Option parser

koodihaaste.cabal

@@ -32,6 +32,7 @@ executable koodihaaste
   build-depends:       base >=4.12 && <4.13
                      , servant
                      , servant-server
+                     , optparse-generic
                      , servant-client
                      , servant-client-core
                      , text

src/Main.hs

@@ -1,17 +1,28 @@
+{-# LANGUAGE DataKinds         #-}
+{-# LANGUAGE DeriveGeneric     #-}
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards   #-}
+{-# LANGUAGE TypeOperators     #-}
 module Main where
 
 import           Control.Monad.App
 import           Data.Config
+import           Data.Language
+import qualified Data.Text.IO            as T
 import           Network.HTTP.Client.TLS (newTlsManager)
+import           Options.Generic
 import           Servant.Client
 import           Server
-import qualified Data.Text.IO as T
-import Data.Language
+
+newtype Cmd = Cmd (FilePath <?> "Config path")
+  deriving Generic
+
+instance ParseRecord Cmd
 
 main :: IO ()
 main = do
-  _config <- readConfigFromFile "config.yaml"
+  Cmd (Helpful configPath) <- getRecord "koodihaaste"
+  _config <- readConfigFromFile configPath
   manager <- newTlsManager
   _languageModel <- buildModel <$> T.readFile (_training _config)
   let state = App{..}