot be destroyed by their card effects. You can only activate 1 "Spiral Reborn" per turn.
--螺旋蘇生
--Spiral Reborn
--Scripted by Naim
local s,id=GetID()
function s.initial_effect(c)
	--Special summon 1 level 7+ dragon monster from GY
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetHintTiming(0,TIMING_END_PHASE)
	e1:SetCountLimit(1,id,EFFECT_COUNT_CODE_OATH)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
end
s.listed_names={CARD_GAIA_CHAMPION}
function s.filter(c,e,tp)
	return c:IsLevelBelow(7) and c:IsRace(RACE_DRAGON) and c:IsCanBeSpecialSummoned(e,0,tp,false,false,POS_FACEUP)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_GRAVE) and chkc:IsControler(tp) and s.filter(chkc,e,tp) end
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and Duel.IsExistingTarget(s.filter,tp,LOCATION_GRAVE,0,1,nil,e,tp) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectTarget(tp,s.filter,tp,LOCATION_GRAVE,0,1,1,nil,e,tp)
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,g,1,0,0)
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc and tc:IsRelateToEffect(e) and Duel.SpecialSummon(tc,0,tp,tp,false,false,POS_FACEUP)~=0 then
			if tc:IsCode(CARD_GAIA_CHAMPION) then
			local c=e:GetHandler()
			--Cannot be targeted or destroyed by opponent's card effects
			local e1=Effect.CreateEffect(c)
			e1:SetDescription(3067)
			e1:SetType(EFFECT_TYPE_SINGLE)
			e1:SetProperty(EFFECT_FLAG_CLIENT_HINT)
			e1:SetCode(EFFECT_INDESTRUCTABLE_EFFECT)
			e1:SetValue(s.indval)
			e1:SetReset(RESET_EVENT|RESETS_STANDARD)
			tc:RegisterEffect(e1)
			local e2=e1:Clone()
			e2:SetCode(EFFECT_CANNOT_BE_EFFECT_TARGET)
			tc:RegisterEffect(e2)
		end
	end
end
function s.indval(e,re,rp)
	return rp==1-e:GetHandlerPlayer()
end