Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
While you control a Spellcaster-Type monster, any damage you take is halved. (You cannot halve the same damage twice this way.) If this card is sent from the field to the Graveyard: You can target 1 Spellcaster-Type monster in your Graveyard; Special Summon it.
--マジシャンズ・プロテクション
--Magicians' Defense
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	c:RegisterEffect(e1)
	--Halve damage
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetRange(LOCATION_SZONE)
	e2:SetCode(EFFECT_CHANGE_DAMAGE)
	e2:SetProperty(EFFECT_FLAG_PLAYER_TARGET)
	e2:SetTargetRange(1,0)
	e2:SetCondition(s.condition)
	e2:SetValue(s.val)
	c:RegisterEffect(e2)
	--Special Summon
	local e4=Effect.CreateEffect(c)
	e4:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e4:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e4:SetCode(EVENT_TO_GRAVE)
	e4:SetProperty(EFFECT_FLAG_CARD_TARGET+EFFECT_FLAG_DELAY)
	e4:SetCondition(s.spcon)
	e4:SetTarget(s.sptg)
	e4:SetOperation(s.spop)
	c:RegisterEffect(e4)
end
function s.condition(e)
	return Duel.IsExistingMatchingCard(aux.FaceupFilter(Card.IsRace,RACE_SPELLCASTER),e:GetHandlerPlayer(),LOCATION_MZONE,0,1,nil)
end
function s.val(e,re,dam,r,rp,rc)
	return math.floor(dam/2)
end
function s.spcon(e,tp,eg,ep,ev,re,r,rp)
	return e:GetHandler():IsPreviousLocation(LOCATION_ONFIELD)
end
function s.spfilter(c,e,tp)
	return c:IsRace(RACE_SPELLCASTER) and c:IsCanBeSpecialSummoned(e,0,tp,false,false)
end
function s.sptg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsLocation(LOCATION_GRAVE) and chkc:IsControler(tp) and s.spfilter(chkc,e,tp) end
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and Duel.IsExistingTarget(s.spfilter,tp,LOCATION_GRAVE,0,1,nil,e,tp) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SPSUMMON)
	local g=Duel.SelectTarget(tp,s.spfilter,tp,LOCATION_GRAVE,0,1,1,nil,e,tp)
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,g,1,0,0)
end
function s.spop(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc and tc:IsRelateToEffect(e) then
		Duel.SpecialSummon(tc,0,tp,tp,false,false,POS_FACEUP)
	end
end