Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
When this card is activated: You can add 1 "K9" monster from your Deck to your hand. "K9" monsters you control gain 900 ATK during any turn in which your opponent has activated a monster effect in the hand or GY. If this card in the Spell & Trap Zone is destroyed by card effect: You can Set 1 "K9" Quick-Play Spell from your Deck or GY. You can only use this effect of ""A Case for K9"" once per turn. You can only activate 1 ""A Case for K9"" per turn.
--＂Ｃａｓｅ ｏｆ Ｋ９＂
--"A Case for K9"
--scripted by pyrQ
local s,id=GetID()
function s.initial_effect(c)
	--When this card is activated: You can add 1 "K9" monster from your Deck to your hand
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_TOHAND+CATEGORY_SEARCH)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetCountLimit(1,id,EFFECT_COUNT_CODE_OATH)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
	--"K9" monsters you control gain 900 ATK the turn your opponent activated a monster effect in the hand or GY
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetCode(EFFECT_UPDATE_ATTACK)
	e2:SetRange(LOCATION_SZONE)
	e2:SetTargetRange(LOCATION_MZONE,0)
	e2:SetCondition(function(e) return Duel.GetCustomActivityCount(id,1-e:GetHandlerPlayer(),ACTIVITY_CHAIN)>0 end)
	e2:SetTarget(function(e,c) return c:IsSetCard(SET_K9) end)
	e2:SetValue(900)
	c:RegisterEffect(e2)
	Duel.AddCustomActivityCounter(id,ACTIVITY_CHAIN,s.chainfilter)
	--Set 1 "K9" Quick-Play Spell from your Deck or GY
	local e3=Effect.CreateEffect(c)
	e3:SetDescription(aux.Stringid(id,1))
	e3:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e3:SetProperty(EFFECT_FLAG_DELAY)
	e3:SetCode(EVENT_DESTROYED)
	e3:SetCountLimit(1,{id,1})
	e3:SetCondition(s.setcon)
	e3:SetTarget(s.settg)
	e3:SetOperation(s.setop)
	c:RegisterEffect(e3)
end
s.listed_series={SET_K9}
function s.chainfilter(re,tp,cid)
	return not (re:IsMonsterEffect() and re:GetActivateLocation()&(LOCATION_HAND|LOCATION_GRAVE)>0)
end
function s.thfilter(c)
	return c:IsSetCard(SET_K9) and c:IsMonster() and c:IsAbleToHand()
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	if Duel.IsExistingMatchingCard(s.thfilter,tp,LOCATION_DECK,0,1,nil)
		and Duel.SelectYesNo(tp,aux.Stringid(id,2)) then
		Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_ATOHAND)
		local g=Duel.SelectMatchingCard(tp,s.thfilter,tp,LOCATION_DECK,0,1,1,nil)
		if #g>0 then
			Duel.SendtoHand(g,nil,REASON_EFFECT)
			Duel.ConfirmCards(1-tp,g)
		end
	end
end
function s.setcon(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	return c:IsReason(REASON_EFFECT) and c:IsPreviousLocation(LOCATION_STZONE)
end
function s.setfilter(c)
	return c:IsSetCard(SET_K9) and c:IsQuickPlaySpell() and c:IsSSetable()
end
function s.settg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(s.setfilter,tp,LOCATION_DECK|LOCATION_GRAVE,0,1,nil) end
end
function s.setop(e,tp,eg,ep,ev,re,r,rp)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SET)
	local g=Duel.SelectMatchingCard(tp,aux.NecroValleyFilter(s.setfilter),tp,LOCATION_DECK|LOCATION_GRAVE,0,1,1,nil)
	if #g>0 then
		Duel.SSet(tp,g)
	end
end