Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
2 Level 4 monsters Once per turn: You can detach 1 material from this card, then target 1 "Gagaga" monster you control; it can make a second attack during each Battle Phase this turn. When another monster you control is targeted for an attack while this card is in Attack Position: You can change this card to face-up Defense Position, and if you do, change the attack target to this card and perform damage calculation.
--ガガガザムライ
--Gagaga Samurai
local s,id=GetID()
function s.initial_effect(c)
	--Must be properly summoned before reviving
	c:EnableReviveLimit()
	--Xyz summon procedure
	Xyz.AddProcedure(c,nil,4,2)
	--Targeted "Gagaga" monster can make a second attack
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetCountLimit(1)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCondition(s.atcon)
	e1:SetCost(Cost.DetachFromSelf(1))
	e1:SetTarget(s.attg)
	e1:SetOperation(s.atop)
	c:RegisterEffect(e1)
	--When your monster is targeted for attack, change the attack target to this card
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e2:SetCode(EVENT_BE_BATTLE_TARGET)
	e2:SetRange(LOCATION_MZONE)
	e2:SetCondition(s.cbcon)
	e2:SetOperation(s.cbop)
	c:RegisterEffect(e2)
end
s.listed_series={SET_GAGAGA}
function s.atcon(e,tp,eg,ep,ev,re,r,rp)
	return Duel.IsAbleToEnterBP()
end
function s.filter(c)
	return c:IsFaceup() and c:IsSetCard(SET_GAGAGA) and c:GetEffectCount(EFFECT_EXTRA_ATTACK)==0
end
function s.attg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsControler(tp) and s.filter(chkc) end
	if chk==0 then return Duel.IsExistingTarget(s.filter,tp,LOCATION_MZONE,0,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_FACEUP)
	Duel.SelectTarget(tp,s.filter,tp,LOCATION_MZONE,0,1,1,nil)
end
function s.atop(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc:IsRelateToEffect(e) then
		--Can make a second attack
		local e1=Effect.CreateEffect(e:GetHandler())
		e1:SetDescription(3201)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_EXTRA_ATTACK)
		e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_CLIENT_HINT)
		e1:SetValue(1)
		e1:SetReset(RESETS_STANDARD_PHASE_END)
		tc:RegisterEffect(e1)
	end
end
function s.cbcon(e,tp,eg,ep,ev,re,r,rp)
	local bt=eg:GetFirst()
	return r~=REASON_REPLACE and bt~=e:GetHandler() and bt:IsControler(tp) and e:GetHandler():IsPosition(POS_ATTACK)
end
function s.cbop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsFaceup() and c:IsRelateToEffect(e) and Duel.ChangePosition(c,POS_FACEUP_DEFENSE)~=0 then
		local at=Duel.GetAttacker()
		if at:CanAttack() and not at:IsImmuneToEffect(e) and not c:IsImmuneToEffect(e) then
			Duel.CalculateDamage(at,c)
		end
	end
end