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{-# OPTIONS -fno-warn-orphans #-}
{-# LANGUAGE OverloadedStrings #-}
-- | This module provides torrent metainfo serialization.
module Data.Torrent
( Torrent(..), TorrentInfo(..), TorrentFile(..)
, fromFile
) where
import Control.Applicative
import Control.Monad
import qualified Data.Map as M
import Data.ByteString (ByteString)
import qualified Data.ByteString as B
import qualified Data.ByteString.Char8 as BC (pack, unpack)
import Data.Text (Text)
import Crypto.Hash.SHA1
import Data.BEncode
import Network.URL
type Time = Text
-- TODO comment fields
-- TODO more convenient form of torrent info.
data Torrent = Torrent {
tInfoHash :: ByteString
, tAnnounce :: URL
, tAnnounceList :: Maybe [[URL]]
, tComment :: Maybe Text
, tCreatedBy :: Maybe ByteString
, tCreationDate :: Maybe Time
, tEncoding :: Maybe ByteString
, tInfo :: TorrentInfo
, tPublisher :: Maybe URL
, tPublisherURL :: Maybe URL
} deriving Show
data TorrentInfo =
SingleFile {
tLength :: Int
, tMD5sum :: Maybe ByteString
, tName :: ByteString
, tPieceLength :: Int
, tPieces :: ByteString -- Vector ByteString?
, tPrivate :: Maybe Bool
}
| MultiFile {
tFiles :: [TorrentFile]
, tName :: ByteString
, tPieceLength :: Int
, tPieces :: ByteString -- Vector ByteString?
, tPrivate :: Maybe Bool
} deriving (Show, Read, Eq)
data TorrentFile = TorrentFile {
tfLength :: Int
, tfMD5sum :: Maybe ByteString
, tfPath :: [ByteString]
} deriving (Show, Read, Eq)
instance BEncodable URL where
toBEncode = toBEncode . BC.pack . exportURL -- TODO utf8 encoding
{-# INLINE toBEncode #-}
fromBEncode (BString s) | Just url <- importURL (BC.unpack s) = return url
fromBEncode b = decodingError $ "url <" ++ show b ++ ">"
{-# INLINE fromBEncode #-}
instance BEncodable Torrent where
toBEncode t = fromAscAssocs
[ "announce" --> tAnnounce t
, "announce-list" -->? tAnnounceList t
, "comment" -->? tComment t
, "created by" -->? tCreatedBy t
, "creation date" -->? tCreationDate t
, "encoding" -->? tEncoding t
, "info" --> tInfo t
, "publisher" -->? tPublisher t
, "publisher-url" -->? tPublisherURL t
]
fromBEncode (BDict d) | Just info <- M.lookup "info" d =
Torrent <$> pure (hashlazy (encode info))
<*> d >-- "announce"
<*> d >--? "announce-list"
<*> d >--? "comment"
<*> d >--? "created by"
<*> d >--? "creation date"
<*> d >--? "encoding"
<*> d >-- "info"
<*> d >--? "publisher"
<*> d >--? "publisher-url"
fromBEncode _ = decodingError "Torrent"
instance BEncodable TorrentInfo where
toBEncode ti@(SingleFile { }) = fromAscAssocs
[ "length" --> tLength ti
, "md5sum" -->? tMD5sum ti
, "name" --> tName ti
, "piece length" --> tPieceLength ti
, "pieces" --> tPieces ti
, "private" -->? tPrivate ti
]
toBEncode ti@(MultiFile {}) = fromAscAssocs
[ "files" --> tFiles ti
, "name" --> tName ti
, "piece length" --> tPieceLength ti
, "pieces" --> tPieces ti
, "private" -->? tPrivate ti
]
fromBEncode (BDict d)
| Just (BList fs) <- M.lookup "files" d =
MultiFile <$> mapM fromBEncode fs
<*> d >-- "name"
<*> d >-- "piece length"
<*> d >-- "pieces"
<*> d >--? "private"
| otherwise =
SingleFile <$> d >-- "length"
<*> d >--? "md5sum"
<*> d >-- "name"
<*> d >-- "piece length"
<*> d >-- "pieces"
<*> d >--? "private"
fromBEncode _ = decodingError "TorrentInfo"
instance BEncodable TorrentFile where
toBEncode tf = fromAssocs
[ "length" --> tfLength tf
, "md5sum" -->? tfMD5sum tf
, "path" --> tfPath tf
]
fromBEncode (BDict d) =
TorrentFile <$> d >-- "length"
<*> d >--? "md5sum"
<*> d >-- "path"
fromBEncode _ = decodingError "TorrentFile"
fromFile :: FilePath -> IO (Result Torrent)
fromFile path = (fromBEncode <=< decode) <$> B.readFile path
|
