1 {-# LANGUAGE DoAndIfThenElse #-}
6 import qualified Data.ByteString as B (hPut)
19 import Network.Curl.Download (openURI)
20 import System.Directory (doesFileExist, getTemporaryDirectory)
21 import System.IO (hClose, hPutStrLn, stderr)
22 import System.IO.Temp (openBinaryTempFile, openTempFile)
24 import LWN.URI (filename)
26 login_url :: URLString
27 login_url = "https://lwn.net/login"
29 username_field :: String
30 username_field = "Username"
32 password_field :: String
33 password_field = "Password"
35 submit_field :: String
36 submit_field = "submit"
39 default_curl_opts :: [CurlOption]
41 [ -- The Global cache is not thread-friendly.
42 CurlDNSUseGlobalCache False,
44 -- And we don't want to use a DNS cache anyway.
45 CurlDNSCacheTimeout 0,
48 CurlFollowLocation True,
50 -- Give it a little time...
54 make_cookie_jar :: IO FilePath
56 temp_dir <- getTemporaryDirectory
57 let file_name_template = "lwn-epub-cookies.txt"
58 (out_path, out_handle) <- openTempFile temp_dir file_name_template
59 hClose out_handle -- We just want to create it for now.
62 get_page :: Maybe FilePath -> URLString -> IO (Either String String)
63 get_page cookie_file url =
65 -- Create a curl instance.
68 -- Perform the request, and get back a CurlResponse object.
69 -- The cast is needed to specify how we would like our headers
70 -- and body returned (Strings).
71 resp <- do_curl_ curl url curl_opts :: IO CurlResponse
73 -- Pull out the response code as a CurlCode.
74 let code = respCurlCode resp
78 CurlOK -> Right (respBody resp)
79 error_code -> Left ("HTTP Error: " ++ (show error_code))
80 -- If an error occurred, we want to dump as much information as
81 -- possible. If this becomes a problem, we can use respGetInfo to
82 -- query the response object for more information
87 Just cookies -> [ CurlCookieFile cookies ]
89 curl_opts = default_curl_opts ++ get_opts
92 -- | Log in using curl. Store the resulting session cookies in the
94 log_in :: FilePath -> String -> String -> IO (Either String String)
95 log_in cookie_jar username password =
97 -- Create a curl instance.
100 -- Perform the request, and get back a CurlResponse object.
101 -- The cast is needed to specify how we would like our headers
102 -- and body returned (Strings).
103 resp <- do_curl_ curl login_url curl_opts :: IO CurlResponse
105 -- Pull out the response code as a CurlCode.
106 let code = respCurlCode resp
110 CurlOK -> Right (respBody resp)
111 error_code -> Left $ "HTTP Error: " ++ (show error_code)
112 -- If an error occurred, we want to dump as much information as
113 -- possible. If this becomes a problem, we can use respGetInfo to
114 -- query the response object for more information
116 post_submit :: String
117 post_submit = submit_field ++ "=Log+In"
119 post_username :: String
120 post_username = username_field ++ "=" ++ username
122 post_password :: String
123 post_password = password_field ++ "=" ++ password
125 post_data :: [String]
126 post_data = [post_username, post_password, post_submit]
128 post_opts :: [CurlOption]
130 [ CurlCookieSession True,
131 CurlCookieJar cookie_jar,
133 CurlPostFields post_data ]
135 curl_opts :: [CurlOption]
136 curl_opts = default_curl_opts ++ post_opts
139 -- | Save the image at 'url'. Saves to a temporary file, and
140 -- returns the path to that file if successful. Otherwise,
141 -- returns 'Nothing'.
143 -- We need to be able to parse the filename out of the URL
144 -- so that when we stick our image in the document, the reader
145 -- knows that type (jpg, png, etc.) it is.
146 save_image :: URLString -> IO (Maybe FilePath)
148 it_exists <- doesFileExist url
150 -- It's local, just use it.
153 let fn = filename url
155 Nothing -> return Nothing
157 temp_dir <- getTemporaryDirectory
158 (out_path, out_handle) <- openBinaryTempFile temp_dir file
159 result <- openURI url
162 hPutStrLn stderr ("HTTP Error: " ++ err)
166 return $ Just out_path