Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
During the Main Phase: Immediately after this effect resolves, Normal Summon 1 Level 4 or lower Winged Beast monster. If you Tribute Summon a Level 7 or higher monster while this card is in your GY: You can banish this card; change all monsters your opponent controls to face-down Defense Position. You can only use this effect of "Floowandereeze and the Dreaming Town" once per turn.
--ふわんだりぃずと夢の町
--Floowandereeze and the Dreaming Town
--scripted by XyLeN
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_SUMMON)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetHintTiming(0,TIMING_MAIN_END)
	e1:SetCondition(s.condition)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
	--Change all Attack Position to face-down Defense Position
	local e2=Effect.CreateEffect(c)
	e2:SetCategory(CATEGORY_POSITION)
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e2:SetProperty(EFFECT_FLAG_DELAY)
	e2:SetRange(LOCATION_GRAVE)
	e2:SetCode(EVENT_SUMMON_SUCCESS)
	e2:SetCountLimit(1,id)
	e2:SetCondition(s.poscon)
	e2:SetCost(Cost.SelfBanish)
	e2:SetTarget(s.postg)
	e2:SetOperation(s.posop)
	c:RegisterEffect(e2)
end
function s.condition(e,tp,eg,ep,ev,re,r,rp)
	return Duel.IsMainPhase()
end
function s.filter(c)
	return c:IsLevelBelow(4) and c:IsRace(RACE_WINGEDBEAST) and c:IsSummonable(true,nil)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(s.filter,tp,LOCATION_HAND|LOCATION_MZONE,0,1,nil) end
	Duel.SetOperationInfo(0,CATEGORY_SUMMON,nil,1,0,0)
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SUMMON)
	local g=Duel.SelectMatchingCard(tp,s.filter,tp,LOCATION_HAND|LOCATION_MZONE,0,1,1,nil)
	if #g>0 then
		Duel.Summon(tp,g:GetFirst(),true,nil)
	end
end
function s.poscon(e,tp,eg,ep,ev,re,r,rp)
	local ec=eg:GetFirst()
	return ec:IsFaceup() and ec:IsSummonPlayer(tp) and ec:IsTributeSummoned() and ec:IsLevelAbove(7)
end
function s.posfilter(c)
	return c:IsFaceup() and c:IsCanTurnSet()
end
function s.postg(e,tp,eg,ep,ev,re,r,rp,chk)
	local g=Duel.GetMatchingGroup(s.posfilter,tp,0,LOCATION_MZONE,nil)
	if chk==0 then return #g>0 end
	Duel.SetOperationInfo(0,CATEGORY_POSITION,g,#g,0,0)
end
function s.posop(e,tp,eg,ep,ev,re,r,rp)
	local g=Duel.GetMatchingGroup(s.posfilter,tp,0,LOCATION_MZONE,nil)
	if #g>0 then
		Duel.ChangePosition(g,POS_FACEDOWN_DEFENSE)
	end
end