#!/usr/bin/lua
--[[
bmx2hosts

Copyright 2017 Nicolas Pace <nico@libre.ws>, Nicolas Echaniz <nicoechaniz@altermundi.net>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

]]--

json = require('luci.jsonc')
fs = require('nixio.fs')

local function map(func, tbl)
     local newtbl = {}
     for i,v in pairs(tbl) do
         newtbl[i] = func(v)
     end
     return newtbl
end

 function filter(func, tbl)
     local newtbl= {}
     for i,v in pairs(tbl) do
         if func(v) then
	     newtbl[i]=v
         end
     end
     return newtbl
 end

local function extract_ips(HNA6_EXTENSION)
  -- Workaround to avoid bmx6 special IP
  if string.find(HNA6_EXTENSION.address,"fd66:66:66:ff00:") then
    return nil
  else
    return HNA6_EXTENSION.address
  end
end

local function only_HNA6_EXTENSION(obj)
  return (obj.HNA6_EXTENSION ~= nil)
end

function readAll(file)
    local f = io.open(file, "rb")
    local content = f:read("*all")
    f:close()
    return content
end

function get_ipv6_ips(host_json)
        json_data = json.parse(host_json)
	hna6_extensions = filter(only_HNA6_EXTENSION, json_data.DESC_ADV.extensions)

	local tupd = {}
	for k in pairs(hna6_extensions) do table.insert(tupd, k) end -- populate
	table.sort(tupd) -- sort
	for k, v in ipairs(tupd) do tupd[k] = hna6_extensions[v] end -- replace

	return map(extract_ips, tupd[1].HNA6_EXTENSION)
end

function get_hostname(s)
	return s:gmatch(".+/([%w_-]+)\.")()
end

local json_iterator, o_count = fs.glob('/var/run/bmx6/json/descriptions/*')

for i=1, o_count do
    local filename = json_iterator()
    hostname = get_hostname(filename)

    local ips = get_ipv6_ips(readAll(filename))
    for k, ip in ipairs(ips) do
      if ip ~= nil then print (ip.."    "..hostname..'.mesh') end
    end
end