#!/usr/bin/lua5.1

local invoker = require "invoker"
local gfmt    = string.format

local function grep_segfault(syslog)
	if not invoker.statfile(syslog) then
		return false
	end
	local _, output = invoker.invoke(invoker.OUTPUT,
		"bash", "-c", gfmt("grep -e segfault %s | tail", syslog))
	if type(output) ~= "string" then return false end
	if string.find(output, "libmutter-15.so", 1, true) then
		io.stdout:write("Warning, gnome-shell segfault found.\n")
		io.stdout:flush()
		return true
	end
	return false
end

local function restore_gnome_settings()
	local hdir = "/home/lnxall"
	if not invoker.chdir(hdir) then
		io.stderr:write(gfmt("Error, chdir(%s) has failed.\n", hdir))
		io.stderr:flush()
		return false
	end

	io.stdout:write("Restoring configuration...\n"); io.stdout:flush()
	io.stdout:flush()
	for i = 1, 3 do
		invoker.invoke(0, "systemctl", "stop", "gdm")
		invoker.invoke(0, "rm", "-rf", "/root/.config/dconf")
		invoker.invoke(0, "rm", "-rf", ".config", ".cache", ".local")
	end
	invoker.invoke(0, "bash", "-c", "tar -Jxf /home/settings-20251202-093734.tar.xz ; sync ; reboot")
	invoker.invoke(0, "bash", "-c", "sleep 5 ; reboot")
end

local function check_segfault()
	invoker.setname("GNOME_SEGFAULT")
	while true do
		if grep_segfault("/tmp/syslog") or grep_segfault("/var/log/messages") then
			local dt = os.date("*t")
			invoker.rename("/var/log/messages", gfmt("/var/log/messages-%d%02d%02d",
				dt.year, dt.month, dt.day))
			restore_gnome_settings()
			break
		end
		invoker.waitsec(invoker.uptime() <= 600 and 5 or 300)
	end
	os.exit(0)
end
check_segfault()