Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Target 1 Level 4 or lower Fish monster in your GY; Special Summon it, then you can add 1 monster from your Deck to your hand with the same original name as that Special Summoned monster. You can only activate "White Mirror" once per turn.
--白の水鏡
--White Mirror
--Scripted by AlphaKretin
local s,id=GetID()
function s.initial_effect(c)
	--Special summon 1 Fish monster and search 1 monster with the same name
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON+CATEGORY_TOHAND+CATEGORY_SEARCH)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetCountLimit(1,id,EFFECT_COUNT_CODE_OATH)
	e1:SetTarget(s.sptg)
	e1:SetOperation(s.spop)
	c:RegisterEffect(e1)
end
function s.spfilter(c,e,tp)
	return c:IsLevelBelow(4) and c:IsRace(RACE_FISH) and c:IsCanBeSpecialSummoned(e,0,tp,false,false)
end
function s.sptg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_GRAVE) and chkc:IsControler(tp) and s.spfilter(chkc,e,tp) end
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and Duel.IsExistingTarget(s.spfilter,tp,LOCATION_GRAVE,0,1,nil,e,tp) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectTarget(tp,s.spfilter,tp,LOCATION_GRAVE,0,1,1,nil,e,tp)
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,g,1,0,LOCATION_GRAVE)
	Duel.SetPossibleOperationInfo(0,CATEGORY_TOHAND,nil,1,tp,LOCATION_DECK)
end
function s.thfilter(c,tc)
	return c:IsOriginalCodeRule(tc:GetOriginalCodeRule()) and c:IsAbleToHand()
end
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local tc=Duel.GetFirstTarget()
	if tc and tc:IsRelateToEffect(e) and Duel.SpecialSummon(tc,0,tp,tp,false,false,POS_FACEUP)~=0
		and Duel.IsExistingMatchingCard(s.thfilter,tp,LOCATION_DECK,0,1,nil,tc) and Duel.SelectYesNo(tp,aux.Stringid(id,0)) then
		Duel.BreakEffect()
		Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_ATOHAND)
		local g=Duel.SelectMatchingCard(tp,s.thfilter,tp,LOCATION_DECK,0,1,1,nil,tc)
		Duel.SendtoHand(g,nil,REASON_EFFECT)
		Duel.ConfirmCards(1-tp,g)
	end
end