Metainfo: fix warnings and refactor

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

diff --git a/src/FuncTorrent/Metainfo.hs b/src/FuncTorrent/Metainfo.hs
index 13e7979644c085b3b3778cad9478f81e5bbd9036..05c9de571097142b861f88f1fd50e071ca075ca2 100644 (file)
--- a/src/FuncTorrent/Metainfo.hs
+++ b/src/FuncTorrent/Metainfo.hs
@@ -27,21 +27,25 @@ module FuncTorrent.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)
@@ -50,30 +54,54 @@ 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 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)
@@ -82,7 +110,7 @@ mkMetaInfo (Bdict m)  =
              , 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"