Implement image download and replacement.

[dead/lwn-epub.git] / src / LWN / HTTP.hs

diff --git a/src/LWN/HTTP.hs b/src/LWN/HTTP.hs
index 8b4c14d0cc04a09badc271f15bd0ea628ca24390..743a99c8fa0fb98429a114e13e621e074b5b825d 100644 (file)
--- a/src/LWN/HTTP.hs
+++ b/src/LWN/HTTP.hs
@@ -1,6 +1,10 @@
+{-# LANGUAGE DoAndIfThenElse #-}
+
 module LWN.HTTP
 where
 
+import qualified Data.ByteString as B (hPut)
+
 import Network.Curl (
   CurlCode(..),
   CurlOption(..),
@@ -12,7 +16,12 @@ import Network.Curl (
   respCurlCode,
   withCurlDo               
   )
+import Network.Curl.Download (openURI)
+import System.Directory (doesFileExist, getTemporaryDirectory)
 import System.IO (hPutStrLn, stderr)
+import System.IO.Temp (openBinaryTempFile)
+
+import LWN.URI (filename)
 
 login_url :: URLString
 login_url = "https://lwn.net/login"
@@ -52,7 +61,7 @@ get_page cookie_jar url =
     -- Perform the request, and get back a CurlResponse object.
     -- The cast is needed to specify how we would like our headers
     -- and body returned (Strings).
-    resp <- do_curl_ curl login_url curl_opts :: IO CurlResponse
+    resp <- do_curl_ curl url curl_opts :: IO CurlResponse
 
     -- Pull out the response code as a CurlCode.
     let code = respCurlCode resp
@@ -107,7 +116,7 @@ log_in cookie_jar username password =
     post_password = password_field ++ "=" ++ password
 
     post_data :: [String]
-    post_data = [post_username, post_password]
+    post_data = [post_username, post_password, post_submit]
 
     post_opts :: [CurlOption]
     post_opts =
@@ -118,3 +127,33 @@ log_in cookie_jar username password =
         
     curl_opts :: [CurlOption]
     curl_opts = default_curl_opts ++ post_opts
+
+
+-- | Save the image at 'url'. Saves to a temporary file, and
+--   returns the path to that file if successful. Otherwise,
+--   returns 'Nothing'.
+--
+--   We need to be able to parse the filename out of the URL
+--   so that when we stick our image in the document, the reader
+--   knows that type (jpg, png, etc.) it is.
+save_image :: URLString -> IO (Maybe FilePath)
+save_image url = do
+  it_exists <- doesFileExist url
+  if it_exists then do
+    -- It's local, just use it.
+    return $ Just url
+  else do
+    let fn = filename url
+    case fn of
+      Nothing -> return Nothing
+      Just file -> do
+        temp_dir <- getTemporaryDirectory
+        (out_path, out_handle) <- openBinaryTempFile temp_dir file
+        result <- openURI url
+        case result of
+          Left err -> do
+            hPutStrLn stderr ("HTTP Error: " ++ err)
+            return Nothing
+          Right bs -> do
+            B.hPut out_handle bs
+            return $ Just out_path