Hammerspoon config for Klipper menubar monitor

init.lua

--------------------------------------------------
-- Klipper menubar monitor
--------------------------------------------------
local SERVER_IP = "192.168.31.76"
local MOONRAKER_PORT = 7125
local FLUIDD_PORT = 80
local MOONRAKER_URL = "http://" .. SERVER_IP .. ":" .. MOONRAKER_PORT .. "/printer/objects/query?virtual_sdcard&print_stats"
local FLUIDD_URL = "http://" .. SERVER_IP .. ":" .. FLUIDD_PORT .. "/"

local REFRESH_SECONDS = 5
local REQUEST_TIMEOUT = 4
local STALE_AFTER = 15

local menubar = hs.menubar.new()
menubar:setTitle("…")

--------------------------------------------------
-- State
--------------------------------------------------
local requestInFlight = false
local lastSuccessTime = 0
local watchdogTimer = nil

--------------------------------------------------
-- Utils
--------------------------------------------------
local function secondsToHhMm(seconds)
    local h = math.floor(seconds / 3600)
    local m = math.floor((seconds % 3600) / 60)
    return string.format("%dh %dm", h, m)
end

local function setDisconnected()
    menubar:setTitle("Disconnected")
end

--------------------------------------------------
-- Core update function
--------------------------------------------------
local function updateKlipperStatus()
    if requestInFlight then return end
    requestInFlight = true

    local requestFinished = false

    -- Watchdog for hung requests
    if watchdogTimer then watchdogTimer:stop() end
    watchdogTimer = hs.timer.doAfter(REQUEST_TIMEOUT, function()
        if not requestFinished then
            requestInFlight = false
            setDisconnected()
        end
    end)

    hs.http.asyncGet(MOONRAKER_URL, nil, function(status, body)
        requestFinished = true
        requestInFlight = false
        if watchdogTimer then watchdogTimer:stop() end

        if status ~= 200 or not body then
            setDisconnected()
            return
        end

        local data = hs.json.decode(body)
        if not data or not data.result or not data.result.status then
            setDisconnected()
            return
        end

        local ps = data.result.status.print_stats
        local vsd = data.result.status.virtual_sdcard

        lastSuccessTime = os.time()

        if not ps or ps.state ~= "printing" or not vsd or not vsd.progress then
            menubar:setTitle("Printer is idle")
            return
        end

        local elapsed = ps.print_duration or 0
        local progress = vsd.progress

        if progress <= 0 then
            menubar:setTitle("Printer is idle")
            return
        end

        local total = elapsed / progress
        local remaining = math.max(0, total - elapsed)

        local progressInPercent = math.floor(progress * 100)

        menubar:setTitle("Printing " .. progressInPercent .. "%" ..", " .. secondsToHhMm(remaining) .. " left" )
    end)
end

--------------------------------------------------
-- Stale connection monitor
--------------------------------------------------
local function staleCheck()
    if lastSuccessTime == 0 then return end
    if os.difftime(os.time(), lastSuccessTime) > STALE_AFTER then
        setDisconnected()
    end
end

--------------------------------------------------
-- Menu
--------------------------------------------------
menubar:setMenu({
    { title = "Open dashboard", fn = function()
        hs.urlevent.openURL(FLUIDD_URL)
    end },
    { title = "Refresh", fn = updateKlipperStatus }
})

--------------------------------------------------
-- Timers (strong references)
--------------------------------------------------
klipperPollTimer = hs.timer.doEvery(REFRESH_SECONDS, updateKlipperStatus)
klipperStaleTimer = hs.timer.doEvery(REFRESH_SECONDS, staleCheck)

--------------------------------------------------
-- Initial run
--------------------------------------------------
updateKlipperStatus()