Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
1 Plant Normal Monster If a "Sunavalon" Link Monster you control leaves the field by card effect: Destroy this card. When an attack is declared involving this card, linked to a "Sunavalon" Link Monster, and an opponent's monster: You can activate this effect; the damage you take from that battle is halved. When this card is destroyed by battle: You can activate this effect; End the Battle Phase after the Damage Step. * The above text is unofficial and describes the card's functionality in the OCG.
--聖蔓の守護者
--Sunvine Gardna
--Scripted by Eerie Code
local s,id=GetID()
function s.initial_effect(c)
	c:EnableReviveLimit()
	Link.AddProcedure(c,s.matfilter,1,1)
	--destroy
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_DESTROY)
	e1:SetProperty(EFFECT_FLAG_DAMAGE_STEP)
	e1:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_F)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCode(EVENT_LEAVE_FIELD)
	e1:SetCondition(s.descon)
	e1:SetTarget(s.destg)
	e1:SetOperation(s.desop)
	c:RegisterEffect(e1)
	--halve damage
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,1))
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e2:SetCode(EVENT_ATTACK_ANNOUNCE)
	e2:SetRange(LOCATION_MZONE)
	e2:SetCondition(s.dmgcon)
	e2:SetOperation(s.dmgop)
	c:RegisterEffect(e2)
	--bp end
	local e3=Effect.CreateEffect(c)
	e3:SetDescription(aux.Stringid(id,2))
	e3:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e3:SetCode(EVENT_BATTLE_DESTROYED)
	e3:SetOperation(s.operation)
	c:RegisterEffect(e3)
end
s.listed_series={SET_SUNAVALON}
function s.matfilter(c,lc,st,tp)
	return c:IsRace(RACE_PLANT,lc,st,tp) and c:IsType(TYPE_NORMAL,lc,st,tp)
end
function s.cfilter(c,tp,rp)
	return c:IsPreviousPosition(POS_FACEUP) and c:IsSetCard(SET_SUNAVALON) and c:IsType(TYPE_LINK) 
		and c:GetPreviousControler()==tp and c:IsReason(REASON_EFFECT)
end
function s.descon(e,tp,eg,ep,ev,re,r,rp)
	return eg:IsExists(s.cfilter,1,nil,tp,rp)
end
function s.destg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetOperationInfo(0,CATEGORY_DESTROY,e:GetHandler(),1,0,0)
end
function s.desop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsRelateToEffect(e) then
		Duel.Destroy(c,REASON_EFFECT)
	end
end
function s.dmgfilter(c,cc)
	return c:IsSetCard(SET_SUNAVALON) and c:IsType(TYPE_LINK) and c:GetLinkedGroup():IsContains(cc)
end
function s.dmgcon(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	return c:IsFaceup() and c:IsRelateToBattle() and c:GetBattleTarget()
		and Duel.IsExistingMatchingCard(s.dmgfilter,tp,LOCATION_MZONE,LOCATION_MZONE,1,nil,c)
end
function s.dmgop(e,tp,eg,ep,ev,re,r,rp)
	local e1=Effect.CreateEffect(e:GetHandler())
	e1:SetType(EFFECT_TYPE_FIELD)
	e1:SetCode(EFFECT_CHANGE_BATTLE_DAMAGE)
	e1:SetProperty(EFFECT_FLAG_PLAYER_TARGET)
	e1:SetTargetRange(1,0)
	e1:SetValue(HALF_DAMAGE)
	e1:SetReset(RESET_PHASE|PHASE_DAMAGE)
	Duel.RegisterEffect(e1,tp)
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	local e2=Effect.CreateEffect(e:GetHandler())
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_CONTINUOUS)
	e2:SetProperty(EFFECT_FLAG_CANNOT_DISABLE)
	e2:SetCode(EVENT_ADJUST)
	e2:SetOperation(s.skop)
	e2:SetReset(RESETS_STANDARD_PHASE_END)
	Duel.RegisterEffect(e2,tp)
end
function s.skop(e,tp,eg,ep,ev,re,r,rp)
	if Duel.GetCurrentPhase()~=PHASE_DAMAGE then
		local p=Duel.GetTurnPlayer()
		Duel.SkipPhase(p,PHASE_BATTLE,RESET_PHASE|PHASE_BATTLE_STEP,1)
		e:Reset()
	end
end