- along with FuncTorrent; if not, see <http://www.gnu.org/licenses/>
-}
+{-# LANGUAGE OverloadedStrings #-}
module FuncTorrent.Metainfo
(Info(..),
Metainfo(..),
import Prelude hiding (lookup)
import Data.ByteString.Char8 (ByteString, unpack)
import Data.Map as M ((!), lookup)
+import Data.List (intersperse)
import Crypto.Hash.SHA1 (hash)
import Data.Maybe (maybeToList)
import FuncTorrent.Bencode (BVal(..), encode, decode, bstrToString, bValToInteger)
--- only single file mode supported for the time being.
+data FileMeta = FileMeta { lengthInBytes :: !Integer
+ , md5sum :: !(Maybe String)
+ , path :: String
+ } deriving (Eq, Show)
+
data Info = Info { pieceLength :: !Integer
, pieces :: !ByteString
, private :: !(Maybe Integer)
, name :: !String
- , lengthInBytes :: !Integer
- , md5sum :: !(Maybe String)
+ , filemeta :: [FileMeta]
} deriving (Eq, Show)
-data Metainfo = Metainfo { info :: !Info
+data Metainfo = Metainfo { info :: !(Maybe Info)
, announceList :: ![String]
, creationDate :: !(Maybe Integer)
, comment :: !(Maybe String)
, infoHash :: !ByteString
} deriving (Eq, Show)
-mkInfo :: BVal -> Maybe Info
-mkInfo (Bdict m) = let (Bint pieceLength') = m ! "piece length"
- (Bstr pieces') = m ! "pieces"
- private' = Nothing
- (Bstr name') = m ! "name"
- (Bint length') = m ! "length"
- md5sum' = Nothing
- in Just Info { pieceLength = pieceLength'
- , pieces = pieces'
- , private = private'
- , name = unpack name'
- , lengthInBytes = length'
- , md5sum = md5sum'}
-mkInfo _ = Nothing
+bvalToInfo :: BVal -> Maybe Info
+bvalToInfo (Bdict minfo) = let (Bint pieceLength') = minfo ! "piece length"
+ (Bstr pieces') = minfo ! "pieces"
+ private' = Nothing
+ (Bstr name') = minfo ! "name"
+ -- is the key "files" present? If so, it is a multi-file torrent
+ -- if not, it is a single file torrent.
+ filesIfMulti = lookup "files" minfo
+ partialInfo = Info { pieceLength = pieceLength'
+ , pieces = pieces'
+ , private = private'
+ , name = unpack name'
+ , filemeta = []
+ }
+ in
+ case filesIfMulti of
+ Nothing -> let (Bint length') = minfo ! "length"
+ filemeta' = FileMeta { lengthInBytes = length'
+ , md5sum = Nothing
+ , path = unpack name' }
+ in Just (partialInfo { filemeta = [filemeta'] })
+ Just (Blist files) -> mapM toFileMeta files >>=
+ \filemeta' ->
+ Just partialInfo { filemeta = filemeta' }
+ Just _ -> Nothing
+bvalToInfo _ = Nothing
+
+toFileMeta :: BVal -> Maybe FileMeta
+toFileMeta (Bdict fm) = let (Bint length') = fm ! "length"
+ (Blist pathElems) = fm ! "path"
+ pathStrings = fmap bstrToString pathElems
+ in
+ sequence pathStrings >>=
+ \pathList -> let path' = concat $ intersperse "/" pathList
+ in Just (FileMeta { lengthInBytes = length'
+ , md5sum = Nothing
+ , path = path' })
+toFileMeta _ = Nothing
mkMetaInfo :: BVal -> Either String Metainfo
-mkMetaInfo (Bdict m) =
- let (Just info') = mkInfo $ m ! "info"
- announce' = lookup "announce" m
- announceList' = lookup "announce-list" m
- creationDate' = lookup "creation date" m
- comment' = lookup "comment" m
- createdBy' = lookup "created by" m
- encoding' = lookup "encoding" m
+mkMetaInfo (Bdict minfo) =
+ let info' = bvalToInfo $ minfo ! "info"
+ announce' = lookup "announce" minfo
+ announceList' = lookup "announce-list" minfo
+ creationDate' = lookup "creation date" minfo
+ comment' = lookup "comment" minfo
+ createdBy' = lookup "created by" minfo
+ encoding' = lookup "encoding" minfo
in Right Metainfo {
info = info'
, announceList = maybeToList (announce' >>= bstrToString)
, comment = bstrToString =<< comment'
, createdBy = bstrToString =<< createdBy'
, encoding = bstrToString =<< encoding'
- , infoHash = hash . encode $ (m ! "info")
+ , infoHash = hash . encode $ (minfo ! "info")
}
mkMetaInfo _ = Left "mkMetaInfo: expect an input dict"
torrentToMetainfo :: ByteString -> Either String Metainfo
torrentToMetainfo s =
case decode s of
- Right d -> mkMetaInfo d
- Left e -> Left $ show e
+ Right d -> mkMetaInfo d
+ Left e -> Left ("Cannot parse the torrent file: " ++ show e)
+