Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If this card attacks a Defense Position monster, before damage calculation: Shuffle that monster into the Deck. Once per turn, during your End Phase: Send the top 3 cards of your Deck to the Graveyard.
--ライトロード・モンク エイリン
--Ehren, Lightsworn Monk
local s,id=GetID()
function s.initial_effect(c)
	--to deck
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_TODECK)
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
	e1:SetCode(EVENT_BATTLE_CONFIRM)
	e1:SetTarget(s.targ)
	e1:SetOperation(s.op)
	c:RegisterEffect(e1)
	--discard deck
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_F)
	e2:SetCategory(CATEGORY_DECKDES)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetCode(EVENT_PHASE+PHASE_END)
	e2:SetRange(LOCATION_MZONE)
	e2:SetCountLimit(1)
	e2:SetCondition(s.discon)
	e2:SetTarget(s.distg)
	e2:SetOperation(s.disop)
	c:RegisterEffect(e2)
end
function s.targ(e,tp,eg,ep,ev,re,r,rp,chk)
	local t=Duel.GetAttackTarget()
	if chk ==0 then	return Duel.GetAttacker()==e:GetHandler() and t~=nil and not t:IsAttackPos() and t:IsAbleToDeck() end
	Duel.SetOperationInfo(0,CATEGORY_TODECK,t,1,0,0)
end
function s.op(e,tp,eg,ep,ev,re,r,rp)
	local t=Duel.GetAttackTarget()
	if t~=nil and t:IsRelateToBattle() and not t:IsAttackPos() then
		Duel.SendtoDeck(t,nil,SEQ_DECKSHUFFLE,REASON_EFFECT)
	end
end
function s.discon(e,tp,eg,ep,ev,re,r,rp)
	return tp==Duel.GetTurnPlayer()
end
function s.distg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetOperationInfo(0,CATEGORY_DECKDES,nil,0,tp,3)
end
function s.disop(e,tp,eg,ep,ev,re,r,rp)
	Duel.DiscardDeck(tp,3,REASON_EFFECT)
end