src/FuncTorrent/Metainfo.hs

   1 module FuncTorrent.Metainfo
   2     (Info,
   3      Metainfo,
   4      mkMetaInfo,
   5      mkInfo,
   6      announce,
   7      lengthInBytes,
   8      info,
   9      name
  10     ) where
  11
  12 import Prelude hiding (lookup)
  13 import Data.ByteString.Char8 (ByteString, pack, unpack)
  14 import Data.Map as M ((!), lookup)
  15
  16 import FuncTorrent.Bencode (BVal(..))
  17
  18 -- only single file mode supported for the time being.
  19 data Info = Info { pieceLength :: !Integer
  20                  , pieces :: !ByteString
  21                  , private :: !(Maybe Integer)
  22                  , name :: !String
  23                  , lengthInBytes :: !Integer
  24                  , md5sum :: !(Maybe String)
  25                  } deriving (Eq, Show)
  26
  27 data Metainfo = Metainfo { info :: !Info
  28                          , announce :: !String
  29                          , announceList :: !(Maybe [[String]])
  30                          , creationDate :: !(Maybe String)
  31                          , comment :: !(Maybe String)
  32                          , createdBy :: !(Maybe String)
  33                          , encoding :: !(Maybe String)
  34                          } deriving (Eq, Show)
  35
  36 mkInfo :: BVal -> Maybe Info
  37 mkInfo (Bdict m) = let (Bint pieceLength') = m ! Bstr (pack "piece length")
  38                        (Bstr pieces') = m ! Bstr (pack "pieces")
  39                        private' = Nothing
  40                        (Bstr name') = m ! Bstr (pack "name")
  41                        (Bint length') = m ! Bstr (pack "length")
  42                        md5sum' = Nothing
  43                    in Just Info { pieceLength = pieceLength'
  44                                 , pieces = pieces'
  45                                 , private = private'
  46                                 , name = unpack name'
  47                                 , lengthInBytes = length'
  48                                 , md5sum = md5sum'}
  49 mkInfo _ = Nothing
  50
  51 maybeBstrToString :: Maybe BVal -> Maybe String
  52 maybeBstrToString Nothing = Nothing
  53 maybeBstrToString (Just s) = let (Bstr bs) = s
  54                              in Just (unpack bs)
  55
  56 mkMetaInfo :: BVal -> Maybe Metainfo
  57 mkMetaInfo (Bdict m) = let (Just info') = mkInfo (m ! Bstr (pack "info"))
  58                            (Bstr announce') = m ! Bstr (pack "announce")
  59                            -- announceList = lookup (Bstr (pack "announce list"))
  60                            announceList' = Nothing
  61                            -- creationDate = lookup (Bstr (pack "creation date")) m
  62                            creationDate' = Nothing
  63                            comment' = lookup (Bstr (pack "comment")) m
  64                            createdBy' = lookup (Bstr (pack "created by")) m
  65                            encoding' = lookup (Bstr (pack "encoding")) m
  66                        in Just Metainfo { info = info'
  67                                         , announce = unpack announce'
  68                                         , announceList = announceList'
  69                                         , creationDate = creationDate'
  70                                         , comment = maybeBstrToString comment'
  71                                         , createdBy = maybeBstrToString createdBy'
  72                                         , encoding = maybeBstrToString encoding'
  73                                         }
  74 mkMetaInfo _ = Nothing