more buggy codes

diff --git a/core.lua b/core.lua
index 2a4c265..6eb7fe5 100644
--- a/core.lua
+++ b/core.lua
@@ -12,6 +12,7 @@ local defaults = {
     },
 }

+
 SATimer.all = {}
 SATimer.unused = {}
 SATimer.using = {}
@@ -35,30 +36,100 @@ function SATimer:OnSAOFEvent(_, event, ...)
 end

 function SATimer:SPELL_ACTIVATION_OVERLAY_SHOW(spellID, texture, position, scale, r, g, b)
+    local f = self:Get(spellID)
+    local endTime = self:GetTimeLeft(spellID)
+
+    if(endTime) then
+        -- XXX
+        if(not f) then
+            f = self:GetUnused()
+            self:SetUsing(f)
+        end
+        f.spellID = spellID
+        f.position = position
+        f.scale = scale
+        f.r = r
+        f.g = g
+        f.b = b
+
+        self:Update(f)
+        self:UpdateTimers()
+    else
+        if(f) then
+            self:Remove(f)
+        end
+    end
+
 end

 function SATimer:SPELL_ACTIVATION_OVERLAY_HIDE(spellID)
     local f = self:Get(spellID)
     if(f) then
         self:Remove(f)
+        self:UpdateTimers()
+    end
+end
+
+function SATimer:UpdateTimers()
+end
+
+do
+    local _SPELLS = setmetatable({}, {__index=function(t,i)
+        local n = GetSpellInfo(i)
+        rawset(t, i, n)
+        return n
+    end})
+    function SATimer:GetTimeLeft(spellID)
+        local spell = _SPELLS[spellID]
+        if(not spell) then return end
+
+        local name, _, _, duration, expiration, caster = UnitAura('player', spell, 'PLAYER')
+        if(name and duration>0 and expiration>GetTime()) then
+            return expiration
+        end
     end
 end

-function SATimer:Update(spellID, texture, position, scale, r, g, b)
+function SATimer:Update(f)
 end

 function SATimer:Remove(f)
     f:Hide()
     f:SetScript('OnUpdate', nil)
+    self:SetUnused(f)
+end
+
+function SATimer:SetUsing(f)
+    self.using[f] = true
+    self.unused[f] = nil
+end
+
+function SATimer:SetUnused(f)
     self.using[f] = nil
     self.unused[f] = true
 end

-function SATimer:Get(spellID, position)
+function SATimer:Get(spellID)
     for f in next, self.using do
-        if(f.spellID == spellID and (position and f.position == position or true)) then
+        if(f.spellID == spellID) then
             return f
         end
     end
 end

+function SATimer:GetUnused()
+    local f = next(self.unused)
+    if(not f) then
+        f = self:CreateTimer()
+    end
+
+    return f
+end
+
+function SATimer:CreateTimer()
+    local f = CreateFrame('Frame', nil, 'SpellActivationOverlayFrame')
+    self:SetUnused(f)
+
+    return f
+end
+