Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
This card can only be activated during Main Phase 1. Select 1 face-up monster on the field. Each time the selected monster inflicts Battle Damage to your opponent's Life Points this turn, your opponent discards 1 random card.
--盗賊の極意
--The Secret of the Bandit
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_MZONE) and chkc:IsFaceup() end
	if chk==0 then return Duel.IsPhase(PHASE_MAIN1)
		and Duel.IsExistingTarget(Card.IsFaceup,tp,LOCATION_MZONE,LOCATION_MZONE,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_FACEUP)
	Duel.SelectTarget(tp,Card.IsFaceup,tp,LOCATION_MZONE,LOCATION_MZONE,1,1,nil)
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc:IsRelateToEffect(e) and tc:IsFaceup() and not tc:IsImmuneToEffect(e) and tc:GetFlagEffect(id)==0 then
		tc:RegisterFlagEffect(id,RESETS_STANDARD_PHASE_END,0,1)
		local e1=Effect.CreateEffect(e:GetHandler())
		e1:SetDescription(aux.Stringid(id,0))
		e1:SetCategory(CATEGORY_HANDES)
		e1:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_F)
		e1:SetCode(EVENT_BATTLE_DAMAGE)
		e1:SetLabelObject(tc)
		e1:SetCondition(s.hdcon)
		e1:SetTarget(s.hdtg)
		e1:SetOperation(s.hdop)
		e1:SetReset(RESET_PHASE|PHASE_END)
		Duel.RegisterEffect(e1,tp)
	end
end
function s.hdcon(e,tp,eg,ep,ev,re,r,rp)
	return ep==1-tp and eg:GetFirst()==e:GetLabelObject() and eg:GetFirst():GetFlagEffect(id)~=0
end
function s.hdtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetOperationInfo(0,CATEGORY_HANDES,nil,0,tp,1)
end
function s.hdop(e,tp,eg,ep,ev,re,r,rp)
	local g=Duel.GetFieldGroup(tp,0,LOCATION_HAND):RandomSelect(tp,1)
	Duel.SendtoGrave(g,REASON_EFFECT+REASON_COST)
end