künstlicher Sonnenaufgang mit OpenHAB, Kalender und Hue

/**
 * Weekly Profiles / Wake-up Light Automation
 */
const { rules, triggers, items, time } = require("openhab");

// Configuration
const STEP_TIME = 2;        // Minutes (Tolerance window for manual intervention)
const SUNRISE_TIME = 30;    // Minutes (Total duration of the fade-in process)
const MAX_VALUE = 60;       // % (Maximum brightness target)

rules.JSRule({
  name: "Weekly Profile Sunrise Math",
  description: "Calculates brightness based on calendar event (sunrise simulation)",
  triggers: [triggers.GenericCronTrigger("0 0/2 * * * ?")], // Every 2 minutes
  execute: (event) => {
    const startItem = items.getItem("KalenderWecken_CurrentEventStart");
    
    // Check if a valid start time is set
    if (startItem.state === "NULL" || startItem.state === "UNDEF") {
      return;
    }

    // Time Calculation
    // time.toZDT() automatically uses the system timezone and parses the item state string
    const now = time.toZDT();
    const eventStarted = time.toZDT(startItem.state);

    // Calculate time difference
    // Using epoch milliseconds to determine the elapsed time since the event started
    const diffMillis = now.toInstant().toEpochMilli() - eventStarted.toInstant().toEpochMilli();
    const diffSec = diffMillis / 1000.0;
    const diffMin = diffSec / 60.0;

    // Calculate the slope (dimming rate)
    const stepPerMin = MAX_VALUE / SUNRISE_TIME;

    // Calculate the target setpoint
    let setpoint = diffMin * stepPerMin;
    if (setpoint > MAX_VALUE) {
      setpoint = MAX_VALUE;
    }

    // Calculate the lower bound (tolerance threshold)
    let setpointLow = (diffMin - STEP_TIME) * stepPerMin;
    if (setpointLow < 0) {
      setpointLow = 0;
    }

    // Get current light status
    const lightItem = items.getItem("SchlafzimmerRoom_Helligkeit");
    let actualValue = parseFloat(lightItem.state);
    
    // Default to 0 if the light is off or the state is unknown
    if (isNaN(actualValue)) { 
        actualValue = 0; 
    }

    // Logic Check
    // Only send a command if the current brightness is below the calculated setpoint 
    // but still above the lower threshold. This prevents the automation from 
    // dimming the light back down if it was manually set to a higher value (e.g., 100%).
    if (actualValue >= setpointLow && actualValue < setpoint) {
      // Use Math.round for clean integer values when sending the command
      lightItem.sendCommand(Math.round(setpoint).toString());
    }
  }
});

rules.JSRule({
  name: "Weekly Profile Off",
  description: "Turns off the light when the calendar event ends",
  triggers: [triggers.ItemStateChangeTrigger("KalenderWecken_CurrentEventPresence", null, "OFF")],
  execute: (event) => {
    items.getItem("SchlafzimmerRoom_Helligkeit").sendCommand("0");
  }
});