-- Author:     Andy Stewart <lazycat.manatee@gmail.com>
-- Maintainer: Andy Stewart <lazycat.manatee@gmail.com>
-- Copyright (C) 2010 Andy Stewart, all rights reserved.
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- any later version.
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- GNU General Public License for more details.
-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see <http://www.gnu.org/licenses/>.

{-# LANGUAGE ExistentialQuantification, RankNTypes, DeriveDataTypeable, NoMonomorphismRestriction, FlexibleContexts, ScopedTypeVariables #-}
{-# LANGUAGE OverloadedStrings #-}
module Manatee.Core.Interactive where

import Data.Text.Lazy (Text)

-- | Parse interactive string.
-- Return error reason if parse failed.
parseInteractiveString :: String -> Either Text [(String, String)]
parseInteractiveString interactiveStr 
    | null prompts
       = Left "Empty interactive string."
    | any null prompts
       = Left "Have null line in interactive string."
    | any (`notElem` "cdfsn") types
       = Left "Have invalid type character in interactive string."
    | otherwise
       = Right $
         map (\x -> (interactiveCandidateName (head x), tail x)) prompts
    where prompts = lines interactiveStr
          types   = map head prompts

-- | Get candidate name for type character.
interactiveCandidateName :: Char -> String
interactiveCandidateName 'c' = "InteractiveChar"
interactiveCandidateName 'd' = "InteractiveDirectory"
interactiveCandidateName 'f' = "InteractiveFile"
interactiveCandidateName 'n' = "InteractiveNumber"
interactiveCandidateName 's' = "InteractiveString"