twidge-0.99.0: Download.hs

{- hpodder component
Copyright (C) 2006-2007 John Goerzen <jgoerzen@complete.org>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-}

{- |
   Module     : Download
   Copyright  : Copyright (C) 2006-2008 John Goerzen
   License    : GNU GPL, version 2 or above

   Maintainer : John Goerzen <jgoerzen@complete.org>
   Stability  : provisional
   Portability: portable

Written by John Goerzen, jgoerzen\@complete.org

-}

module Download(sendAuthRequest, simpleDownload) where
import System.Log.Logger
import Data.ConfigFile
import HSH
import Data.Either.Utils(forceEither)
import Network.URI
import Data.List
import Control.Exception(evaluate)

d = debugM "download"
i = infoM "download"

curl = "curl"
curlopts = ["-A", "twidge v1.0.0; Haskell; GHC", -- Set User-Agent
            "-s",               -- Silent mode
            "-S",               -- Still show error messages
            "-L",               -- Follow redirects
            "-y", "60", "-Y", "1", -- Timeouts
            "--retry", "2",     -- Retry twice
            "-f"                -- Fail on server errors
           ]

simpleDownload :: String -> IO String
simpleDownload url = run (curl, curlopts ++ [url])

sendAuthRequest :: ConfigParser -> String -> [(String, String)] -> [(String, String)] -> IO String
sendAuthRequest cp url getopts postoptlist =
    do -- Force this to be evaluated in the parent process
       authopts <- evaluate (getAuthOpts cp)
       run (curl, curlopts ++ authopts ++ postopts ++ [urlbase ++ url ++ optstr])
    where urlbase = forceEither $ get cp "DEFAULT" "urlbase"
          optstr = case getopts of
                     [] -> ""
                     _ -> "?" ++ (concat . intersperse "&" . map conv $ getopts)
          conv (k, v) = k ++ "=" ++ escapeURIString isUnreserved v
          postopts = concatMap postopt postoptlist
          postopt (k, v) = ["-d", escapeURIString isUnreserved k ++ "=" ++
                                  escapeURIString isUnreserved v]

getAuthOpts :: ConfigParser -> [String]
getAuthOpts cp =
    case (get cp "DEFAULT" "username", get cp "DEFAULT" "password") of
      (Right user, Right pass) ->
          ["--user", user ++ ":" ++ pass]
      _ -> error "Missing username or password option in config file"