-- |
--   Copyright   :  (c) Sam T. 2013
--   License     :  MIT
--   Maintainer  :  pxqr.sta@gmail.com
--   Stability   :  experimental
--   Portability :  portable
--
{-# LANGUAGE RecordWildCards #-}
module Network.BitTorrent
       (
         module Data.Torrent

         -- * Session
       , ThreadCount
       , defaultThreadCount

         -- ** Client
       , ClientSession( clientPeerId, allowedExtensions )

       , newClient
       , defaultClient

       , Progress(..)
       , getCurrentProgress
       , getPeerCount
       , getSwarmCount

       , TorrentLoc(..)
       , addTorrent
       , removeTorrent

         -- ** Swarm
       , SwarmSession(torrentMeta)

       , newLeecher
       , newSeeder

       , SessionCount
       , getSessionCount

         -- * Storage
       , Storage
       , ppStorage

       , bindTo
       , unbind

         -- * Discovery
       , discover
       , exchange


         -- * Peer to Peer
       , P2P

         -- ** Session
       , PeerSession( PeerSession, connectedPeerAddr
                    , swarmSession, enabledExtensions
                    )

       , getHaveCount
       , getWantCount
       , getPieceCount


         -- ** Transfer
       , Block(..), ppBlock
       , BlockIx(..), ppBlockIx

         -- ** Control
       , SessionException
       , disconnect
       , protocolError

         -- ** Events
       , Event(..)
       , awaitEvent, yieldEvent

         -- * Extensions
       , Extension, defaultExtensions, ppExtension
       ) where

import Control.Concurrent
import Control.Concurrent.STM
import Control.Exception
import Control.Monad
import Control.Monad.Reader

import Network

import Data.Bitfield as BF
import Data.Torrent
import Network.BitTorrent.Internal
import Network.BitTorrent.Exchange
import Network.BitTorrent.Exchange.Protocol
import Network.BitTorrent.Tracker
import Network.BitTorrent.Extension
import Network.BitTorrent.Peer

import System.Torrent.Storage


-- | Client session with default parameters. Use it for testing only.
defaultClient :: IO ClientSession
defaultClient = newClient defaultThreadCount defaultExtensions

-- discover should hide tracker and DHT communication under the hood
-- thus we can obtain an unified interface

discover :: SwarmSession -> P2P () -> IO ()
discover swarm @ SwarmSession {..} action = {-# SCC discover #-} do
  let conn = TConnection (tAnnounce torrentMeta)
                         (tInfoHash torrentMeta)
                         (clientPeerId clientSession)
                         (listenerPort clientSession)

  progress <- getCurrentProgress clientSession

  withTracker progress conn $ \tses -> do
    forever $ do
      addr <- getPeerAddr tses
      spawnP2P swarm addr $ do
        action

{-----------------------------------------------------------------------
    Torrent management
-----------------------------------------------------------------------}

-- | Used to check torrent location before register torrent.
validateLocation :: TorrentLoc -> IO Torrent
validateLocation TorrentLoc {..} = do
  t <- fromFile metafilePath
--  exists <- doesDirectoryExist dataDirPath
--  unless exists $ do
--    throw undefined
  return t


-- | Register torrent and start downloading.
addTorrent :: ClientSession -> TorrentLoc -> IO ()
addTorrent clientSession loc @ TorrentLoc {..} = do
  torrent <- validateLocation loc
--  registerTorrent loc tInfoHash
--  when (bf is not full)

  swarm   <- newLeecher  clientSession torrent
  storage <- swarm `bindTo` dataDirPath
  forkIO $ discover swarm $ do
    liftIO $ putStrLn "connected to peer"
    forever $ do
      liftIO $ putStrLn "from mesage loop"
      exchange storage
  return ()

-- | Unregister torrent and stop all running sessions.
removeTorrent :: ClientSession -> InfoHash ->  IO ()
removeTorrent ses loc = undefined -- atomically $ unregisterTorrent ses loc

{-
-- | The same as 'removeTorrrent' torrent, but delete all torrent
--   content files.
deleteTorrent :: ClientSession -> TorrentLoc -> IO ()
deleteTorrent ClientSession {..} TorrentLoc {..} = undefined
-}