Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Add 1 Spell Card from your hand to your opponent's hand, then add 1 Level 7 or 8 DARK monster from your Deck to your hand.
--魔導契約の扉
--Magical Contract Door
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_TOHAND+CATEGORY_SEARCH)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
end
function s.filter(c)
	return (c:GetLevel()==7 or c:GetLevel()==8) and c:IsAttribute(ATTRIBUTE_DARK) and c:IsAbleToHand()
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(Card.IsSpell,tp,LOCATION_HAND,0,1,e:GetHandler())
		and Duel.IsExistingMatchingCard(s.filter,tp,LOCATION_DECK,0,1,nil) end
	Duel.SetOperationInfo(0,CATEGORY_TOHAND,nil,1,tp,LOCATION_DECK)
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	Duel.Hint(HINT_SELECTMSG,tp,aux.Stringid(id,0))
	local ag=Duel.SelectMatchingCard(tp,Card.IsSpell,tp,LOCATION_HAND,0,1,1,nil)
	if #ag>0 then
		Duel.SendtoHand(ag,1-tp,REASON_EFFECT)
		Duel.ConfirmCards(tp,ag)
		Duel.ShuffleHand(tp)
		Duel.ShuffleHand(1-tp)
		Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_ATOHAND)
		local g=Duel.SelectMatchingCard(tp,s.filter,tp,LOCATION_DECK,0,1,1,nil)
		if #g>0 then
			Duel.BreakEffect()
			Duel.SendtoHand(g,nil,REASON_EFFECT)
			Duel.ConfirmCards(1-tp,g)
		end
	end
end