--ツーヘッド・シャーク
--Double Shark
local s,id=GetID()
function s.initial_effect(c)
	--lvup
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_O)
	e1:SetCode(EVENT_SUMMON_SUCCESS)
	e1:SetTarget(s.lvtg)
	e1:SetOperation(s.lvop)
	c:RegisterEffect(e1)
	--attack twice
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_SINGLE)
	e2:SetCode(EFFECT_EXTRA_ATTACK)
	e2:SetValue(1)
	c:RegisterEffect(e2)
end
function s.filter(c)
	return c:IsFaceup() and c:GetLevel()==4 and c:IsRace(RACE_FISH)
end
function s.lvtg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(s.filter,tp,LOCATION_MZONE,0,1,nil) end
end
function s.lvop(e,tp,eg,ep,ev,re,r,rp)
	local g=Duel.GetMatchingGroup(s.filter,tp,LOCATION_MZONE,0,nil)
	local tc=g:GetFirst()
	for tc in aux.Next(g) do
		local e1=Effect.CreateEffect(e:GetHandler())
		e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_UPDATE_LEVEL)
		e1:SetValue(-1)
		e1:SetReset(RESET_EVENT|RESETS_STANDARD)
		tc:RegisterEffect(e1)
	end
end