Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
This card can attack your opponent directly, but when it uses this effect, any battle damage it inflicts to your opponent is halved. If this face-up card is destroyed in a Monster Zone, you can place it face-up in your Spell & Trap Zone as a Continuous Spell, instead of sending it to the GY.
--宝玉獣 アメジスト・キャット
--Crystal Beast Amethyst Cat
local s,id=GetID()
function s.initial_effect(c)
	--Place itself in the S/T zone
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_TO_GRAVE_REDIRECT_CB)
	e1:SetProperty(EFFECT_FLAG_UNCOPYABLE)
	e1:SetCondition(s.repcon)
	e1:SetOperation(s.repop)
	c:RegisterEffect(e1)
	--Direct attack
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_SINGLE)
	e2:SetCode(EFFECT_DIRECT_ATTACK)
	c:RegisterEffect(e2)
	--Reduce damage
	local e3=Effect.CreateEffect(c)
	e3:SetType(EFFECT_TYPE_SINGLE)
	e3:SetCode(EFFECT_CHANGE_BATTLE_DAMAGE)
	e3:SetCondition(s.rdcon)
	e3:SetValue(aux.ChangeBattleDamage(1,HALF_DAMAGE))
	c:RegisterEffect(e3)
end
function s.repcon(e)
	local c=e:GetHandler()
	return c:IsFaceup() and c:IsLocation(LOCATION_MZONE) and c:IsReason(REASON_DESTROY)
end
function s.repop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local e1=Effect.CreateEffect(c)
	e1:SetCode(EFFECT_CHANGE_TYPE)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE)
	e1:SetReset(RESET_EVENT|RESETS_STANDARD&~RESET_TURN_SET)
	e1:SetValue(TYPE_SPELL+TYPE_CONTINUOUS)
	c:RegisterEffect(e1)
	Duel.RaiseEvent(c,EVENT_CUSTOM+CARD_CRYSTAL_TREE,e,0,tp,0,0)
end
function s.rdcon(e)
	local c,tp=e:GetHandler(),e:GetHandlerPlayer()
	return Duel.GetAttackTarget()==nil and c:GetEffectCount(EFFECT_DIRECT_ATTACK)<2
		and Duel.GetFieldGroupCount(tp,0,LOCATION_MZONE)>0
end