{-# LANGUAGE NoImplicitPrelude #-}

module Stack.Options.PackageParser
  ( readFlag
  ) where

import qualified Data.Map as Map
import           Options.Applicative ( ReadM, readerError )
import           Options.Applicative.Types ( readerAsk )
import           Stack.Prelude
import           Stack.Types.BuildOptsCLI ( ApplyCLIFlag (..) )

-- | Parser for package:[-]flag
readFlag :: ReadM (Map ApplyCLIFlag (Map FlagName Bool))
readFlag = do
  s <- readerAsk
  case break (== ':') s of
    (pn, ':':mflag) -> do
      pn' <- case parsePackageName pn of
               Nothing
                 | pn == "*" -> pure ACFAllProjectPackages
                 | otherwise -> readerError $ "Invalid package name: " ++ pn
               Just x -> pure $ ACFByName x
      let (b, flagS) = case mflag of
                         '-':x -> (False, x)
                         _ -> (True, mflag)
      flagN <- case parseFlagName flagS of
                 Nothing -> readerError $ "Invalid flag name: " ++ flagS
                 Just x -> pure x
      pure $ Map.singleton pn' $ Map.singleton flagN b
    _ -> readerError "Must have a colon."