module Context (
      CodePath(..)
    , Context(..)
    , Contextual
    , Path(..)
  ) where

import Control.Monad.RWS (RWST)
import Data.List (intercalate)
import Data.Map (Map)
import Text.ParserCombinators.ReadP (char, munch, sepBy)
import Text.ParserCombinators.ReadPrec (lift)
import Text.Read (readPrec)

newtype Path = Path [String]
newtype CodePath = CodePath [FilePath]
type Dependencies = Map Path [Path]

data Context = Context {
      codePaths :: CodePath
    , mainModule :: Path
  }

type Contextual = RWST Context [String] Dependencies IO

instance Show Path where
  show (Path components) = intercalate "." components

instance Read Path where
  readPrec = fmap Path . lift $
    munch (/= '.') `sepBy` char '.'

instance Show CodePath where
  show (CodePath dirs) = intercalate ":" dirs