Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
You can Ritual Summon this card with "White Dragon Ritual". At the start of the Damage Step, if this card attacks a face-down Defense Position monster: Destroy that face-down monster. You can Tribute this card; Special Summon 1 "Blue-Eyes White Dragon" from your hand or Deck, but "Blue-Eyes White Dragon" cannot attack for the rest of this turn.
--白竜の聖騎士
--Paladin of White Dragon
local s,id=GetID()
function s.initial_effect(c)
	c:EnableReviveLimit()
	--destroy
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_DESTROY)
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
	e1:SetCode(EVENT_BATTLE_START)
	e1:SetCondition(s.descon)
	e1:SetTarget(s.destg)
	e1:SetOperation(s.desop)
	c:RegisterEffect(e1)
	--spsummon
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e2:SetType(EFFECT_TYPE_IGNITION)
	e2:SetRange(LOCATION_MZONE)
	e2:SetCost(Cost.SelfTribute)
	e2:SetTarget(s.sptg)
	e2:SetOperation(s.spop)
	c:RegisterEffect(e2)
end
s.listed_names={9786492,CARD_BLUEEYES_W_DRAGON}
function s.descon(e,tp,eg,ep,ev,re,r,rp)
	local d=Duel.GetAttackTarget()
	return e:GetHandler()==Duel.GetAttacker() and d and d:IsPosition(POS_FACEDOWN_DEFENSE)
end
function s.destg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetOperationInfo(0,CATEGORY_DESTROY,Duel.GetAttackTarget(),1,0,0)
end
function s.desop(e,tp,eg,ep,ev,re,r,rp)
	local d=Duel.GetAttackTarget()
	if d:IsRelateToBattle() then
		Duel.Destroy(d,REASON_EFFECT)
	end
end
function s.spfilter(c,e,tp)
	return c:IsCode(CARD_BLUEEYES_W_DRAGON) and c:IsCanBeSpecialSummoned(e,0,tp,false,false)
end
function s.sptg(e,tp,eg,ep,ev,re,r,rp,chk)
	local ft=Duel.GetLocationCount(tp,LOCATION_MZONE)
	if e:GetHandler():GetSequence()<5 then ft=ft+1 end
	if chk==0 then return ft>0 and Duel.IsExistingMatchingCard(s.spfilter,tp,LOCATION_HAND|LOCATION_DECK,0,1,nil,e,tp) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,nil,1,tp,LOCATION_HAND|LOCATION_DECK)
end
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	if Duel.GetLocationCount(tp,LOCATION_MZONE)<=0 then return end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectMatchingCard(tp,s.spfilter,tp,LOCATION_HAND|LOCATION_DECK,0,1,1,nil,e,tp)
	Duel.SpecialSummon(g,0,tp,tp,false,false,POS_FACEUP)
	local e1=Effect.CreateEffect(e:GetHandler())
	e1:SetType(EFFECT_TYPE_FIELD)
	e1:SetCode(EFFECT_CANNOT_ATTACK)
	e1:SetTarget(aux.TargetBoolFunction(Card.IsCode,CARD_BLUEEYES_W_DRAGON))
	e1:SetTargetRange(LOCATION_MZONE,LOCATION_MZONE)
	e1:SetReset(RESET_PHASE|PHASE_END)
	Duel.RegisterEffect(e1,tp)
end