Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
During your Main Phase, you can Normal Summon 1 "Starry Knight" monster, or 1 Level 7 LIGHT Dragon monster, in addition to your Normal Summon/Set. (You can only gain this effect once per turn.) During your turn, if a face-up Level 7 LIGHT Dragon monster you control returns to the hand: You can draw 1 card. You can only use this effect of "Starry Knight Sky" once per turn.
--煌めく聖夜
--Starry Knight Sky
--Scripted by The Razgriz
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)
	--Additional Normal summon
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetCode(EFFECT_EXTRA_SUMMON_COUNT)
	e2:SetRange(LOCATION_FZONE)
	e2:SetTargetRange(LOCATION_HAND|LOCATION_MZONE,0)
	e2:SetTarget(s.extg)
	c:RegisterEffect(e2)
	--Draw if a Level 7 Dragon monster(s) returns to hand
	local e3=Effect.CreateEffect(c)
	e3:SetCategory(CATEGORY_DRAW)
	e3:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e3:SetCode(EVENT_TO_HAND)
	e3:SetRange(LOCATION_FZONE)
	e3:SetProperty(EFFECT_FLAG_DELAY+EFFECT_FLAG_PLAYER_TARGET)
	e3:SetCountLimit(1,id)
	e3:SetCondition(s.dcon)
	e3:SetTarget(s.dtg)
	e3:SetOperation(s.dop)
	c:RegisterEffect(e3)
end
s.listed_series={SET_STARRY_KNIGHT}
function s.ldlv7filter(c)
	return c:IsAttribute(ATTRIBUTE_LIGHT) and c:IsRace(RACE_DRAGON) and c:IsLevel(7)
end
function s.extg(e,c)
	return (c:IsSetCard(SET_STARRY_KNIGHT) and c:IsMonster()) or s.ldlv7filter(c)
end
function s.filter(c,tp)
	return c:IsControler(tp) and c:IsPreviousLocation(LOCATION_MZONE) and s.ldlv7filter(c)
end
function s.dcon(e,tp,eg,ev,ep,re,r,rp)
	return Duel.IsTurnPlayer(tp) and eg:IsExists(s.filter,1,nil,tp)
end
function s.dtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsPlayerCanDraw(tp,1) end
	Duel.SetTargetPlayer(tp)
	Duel.SetTargetParam(1)
	Duel.SetOperationInfo(0,CATEGORY_DRAW,nil,0,tp,1)
end
function s.dop(e,tp,eg,ep,ev,re,r,rp)
	local p,d=Duel.GetChainInfo(0,CHAININFO_TARGET_PLAYER,CHAININFO_TARGET_PARAM)
	Duel.Draw(p,d,REASON_EFFECT)
end