--
-- (C) 2014-18 - ntop.org
--

i18n = require "i18n"
local dirs = ntop.getDirs()

local locales = {}

local default_locale = "en"
local default_locale_path = dirs.installdir..'/scripts/locales/en.lua'

function i18n.loadLocaleFile(path, locale)
  local chunk = assert(loadfile(path))
  local data = chunk()

  -- Check if plugin specific locales exist
  local plugins_locales = dirs.workingdir .. "/plugins/locales/" .. locale .. ".lua"

  if ntop.exists(plugins_locales) then
    local chunk = assert(loadfile(plugins_locales))
    local plugins_data = chunk()

    -- Add the plugins localized strings
    for k, v in pairs(plugins_data) do
      data[k] = v
    end
  end
  
  i18n.load({[locale]=data})
end

-- Provides a fallback for not already localized strings
i18n.loadLocaleFile(default_locale_path, default_locale)

locales.default_locale = default_locale

-- language is a global variable set from C that corresponds to the user default language
-- it may be null when lua_utils are imported from periodic scripts
if language == nil then
   local admin_lang = ntop.getPref("ntopng.user.admin.language")
   language = ternary(isEmptyString(admin_lang), locales.default_locale, admin_lang)
end

i18n.setLocale(language)

local supported_locales = {
   {code = "en"},
   {code = "it"},
   {code = "de"},
   {code = "jp"},
   {code = "pt"},
   {code = "cz"}
}

local function lookupLocale(localename)
   local base_path = dirs.installdir..'/scripts/locales/'
   local locale_path = base_path .. localename .. ".lua"

   if ntop.exists(locale_path) then
      return locale_path
   end

   return nil
end

-- Note: en already loaded
if (language ~= "en") and (not ntop.isnEdge()) then
   local locale_path = lookupLocale(language)

   if locale_path then
      i18n.loadLocaleFile(locale_path, language)
   end
end

local available_locales = {}

-- use pairsByKeys to impose an order
for _, locale in ipairs(supported_locales) do
   local localename = locale["code"]

   if lookupLocale(localename) then
      available_locales[#available_locales + 1] = locale
   end
end

-- ##############################################

function locales.getAvailableLocales()
   return available_locales
end

-- ##############################################

function locales.readDefaultLocale()
  local path = default_locale_path
  local chunk = assert(loadfile(path))
  local data = chunk()

  return(data)
end

-- ##############################################

return locales