Add command line arguments to tiny client

1 files changed, 54 insertions, 15 deletions

diff --git a/examples/Client.hs b/examples/Client.hs
index 320b4269..abf62657 100644
--- a/examples/Client.hs
+++ b/examples/Client.hs
@@ -1,26 +1,65 @@
+{-# LANGUAGE RankNTypes                #-}
+{-# LANGUAGE ExistentialQuantification #-}
+{-# LANGUAGE RecordWildCards           #-}
 module Main (main) where
 import Control.Concurrent
 import Control.Monad.Trans
+import Options.Applicative
 import System.Environment
 import System.Exit
 import System.IO
+import Text.Read
+
 import Network.BitTorrent
 
 
-parseArgs :: IO FilePath
-parseArgs = do
-  args <- getArgs
-  case args of
-    [path] -> return path
-    _      -> do
-      hPutStrLn stderr "Usage: client file.torrent"
-      exitFailure
+{-----------------------------------------------------------------------
+--  Command line arguments
+-----------------------------------------------------------------------}
+
+data TorrentBox = forall s. TorrentSource s => TorrentBox { unTorrentBox :: s }
+
+data Args = Args
+  { topic       :: TorrentBox
+  , contentDir  :: FilePath
+  }
+
+argsParser :: Parser Args
+argsParser = Args <$> (TorrentBox <$> infohashP <|> TorrentBox <$> torrentP)
+                  <*> destDirP
+  where
+    infohashP :: Parser InfoHash
+    infohashP = argument readMaybe
+                (metavar "SHA1"     <> help "infohash of torrent file")
+
+    torrentP :: Parser FilePath
+    torrentP  = argument Just
+                ( metavar "FILE"
+               <> help    "A .torrent file"
+                )
+
+    destDirP :: Parser FilePath
+    destDirP  = argument Just
+                ( metavar "DIR"
+               <> help    "Directory to put content"
+                )
+
+argsInfo :: ParserInfo Args
+argsInfo = info (helper <*> argsParser)
+   ( fullDesc
+  <> progDesc "A simple CLI bittorrent client"
+  <> header   "foo"
+   )
+
+{-----------------------------------------------------------------------
+--  Client
+-----------------------------------------------------------------------}
+
+run :: Args -> BitTorrent ()
+run (Args (TorrentBox t) dir)  = do
+  h <- openHandle dir t
+  start h
+  liftIO $ threadDelay 10000000000
 
 main :: IO ()
-main = do
-  path    <- parseArgs
-  torrent <- fromFile path
-  simpleClient $ do
-    h <- openTorrent "data" torrent
-    start h
-    liftIO $ threadDelay 10000000000
+main = execParser argsInfo >>= simpleClient . run