#!/usr/bin/lua
local fs = require('nixio.fs')
local uci = require('luci.model.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 data = uci:get_all('wireless', iface)
  if data.disabled then
    return null
  end
  local radio = uci:get_all('wireless', data.radio)
  if not radio.hwmode == '11g' or radio.disabled then
    return null
  end
  local wifitype = iwinfo.type(data.radio)
  local iw = iwinfo[wifitype]
  if iw.assoclist(iface) 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 blackout = false
  for _, iface in ipairs(ifaces) do
    local tmp = devOk(iface)
    if tmp then
      return true
    elseif tmp == false then
      blackout = true
    end
  end
  return not blackout
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")