{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
module Hcompta.CLI.Context where

import           Control.Monad (liftM)
import qualified Data.List
import           Data.Maybe (catMaybes)
import           System.Environment (getEnvironment)
import           System.IO.Memoize (once)

data App = App

data Context
 =   Context
 { verbosity :: Verbosity
 , command   :: String
 , color     :: Maybe Bool
 , langs     :: [String]
 } deriving (Show)

context :: IO Context
context = do
	langs <- get_langs
	return $
		Context
		 { verbosity = Verbosity_Info
		 , command   = ""
		 , color     = Nothing
		 , langs
		 }

data Verbosity
 = Verbosity_Error
 | Verbosity_Warn
 | Verbosity_Info
 | Verbosity_Debug
 deriving (Bounded, Enum, Eq, Ord, Show)

-- TODO: check that this is expected behavior
--       and portability issues
get_langs :: IO [String]
get_langs = do
	once getEnvironment
	>>= liftM (\env ->
		Data.List.concatMap
		 ((\lang ->
			let short = takeWhile ('_' /=) lang in
			if short == lang
			then [lang]
			else [lang, short])
		 . Data.List.takeWhile (\c -> c /= '.') ) $
		catMaybes
		 [ Data.List.lookup "LC_ALL"   env
		 , Data.List.lookup "LC_CTYPE" env
		 , Data.List.lookup "LANG"     env
		 , Just "en"
		 ])