Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
You can target 1 Dragon monster you control; it gains ATK/DEF equal to the total Link Rating of the Link Monsters currently on the field x 100, until the end of the opponent's turn. You can only use this effect of "Guardragon Shield" once per turn. Once per turn, if exactly 1 Dragon monster you control would be destroyed by battle or card effect, you can send 1 Normal Monster from your hand or Deck to the GY instead.
--守護竜の結界
--Guardragon Shield
--Scripted by Eerie Code
local s,id=GetID()
function s.initial_effect(c)
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	c:RegisterEffect(e1)
	--boost
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetCategory(CATEGORY_ATKCHANGE+CATEGORY_DEFCHANGE)
	e2:SetType(EFFECT_TYPE_IGNITION)
	e2:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e2:SetRange(LOCATION_FZONE)
	e2:SetCountLimit(1,id)
	e2:SetTarget(s.atktg)
	e2:SetOperation(s.atkop)
	c:RegisterEffect(e2)
	--destroy replace
	local e3=Effect.CreateEffect(c)
	e3:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_CONTINUOUS)
	e3:SetCode(EFFECT_DESTROY_REPLACE)
	e3:SetRange(LOCATION_FZONE)
	e3:SetCountLimit(1)
	e3:SetTarget(s.reptg)
	e3:SetValue(s.repval)
	c:RegisterEffect(e3)
end
function s.atkfilter(c)
	return c:IsFaceup() and c:IsRace(RACE_DRAGON) and Duel.IsExistingMatchingCard(Card.IsType,0,LOCATION_MZONE,LOCATION_MZONE,1,nil,TYPE_LINK)
end
function s.atktg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsControler(tp) and s.atkfilter(chkc) end
	if chk==0 then return Duel.IsExistingTarget(s.atkfilter,tp,LOCATION_MZONE,0,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_FACEUP)
	Duel.SelectTarget(tp,s.atkfilter,tp,LOCATION_MZONE,0,1,1,nil)
end
function s.atkop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local tc=Duel.GetFirstTarget()
	if c:IsRelateToEffect(e) and tc:IsRelateToEffect(e) and tc:IsFaceup() then
		local e1=Effect.CreateEffect(c)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
		e1:SetCode(EFFECT_UPDATE_ATTACK)
		e1:SetRange(LOCATION_MZONE)
		e1:SetValue(s.atkval)
		e1:SetReset(RESETS_STANDARD_PHASE_END|RESET_OPPO_TURN)
		tc:RegisterEffect(e1)
		local e2=e1:Clone()
		e2:SetCode(EFFECT_UPDATE_DEFENSE)
		tc:RegisterEffect(e2)
	end
end
function s.atkval(e,c)
	local g=Duel.GetMatchingGroup(Card.IsType,0,LOCATION_MZONE,LOCATION_MZONE,nil,TYPE_LINK)
	return g:GetSum(Card.GetLink)*100
end
function s.repfilter(c,tp)
	return c:IsFaceup() and c:IsRace(RACE_DRAGON)
		and c:IsLocation(LOCATION_MZONE) and c:IsControler(tp) and c:IsReason(REASON_BATTLE|REASON_EFFECT) and not c:IsReason(REASON_REPLACE)
end
function s.tgfilter(c)
	return c:IsType(TYPE_NORMAL) and c:IsAbleToGrave()
end
function s.reptg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return eg:IsExists(s.repfilter,1,nil,tp) and #eg==1
		and Duel.IsExistingMatchingCard(s.tgfilter,tp,LOCATION_HAND|LOCATION_DECK,0,1,nil) end
	if Duel.SelectEffectYesNo(tp,e:GetHandler(),96) then
		Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TOGRAVE)
		local sg=Duel.SelectMatchingCard(tp,s.tgfilter,tp,LOCATION_HAND|LOCATION_DECK,0,1,1,nil)
		Duel.Hint(HINT_CARD,0,id)
		Duel.SendtoGrave(sg,REASON_EFFECT|REASON_REPLACE)
		return true
	else return false end
end
function s.repval(e,c)
	return s.repfilter(c,e:GetHandlerPlayer())
end