#!/usr/bin/lua
local fs = require 'nixio.fs'
local uci = require('simple-uci').cursor()
local iwinfo = require 'iwinfo'
local site = require 'gluon.site_config'

local fileOk = '/tmp/ath9k-ok'
local fileReset = '/tmp/ath9k-reset'

function time2file (file)
  local f = io.open(file, 'w')
  f:write(string.format('%i', os.time()))
  f:close()
end

function devOk (iface)
  local radio = uci:get_all('wireless', iface, 'device')
  local disabled = uci:get_bool('wireless', iface, 'disabled') or uci:get_bool('wireless', radio, 'disabled')
  if disabled then
    return null
  end
  local hwmode = uci:get_all('wireless', radio, 'hwmode')
  if not hwmode == '11g' then
    return null
  end
  local wifitype = iwinfo.type(radio)
  local assoclist = iwinfo[wifitype].assoclist(iface)
  if assoclist and #assoclist > 0 then
    return true
  end
  return false
end

function check_wifi()
  local ifaces = {}
  uci:foreach('wireless', 'wifi-iface',
    function(s)
      table.insert(ifaces, s['.name'])
    end
  )
  local ok = false
  for _, iface in ipairs(ifaces) do
    ok = ok or devOk(iface)
  end
  return ok
end

if not fs.readfile(fileReset) then
  time2file(fileReset)
end

if check_wifi() or not fs.readfile(fileOk) then
  time2file(fileOk)
  os.exit(0)
end

local blackout_wait_secs = site.ath9k-workaround.blackout_wait *60
local reset_wait_secs = site.ath9k-workaround.reset_wait *60

if os.difftime(os.time(), tonumber(fs.readfile(fileReset))) <= reset_wait_secs then
  os.exit(0)
end

if os.difftime(os.time(), tonumber(fs.readfile(fileOk))) <= blackout_wait_secs then
  os.exit(0)
end

io.popen('logger -s -t ath9k-blackout-workaround -p local0.info "blackout detected, resart wifi"')
time2file(fileReset)
os.execute('wifi')