Sunrise for Hue lamp

Setup, Configuration and Use Scripts & Rules
1

Hi,
I’ve made some rules for simulating sunrise in the morning which I’d like to use in wake-up routine. The sunrise is triggered by a switch and can be cancelled by switching off. I use HomeKit to automate the daily wake-up so the switch is simply exposed in HomeKit.
Below is the items file:

Color Bedroom_lamp "Bedroom Ceiling Lamp" <colorwheel> { channel="hue:xxxx:xxxxxxxx:2:color" }
Switch Sunrise_switch "Bedroom Sunrise" {homekit="Switchable"}
String Sunrise_next

Below is the rules:

// Rules
var Timer timer = null
var HSBType initial = new HSBType(new DecimalType(0),new PercentType(100),new PercentType(2))

rule "Startup"
when
    System started
then
    logInfo("Info", "Hue: System started")
    Sunrise_switch.sendCommand(OFF)
end

rule "Start sunrise"
 when 
  Item Sunrise_switch changed from OFF to ON
 then
  var hsb = Bedroom_lamp.state as HSBType
  var DecimalType brightness = new DecimalType(hsb.brightness.intValue)
  logInfo("Info", "Hue: Sunrise switch turned on when the lamp has brightness "+ brightness)
  if (brightness == 0) {
    // set a timer to sligtly change the color again and again
    timer = createTimer(now, [|
      Sunrise_next.sendCommand(now.toString)
      if (timer !== null) {
        timer.reschedule(now.plusSeconds(30))
      }
    ])      
  }
  else {
    Sunrise_switch.sendCommand(OFF)
  }
end

rule "Continue sunrise"
  when 
    Item Sunrise_next changed
  then
    if (Sunrise_switch.state == ON) {
      // get your current color
      var hsb = Bedroom_lamp.state as HSBType
      // if current brightness is 0, turn on the lamp with initial colour
      if (new DecimalType(hsb.brightness.intValue) == 0){
        logInfo("Info", "Hue: Turn on the lamp and set the initial colour "+initial)
        Bedroom_lamp.send(initial)
      }
      else {
        // change it a little bit
        var DecimalType hue = new DecimalType(hsb.hue.intValue + 1) // 0-360; 0=red, 120=green, 240=blue, 360=red(again)
        if(new DecimalType(hsb.hue.intValue) >= 35){
          hue = new DecimalType(35)
        }
        var PercentType sat = new PercentType(hsb.saturation.intValue -1) // 0-100
        var PercentType bright = new PercentType(hsb.brightness.intValue + 2) // 0-100
        var HSBType newHsb = new HSBType(hue,sat,bright)
        if (hsb.brightness.intValue < 90){
          // set the new color    
          logInfo("Info", "Hue: Sending command to the light " + newHsb)
          Bedroom_lamp.send(newHsb)
        }
        else {
          logInfo("Info", "Hue: Reach birghtness 90, cancel the timer")
          Sunrise_switch.sendCommand(OFF)
        }
      }
    } 
    else {
      if (timer !== null) {
        timer.cancel()
      }
      timer = null
  } 
end

rule "Cancel sunrise"
 when 
  Item Sunrise_switch changed from ON to OFF
 then
    logInfo("Info", "Hue: Sunrise switch turned off")
    if (timer !== null) {
      timer.cancel()
    }
    timer = null
    //Bedroom_lamp.sendCommand(OFF)  
end

It kind of works but I have a few questions:

  1. Is the script optimal? Particularly I’d like to avoid running the rules in parallel, so am I doing things correctly?
  2. Is it correct to cancel the timer by " timer.cancel()"?
  3. For settings the values, I can’t seem to use float numbers, for example var DecimalType hue = new DecimalType(hsb.hue.intValue + 0.5) doesn’t work. Does Hue only support integers? If so how can I increment “hue” value by 1 for every 2nd iteration?

Any suggestion is appreciated!