REBOOT on very long button down

let CONFIG = {
    defaultTickerDelay   : 0.500, // secs for checking state
    defaultLongPressTime : 20.000 // secs before reboot
};

let debug = true;  // TRUE for print to console, false by default

let btn_down_ts = 0;
let buttonHandle = 0;

function checkButton (ts)
{
    if (debug) { print("checkButton ", ts); }
    let btn_down_duration = ts - btn_down_ts;
    if (debug) { print ("Button down for ", btn_down_duration  , " ( ", ts, " - ", btn_down_ts, " )"); }
    if (btn_down_duration > CONFIG.defaultLongPressTime)
    {
        if (debug) { print ("Long press detected - REBOOT"); }
        Shelly.call("Shelly.Reboot", null, null);
    } else
    {
        buttonHandle = Timer.set(CONFIG.defaultTickerDelay*1000,false,checkButton,ts + CONFIG.defaultTickerDelay); // restart timer on new ts
    }
}

function Check(event){
    let info = event.info;
    if (debug) { print(JSON.stringify(info));}
   
    if (info.component === "input:0")
    {     
        if (info.event === "btn_up")
        {
          if (buttonHandle !== 0) {Timer.clear(buttonHandle);}
        } 
        else if (info.event === "btn_down")
        {
            btn_down_ts = info.ts;
            buttonHandle = Timer.set(CONFIG.defaultTickerDelay*1000,false,checkButton,info.ts + CONFIG.defaultTickerDelay);
               if (debug) { print ("button down now: ", info.ts); }
        } 
    }
}

Shelly.addEventHandler(Check);