local lgi = require("lgi")
local Gio = lgi.require("Gio")
local GLib = lgi.require("GLib")

-- Workaround for https://github.com/pavouk/lgi/issues/142
local function bus_get_async(type)
    Gio.bus_get(type, nil, coroutine.running())
    local a, b = coroutine.yield()
    return Gio.bus_get_finish(b)
end

local function inhibit(bus, what, who, why, mode)
    local name = "org.freedesktop.login1"
    local object = "/org/freedesktop/login1"
    local interface = "org.freedesktop.login1.Manager"
    local message = Gio.DBusMessage.new_method_call(name, object, interface, "Inhibit")
    message:set_body(GLib.Variant("(ssss)",
        { what, who, why, mode }))

    local timeout = -1 -- Just use the default
    local result, err = bus:async_send_message_with_reply(message, Gio.DBusSendMessageFlags.NONE,
        timeout, nil)

    if err then
        print("error: " .. tostring(err))
        return
    end

    if result:get_message_type() == "ERROR" then
        local _, err = result:to_gerror()
        print("error: " .. tostring(err))
        return
    end

    local fd_list = result:get_unix_fd_list()
    local fd, err = fd_list:get(0)
    if err then
        print("error: " .. tostring(err))
        return
    end

    -- Now... somehow turn this fd into something we can close
    return Gio.UnixInputStream.new(fd, true)
end

Gio.Async.call(function()
    local bus = bus_get_async(Gio.BusType.SYSTEM)
    local a = inhibit(bus, "shutdown:sleep", "hi, it's me!", "Just because", "delay")
    print("got lock")
    io.popen("sleep 10"):read("*a")
    a:async_close()
    -- Speed up deletion of the GDBusMessage that still references the FD
    collectgarbage("collect")
    collectgarbage("collect")

    print("released lock")
    io.popen("sleep 10"):read("*a")
end)()