Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Cannot be Normal Summoned, unless you control a "Ghostrick" monster. Once per turn: You can change this card to face-down Defense Position. When this card is flipped face-up: You can target 1 "Ghostrick" monster on the field; this turn, it cannot be destroyed by battle or card effects.
--ゴーストリック・イエティ
--Ghostrick Yeti
local s,id=GetID()
function s.initial_effect(c)
	--Cannot be normal summoned if player controls no "Ghostrick" monster
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_CANNOT_SUMMON)
	e1:SetCondition(s.sumcon)
	c:RegisterEffect(e1)
	--Change itself to face-down defense position
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetCategory(CATEGORY_POSITION)
	e2:SetType(EFFECT_TYPE_IGNITION)
	e2:SetRange(LOCATION_MZONE)
	e2:SetTarget(s.postg)
	e2:SetOperation(s.posop)
	c:RegisterEffect(e2)
	--Targeted "Ghostrick" monster cannot be destroyed by battle or card effect
	local e3=Effect.CreateEffect(c)
	e3:SetDescription(aux.Stringid(id,1))
	e3:SetCategory(CATEGORY_REMOVE)
	e3:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e3:SetProperty(EFFECT_FLAG_CARD_TARGET+EFFECT_FLAG_DAMAGE_STEP)
	e3:SetCode(EVENT_FLIP)
	e3:SetTarget(s.indestg)
	e3:SetOperation(s.indesop)
	c:RegisterEffect(e3)
end
s.listed_series={SET_GHOSTRICK}
function s.sfilter(c)
	return c:IsFaceup() and c:IsSetCard(SET_GHOSTRICK)
end
function s.sumcon(e)
	return not Duel.IsExistingMatchingCard(s.sfilter,e:GetHandlerPlayer(),LOCATION_MZONE,0,1,nil)
end
function s.postg(e,tp,eg,ep,ev,re,r,rp,chk)
	local c=e:GetHandler()
	if chk==0 then return c:IsCanTurnSet() and c:GetFlagEffect(id)==0 end
	c:RegisterFlagEffect(id,RESET_EVENT|(RESETS_STANDARD_PHASE_END&~RESET_TURN_SET),0,1)
	Duel.SetOperationInfo(0,CATEGORY_POSITION,c,1,0,0)
end
function s.posop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsRelateToEffect(e) and c:IsFaceup() then
		Duel.ChangePosition(c,POS_FACEDOWN_DEFENSE)
	end
end
function s.indestg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and s.sfilter(chkc) end
	if chk==0 then return Duel.IsExistingTarget(s.sfilter,tp,LOCATION_MZONE,LOCATION_MZONE,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_FACEUP)
	Duel.SelectTarget(tp,s.sfilter,tp,LOCATION_MZONE,LOCATION_MZONE,1,1,nil)
end
function s.indesop(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc:IsRelateToEffect(e) then
		--Cannot be destroyed by battle or card effects
		local e1=Effect.CreateEffect(e:GetHandler())
		e1:SetDescription(3008)
		e1:SetProperty(EFFECT_FLAG_CLIENT_HINT)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_INDESTRUCTABLE_BATTLE)
		e1:SetReset(RESETS_STANDARD_PHASE_END)
		e1:SetValue(1)
		tc:RegisterEffect(e1)
		local e2=e1:Clone()
		e2:SetCode(EFFECT_INDESTRUCTABLE_EFFECT)
		tc:RegisterEffect(e2)
	end
end