Print an error before usage if we can't parse the page.

[dead/lwn-epub.git] / src / Main.hs

diff --git a/src/Main.hs b/src/Main.hs
index 5ce40269bd950a382201501f2101ed7ba7505ccf..1f6d7c5f436a583d5143b05c1cf55aaf4126995e 100644 (file)
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -2,8 +2,7 @@
 module Main
 where
 
-import Data.Maybe (fromJust)
-import Prelude hiding (readFile)
+import Control.Concurrent.ParallelIO (stopGlobalPool)
 import System.Directory (doesFileExist)
 import System.IO (
   Handle,
@@ -11,63 +10,14 @@ import System.IO (
   hPutStrLn,
   openBinaryFile,
   stderr,
-  stdout)
-import System.IO.UTF8 (readFile)
-import Text.XML.HXT.Core (
-  IOStateArrow,
-  XmlTree)
+  stdout
+  )
 
 import CommandLine (show_help)
-import Configuration (Cfg(..), get_cfg, use_account)
+import Configuration (Cfg(..), get_cfg)
 import LWN.Article (real_article_path)
-import LWN.HTTP (get_page, log_in, make_cookie_jar)
-import LWN.Page (epublish, parse)
-import LWN.XHTML (parse_lwn)
-
-
-
--- | Try to parse the given article using HXT. We try a few different
---   methods; if none of them work, we return 'Nothing'.
-get_xml_from_article :: Cfg -> IO (Maybe (IOStateArrow s b XmlTree))
-get_xml_from_article cfg = do  
-  my_article <- real_article_path (article cfg)
-  is_file <- doesFileExist my_article
-  case is_file of
-    True -> do
-      contents <- readFile my_article
-      return $ Just $ parse_lwn contents
-    False -> do
-      -- Download the URL and try to parse it.
-      if use_account cfg then do
-        -- use_account would be false if these fromJusts would fail.
-        cj <- make_cookie_jar
-        li_result <- log_in cj
-                      (fromJust $ username cfg)
-                      (fromJust $ password cfg)
-
-        case li_result of
-          Left err -> do
-            let msg = "Failed to log in. " ++ err
-            hPutStrLn stderr msg
-          Right response_body -> do
-            hPutStrLn stderr response_body
-
-        html <- get_page (Just cj) my_article
-
-        case html of
-          Left err -> do
-            let msg = "Failed to retrieve page. " ++ err
-            hPutStrLn stderr msg
-            return Nothing
-          Right h -> return $ Just $ parse_lwn h
-      else do
-        html <- get_page Nothing my_article
-        case html of
-          Left err -> do
-            let msg = "Failed to retrieve page. " ++ err
-            hPutStrLn stderr msg
-            return Nothing
-          Right h -> return $ Just $ parse_lwn h
+import LWN.HTTP (get_login_cookie)
+import LWN.Page (epublish, page_from_url)
 
 
 -- | If we're given an empty path, return a handle to
@@ -81,21 +31,28 @@ get_output_handle path =
     openBinaryFile path WriteMode
 
 
+argument_is_file :: Cfg -> IO Bool
+argument_is_file cfg = do
+  path <- real_article_path (article cfg)
+  doesFileExist path
+
 main :: IO ()
 main = do
-  cfg <- get_cfg
-  output_handle <- get_output_handle (output cfg)
-  maybe_html <- get_xml_from_article cfg
-
-  case maybe_html of
-    Just html -> do
-      result <- parse html
-      case result of
-        Just stuff  -> epublish stuff output_handle
-        Nothing     -> do
-         _ <- show_help
-         return ()
-
+  cfg' <- get_cfg
+  aif <- argument_is_file cfg'
+  cfg  <- case aif of
+           False -> get_login_cookie cfg'
+           True  -> return cfg'
+
+  page <- page_from_url cfg (article cfg)
+  case page of
+    Just p -> do
+      output_handle <- get_output_handle (output cfg)
+      epublish p output_handle
     Nothing -> do
+      hPutStrLn stderr "ERROR: could not parse an LWN page from the given URL."
       _ <- show_help
       return ()
+
+  -- Necessary, for some reason.
+  stopGlobalPool