Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
During your Draw Phase, if you draw a DARK monster(s): You can reveal any number of them; send them to the GY, then you can draw 1 more card.
--漆黒のトバリ
--Veil of Darkness
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	c:RegisterEffect(e1)
	--draw
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetCategory(CATEGORY_TOGRAVE+CATEGORY_DRAW)
	e2:SetRange(LOCATION_SZONE)
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e2:SetCode(EVENT_DRAW)
	e2:SetCondition(s.drcon)
	e2:SetCost(s.drcost)
	e2:SetTarget(s.drtg)
	e2:SetOperation(s.drop)
	c:RegisterEffect(e2)
end
function s.drcon(e,tp,eg,ep,ev,re,r,rp)
	return Duel.IsTurnPlayer(tp) and Duel.IsPhase(PHASE_DRAW)
end
function s.filter(c)
	return c:IsAttribute(ATTRIBUTE_DARK) and not c:IsPublic()
end
function s.drcost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return ep==tp and eg:IsExists(s.filter,1,nil) end
	local g=eg:Filter(s.filter,nil)
	if #g==1 then
		Duel.ConfirmCards(1-tp,g)
		Duel.ShuffleHand(tp)
		e:SetLabelObject(g:GetFirst())
	else
		Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_CONFIRM)
		local sg=g:Select(tp,1,1,nil)
		Duel.ConfirmCards(1-tp,sg)
		Duel.ShuffleHand(tp)
		e:SetLabelObject(sg:GetFirst())
	end
end
function s.drtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	local tc=e:GetLabelObject()
	tc:CreateEffectRelation(e)
	Duel.SetOperationInfo(0,CATEGORY_TOGRAVE,tc,1,0,0)
	Duel.SetPossibleOperationInfo(0,CATEGORY_DRAW,nil,1,tp,1)
end
function s.drop(e,tp,eg,ep,ev,re,r,rp)
	local tc=e:GetLabelObject()
	if not e:GetHandler():IsRelateToEffect(e) or not tc:IsRelateToEffect(e) then return end
	Duel.SendtoGrave(tc,REASON_EFFECT)
	if tc:IsLocation(LOCATION_GRAVE) and Duel.IsPlayerCanDraw(tp,1) and Duel.SelectYesNo(tp,aux.Stringid(id,1)) then
		Duel.BreakEffect()
		Duel.Draw(tp,1,REASON_EFFECT)
	end
end