#!/usr/bin/lua

util = require 'luci.util'
json = require 'luci.jsonc'
nixio = require 'nixio'
iwinfo = require 'iwinfo'

function badrequest()
  io.write("Status: 400 Bad Request\n\n")
  os.exit(1)
end

function get_stations(iw, ifname)
  local stations = {}

  for k, v in pairs(iw.assoclist(ifname)) do
    stations[k:lower()] = {signal = v.signal, noise = v.noise, inactive = v.inactive}
  end

  return stations
end

local ifname = os.getenv("QUERY_STRING")

if ifname == nil then badrequest() end

local list = util.exec('batctl if')
local found = false
for _, line in ipairs(util.split(list)) do
  if ifname == line:match('^(.-):') then
    found = true
    break
  end
end

if found == false then badrequest() end

local wifitype = iwinfo.type(ifname)

if wifitype == nil then badrequest() end

local iw = iwinfo[wifitype]

io.write("Access-Control-Allow-Origin: *\n")
io.write("Content-type: text/event-stream\n\n")

while true do
  local stations = json.stringify(get_stations(iw, ifname))
  io.write("data: " .. stations .. "\n\n")
  io.flush()
  nixio.nanosleep(0, 150e6)
end