Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If you control a "Photon" or "Galaxy" monster, you can Normal Summon this card without Tributing. If Summoned this way: Target 1 "Galaxy-Eyes Photon Dragon" in your GY (if possible); regardless, this card loses 1000 ATK, and if it does, Special Summon that target (if any) in Defense Position. This ATK decrease lasts until the end of this turn.
--銀河騎士
--Galaxy Knight
local s,id=GetID()
function s.initial_effect(c)
	--summon with no tribute
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_UNCOPYABLE)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_SUMMON_PROC)
	e1:SetCondition(s.ntcon)
	e1:SetValue(1)
	c:RegisterEffect(e1)
	--spsummon
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetCategory(CATEGORY_ATKCHANGE+CATEGORY_SPECIAL_SUMMON)
	e2:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
	e2:SetCode(EVENT_SUMMON_SUCCESS)
	e2:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e2:SetCondition(s.spcon)
	e2:SetTarget(s.sptg)
	e2:SetOperation(s.spop)
	c:RegisterEffect(e2)
end
s.listed_series={SET_PHOTON,SET_GALAXY}
s.listed_names={CARD_GALAXYEYES_P_DRAGON}
function s.cfilter(c)
	return c:IsFaceup() and c:IsSetCard({SET_PHOTON,SET_GALAXY})
end
function s.ntcon(e,c,minc)
	if c==nil then return true end
	return minc==0 and c:GetLevel()>4 and Duel.GetLocationCount(c:GetControler(),LOCATION_MZONE)>0
		and Duel.IsExistingMatchingCard(s.cfilter,c:GetControler(),LOCATION_MZONE,0,1,nil)
end
function s.spcon(e,tp,eg,ep,ev,re,r,rp)
	return e:GetHandler():GetSummonType()==SUMMON_TYPE_NORMAL+1
end
function s.spfilter(c,e,tp)
	return c:IsCode(CARD_GALAXYEYES_P_DRAGON) and c:IsCanBeSpecialSummoned(e,0,tp,false,false,POS_FACEUP_DEFENSE)
end
function s.sptg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsControler(tp) and chkc:IsLocation(LOCATION_GRAVE) and s.spfilter(chkc,e,tp) end
	if chk==0 then return true end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectTarget(tp,s.spfilter,tp,LOCATION_GRAVE,0,1,1,nil,e,tp)
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,g,1,0,0,nil)
end
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsFaceup() and c:IsRelateToEffect(e) then
		local e1=Effect.CreateEffect(c)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_UPDATE_ATTACK)
		e1:SetValue(-1000)
		e1:SetReset(RESETS_STANDARD_DISABLE_PHASE_END)
		c:RegisterEffect(e1)
		local tc=Duel.GetFirstTarget()
		if tc and tc:IsRelateToEffect(e) then
			Duel.SpecialSummon(tc,0,tp,tp,false,false,POS_FACEUP_DEFENSE)
		end
	end
end