module BNFC.Options where

import BNFC.Prelude

import BNFC.Options.Commands
import BNFC.Options.GlobalOptions
import BNFC.Options.InfoOptions

import Options.Applicative
import Options.Applicative.Help.Pretty (vcat, text)

import System.Environment (getArgs)


data Options = Options
  { globalOptions :: GlobalOptions
  , command       :: Command
  }

programOptions :: Parser Options
programOptions = Options <$> globalOptionsParser <*> commandsParser

getOptInput :: Options -> FilePath
getOptInput = optInput . globalOptions

-- * Option parsing and handling

options :: IO Options
options = options' =<< getArgs

options' :: [String] -> IO Options
options' args =
  execParser' args $
    info (helper <*> versionOption <*> numericVersionOption <*> licenseOption <*> programOptions)
         (header "The BNF Converter"
          <> footerDoc (Just foot))
  where
    foot = vcat $ map text $ concat
      [ [ ""
        ]
      ]

type Target = Maybe FilePath

-- * Patch to optparse-applicative

-- | Like 'execParser', but parse given argument list rather than those from 'getArgs'.
execParser' :: [String] -> ParserInfo a -> IO a
execParser' = customExecParser' defaultPrefs

-- | Run a program description with custom preferences.
customExecParser' :: ParserPrefs -> [String] -> ParserInfo a -> IO a
customExecParser' pprefs args pinfo =
  handleParseResult $ execParserPure pprefs pinfo args