Type.hs

------------------------------------------------------------------------------
-- HTTP dates

-- | Converts a 'CTime' into an HTTP timestamp.
formatHttpTime :: CTime -> IO ByteString

-- | Converts an HTTP timestamp into a 'CTime'.
parseHttpTime :: ByteString -> IO CTime

#ifdef WIN32

formatHttpTime = return . format . posixSecondsToUTCTime . toPOSIXTime
  where
    format :: UTCTime -> ByteString
    format = fromStr . formatTime defaultTimeLocale "%a, %d %b %Y %X GMT"

    toPOSIXTime :: CTime -> POSIXTime
    toPOSIXTime = toEnum . fromEnum

parseHttpTime = return . toCTime . parse . toStr
  where
    parse :: String -> Maybe UTCTime
    parse = parseTime defaultTimeLocale "%a, %d %b %Y %H:%M:%S GMT"

    toCTime :: Maybe UTCTime -> CTime
    toCTime (Just t) = toEnum $ fromEnum $ utcTimeToPOSIXSeconds t
    toCTime Nothing  = toEnum $ 0

#else

formatHttpTime t = allocaBytes 40 $ \ptr -> do
    c_format_http_time t ptr
    S.packCString ptr

parseHttpTime s = S.useAsCString s $ \ptr ->
    c_parse_http_time ptr

#endif