time/trigger script with diming over time

[Habib]

Hi,

I want to realize based on the timer script example following function:

-the offstate is an minimum brightness level of e.g. 25% (should be adjustable with an external object)
-maximum (on state) brightness level of e.g. 90% (should be adjustable with an external object)
-time should be adjustable with an external object
-during the time counts down, each X seconds the light dims down -10% until it's on the minimum level 
-the whole function can be switch off (0% brightness)

My customer would like to illuminate an show room. The base illumination should be a brightness level of 50%. If somebody walks through the presentation the light triggers up to 95% until X seconds the motion sensors don't triggers motion again and dims the brightness level down to the default brightness of 50%.

At end of working day he completly switchs off the whole light.

Has somebody already realized such a function?
How it's the best way to handle such scripts. resident script or event based? I want to use it for up to 16 Light Circles...

Thank you forwards for any help :-)

Code:

-- maximum time that object can be on, in seconds
ontime = 4 * 60 * 60

-- current timestamp, in seconds
now = os.time()

-- get all objects with AutoOff tag
objects = grp.tag('AutoOff')

-- check all objects
for _, object in ipairs(objects) do
  -- object is on
  if toboolean(object.data) then
    delta = now - object.updatetime

    -- timer expired, turn off 
    if delta >= ontime then
      object:write(0)
    end
  end
end