remove redundant import

[functorrent.git] / src / FuncTorrent / Metainfo.hs

diff --git a/src/FuncTorrent/Metainfo.hs b/src/FuncTorrent/Metainfo.hs
index dfedb59dbdd3d57cf3643348d9e70e287f2192d0..898cc54a037b7e009a60a172b9fdf31fc814b98b 100644 (file)
--- a/src/FuncTorrent/Metainfo.hs
+++ b/src/FuncTorrent/Metainfo.hs
@@ -1,9 +1,26 @@
+{-
+ - 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/>
+ -}
+
 module FuncTorrent.Metainfo
     (Info(..),
      Metainfo(..),
-     infoHash,
-     mkInfo,
-     mkMetaInfo
+     torrentToMetainfo
     ) where
 
 import Prelude hiding (lookup)
@@ -12,7 +29,7 @@ import Data.Map as M ((!), lookup)
 import Crypto.Hash.SHA1 (hash)
 import Data.Maybe (maybeToList)
 
-import FuncTorrent.Bencode (BVal(..), InfoDict, encode, bstrToString)
+import FuncTorrent.Bencode (BVal(..), encode, decode, bstrToString, bValToInteger)
 
 -- only single file mode supported for the time being.
 data Info = Info { pieceLength :: !Integer
@@ -29,6 +46,7 @@ data Metainfo = Metainfo { info :: !Info
                          , comment :: !(Maybe String)
                          , createdBy :: !(Maybe String)
                          , encoding :: !(Maybe String)
+                         , infoHash :: !ByteString
                          } deriving (Eq, Show)
 
 mkInfo :: BVal -> Maybe Info
@@ -46,31 +64,26 @@ mkInfo (Bdict m) = let (Bint pieceLength') = m ! "piece length"
                                 , md5sum = md5sum'}
 mkInfo _ = Nothing
 
-maybeBstrToString :: Maybe BVal -> Maybe String
-maybeBstrToString (Just (Bstr bs)) = Just $ unpack bs
-maybeBstrToString _ = Nothing
-
-maybeBstrToInteger :: Maybe BVal -> Maybe Integer
-maybeBstrToInteger (Just (Bint bs)) = Just  bs
-maybeBstrToInteger _ = 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 "creation date" m
-                           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 = maybeBstrToInteger creationDate'
-                                        , comment = maybeBstrToString comment'
-                                        , createdBy = maybeBstrToString createdBy'
-                                        , encoding = maybeBstrToString encoding'
-                                        }
-mkMetaInfo _ = 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
+    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 $ (m ! "info")
+             }
+mkMetaInfo _ = Left "mkMetaInfo: expect an input dict"
 
 getAnnounceList :: Maybe BVal -> [String]
 getAnnounceList Nothing = []
@@ -82,11 +95,10 @@ getAnnounceList (Just (Blist l)) = map (\s -> case s of
                                                               [Bstr s''] -> unpack s''
                                                               _ -> ""
                                                _ -> "") l
-
 getAnnounceList (Just (Bdict _)) = []
 
--- | Info hash is urlencoded 20 byte SHA1 hash of the value of the info key from
--- the Metainfo file. Note that the value will be a bencoded dictionary, given
--- the definition of the info key above. TODO: `Metainfo -> ByteString`
-infoHash :: InfoDict -> ByteString
-infoHash m = hash . encode $ (m ! "info")
+torrentToMetainfo :: ByteString -> Either String Metainfo
+torrentToMetainfo s =
+  case decode s of
+   Right d -> mkMetaInfo d
+   Left e -> Left $ show e