--清浄の蛇姫
--Snake Princess of Purity
--scripted by YoshiDuels
local s,id=GetID()
function s.initial_effect(c)
	--Reduce ATK
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_ATKCHANGE+CATEGORY_DRAW)
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCountLimit(1)
	e1:SetCost(s.cost)
	e1:SetTarget(s.target)
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
end
function s.cost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsPlayerCanDiscardDeckAsCost(tp,1) end
end
function s.filter(c)
	return c:IsFaceup() and c:IsNotMaximumModeSide()
end
function s.cfilter(c)
	return c:IsFaceup() and c:IsAttribute(ATTRIBUTE_LIGHT)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(s.filter,tp,0,LOCATION_MZONE,1,nil)
		and Duel.IsExistingMatchingCard(s.cfilter,tp,LOCATION_MZONE,0,1,nil) end
	Duel.SetOperationInfo(0,CATEGORY_ATKCHANGE,nil,1,tp,-600)
	Duel.SetPossibleOperationInfo(0,CATEGORY_DRAW,nil,1,tp,-600)
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	--Requirement
	if Duel.DiscardDeck(tp,1,REASON_COST)<1 then return end
	--Effect
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_ATKDEF)
	local g=Duel.SelectMatchingCard(tp,s.filter,tp,0,LOCATION_MZONE,1,1,nil)
	local atk=Duel.GetMatchingGroupCount(s.cfilter,tp,LOCATION_MZONE,0,nil)
	if #g>0 then
		Duel.HintSelection(g,true)
		local e1=Effect.CreateEffect(c)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_UPDATE_ATTACK)
		e1:SetValue(atk*-600)
		e1:SetReset(RESETS_STANDARD_PHASE_END)
		g:GetFirst():RegisterEffect(e1)
		local sg=Duel.GetMatchingGroup(s.filter,tp,LOCATION_MZONE,0,nil)
		if #sg==3 then
			Duel.Draw(tp,1,REASON_EFFECT)
		end
	end
end