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diff --git a/src/Network/BitTorrent/Tracker/Protocol.hs b/src/Network/BitTorrent/Tracker/Protocol.hs
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+-- |
+--   Copyright   :  (c) Sam T. 2013
+--   License     :  MIT
+--   Maintainer  :  pxqr.sta@gmail.com
+--   Stability   :  experimental
+--   Portability :  non-portable
+--
+--
+--   This module provides straigthforward Tracker protocol
+--   implementation. The tracker is an HTTP/HTTPS service:
+--
+--     * A tracker request is HTTP GET request; used to include
+--   metrics from clients that help the tracker keep overall
+--   statistics about the torrent.
+--
+--     * The tracker response includes a peer list that helps the
+--   client participate in the torrent.
+--
+--   For more convenient high level API see Network.BitTorrent.Tracker
+--   module.
+--
+{-# OPTIONS -fno-warn-orphans #-}
+{-# LANGUAGE OverloadedStrings #-}
+-- TODO: add "compact" field to TRequest
+module Network.BitTorrent.Tracker.Protocol
+       ( module Network.BitTorrent.Tracker.Scrape
+
+       , Event(..), TRequest(..), TResponse(..)
+       , sendRequest
+
+         -- * Defaults
+       , defaultPorts, defaultNumWant
+       )
+       where
+
+import Control.Applicative
+import Data.Char as Char
+import Data.Word (Word32)
+import Data.List as L
+import Data.Map  as M
+import Data.Monoid
+import Data.BEncode
+import Data.ByteString as B
+import           Data.ByteString.Char8 as BC
+import           Data.Text as T
+import Data.Serialize.Get hiding (Result)
+import Data.URLEncoded as URL
+import Data.Torrent
+
+import Network
+import Network.Socket
+import Network.HTTP
+import Network.URI
+
+import Network.BitTorrent.Peer
+import Network.BitTorrent.PeerID
+import Network.BitTorrent.Tracker.Scrape
+
+
+data Event = Started   -- ^ For first request.
+           | Stopped   -- ^ Sent when the peer is shutting down.
+           | Completed -- ^ To be sent when the peer completes a download.
+             deriving (Show, Read, Eq, Ord, Enum, Bounded)
+
+data TRequest = TRequest { -- TODO peer here -- TODO detach announce
+     reqAnnounce   :: URI         -- ^ Announce url of the torrent.
+   , reqInfoHash   :: InfoHash    -- ^ Hash of info part of the torrent.
+   , reqPeerID     :: PeerID      -- ^ Id of the peer doing request. ()
+   , reqPort       :: PortNumber  -- ^ Port to listen to for connection from other peers.
+   , reqUploaded   :: Integer     -- ^ # of bytes that the peer has uploaded in the swarm.
+   , reqDownloaded :: Integer     -- ^ # of bytes downloaded in the swarm by the peer.
+   , reqLeft       :: Integer     -- ^ # of bytes needed in order to complete download.
+   , reqIP         :: Maybe HostAddress    -- ^ The peer IP.
+   , reqNumWant    :: Maybe Int   -- ^ Number of peers that the peers wants to receive from.
+   , reqEvent      :: Maybe Event -- ^ If not specified,
+                                  --   the request is regular periodic request.
+   } deriving Show
+
+data TResponse =
+     Failure Text           -- ^ Failure reason in human readable form.
+   | OK {
+       respWarning     :: Maybe Text
+     , respInterval    :: Int       -- ^ Recommended interval to wait between requests.
+     , respMinInterval :: Maybe Int -- ^ Minimal amount of time between requests.
+     , respComplete    :: Maybe Int -- ^ Number of peers completed the torrent. (seeders)
+     , respIncomplete  :: Maybe Int -- ^ Number of peers downloading the torrent.
+     , respPeers       :: [Peer]    -- ^ Peers that must be contacted.
+     } deriving Show
+
+instance BEncodable PortNumber where
+  toBEncode = toBEncode . fromEnum
+  fromBEncode b = toEnum <$> fromBEncode b
+
+instance BEncodable Peer where
+  toBEncode (Peer pid pip pport) = fromAssocs
+    [ "peer id" -->? pid
+    , "ip"      -->  pip
+    , "port"    -->  pport
+    ]
+
+  fromBEncode (BDict d) =
+    Peer <$> d >--? "peer id"
+         <*> d >--  "ip"
+         <*> d >--  "port"
+
+  fromBEncode _ = decodingError "Peer"
+
+instance BEncodable TResponse where
+  toBEncode (Failure t)  = fromAssocs ["failure reason" --> t]
+  toBEncode resp@(OK {}) = fromAssocs
+    [ "interval"     -->  respInterval resp
+    , "min interval" -->? respMinInterval resp
+    , "complete"     -->? respComplete resp
+    , "incomplete"   -->? respIncomplete resp
+    , "peers"        -->  respPeers resp
+    ]
+
+  fromBEncode (BDict d)
+    | Just t <- M.lookup "failure reason" d = Failure <$> fromBEncode t
+    | otherwise = OK <$> d >--? "warning message"
+                     <*> d >--  "interval"
+                     <*> d >--? "min interval"
+                     <*> d >--? "complete"
+                     <*> d >--? "incomplete"
+                     <*> getPeers (M.lookup "peers" d)
+
+      where
+        getPeers :: Maybe BEncode -> Result [Peer]
+        getPeers (Just (BList l))     = fromBEncode (BList l)
+        getPeers (Just (BString s))
+            | B.length s `mod` 6 == 0 =
+              let cnt = B.length s `div` 6 in
+              runGet (sequence (L.replicate cnt peerG)) s
+            | otherwise = decodingError "peers length not a multiple of 6"
+          where
+            peerG = do
+              pip   <- getWord32be
+              pport <- getWord16be
+              return (Peer Nothing (fromIntegral pip) (fromIntegral pport))
+
+        getPeers _ = decodingError "Peers"
+
+  fromBEncode _ = decodingError "TResponse"
+
+
+instance URLShow PortNumber where
+  urlShow = urlShow . fromEnum
+
+instance URLShow Word32 where
+  urlShow = show
+
+instance URLShow Event where
+  urlShow e = urlShow (Char.toLower x : xs)
+    where
+      -- this is always nonempty list
+      (x : xs) = show e
+
+instance URLEncode TRequest where
+  urlEncode req = mconcat
+      [ s "peer_id"    %=  reqPeerID req
+      , s "port"       %=  reqPort req
+      , s "uploaded"   %=  reqUploaded req
+      , s "downloaded" %=  reqDownloaded req
+      , s "left"       %=  reqLeft req
+      , s "ip"         %=? reqIP req
+      , s "numwant"    %=? reqNumWant req
+      , s "event"      %=? reqEvent req
+      ]
+    where s :: String -> String;  s = id; {-# INLINE s #-}
+
+encodeRequest :: TRequest -> URI
+encodeRequest req = URL.urlEncode req
+                    `addToURI`      reqAnnounce req
+                    `addHashToURI`  reqInfoHash req
+
+
+-- | Ports typically reserved for bittorrent.
+defaultPorts :: [PortNumber]
+defaultPorts = [6881..6889]
+
+-- | Above 25, new peers are highly unlikely to increase download speed.
+--   Even 30 peers is _plenty_, the official client version 3 in fact only
+--   actively forms new connections if it has less than 30 peers and will
+--   refuse connections if it has 55. So default value is set to 25.
+--
+defaultNumWant :: Int
+defaultNumWant = 25
+
+
+
+
+-- | TODO rename to ask for peers
+--
+sendRequest :: TRequest -> IO (Result TResponse)
+sendRequest req = do
+  let r = mkHTTPRequest (encodeRequest req)
+
+  rawResp  <- simpleHTTP r
+  respBody <- getResponseBody rawResp
+  return (decoded (BC.pack respBody))
+
+  where
+    mkHTTPRequest :: URI -> Request String
+    mkHTTPRequest uri = Request uri GET [] ""