baticon = wibox.widget.imagebox()
baticon:set_image(beautiful.widget_battery)

function batstate()

  local file = io.open("/sys/class/power_supply/BAT0/status", "r")

  if (file == nil) then
    return "Cable plugged"
  end

  local batstate = file:read("*line")
  file:close()

  if (batstate == 'Discharging' or batstate == 'Charging') then
    return batstate
  else
    return "Fully charged"
  end
end

batwidget = wibox.widget.textbox()
vicious.register(batwidget, vicious.widgets.bat,
function (widget, args)
  -- plugged
  if (batstate() == 'Cable plugged') then
    baticon:set_image(beautiful.widget_ac)
    return ''
    -- critical
  elseif (args[2] <= 5 and batstate() == 'Discharging') then
    baticon:set_image(beautiful.widget_battery_empty)
    naughty.notify({
      text = "sto per spegnermi...",
      title = "Carica quasi esaurita!",
      position = "top_right",
      timeout = 1,
      fg="#000000",
      bg="#ffffff",
      screen = 1,
      ontop = true,
    })
    -- low
  elseif (args[2] <= 20 and batstate() == 'Discharging') then
    baticon:set_image(beautiful.widget_battery_low)
    naughty.notify({
      text = "attacca il cavo!",
      title = "Carica bassa",
      position = "top_right",
      timeout = 1,
      fg="#ffffff",
      bg="#262729",
      screen = 1,
      ontop = true,
    })
   else baticon:set_image(beautiful.widget_battery)
  end
  return gray .. "Bat " .. coldef .. white .. args[2] .. " " .. coldef
end, 1, 'BAT0')