Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Once per turn: You can target 1 DARK Machine monster you control and 1 face-up card your opponent controls; destroy them. If a monster you control that was originally a DARK Machine destroys an opponent's monster(s) by battle or card effect and sends it to the GY: You can inflict damage to your opponent equal to half the original ATK of 1 of those monster(s) destroyed and sent to the GY. You can only use this effect of "BM-4 Blast Spider" once per turn.
--BM-4 ボムスパイダー
--BM-4 Blast Spider
--Scripted by Eerie Code
local s,id=GetID()
function s.initial_effect(c)
	--Destroy 1 DARK Machine monster you control and 1 face-up card your opponent controls
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_DESTROY)
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCountLimit(1)
	e1:SetTarget(s.destg)
	e1:SetOperation(s.desop)
	c:RegisterEffect(e1)
	--Inflict damage equal to half the ATK of a destroyed monster
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetCategory(CATEGORY_DAMAGE)
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e2:SetCode(EVENT_BATTLE_DESTROYED)
	e2:SetRange(LOCATION_MZONE)
	e2:SetProperty(EFFECT_FLAG_DELAY)
	e2:SetCountLimit(1,id)
	e2:SetCondition(s.damcon1)
	e2:SetTarget(s.damtg)
	e2:SetOperation(s.damop)
	c:RegisterEffect(e2)
	local e3=e2:Clone()
	e3:SetCode(EVENT_TO_GRAVE)
	e3:SetCondition(s.damcon2)
	c:RegisterEffect(e3)
end
function s.desfilter(c)
	return c:IsFaceup() and c:IsRace(RACE_MACHINE) and c:IsAttribute(ATTRIBUTE_DARK)
end
function s.destg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return false end
	if chk==0 then return Duel.IsExistingTarget(s.desfilter,tp,LOCATION_MZONE,0,1,nil)
		and Duel.IsExistingTarget(Card.IsFaceup,tp,0,LOCATION_ONFIELD,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_DESTROY)
	local g1=Duel.SelectTarget(tp,s.desfilter,tp,LOCATION_MZONE,0,1,1,nil)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_DESTROY)
	local g2=Duel.SelectTarget(tp,Card.IsFaceup,tp,0,LOCATION_ONFIELD,1,1,nil)
	g1:Merge(g2)
	Duel.SetOperationInfo(0,CATEGORY_DESTROY,g1,2,0,0)
end
function s.desop(e,tp,eg,ep,ev,re,r,rp)
	local tg=Duel.GetTargetCards(e)
	if #tg>0 then
		Duel.Destroy(tg,REASON_EFFECT)
	end
end
function s.damcon1(e,tp,eg,ep,ev,re,r,rp)
	local tc=eg:GetFirst()
	local bc=tc:GetBattleTarget()
	return not tc:IsPreviousControler(tp) and tc:IsLocation(LOCATION_GRAVE) and tc:GetTextAttack()>0
		and bc:IsControler(tp) and bc:GetOriginalAttribute()==ATTRIBUTE_DARK and bc:GetOriginalRace()==RACE_MACHINE
end
function s.damfilter1(c,tp)
	return c:IsMonster() and c:GetTextAttack()>0 and c:IsReason(REASON_EFFECT)
		and c:IsReason(REASON_DESTROY) and c:IsLocation(LOCATION_GRAVE) and not c:IsPreviousControler(tp)
end
function s.damcon2(e,tp,eg,ep,ev,re,r,rp)
	if not re then return false end
	local rc=re:GetHandler()
	return rc:IsControler(tp) and rc:GetOriginalAttribute()==ATTRIBUTE_DARK
		and rc:GetOriginalRace()==RACE_MACHINE
		and eg:IsExists(s.damfilter1,1,nil,tp)
end
function s.damtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetOperationInfo(0,CATEGORY_DAMAGE,nil,0,1-tp,0)
end
function s.damfilter2(c,tp)
	return c:IsReason(REASON_BATTLE|REASON_EFFECT) and c:IsReason(REASON_DESTROY)
		and c:GetTextAttack()>0 and c:IsLocation(LOCATION_GRAVE) and not c:IsPreviousControler(tp)
end
function s.damop(e,tp,eg,ep,ev,re,r,rp)
	local g=eg:Filter(s.damfilter2,nil,tp)
	if #g>0 then
		if #g>1 then
			Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SELECT)
			g=g:Select(tp,1,1,nil)
		end
		Duel.Damage(1-tp,math.ceil(g:GetFirst():GetBaseAttack()/2),REASON_EFFECT)
	end
end