src/Main.hs

   1 {-# LANGUAGE DoAndIfThenElse #-}
   2 module Main
   3 where
   4
   5 import Control.Concurrent.ParallelIO (stopGlobalPool)
   6 import System.Directory (doesFileExist)
   7 import System.IO (
   8   Handle,
   9   IOMode (WriteMode),
  10   openBinaryFile,
  11   stdout)
  12
  13 import CommandLine (show_help)
  14 import Configuration (Cfg(..), get_cfg)
  15 import LWN.Article (real_article_path)
  16 import LWN.HTTP (get_login_cookie)
  17 import LWN.Page (epublish, page_from_url)
  18
  19
  20 -- | If we're given an empty path, return a handle to
  21 --   'stdout'. Otherwise, open the given file and return a read/write
  22 --   handle to that.
  23 get_output_handle :: FilePath -> IO Handle
  24 get_output_handle path =
  25   if (null path) then
  26     return stdout
  27   else
  28     openBinaryFile path WriteMode
  29
  30
  31 argument_is_file :: Cfg -> IO Bool
  32 argument_is_file cfg = do
  33   path <- real_article_path (article cfg)
  34   doesFileExist path
  35
  36 main :: IO ()
  37 main = do
  38   cfg' <- get_cfg
  39   aif <- argument_is_file cfg'
  40   cfg  <- case aif of
  41            False -> get_login_cookie cfg'
  42            True  -> return cfg'
  43   page <- page_from_url cfg (article cfg)
  44   case page of
  45     Just p -> do
  46       output_handle <- get_output_handle (output cfg)
  47       epublish p output_handle
  48     Nothing -> do
  49       _ <- show_help
  50       return ()
  51
  52   -- Necessary, for some reason.
  53   stopGlobalPool