noctalia.setUpdateInterval(100)

function tr(key)
    return noctalia.tr(key)
end

function cfg(key)
    return noctalia.getConfig(key)
end

function getState(key)
    return noctalia.state.get(key)
end

function setState(key, val)
    noctalia.state.set(key, val)
end

function watchState(key, cb)
    noctalia.state.watch(key, cb)
end

local branch = cfg("branch")
local updateCheckInterval = cfg("check_interval")
local completedCommands = 0

local localHashCmd  = "nixos-version --hash 2> /dev/null | cut -c -7"
local remoteHashCmd = "git ls-remote https://github.com/NixOS/nixpkgs " .. branch .. " 2>/dev/null | cut -c 1-7"
local nixosGenerationsCmd = "nixos-rebuild list-generations | tail -n +2 | wc -l"
local nixosCurrentGenCmd = "nixos-rebuild list-generations | grep True | awk '{print $1}'"
local hmGenerationsCmd = "home-manager generations | wc -l"
local hmCurrentGenCmd = "home-manager generations | grep '(current)' | awk '{print $5}'"
local nixStoreSizeCmd = `du -s --block-size=1GiB /nix/store | awk '\{print $1 " GiB"\}'`
local closureSizeCmd = "nix path-info --closure-size --human-readable /run/current-system | awk '{print $2, $3}'"

setState("lastCheckTime", 0)
setState("lastCheckTimeStr", "n/a")
setState("localHash", "n/a")
setState("remoteHash", "n/a")
setState("isRunning", false)
setState("isUpdateAvailable", false)

function update()
    if (os.time() - getState("lastCheckTime")) >= 60 * updateCheckInterval then
        checkUpdate()
    end
end

function checkUpdate()
    if getState("isRunning") then
        return
    end

    setState("lastCheckTime", os.time())
    noctalia.runAsync("date", function(date) setState("lastCheckTimeStr", date.stdout) end)

    if cfg("show_checking_notification") then
        noctalia.notify(tr("notification.checking_update"))
    end

    setState("isRunning", true)

    completedCommands = 0

    noctalia.runAsync(localHashCmd, getLocalHash)
    noctalia.runStream(remoteHashCmd, getRemoteHash)
end

function getLocalHash(result)
    if getState("isRunning") ~= true then
        return
    end

    setState("localHash", result.stdout)
    completedCommands += 1
    onHashCheckCompleted()
end

function getRemoteHash(line)
    if getState("isRunning") ~= true then
        return
    end

    setState("remoteHash", line)
    completedCommands += 1
    onHashCheckCompleted()
end

function onHashCheckCompleted()
    if completedCommands < 2 then
        return
    end

    if getState("localHash") ~= getState("remoteHash") then
        setState("isUpdateAvailable", true)
        if cfg("show_update_notification") then
            noctalia.notify(tr("notification.update_is_available"))
        end
    end

    if cfg("show_checking_notification") then
        noctalia.notify(tr("notification.update_check_completed"))
    end

    setState("isRunning", false)
end

watchState("command", function(command)
    if command == "check" then
        checkUpdate()
    end

    if command == "cancel" then
        noctalia.runAsync(`kill $(ps -ef | grep "git ls-remote https://github.com/NixOS/nixpkgs" | grep -v grep | awk '\{print $2\}')`)
        setState("isRunning", false)
        completedCommands = 0
    end
end)