addressbook/app/Main.hs

{-# LANGUAGE LambdaCase #-}
module Main where

import Options.Applicative

import Data.Text
       (Text)
import qualified Data.Text as T

import qualified Control.Addressbook.Query as Query
import qualified Control.Addressbook.Streaming as Streaming

data CmdLine
  = Stream
  | Query Text
  deriving Show

cmdline :: Parser CmdLine
cmdline = subparser
  (  command "stream" (info (pure Stream) (progDesc "Record a stream of filenames"))
  <> command "query" (info (Query . T.pack <$> argument str (metavar "QUERY")) (progDesc "Query email addresses"))
  )

handler :: CmdLine -> IO ()
handler = \case
  Stream -> Streaming.run
  Query q -> Query.query q

main :: IO ()
main = execParser opts >>= handler
  where
    opts = info (cmdline <**> helper) (fullDesc <> progDesc "Email addressbook")