Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
(This card is also always treated as a "Gaia The Fierce Knight" card.) If you control no monsters, or your opponent controls a monster with 2300 or more ATK, you can Normal Summon this card without Tributing. If this card is Normal or Special Summoned: You can Special Summon 1 Level 5 Dragon monster from your hand or GY in Defense Position. You can only use this effect of "Gaia the Magical Knight" once per turn.
--魔道騎士ガイア
--Gaia the Magical Knight
--Scripted by Eerie Code
local s,id=GetID()
function s.initial_effect(c)
	--Normal Summon without tribute
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_UNCOPYABLE)
	e1:SetCode(EFFECT_SUMMON_PROC)
	e1:SetCondition(s.ntcon)
	c:RegisterEffect(e1)
	--Special Summon 1 level 5 Dragon from hand or GY
	local e2=Effect.CreateEffect(c)
	e2:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e2:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e2:SetCode(EVENT_SUMMON_SUCCESS)
	e2:SetProperty(EFFECT_FLAG_DELAY)
	e2:SetCountLimit(1,id)
	e2:SetTarget(s.sptg)
	e2:SetOperation(s.spop)
	c:RegisterEffect(e2)
	local e3=e2:Clone()
	e3:SetCode(EVENT_SPSUMMON_SUCCESS)
	c:RegisterEffect(e3)
end
s.listed_series={SET_GAIA_THE_FIERCE_KNIGHT}
function s.ntcon(e,c,minc)
	if c==nil then return true end
	local tp=c:GetControler()
	return minc==0 and c:GetLevel()>4 and Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and (Duel.GetFieldGroupCount(tp,LOCATION_MZONE,0)==0 or Duel.IsExistingMatchingCard(aux.FaceupFilter(Card.IsAttackAbove,2300),tp,0,LOCATION_MZONE,1,nil))
end
function s.spfilter(c,e,tp)
	return c:IsRace(RACE_DRAGON) and c:GetLevel()==5 and c:IsCanBeSpecialSummoned(e,0,tp,false,false,POS_FACEUP_DEFENSE)
end
function s.sptg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0 and Duel.IsExistingMatchingCard(s.spfilter,tp,LOCATION_HAND|LOCATION_GRAVE,0,1,nil,e,tp) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,nil,1,tp,LOCATION_GRAVE|LOCATION_HAND)
end
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	if Duel.GetLocationCount(tp,LOCATION_MZONE)<1 then return end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectMatchingCard(tp,aux.NecroValleyFilter(s.spfilter),tp,LOCATION_GRAVE|LOCATION_HAND,0,1,1,nil,e,tp)
	if #g>0 then
		Duel.SpecialSummon(g,0,tp,tp,false,false,POS_FACEUP_DEFENSE)
	end
end