{-# LANGUAGE ApplicativeDo #-}
{-# LANGUAGE BlockArguments #-}

module Main where

import qualified Data.Text.Lazy.IO as TL
import Network.HTTP.Simple
import Options.Applicative
import qualified Readability as R
import Text.XML

data Source = File FilePath | Web Request deriving (Show)

data Opts = Opts {optInput :: Source} deriving (Show)

main :: IO ()
main = do
  (Opts src) <- execParser opts
  article <- case src of
    File f -> R.fromFile f
    Web req -> R.fromByteString . getResponseBody <$> httpLBS req
  case R.summary <$> article of
    Just doc -> TL.putStrLn $ renderText def {rsPretty = True, rsXMLDeclaration = True} doc
    Nothing -> return ()

opts :: ParserInfo Opts
opts =
  info
    (options <**> helper)
    ( fullDesc
        <> progDesc "Provide FILE or URL as source"
        <> header "readability - extract article from HTML"
    )

options :: Parser Opts
options = do
  inf <- argument source (metavar "SOURCE")
  pure $ Opts inf

source :: ReadM Source
source = maybeReader \s -> Web <$> parseRequest s <|> Just (File s)