+{-
+ - Copyright (C) 2015-2016 Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
+ -
+ - This file is part of FuncTorrent.
+ -
+ - FuncTorrent 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 3 of the License, or
+ - (at your option) any later version.
+ -
+ - FuncTorrent 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 FuncTorrent; if not, see <http://www.gnu.org/licenses/>
+ -}
+
+{-# LANGUAGE OverloadedStrings #-}
module FuncTorrent.Metainfo
- (Info,
- Metainfo,
- announceList,
- mkMetaInfo,
- mkInfo,
- lengthInBytes,
- info,
- name,
+ (Info(..),
+ Metainfo(..),
+ torrentToMetainfo
) where
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(..), bstrToString)
+import FuncTorrent.Bencode (BVal(..), encode, decode, bstrToString, bValToInteger)
+
+data FileMeta = FileMeta { lengthInBytes :: !Integer
+ , md5sum :: !(Maybe String)
+ , path :: String
+ } deriving (Eq, Show)
--- only single file mode supported for the time being.
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 String)
+ , creationDate :: !(Maybe Integer)
, comment :: !(Maybe String)
, createdBy :: !(Maybe String)
, encoding :: !(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
-maybeBstrToString :: Maybe BVal -> Maybe String
-maybeBstrToString Nothing = Nothing
-maybeBstrToString (Just s) = let (Bstr bs) = s
- in Just (unpack bs)
+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 -> Maybe Metainfo
-mkMetaInfo (Bdict m) = let (Just info') = mkInfo $ m ! "info"
- announce' = lookup "announce" m
- announceList' = lookup "announce-list" m
- -- creationDate = lookup (Bstr (pack "creation date")) m
- creationDate' = Nothing
- comment' = lookup "comment" m
- createdBy' = lookup "created by" m
- encoding' = lookup "encoding" m
- in Just Metainfo { info = info'
- , announceList = maybeToList (announce' >>= bstrToString)
- ++ getAnnounceList announceList'
- , creationDate = creationDate'
- , comment = maybeBstrToString comment'
- , createdBy = maybeBstrToString createdBy'
- , encoding = maybeBstrToString encoding'
- }
-mkMetaInfo _ = Nothing
+mkMetaInfo :: BVal -> Either String Metainfo
+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)
+ ++ getAnnounceList announceList'
+ , creationDate = bValToInteger =<< creationDate'
+ , comment = bstrToString =<< comment'
+ , createdBy = bstrToString =<< createdBy'
+ , encoding = bstrToString =<< encoding'
+ , infoHash = hash . encode $ (minfo ! "info")
+ }
+mkMetaInfo _ = Left "mkMetaInfo: expect an input dict"
getAnnounceList :: Maybe BVal -> [String]
getAnnounceList Nothing = []
[Bstr s''] -> unpack s''
_ -> ""
_ -> "") l
-
getAnnounceList (Just (Bdict _)) = []
+
+torrentToMetainfo :: ByteString -> Either String Metainfo
+torrentToMetainfo s =
+ case decode s of
+ Right d -> mkMetaInfo d
+ Left e -> Left ("Cannot parse the torrent file: " ++ show e)
+