import Control.Monad
import System

type Arg  = (String, String)
type Args = [Arg]

defaultArgs :: Args
defaultArgs = [
	("-inputXMLPath",  "localization_client.txt"),
	("-outputXMLPath", "locale"),
	("-outputXMLName", "localization"),
	("-packagePath",   "")
	]

parseArgs :: Args -> [String] -> (Args, [String])
parseArgs defaults rawArgs = parse defaults rawArgs [] where
	parse args      []  errs = (args, errs)
	parse args (  x:[]) errs = (args, ("Error: alone argument option " ++ x):errs)
	parse args (k:v:tl) errs = case tryReplace k v args of
		Just args -> parse args tl errs
		Nothing   -> parse args tl (("Error: unknown option " ++ k):errs)

tryReplace :: String -> String -> Args -> Maybe Args
tryReplace _ _ [] = Nothing
tryReplace key val ((k, v):rest) = if key == k
	then Just ((key, val):rest)
	else case tryReplace key val rest of
		Just xs -> Just ((k, v):xs)
		Nothing -> Nothing

main = do
	rawArgs <- getArgs
	let (args, errs) = parseArgs defaultArgs rawArgs
	forM_ (reverse errs) putStrLn
	putStrLn "Parameters:"
	forM_  args $ \(arg, val) ->
		putStrLn (arg ++ " = " ++ val)