Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
You can Special Summon this card (from your hand) by discarding 1 Level 5 or higher DARK monster. Once per turn: You can discard 1 DARK monster; send 1 DARK monster from your Deck to the GY.
--ダーク・グレファー
--Dark Grepher
local s,id=GetID()
function s.initial_effect(c)
	--special summon
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_FIELD)
	e1:SetCode(EFFECT_SPSUMMON_PROC)
	e1:SetProperty(EFFECT_FLAG_UNCOPYABLE)
	e1:SetRange(LOCATION_HAND)
	e1:SetCondition(s.spcon)
	e1:SetTarget(s.sptg)
	e1:SetOperation(s.spop)
	c:RegisterEffect(e1)
	--to grave
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetCategory(CATEGORY_TOGRAVE)
	e2:SetType(EFFECT_TYPE_IGNITION)
	e2:SetCountLimit(1)
	e2:SetRange(LOCATION_MZONE)
	e2:SetCost(s.sgcost)
	e2:SetTarget(s.sgtg)
	e2:SetOperation(s.sgop)
	c:RegisterEffect(e2)
end
function s.spfilter(c)
	return c:IsLevelAbove(5) and c:IsAttribute(ATTRIBUTE_DARK)
end
function s.spcon(e,c)
	if c==nil then return true end
	local tp=e:GetHandlerPlayer()
	local rg=Duel.GetMatchingGroup(s.spfilter,tp,LOCATION_HAND,0,nil)
	return aux.SelectUnselectGroup(rg,e,tp,1,1,aux.ChkfMMZ(1),0,c)
end
function s.sptg(e,tp,eg,ep,ev,re,r,rp,c)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_DISCARD)
	local rg=Duel.GetMatchingGroup(s.spfilter,tp,LOCATION_HAND,0,nil)
	local g=aux.SelectUnselectGroup(rg,e,tp,1,1,aux.ChkfMMZ(1),1,tp,HINTMSG_REMOVE,nil,nil,true)
	if #g>0 then
		g:KeepAlive()
		e:SetLabelObject(g)
		return true
	end
	return false
end
function s.spop(e,tp,eg,ep,ev,re,r,rp,c)
	local g=e:GetLabelObject()
	if not g then return end
	Duel.SendtoGrave(g,REASON_DISCARD|REASON_COST)
	g:DeleteGroup()
end
function s.costfilter(c)
	return c:IsAttribute(ATTRIBUTE_DARK) and c:IsDiscardable()
end
function s.sgcost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(s.costfilter,tp,LOCATION_HAND,0,1,nil) end
	Duel.DiscardHand(tp,s.costfilter,1,1,REASON_COST|REASON_DISCARD)
end
function s.filter(c)
	return c:IsAttribute(ATTRIBUTE_DARK) and c:IsAbleToGrave()
end
function s.sgtg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	local c=e:GetHandler()
	if chk==0 then return Duel.IsExistingMatchingCard(s.filter,tp,LOCATION_DECK,0,1,nil) end
	Duel.SetOperationInfo(0,CATEGORY_TOGRAVE,nil,1,tp,LOCATION_DECK)
end
function s.sgop(e,tp,eg,ep,ev,re,r,rp)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TOGRAVE)
	local g=Duel.SelectMatchingCard(tp,s.filter,tp,LOCATION_DECK,0,1,1,nil)
	if #g>0 then
		Duel.SendtoGrave(g,REASON_EFFECT)
	end
end