#!/usr/bin/lua

local unistd = require 'posix.unistd'
local util = require 'gluon.util'
local site = require 'gluon.site'

local offline_flag_file = "/tmp/gluon_offline"
local is_offline = true

-- Check if domain-switch is scheduled
if site.domain_switch() == nil then
	-- Switch not applicable for current domain
	os.exit(0)
end

-- Check reachability of pre-defined targets
for _, ip in ipairs(site.domain_switch.connection_check_targets()) do
	local exit_code = os.execute("ping -c 1 -w 10 " .. ip)
	if exit_code == 0 then
		is_offline = false
		break
	end
end

if is_offline then
	-- Check if we were previously offline
	if unistd.access(offline_flag_file) then
		os.exit(0)
	end
	-- Create offline flag
	local f = io.open(offline_flag_file, "w")
	f:write(tostring(util.get_uptime()))
	f:close()
else
	os.remove(offline_flag_file)
end
