Metainfo: rename mkInfo -> bvalToInfo

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

diff --git a/src/FuncTorrent/Metainfo.hs b/src/FuncTorrent/Metainfo.hs
index a3313d18cbb5c6338de4a38466719af25ad47258..4cc6ed126c2685528427f0145db03f9dbc5ae6a6 100644 (file)
--- a/src/FuncTorrent/Metainfo.hs
+++ b/src/FuncTorrent/Metainfo.hs
@@ -1,8 +1,27 @@
+{-
+ - 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(..),
-     mkInfo,
-     mkMetaInfo
+     torrentToMetainfo
     ) where
 
 import Prelude hiding (lookup)
@@ -11,7 +30,7 @@ import Data.Map as M ((!), lookup)
 import Crypto.Hash.SHA1 (hash)
 import Data.Maybe (maybeToList)
 
-import FuncTorrent.Bencode (BVal(..), encode, bstrToString, bValToInteger)
+import FuncTorrent.Bencode (BVal(..), encode, decode, bstrToString, bValToInteger)
 
 -- only single file mode supported for the time being.
 data Info = Info { pieceLength :: !Integer
@@ -22,7 +41,7 @@ data Info = Info { pieceLength :: !Integer
                  , md5sum :: !(Maybe String)
                  } deriving (Eq, Show)
 
-data Metainfo = Metainfo { info :: !Info
+data Metainfo = Metainfo { info :: !(Maybe Info)
                          , announceList :: ![String]
                          , creationDate :: !(Maybe Integer)
                          , comment :: !(Maybe String)
@@ -31,42 +50,41 @@ data Metainfo = Metainfo { info :: !Info
                          , 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 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'}
+bvalToInfo _ = Nothing
 
-mkMetaInfo :: BVal   -> Maybe Metainfo
+mkMetaInfo :: BVal   -> Either String Metainfo
 mkMetaInfo (Bdict m)  =
-    let (Just info')  = mkInfo $ m ! "info"
+    let info'         = bvalToInfo $ 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 = bValToInteger =<< creationDate'
-           , comment      = bstrToString  =<< comment'
-           , createdBy    = bstrToString  =<< createdBy'
-           , encoding     = bstrToString  =<< encoding'
-           , infoHash     = hash . encode $ (m ! "info")
-        }
-
-mkMetaInfo _ = Nothing
+    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 = []
@@ -78,5 +96,10 @@ getAnnounceList (Just (Blist l)) = map (\s -> case s of
                                                               [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 $ show e