git-annex/Command/ImportFeed.hs

148 lines
4.3 KiB
Haskell

{- git-annex command
-
- Copyright 2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.ImportFeed where
import Text.Feed.Import
import Text.Feed.Query
import Text.Feed.Types
import qualified Data.Set as S
import qualified Data.Map as M
import Data.Char
import Common.Annex
import Command
import qualified Utility.Url as Url
import Logs.Web
import qualified Option
import qualified Utility.Format
import Utility.Tmp
import Command.AddUrl (addUrlFile, relaxedOption)
data ToDownload = ToDownload
{ feed :: Feed
, item :: Item
, location :: URLString
}
mkToDownload :: Feed -> Item -> Maybe ToDownload
mkToDownload f i = case getItemEnclosure i of
Nothing -> Nothing
Just (enclosureurl, _, _) -> Just $ ToDownload f i enclosureurl
def :: [Command]
def = [notBareRepo $ withOptions [templateOption, relaxedOption] $
command "importfeed" (paramRepeating paramUrl) seek
SectionCommon "import files from podcast feeds"]
templateOption :: Option
templateOption = Option.field [] "template" paramFormat "template for filenames"
seek :: [CommandSeek]
seek = [withField templateOption return $ \tmpl ->
withFlag relaxedOption $ \relaxed ->
withWords $ start relaxed tmpl]
start :: Bool -> Maybe String -> [URLString] -> CommandStart
start relaxed opttemplate = go Nothing
where
go _ [] = stop
go cache (url:urls) = do
showStart "importfeed" url
v <- findEnclosures url
if isJust v then showEndOk else showEndFail
case v of
Just l | not (null l) -> do
knownurls <- getknownurls cache
mapM_ (downloadEnclosure relaxed template knownurls) l
go (Just knownurls) urls
_ -> go cache urls
defaulttemplate = "${feedtitle}/${itemtitle}.${extension}"
template = Utility.Format.gen $ fromMaybe defaulttemplate opttemplate
{- This is expensive, so avoid running it more than once. -}
getknownurls (Just cached) = return cached
getknownurls Nothing = S.fromList <$> knownUrls
findEnclosures :: URLString -> Annex (Maybe [ToDownload])
findEnclosures url = go =<< downloadFeed url
where
go Nothing = do
warning $ "failed to parse feed " ++ url
return Nothing
go (Just f) = return $ Just $
mapMaybe (mkToDownload f) (feedItems f)
{- Feeds change, so a feed download cannot be resumed. -}
downloadFeed :: URLString -> Annex (Maybe Feed)
downloadFeed url = do
showOutput
liftIO $ withTmpFile "feed" $ \f h -> do
ifM (Url.download url [] [] f)
( parseFeedString <$> hGetContentsStrict h
, return Nothing
)
{- Avoids downloading any urls that are already known to be associated
- with a file in the annex. -}
downloadEnclosure :: Bool -> Utility.Format.Format -> S.Set URLString -> ToDownload -> Annex ()
downloadEnclosure relaxed template knownurls enclosure
| S.member url knownurls = noop
| otherwise = do
dest <- liftIO $ feedFile template enclosure
showStart "addurl" dest
ifM (addUrlFile relaxed url dest)
( showEndOk
, showEndFail
)
where
url = location enclosure
{- Generate a unique filename for the feed item by filling
- out the template.
-
- Since each feed url is only downloaded once,
- if the file already exists, two items with different urls
- has the same title. A number is added to disambiguate.
-}
feedFile :: Utility.Format.Format -> ToDownload -> IO FilePath
feedFile template i = makeUnique 0 $
Utility.Format.format template $ M.fromList
[ field "feedtitle" $ getFeedTitle $ feed i
, fieldMaybe "itemtitle" $ getItemTitle $ item i
, fieldMaybe "feedauthor" $ getFeedAuthor $ feed i
, fieldMaybe "itemauthor" $ getItemAuthor $ item i
, fieldMaybe "itemsummary" $ getItemSummary $ item i
, fieldMaybe "itemdescription" $ getItemDescription $ item i
, fieldMaybe "itemrights" $ getItemRights $ item i
, fieldMaybe "itemid" $ snd <$> getItemId (item i)
, field "extension" $ takeExtension $ location i
]
where
field k v =
let s = map sanitize v in
if null s then (k, "none") else (k, s)
fieldMaybe k Nothing = (k, "none")
fieldMaybe k (Just v) = field k v
sanitize c
| isSpace c || isPunctuation c || c == '/' = '_'
| otherwise = c
makeUnique :: Integer -> FilePath -> IO FilePath
makeUnique n file =
ifM (isJust <$> catchMaybeIO (getSymbolicLinkStatus f))
( makeUnique (n + 1) file
, return file
)
where
f = if n == 0
then file
else
let (d, base) = splitFileName file
in d </> show n ++ "_" ++ base