Phone message when the power comes back, with how long it was off

1// Power outage report: when the power comes back, sends your phone a message through2// ntfy saying how long it was off. Runs on any Gen2 or newer Shelly on mains power.3 4let CONFIG = {5  ntfyTopic: "",6  placeName: "Home",7  minOffMin: 1,8};9 10// The Shelly notes the time on its own storage every 5 minutes. When it starts11// again, the power went off at some point in the 5 minutes after the last note.12let NOTE_EVERY_MIN = 5;13// Only a start this soon after power-up counts as the power coming back, so14// pressing Run by hand later doesn't send a report.15let BOOT_WINDOW_SEC = 300;16// After a blackout the modem is often still starting, so keep trying to send17// once a minute for up to two hours.18let RETRY_SEC = 60;19let MAX_TRIES = 120;20let KVS_KEY = "outage-note";21 22// Seconds since power-up when the script started.23let startedAt = Shelly.getComponentStatus("sys").uptime;24let message = "";25let tries = 0;26let clockTimer = null;27 28function clock() {29  let s = Shelly.getComponentStatus("sys");30  if (s === null || typeof s.unixtime !== "number" || s.time === null) return null;31  return s;32}33 34function note() {35  let s = clock();36  if (s === null) return;37  Shelly.call("KVS.Set", { key: KVS_KEY, value: JSON.stringify(s.unixtime) });38}39 40function onSent(res, err) {41  if (err === 0 && res.code === 200) {42    print("Report sent.");43    return;44  }45  tries++;46  if (tries >= MAX_TRIES) {47    print("Couldn't reach ntfy for two hours. Giving up on this report.");48    return;49  }50  Timer.set(RETRY_SEC * 1000, false, send);51}52 53function send() {54  if (CONFIG.ntfyTopic === "") return;55  Shelly.call("HTTP.Request", {56    method: "POST",57    url: "https://ntfy.sh/" + CONFIG.ntfyTopic,58    body: message,59    headers: { "Content-Type": "text/plain" },60    timeout: 15,61  }, onSent);62}63 64function report(lastNote, s) {65  let bootAt = s.unixtime - s.uptime;66  let longest = Math.ceil((bootAt - lastNote) / 60);67  let shortest = Math.max(0, longest - NOTE_EVERY_MIN);68  // Report only an outage known to be at least minOffMin long, so a restart69  // for a firmware update doesn't send a message.70  if (shortest < CONFIG.minOffMin) {71    print("Off for up to " + longest + " min, which may have been a restart. No report.");72    return;73  }74  message = "Power is back at " + CONFIG.placeName + " (" + s.time + "). It was off for " +75    shortest + " to " + longest + " min.";76  print(message);77  send();78}79 80function onNote(res, err) {81  let s = clock();82  let last = null;83  if (err === 0 && res && typeof res.value === "string") {84    try {85      let n = JSON.parse(res.value);86      if (typeof n === "number") last = n;87    } catch (e) {88      last = null;89    }90  }91  if (last === null) print("No earlier note found, so nothing to report this time.");92  else report(last, s);93  note();94  Timer.set(NOTE_EVERY_MIN * 60 * 1000, true, note);95}96 97function waitForClock() {98  let s = clock();99  if (s === null) return;100  Timer.clear(clockTimer);101  if (startedAt > BOOT_WINDOW_SEC) {102    print("Started by hand, not by a power-up. Watching from now.");103    note();104    Timer.set(NOTE_EVERY_MIN * 60 * 1000, true, note);105    return;106  }107  Shelly.call("KVS.Get", { key: KVS_KEY }, onNote);108}109 110print("Outage report started. Waiting for the clock.");111// It can't time anything until the clock has synced, so it checks every 10 s.112clockTimer = Timer.set(10 * 1000, true, waitForClock);113waitForClock();