Cap how many hours a heater or pump runs each day

1// Daily run limit: adds up how long a relay has been on since midnight and switches2// it off for the rest of the day once your allowance is used. Needs a Shelly relay.3 4let CONFIG = {5  maxHours: 4,6  switchId: 0,7};8 9// How often the on-time is added up. The relay goes off within this long of the limit.10let TICK_SEC = 10;11// Save the count every few minutes rather than every tick, to spare the flash memory.12let SAVE_EVERY_SEC = 300;13let KVS_KEY = "daily-run-limit";14 15// The local date and the seconds the relay has been on so far that day. Saved,16// so a restart mid-day doesn't reset the allowance.17let day = { date: -1, onSec: 0 };18let lastUptime = -1;19let sinceSave = 0;20let limitHit = false;21 22function localDate() {23  let s = Shelly.getComponentStatus("sys");24  if (s === null || typeof s.unixtime !== "number" || s.time === null) return -1;25  return Math.floor((s.unixtime + (s.utc_offset || 0)) / 86400);26}27 28function isOn() {29  let s = Shelly.getComponentStatus("switch", CONFIG.switchId);30  return s !== null && s.output === true;31}32 33function save() {34  sinceSave = 0;35  Shelly.call("KVS.Set", { key: KVS_KEY, value: JSON.stringify(day) });36}37 38function hours(sec) {39  return (sec / 3600).toFixed(1);40}41 42function switchOff() {43  Shelly.call("Switch.Set", { id: CONFIG.switchId, on: false });44}45 46function tick() {47  let up = Shelly.getComponentStatus("sys").uptime;48  let step = lastUptime < 0 ? 0 : up - lastUptime;49  lastUptime = up;50  let date = localDate();51  // Without the clock it can't tell when the day starts, so it doesn't count or switch.52  if (date === -1) return;53  if (day.date !== date) {54    if (day.date === date - 1) print("Yesterday's run time: " + hours(day.onSec) + " h.");55    day = { date: date, onSec: 0 };56    limitHit = false;57    save();58    print("New day. Allowance of " + CONFIG.maxHours + " h.");59  }60  if (isOn()) {61    day.onSec += step;62    sinceSave += step;63  }64  if (sinceSave >= SAVE_EVERY_SEC) save();65  if (day.onSec >= CONFIG.maxHours * 3600 && !limitHit) {66    limitHit = true;67    save();68    print("Used today's " + CONFIG.maxHours + " h. Off until midnight.");69  }70  if (limitHit && isOn()) switchOff();71}72 73// Turned back on after the limit, from the app, a schedule or a switch: off it goes.74function onStatus(ev) {75  if (ev.component !== "switch:" + CONFIG.switchId) return;76  if (!limitHit || ev.delta.output !== true) return;77  print("Today's allowance is used, so switching it back off.");78  switchOff();79}80 81function start() {82  Timer.set(TICK_SEC * 1000, true, tick);83  Shelly.addStatusHandler(onStatus);84  print("Daily run limit started. " + CONFIG.maxHours + " h a day, " + hours(day.onSec) +85    " h used so far today.");86  tick();87}88 89function onLoaded(res, err) {90  if (err === 0 && res && typeof res.value === "string") {91    try {92      let saved = JSON.parse(res.value);93      if (typeof saved.date === "number") day = saved;94    } catch (e) {95      print("Couldn't read the saved count. Starting from zero.");96    }97  }98  start();99}100 101Shelly.call("KVS.Get", { key: KVS_KEY }, onLoaded);