path: root/examples/dhtd.hs

{-# LANGUAGE BangPatterns              #-}
{-# LANGUAGE CPP                       #-}
{-# LANGUAGE ExistentialQuantification #-}
{-# LANGUAGE FlexibleContexts          #-}
{-# LANGUAGE FlexibleInstances         #-}
{-# LANGUAGE LambdaCase                #-}
{-# LANGUAGE MultiParamTypeClasses     #-}
{-# LANGUAGE NamedFieldPuns            #-}
{-# LANGUAGE NondecreasingIndentation  #-}
{-# LANGUAGE OverloadedStrings         #-}
{-# LANGUAGE PartialTypeSignatures     #-}
{-# LANGUAGE PatternSynonyms           #-}
{-# LANGUAGE RankNTypes                #-}
{-# LANGUAGE RecordWildCards           #-}
{-# LANGUAGE ScopedTypeVariables       #-}
{-# LANGUAGE TupleSections             #-}
{-# LANGUAGE TypeFamilies              #-}
{-# LANGUAGE TypeOperators             #-}

module Main where

import Control.Arrow
import Control.Applicative
import Control.Concurrent.STM
import Control.Concurrent.STM.TMChan
import Control.Exception
import Control.Monad
import Control.Monad.IO.Class (liftIO)
import Control.Monad.Trans.Control
import Control.Monad.Trans.Resource (runResourceT)
import Data.Bool
import Data.Char
import Data.Conduit as C
import Data.Function
import Data.Hashable
import Data.List
import Data.Word
import qualified Data.IntMap.Strict as IntMap
import qualified Data.Map.Strict as Map
import Data.Maybe
import qualified Data.Set        as Set
import Data.Tuple
import Data.Time.Clock
import qualified Data.XML.Types  as XML
import GHC.Conc (threadStatus,ThreadStatus(..))
import GHC.Stats
import Network.Socket
import System.Environment
import System.IO
import System.Mem
import System.Posix.Process
import Text.PrettyPrint.HughesPJClass
import Text.Printf
import Text.Read
#ifdef THREAD_DEBUG
import Control.Concurrent.Lifted.Instrument
#else
import Control.Concurrent.Lifted
import GHC.Conc                  (labelThread)
#endif
import qualified Data.HashMap.Strict as HashMap
import qualified Data.Vector as V
import qualified Data.Text as T
import qualified Data.Text.Encoding as T
import System.Posix.Signals


import Announcer
import Crypto.Tox -- (zeros32,SecretKey,PublicKey, generateSecretKey, toPublic, encodeSecret, decodeSecret, userKeys)
import Network.UPNP as UPNP
import Network.Address hiding (NodeId, NodeInfo(..))
import Network.QueryResponse
import Network.StreamServer
import Network.Kademlia.Search
import qualified Network.BitTorrent.MainlineDHT as Mainline
import qualified Network.Tox as Tox
import Network.Kademlia.Routing as R
import Data.Aeson as J (ToJSON, FromJSON)
import qualified Data.Aeson as J
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString.Char8 as B
import Control.Concurrent.Tasks
import System.IO.Error
import qualified Data.Serialize as S
import Network.BitTorrent.DHT.ContactInfo as Peers
import qualified Data.MinMaxPSQ as MM
import Data.Wrapper.PSQ as PSQ (pattern (:->))
import qualified Data.Wrapper.PSQ as PSQ
import Data.Ord
import Data.Time.Clock.POSIX
import qualified Network.Tox.DHT.Transport as Tox
import qualified Network.Tox.DHT.Handlers as Tox
import qualified Network.Tox.Onion.Transport as Tox
import qualified Network.Tox.Onion.Handlers as Tox
import qualified Network.Tox.Crypto.Transport as Tox (CryptoMessage(..),CryptoData(..), isOFFLINE, isKillPacket)
import qualified Network.Tox.Crypto.Handlers as Tox
import Data.Typeable
import Network.Tox.ContactInfo as Tox
import OnionRouter
import PingMachine
import Data.PacketQueue

-- Presence imports.
import ConsoleWriter
import Presence
import XMPPServer
import Connection
import ToxToXMPP
import qualified Connection.Tcp as Tcp (ConnectionEvent(..))


showReport :: [(String,String)] -> String
showReport kvs = showColumns $ map (\(x,y)->[x,y]) kvs

showColumns :: [[String]] -> String
showColumns rows = do
    let cols = transpose rows
        ws = map (maximum . map (succ . length)) cols
    fs <- rows
    _ <- take 1 fs -- Guard against empty rows so that 'last' is safe.
    "  " ++ concat (zipWith (printf "%-*s") (init ws) (init fs)) ++ last fs ++ "\n"


marshalForClient :: String -> String
marshalForClient s = show (length s) ++ ":" ++ s

data ClientHandle = ClientHandle Handle (MVar Int)

-- | Writes a message and signals ready for next command.
hPutClient :: ClientHandle -> String -> IO ()
hPutClient (ClientHandle h hstate) s = do
    st <- takeMVar hstate
    hPutStr h ('.' : marshalForClient s)
    putMVar hstate 1 -- ready for input

-- | Writes message, but signals there is more to come.
hPutClientChunk :: ClientHandle -> String -> IO ()
hPutClientChunk (ClientHandle h hstate) s = do
    st <- takeMVar hstate
    hPutStr h (' ' : marshalForClient s)
    putMVar hstate 2 -- ready for more output

data DHTQuery nid ni = forall addr r tok.
                        ( Ord addr
                        , Typeable r
                        , Typeable tok
                        , Typeable ni
                        ) => DHTQuery
    { qsearch     :: Search nid addr tok ni r
    , qhandler    :: ni -> nid -> IO ([ni], [r], Maybe tok) -- ^ Invoked on local node, when there is no query destination.
    , qshowR      :: r -> String
    , qshowTok    :: tok -> Maybe String
    }

data DHTAnnouncable nid = forall dta tok ni r.
                        ( Show r
                        , Typeable dta -- information being announced
                        , Typeable tok -- token
                        , Typeable r   -- search result
                        , Typeable ni  -- node
                        ) => DHTAnnouncable
    { announceParseData    :: String -> Either String dta
    , announceParseToken   :: dta -> String -> Either String tok
    , announceParseAddress :: String -> Either String ni
    , announceSendData     :: Either ( String {- search name -}
                                     , String -> Either String r
                                     , PublicKey {- me -} -> dta -> r -> IO ())
                                     (dta -> tok -> Maybe ni -> IO (Maybe r))
    , announceInterval     :: POSIXTime
    , announceTarget       :: dta -> nid
    }

data DHTSearch nid ni = forall addr tok r. DHTSearch
    { searchThread     :: ThreadId
    , searchState      :: SearchState nid addr tok ni r
    , searchShowTok    :: tok -> Maybe String
    , searchResults    :: TVar (Set.Set String)
    }

data DHTPing ni = forall r. DHTPing
    { pingQuery :: [String] -> ni -> IO (Maybe r)
    , pingShowResult :: r -> String
    }

data DHT = forall nid ni. ( Show     ni
                          , Read     ni
                          , ToJSON   ni
                          , FromJSON ni
                          , Ord      ni
                          , Hashable ni
                          , Show     nid
                          , Ord      nid
                          , Hashable nid
                          , Typeable ni
                          , S.Serialize nid
                          ) =>
    DHT
    { dhtBuckets       :: TVar (BucketList ni)
    , dhtSecretKey     :: STM (Maybe SecretKey)
    , dhtPing          :: Map.Map String (DHTPing ni)
    , dhtQuery         :: Map.Map String (DHTQuery nid ni)
    , dhtAnnouncables  :: Map.Map String (DHTAnnouncable nid)
    , dhtParseId       :: String -> Either String nid
    , dhtSearches      :: TVar (Map.Map (String,nid) (DHTSearch nid ni))
    , dhtFallbackNodes :: IO [ni]
    , dhtBootstrap     :: [ni] -> [ni] -> IO ()
    }

nodesFileName :: String -> String
nodesFileName netname = netname ++ "-nodes.json"

saveNodes :: String -> DHT -> IO ()
saveNodes netname DHT{dhtBuckets} = do
    bkts <- atomically $ readTVar dhtBuckets
    let ns = map fst $ concat $ R.toList bkts
        bs = J.encode ns
        fname = nodesFileName netname
    L.writeFile fname bs

loadNodes :: FromJSON ni => String -> IO [ni]
loadNodes netname = do
    let fname = nodesFileName netname
    attempt <- tryIOError $ do
        J.decode <$> L.readFile fname
         >>= maybe (ioError $ userError "Nothing") return
    either (const $ fallbackLoad fname) return attempt

fallbackLoad :: FromJSON t => FilePath -> IO [t]
fallbackLoad fname = do
    attempt <- tryIOError $ do
        J.decode <$> L.readFile fname
         >>= maybe (ioError $ userError "Nothing") return
    let go r = do
            let m = HashMap.lookup "nodes" (r :: J.Object)
                ns0 = case m of Just (J.Array v) -> V.toList v
                                Nothing        -> []
                ns1 = zip (map J.fromJSON ns0) ns0
                issuc (J.Error _,_) = False
                issuc _             = True
                (ss,fs) = partition issuc ns1
                ns = map (\(J.Success n,_) -> n) ss
            mapM_ print (map snd fs)  >> return ns
    either (const $ return []) go attempt


{-
pingNodes :: String -> DHT -> IO Bool
pingNodes netname DHT{dhtPing} | Just DHTPing{pingQuery=ping} <- Map.lookup "ping" dhtPing = do
    let fname = nodesFileName netname
    attempt <- tryIOError $ do
        J.decode <$> L.readFile fname
         >>= maybe (ioError $ userError "Nothing") return
-}

asProxyTypeOf :: a -> proxy a -> a
asProxyTypeOf = const

pingNodes :: String -> DHT -> IO (Maybe Int)
pingNodes netname dht@DHT{dhtPing} | Just DHTPing{pingQuery=ping} <- Map.lookup "ping" dhtPing = do
    let fname = nodesFileName netname
    ns <- loadNodes netname
    case ns of
        [] -> return Nothing
        _ -> do
            fork $ do
                 myThreadId >>= flip labelThread ("pinging."++fname)
                 putStrLn $ "Forked "++show fname
                 withTaskGroup ("withTaskGroup."++fname) 10 $ \g -> do
                   forM_ (ns `asTypeOf` [])
                        $ \n -> forkTask g (show n)
                                $ void
                                $ ping [] n
                 putStrLn $ "Load finished "++show fname
            return $ Just $ length ns
pingNodes _ _ = return Nothing



reportTable :: Show ni => BucketList ni -> [(String,String)]
reportTable bkts = map (show *** show . fst)
                 $ concat
                 $ zipWith map (map (,) [0::Int ..])
                 $ R.toList
                 $ bkts

reportResult ::
    String
    -> (r -> String)
    -> (tok -> Maybe String)
    -> (ni -> String)
    -> ClientHandle
    -> Either String ([ni],[r],Maybe tok)
    -> IO ()
reportResult meth showR showTok showN h (Left e)            = hPutClient h e
reportResult meth showR showTok showN h (Right (ns,rs,tok)) = do
    hPutClient h $ showReport report
 where
    report = intercalate [("","")] [ tok_r , node_r , result_r ]

    tok_r = maybe [] (pure . ("token:",)) $ showTok =<< tok

    node_r = map ( ("n",) . showN ) ns

    result_r | (meth=="node") = []
             | otherwise      = map ( (take 1 meth,) . showR ) rs

-- example:
-- * 10 peer 141d6c6ee2810f46d28bbe8373d4f454a4122535
-- - 1  peer 141d6c6ee2810f46d28bbe8373d4f454a4122535
--   22 node 141d6c6ee2810f46d28bbe8373d4f454a4122535
--
-- key: '*' in progress
--      '-' stopped
--      ' ' finished
showSearches :: ( Show nid
                , Ord nid
                , Hashable nid
                , Ord ni
                , Hashable ni
                ) => Map.Map (String,nid) (DHTSearch nid ni) -> IO String
showSearches searches = do
    tups <- forM (Map.toList searches) $ \((meth,nid),DHTSearch{..}) -> do
        (is'fin, cnt) <- atomically $
                (,) <$> searchIsFinished searchState
                    <*> (Set.size <$> readTVar searchResults)
        tstat <- threadStatus searchThread
        let stat = case tstat of
                _ | is'fin     -> ' '
                ThreadFinished -> '-'
                ThreadDied     -> '-'
                _              -> '*'
        return (stat,show cnt,meth,show nid)
    let cnt'width = maximum $ map (\(_,cnt,_,_)->length cnt) tups
        mth'width = maximum $ map (\(_,_,mth,_)->length mth) tups
    return $ do -- List monad.
        (stat,cnt,meth,nid) <- tups
        printf "  %c %-*s %-*s %s\n" stat cnt'width cnt mth'width meth nid

forkSearch ::
    ( Ord nid
    , Hashable nid
    , Ord ni
    , Hashable ni
    , Show nid
    ) =>
    String
    -> nid
    -> DHTQuery nid ni
    -> TVar (Map.Map (String,nid) (DHTSearch nid ni))
    -> TVar (BucketList ni)
    -> ThreadId
    -> TVar (Maybe (IO ()))
    -> STM ()
forkSearch method nid DHTQuery{qsearch,qshowTok,qshowR} dhtSearches dhtBuckets  tid kvar = do
    ns <- R.kclosest (searchSpace qsearch) searchK nid <$> readTVar dhtBuckets
    st <- newSearch qsearch nid ns
    results <- newTVar Set.empty
    let storeResult r = modifyTVar' results (Set.insert (qshowR r))
                        >> return True
        new = DHTSearch
            { searchThread  = tid
            , searchState   = st
            , searchShowTok = qshowTok
            , searchResults = results
            }
    modifyTVar' dhtSearches $ Map.insert (method,nid) new
    -- Finally, we write the search loop action into a tvar that will be executed in a new
    -- thread.
    writeTVar kvar $ Just $ searchLoop qsearch nid storeResult st

reportSearchResults :: (Show t, Ord t1, Ord t, Hashable t) =>
                                   String -> ClientHandle -> DHTSearch t1 t -> IO ()
reportSearchResults meth h DHTSearch{searchShowTok,searchState,searchResults} = do
    (ns,rs) <- atomically $ do
        mm <- readTVar $ searchInformant searchState
        rset <- readTVar searchResults
        let ns = map (\(MM.Binding ni tok _) -> (ni,tok))
                     $ MM.toList mm
            rs = Set.toList rset
        return (ns,rs)
    let n'width       = succ $ maximum $ map (length . show . fst) ns
        showN (n,tok) = take n'width (show n ++ repeat ' ') ++ (fromMaybe "" $ searchShowTok =<< tok)
        ns'           = map showN ns
    reportResult meth id (const Nothing) id h (Right (ns',rs, Just ()))

data ConnectionManager = forall status k. ConnectionManager { typedManager :: Connection.Manager status k }

data Session = Session
    { netname           :: String
    , selectedKey       :: Maybe PublicKey
    , dhts              :: Map.Map String DHT
    , externalAddresses :: IO [SockAddr]
    , swarms            :: Mainline.SwarmsDatabase
    , cryptosessions    :: Tox.NetCryptoSessions
    , toxkeys           :: TVar Tox.AnnouncedKeys
    , userkeys          :: TVar [(SecretKey,PublicKey)]
    , roster            :: Tox.ContactInfo
    , announceToLan     :: IO ()
    , sessions          :: TVar [PerSession]
    , connectionManager :: Maybe ConnectionManager
    , onionRouter       :: OnionRouter
    , announcer         :: Announcer
    , signalQuit        :: IO ()
    }

exceptionsToClient :: ClientHandle -> IO () -> IO ()
exceptionsToClient (ClientHandle h hstate) action =
    action `catch` \(SomeException e) -> do
                        st <- takeMVar hstate
                        when (st /= 1) $ do
                            hPutStr h ('.': marshalForClient (show e))
                        putMVar hstate 1 -- ready for input

hGetClientLine :: ClientHandle -> IO String
hGetClientLine (ClientHandle h hstate) = do
    st <- takeMVar hstate
    -- st should be 1
    x <- hGetLine h
    putMVar hstate 0 -- ready for output
    return x

hCloseClient :: ClientHandle -> IO ()
hCloseClient (ClientHandle h hstate) = do
    st <- takeMVar hstate
    hClose h
    putMVar hstate 3 -- closed file handle

clientSession0 :: Session -> t1 -> t -> Handle -> IO ()
clientSession0 s sock cnum h = do
    hstate <- newMVar 1 -- ready for input
    clientSession s sock cnum (ClientHandle h hstate)
  `catch` \e -> if isEOFError e then return ()
                                else throwIO e

readKeys :: TVar [(SecretKey, PublicKey)]
            -> TVar (HashMap.HashMap Tox.NodeId Account)
            -> STM [(SecretKey, PublicKey)]
readKeys userkeys roster = do
    uks <- readTVar userkeys
    as <- readTVar roster
    return $ uks ++ map ((userSecret *** Tox.id2key) . swap) (HashMap.toList as)

clientSession :: Session -> t1 -> t -> ClientHandle -> IO ()
clientSession s@Session{..} sock cnum h = do
    line <- dropWhile isSpace <$> hGetClientLine h
    let (c,args) = second (dropWhile isSpace) $ break isSpace line
        cmd0 :: IO () -> IO ()
        cmd0 action = exceptionsToClient h action >> clientSession s sock cnum h
        switchNetwork dest = do hPutClient h ("Network: "++dest)
                                clientSession s{netname=dest} sock cnum h
        switchKey key = clientSession s { selectedKey = key } sock cnum h
        strp = B.unpack . fst . until snd dropEnd . (,False) . B.dropWhile isSpace . B.pack
            where
                dropEnd (x,_) =
                    case B.unsnoc x of
                                 Just (str,c) | isSpace c -> (str,False)
                                 _ -> (x,True)
    let mkrow :: (SecretKey, PublicKey) -> (String,String)
        mkrow (a,b) | Just x <- encodeSecret a= (B.unpack x, show (Tox.key2id b))
        mkrow _ = error (concat ["Assertion fail in 'mkrow' function at ", __FILE__, ":", show __LINE__])
        sessionCommands :: [[String]]
        sessionCommands =
            [ ["ping"]   -- pinglike
            , ["cookie"] -- pinglike
            , ["stop"]
            , ["throw"]
            , ["quit"]
            , ["pid"]
            , ["external-ip"]
            , ["threads"]
            , ["mem"]
            , ["nid"]
            , ["lan"]
            , ["ls"]
            , ["k"]
            , ["roster"]
            , ["sessions"]
            , ["onion"]
            , ["g"]
            , ["p"]
            , ["a"]
            , ["s"]
            , ["x"]
            , ["save"]
            , ["load"]
            , ["swarms"]
            , ["peers"]
            , ["toxids"]
            , ["c"]
            , ["help"]
            ]
    case (map toLower c,args) of
        (n, _) | n `elem` Map.keys dhts -> switchNetwork n
        -- "ping"
        -- "cookie"
        (pinglike, s) | Just DHT{dhtPing} <- Map.lookup netname dhts
                      , Just DHTPing{ pingQuery=ping
                                    , pingShowResult=showr } <- Map.lookup pinglike dhtPing
                      , ws@(_:_) <- words s
                    -> cmd0 $ do
                        case readEither $ last ws of
                          Right addr -> do result <- ping (init ws) addr
                                           let rs = [" ", maybe "Timeout." showr result]
                                           hPutClient h $ unlines rs
                          Left er -> hPutClient h er
        (x,_) | not (null (strp x))
              , x `notElem` map head sessionCommands -> cmd0 $ do
                hPutClient h $ "error."

        ("stop", _) -> do hPutClient h "Terminating DHT Daemon."
                          hCloseClient h
                          signalQuit

        ("throw", er) -> cmd0 $ do
                            throwIO $ userError er
                            hPutClient h "The impossible happened!"

        ("quit", _) -> hPutClient h "" >> hCloseClient h

        ("pid", _) -> cmd0 $ do
                    pid <- getProcessID
                    hPutClient h (show pid)
        ("external-ip", _) -> cmd0 $ do
                    unlines . map (either show show . either4or6) <$> externalAddresses
                        >>= hPutClient h
#ifdef THREAD_DEBUG
        ("threads", _) -> cmd0 $ do
                    ts <- threadsInformation
                    tm <- getCurrentTime
                    r <- forM ts $ \(tid,PerThread{..}) -> do
                        stat <- threadStatus tid
                        let showStat (ThreadBlocked reason) = show reason
                            showStat stat                   = show stat
                        return [show lbl,show (diffUTCTime tm startTime),showStat stat]
                    hPutClient h $ showColumns r
#endif
        ("mem", s) -> cmd0 $ do
                    case s of
                        "gc" -> do hPutClient h "Performing garbage collection..."
                                   performMajorGC
                        "" -> do
                            is_enabled <- getGCStatsEnabled
                            if is_enabled
                             then do
                                GCStats{..} <- getGCStats
                                let r = [ ("bytesAllocated", show bytesAllocated)
                                        , ("numGcs", show numGcs)
                                        , ("maxBytesUsed", show maxBytesUsed)
                                        , ("numByteUsageSamples", show numByteUsageSamples)
                                        , ("cumulativeBytesUsed", show cumulativeBytesUsed)
                                        , ("bytesCopied", show bytesCopied)
                                        , ("currentBytesUsed", show currentBytesUsed)
                                        , ("currentBytesSlop", show currentBytesSlop)
                                        , ("maxBytesSlop", show maxBytesSlop)
                                        , ("peakMegabytesAllocated", show peakMegabytesAllocated)
                                        , ("mutatorCpuSeconds", show mutatorCpuSeconds)
                                        , ("mutatorWallSeconds", show mutatorWallSeconds)
                                        , ("gcCpuSeconds", show gcCpuSeconds)
                                        , ("gcWallSeconds", show gcWallSeconds)
                                        , ("cpuSeconds", show cpuSeconds)
                                        , ("wallSeconds", show wallSeconds)
                                        , ("parTotBytesCopied", show parTotBytesCopied)
                                        , ("parMaxBytesCopied", show parMaxBytesCopied)
                                        ]
                                hPutClient h $ showReport r
                            else hPutClient h "Run with +RTS -T to obtain live memory-usage information."
                        _ -> hPutClient h "error."

        ("nid", s) | Just DHT{dhtParseId} <- Map.lookup netname dhts
                    -> cmd0 $ do
                        hPutClient h $ case dhtParseId s of
                            Left e    ->
                                -- HACK: split nospam from hex toxid
                                case dhtParseId (take 64 s) of
                                    Left e -> "Error: " ++ e
                                    Right nid -> show nid ++ " nospam:" ++ drop 64 s
                            Right nid -> show nid

        ("lan", _)  -> cmd0 $ do
                        announceToLan
                        hPutClient h "ok"

        ("ls", _) | Just DHT{dhtBuckets} <- Map.lookup netname dhts
                    -> cmd0 $ do
                        bkts <- atomically $ readTVar dhtBuckets
                        let r = reportTable bkts
                        hPutClient h $
                            showReport $
                                    r ++ [ ("buckets", show $ R.shape bkts)
                                         , ("node-id", show $ thisNode bkts)
                                         , ("network", netname) ]

        --  TODO: online documentation.
        --
        --  k - manage key-pairs
        --
        --      k                  (list keys)
        --      k gen              (generate new key and list keys)
        --      k add <secret-key> (input a specific secret key)
        --      k del <secret-key>
        --      k secrets          (list key pairs, including secret keys)

        ("k", s) | ""           <- strp s -> cmd0 $ do
                        ks <- atomically $ readKeys userkeys (accounts roster)
                        let spaces k | Just sel <- selectedKey, (sel == k) = " *"
                                     | otherwise                           = "  "
                        hPutClient h $ unlines $ map (\(_,k) -> mappend (spaces k) . show . Tox.key2id $ k) ks
                 | "gen"        <- strp s -> do
                        secret <- generateSecretKey
                        let pubkey = toPublic secret
                        oldks <- atomically $ do
                            ks <- readTVar userkeys
                            modifyTVar userkeys ((secret,pubkey):)
                            Tox.addContactInfo roster secret
                            return ks
                        let asString = show . Tox.key2id
                        hPutClient h $ unlines $ map (mappend "  " . show . Tox.key2id . snd) oldks
                                                  ++ [mappend " *" . show . Tox.key2id $ pubkey]
                        switchKey $ Just pubkey
                 | "secrets"    <- strp s -> cmd0 $ do
                        ks <- atomically $ readKeys userkeys (accounts roster)
                        skey <- maybe (return Nothing) (atomically . dhtSecretKey)
                                      $ Map.lookup netname dhts
                        hPutClient h . showReport $ map mkrow ks ++ case skey >>= encodeSecret of
                            Just x  -> [("",""),("dht-key:",B.unpack x)]
                            Nothing -> []
                 | ("sel",_:expr) <- break isSpace s -> do
                         ks <- atomically $ map (show . Tox.key2id . snd) <$> readKeys userkeys (accounts roster)
                         case find (isInfixOf expr) ks of
                            Just k -> do
                                hPutClient h $ "Selected key: "++k
                                switchKey $ Just $ Tox.id2key $ read k
                            Nothing -> cmd0 $ hPutClient h "no match."
                 | ("add":secs) <- words s
                 , mbSecs <- map (decodeSecret . B.pack) secs
                 , all isJust mbSecs -> do
                        let f (Just b) = b
                            f x = error (concat ["Assertion fail at ", __FILE__, ":", show __LINE__])
                        let toPair x = (x,toPublic x)
                            pairs = map (toPair . f) mbSecs
                        oldks <- atomically $ do
                            oldks <- readTVar userkeys
                            modifyTVar userkeys (pairs ++)
                            forM pairs $ \(sk,_) -> Tox.addContactInfo roster sk
                            return oldks
                        hPutClient h $ unlines $ map (mappend "  " . show . Tox.key2id . snd) oldks
                                                  ++ map (mappend " *" . show . Tox.key2id .snd) pairs
                        switchKey $ listToMaybe $ map snd pairs
                 | ("del":secs) <- words s
                 , mbSecs <- map (decodeSecret . B.pack) secs
                 , all isJust mbSecs -> do
                        let f (Just b) = b
                            f x = error (concat ["Assertion fail at ", __FILE__, ":", show __LINE__])
                        let toPair x = (x,toPublic x)
                            pairs = map (toPair . f) mbSecs
                        ks <- atomically $ do
                            modifyTVar userkeys (filter (`notElem` pairs) )
                            forM pairs $ \(_,pk) -> Tox.delContactInfo roster pk
                            readTVar userkeys
                        hPutClient h . showReport $ map mkrow ks
                        switchKey $ do
                            k <- selectedKey
                            guard $ k `notElem` map snd pairs
                            Just k

        ("roster", s) -> cmd0 $ join $ atomically $ do
            dns <- dnsPresentation roster
            fs <- HashMap.toList <$> friendRequests roster
            let showFriend (remotekey,fr) =
                    ("  " ++ show remotekey, T.unpack $ T.decodeUtf8 $ Tox.friendRequestText fr)
                showAccount (me,cs) =
                    [(show me,"")] ++ map showFriend cs
                frs = fs >>= showAccount
            return $ do
                hPutClientChunk h $ unlines [ dns, "", "Friend Requests" ]
                hPutClient h $ showReport frs

        ("sessions", s) | "" <- strp s
            -> cmd0 $ do
                sessions' <- atomically $ readTVar sessions :: IO [PerSession]
                let sessionsReport = mapM showPerSession sessions'
                    headers = ["Key", "NextMsg", "Dropped","Handled","Unhandled"]
                    showPerSession (PerSession
                                        { perSessionMsgs = msgQ
                                        , perSessionPublicKey = pubKey
                                        , perSessionAddr = sockAddr
                                        , perSessionNumVar = msgNumVar
                                        , perSessionDropCount = dropCntVar
                                        }) = do
                        num <- atomically (readTVar msgNumVar)
                        dropped <- atomically (readTVar dropCntVar)
                        as <- atomically (packetQueueViewList msgQ)
                        let (h,u) = partition (fst . snd) as
                            countHandled   = length h
                            countUnhandled = length u
                        return [ show (Tox.key2id pubKey) -- "Key"
                               , show num                 -- "NextMsg"
                               , show dropped             -- "Dropped"
                               , show countHandled        -- "Handled"
                               , show countUnhandled      -- "Unhandled"
                               ]
                if null sessions'
                 then hPutClient h "No sessions."
                 else do
                    rows <- sessionsReport
                    hPutClient h (showColumns (headers:rows))

        ("onion", s) -> cmd0 $ join $ atomically $ do
            rm <- readTVar $ routeMap onionRouter
            ts <- readTVar $ trampolineNodes onionRouter
            rs <- mapM readTVar (pendingRoutes onionRouter)
            let showRecord :: Int -> Bool -> [String]
                showRecord n True = [show n, "pending", ""]
                showRecord n False
                    | Just RouteRecord{responseCount,timeoutCount} <- IntMap.lookup n rm
                                = [show n, show responseCount, show timeoutCount]
                    | otherwise = [show n, "error!",""]
                r = map (uncurry showRecord) $ IntMap.toAscList rs
            return $ do
                hPutClientChunk h $ "trampolines: " ++ show (IntMap.size ts) ++ "\n"
                hPutClient h $ showColumns $ ["","responses","timeouts"]:r

        ("g", s) | Just DHT{..} <- Map.lookup netname dhts
                    -> cmd0 $ do
                        -- arguments: method
                        --            nid
                        --            (optional dest-ni)
                        self <- atomically $ thisNode <$> readTVar dhtBuckets
                        let (method,xs) = break isSpace $ dropWhile isSpace s
                            (nidstr,ys) = break isSpace $ dropWhile isSpace xs
                            destination = dropWhile isSpace ys
                            goQuery qry = either (hPutClient h . ("Bad search target: "++))
                                                 (goTarget qry)
                                                 $ dhtParseId nidstr
                            goTarget DHTQuery{..} nid =
                                go nid >>= reportResult method qshowR qshowTok show h
                              where
                                go | null destination = fmap Right . qhandler self
                                   | otherwise        = case readEither destination of
                                        Right ni -> fmap (maybe (Left "Timeout.") Right)
                                                    . flip (searchQuery qsearch) ni
                                        Left  e  -> const $ return $ Left ("Bad destination: "++e)
                        maybe (hPutClient h ("Unsupported method: "++method))
                              goQuery
                              $ Map.lookup method dhtQuery

        -- TODO: Online help.
        --
        -- p - put/publish a single given datum on a single given node.
        --
        --         When destination address (node-addr) is optional, it's absense means to
        --         publish information in the local node's own database.
        --
        --         Bittorrent: (peer) publish yourself as peer in swarm.
        --                     (port) set your current bittorrent listen port.
        --
        --             p peer <infohash> <token> [node-addr]
        --
        --             p port <num>
        --
        --         Tox: (toxid) publish a rendezvous onion route to dht node.
        --              (friend) send a friend-request over a rendezvous point.
        --              (dhtkey) send your dht node-id over a rendezvous point.
        --
        --             p toxid <key> <token> <node-addr>
        --
        --             p friend <nospamid> <rendezvous-addr> <text>
        --
        --             p dhtkey <key> <rendezvous-addr>

        ("p", s) | Just DHT{..} <- Map.lookup netname dhts
                    -> cmd0 $ do
                        -- arguments:  Left                  Right
                        --             ----                  -----
                        --             method                method
                        --             data (jid or key)     data
                        --             dest-rendezvous(r)    token
                        --             (optional extra-text) (optional dest-ni)
                        self <- atomically $ thisNode <$> readTVar dhtBuckets
                        let (method,xs) = break isSpace $ dropWhile isSpace s
                            (dtastr,ys) = break isSpace $ dropWhile isSpace xs
                            (tokenstr,zs) = break isSpace $ dropWhile isSpace ys
                            destination = dropWhile isSpace zs
                            goTarget DHTAnnouncable{..} | Right asend <- announceSendData = do
                                let dta = announceParseData dtastr
                                    tok = dta >>= flip announceParseToken tokenstr
                                case liftA2 (,) dta tok of
                                    Left e    -> hPutClient h e
                                    Right nid -> go asend nid >>= either (hPutClient h) (hPutClient h . show)
                              where
                                go asend | null destination = fmap (maybe (Left "Timeout.") Right)
                                                              . flip (uncurry asend) Nothing
                                         | otherwise        = case announceParseAddress destination of
                                            Right ni -> fmap (maybe (Left "Timeout.") Right)
                                                        . flip (uncurry asend) (Just ni)
                                            Left  e  -> const $ return $ Left ("Bad destination: "++e)
                            goTarget DHTAnnouncable{..} | Left (searchName,parseResult,asend) <- announceSendData = do
                                either (hPutClient h) id $ do
                                    dta <- announceParseData $ unwords [dtastr,destination]
                                    r   <- parseResult tokenstr
                                    return $ case selectedKey of
                                        Nothing -> hPutClient h "Missing secret user-key."
                                        Just k  -> do
                                            asend k dta r
                                            hPutClient h "Sent."
                        maybe (hPutClient h ("Unsupported method: "++method))
                              goTarget
                              $ Map.lookup method dhtAnnouncables

        -- TODO: Online documentation.
        --
        -- a - announce, like put/publish but automatically selects nodes to publish on
        --     and periodically refreshes them.
        --
        --     The method name is preceded with a + to start or a - to stop a given
        --     recurring publication.
        --
        --     BitTorrent: (peer) Every minute, announce you are participating
        --                        in a torrent swarm.
        --
        --         a +peer <infohash> a -peer <infohash>
        --
        --     Tox: (toxid) Every 15 seconds, announce your tox identity to the
        --                  DHT so friends can find you.
        --
        --         a +toxid <key>
        --         a -toxid <key>
        --
        --         a +friend <jid> <text>
        --         a +dhtkey <key>
        ("a", "") -> cmd0 $ do
                        now <- getPOSIXTime
                        rs <- atomically $ do
                            as <- readTVar (scheduled $ announcer)
                            forM (PSQ.toList as) $ \(k,ptm,item) -> do
                                kstr <- unpackAnnounceKey announcer k
                                return [ show (ptm - now)
                                       , show (itemStatusNum item)
                                       , kstr
                                       ]
                        hPutClient h $ showColumns rs
        ("a", s) | Just DHT{..} <- Map.lookup netname dhts
                 , not (null s)
                    -> cmd0 $ do
                        let (op:method,xs) = break isSpace $ dropWhile isSpace s
                            dtastr         = dropWhile isSpace xs

                            a = Map.lookup method dhtAnnouncables
                            q = do DHTAnnouncable { announceSendData } <- a
                                   Map.lookup (either (\(search,_,_)->search)
                                                      (const method)
                                                      announceSendData)
                                              dhtQuery
                            doit :: Char -> Announcer -> AnnounceKey -> AnnounceMethod r -> r -> IO ()
                            doit '+' = schedule
                            doit '-' = cancel
                            doit _   = \_ _ _ _ -> hPutClientChunk h "Starting(+) or canceling(-)?"
                            matchingResult ::
                                ( Typeable stok
                                , Typeable ptok
                                , Typeable sni
                                , Typeable pni )
                                            => Search nid addr stok sni sr
                                            -> (pr -> ptok -> Maybe pni -> IO (Maybe pubr))
                                            -> Maybe (stok :~: ptok, sni :~: pni)
                            matchingResult _ _ = liftA2 (,) eqT eqT
                            matchingResult2 ::
                                ( Typeable sr
                                , Typeable pr )
                                            => Search nid addr stok sni sr
                                            -> (PublicKey -> pdta -> pr -> IO ())
                                            -> (pdta -> nid)
                                            -> Maybe (pr :~: sr)
                            matchingResult2 _ _ _ = eqT
                            reportit target = case op of
                                        '+' -> hPutClient h $ "Announcing at " ++ target ++ "."
                                        '-' -> hPutClient h $ "Canceling " ++ target ++ "."
                            -- mameth is for typical kademlia announce.
                            mameth = do
                                DHTAnnouncable { announceSendData
                                               , announceParseData
                                               , announceInterval
                                               , announceTarget } <- a
                                DHTQuery { qsearch } <- q
                                asend <- either (const Nothing) Just announceSendData
                                (Refl, Refl) <- matchingResult qsearch asend
                                -- return $ hPutClient h "Type matches."
                                dta <- either (const Nothing) Just $ announceParseData dtastr
                                return $ do
                                    akey <- atomically $ packAnnounceKey announcer (method ++ ":" ++ dtastr)
                                    doit op announcer
                                            akey
                                            (AnnounceMethod qsearch (Right asend) dhtBuckets
                                                            (announceTarget dta)
                                                            announceInterval)
                                            dta
                                    reportit $ show $ announceTarget dta
                            -- lmeth is for atypical announce messages such as
                            --   Tox dht-key and friend-request messages.
                            lmeth :: Maybe (IO ())
                            lmeth = do
                                DHTAnnouncable { announceSendData
                                               , announceParseData
                                               , announceInterval
                                               , announceTarget } <- a
                                DHTQuery { qsearch } <- q
                                (_,_,asend) <- either Just (const Nothing) announceSendData
                                Refl <- matchingResult2 qsearch asend announceTarget
                                dta <- either (const Nothing) Just $ announceParseData dtastr
                                pub <- selectedKey
                                return $ do
                                    akey <- atomically $ packAnnounceKey announcer (method ++ ":" ++ dtastr)
                                    doit op announcer
                                            akey
                                            (AnnounceMethod qsearch (Left $ asend pub) dhtBuckets
                                                            (announceTarget dta)
                                                            announceInterval)
                                            dta
                                    reportit $ show $ announceTarget dta
                            ptest = fromMaybe "E:NoMethod"
                                        $ fmap (\DHTAnnouncable { announceParseData
                                                                , announceTarget }
                                                  -> either ("E:"++) (show . announceTarget)
                                                          $ announceParseData dtastr)
                                               a

                        let aerror = unlines
                                [ "announce error."
                                , "method = " ++ method
                                , "query = " ++ maybe "nil" (const "ok") q
                                , "publish = " ++ maybe "nil" (const "ok") a
                                -- , "chktok = " ++ maybe "nil" (const "ok") chktok -- chktok = nil
                                -- , "chkni = " ++ maybe "nil" (const "ok") chkni
                                , "ptest = " ++ ptest
                                , "mameth = " ++ show (fmap (const ()) mameth)
                                , "lmeth  = " ++ show (fmap (const ()) lmeth)
                                , "selectedKey = " ++ show selectedKey
                                ]
                        fromMaybe (hPutClient h aerror) $ mameth <|> lmeth

        ("s", s) | Just dht@DHT{..} <- Map.lookup netname dhts
                    -> cmd0 $ do
                        let (method,xs) = break isSpace s
                            (nidstr,ys) = break isSpace $ dropWhile isSpace xs
                            presentSearches = hPutClient h
                                              =<< showSearches
                                              =<< atomically (readTVar dhtSearches)
                            goTarget qry nid = do
                                kvar <- atomically $ newTVar Nothing
                                -- Forking a thread, but it may ubruptly quit if the following
                                -- STM action decides not to add a new search.  This is so that
                                -- I can store the ThreadId into new DHTSearch structure.
                                tid <- fork $ join $ atomically (readTVar kvar >>= maybe retry return)
                                join $ atomically $ do
                                    schs <- readTVar dhtSearches
                                    case Map.lookup (method,nid) schs of
                                        Nothing  -> do forkSearch method nid qry dhtSearches dhtBuckets tid kvar
                                                       return $ presentSearches
                                        Just sch -> do writeTVar kvar (Just $ return ())
                                                       return $ reportSearchResults method h sch
                            goQuery qry = either (hPutClient h . ("Bad search target: "++))
                                                 (goTarget qry)
                                                 $ dhtParseId nidstr
                        if null method then presentSearches
                                       else maybe (hPutClient h ("Unsupported method: "++method))
                                                  goQuery
                                                  $ Map.lookup method dhtQuery

        ("x", s) | Just DHT{..} <- Map.lookup netname dhts
                    -> cmd0 $ do
                        let (method,xs) = break isSpace s
                            (nidstr,ys) = break isSpace $ dropWhile isSpace xs
                            go nid = join $ atomically $ do
                                schs <- readTVar dhtSearches
                                case Map.lookup (method,nid) schs of
                                    Nothing -> return $ hPutClient h "No match."
                                    Just DHTSearch{searchThread} -> do
                                        modifyTVar' dhtSearches (Map.delete (method,nid))
                                        return $ do
                                            killThread searchThread
                                            hPutClient h "Removed search."
                        either (hPutClient h . ("Bad search target: "++)) go $ dhtParseId nidstr

        ("save", _) | Just dht <- Map.lookup netname dhts
                    -> cmd0 $ do
                        saveNodes netname dht
                        hPutClient h $ "Saved " ++ nodesFileName netname ++ "."

        ("load", _) | Just dht <- Map.lookup netname dhts
                    -> cmd0 $ do
                        b <- pingNodes netname dht
                        case b of
                            Just num ->
                                  hPutClient h $ unwords [ "Pinging"
                                                         , show num
                                                         , "nodes from"
                                                         , nodesFileName netname ++ "."
                                                         ]
                            Nothing ->
                                  hPutClient h $ "Failed: " ++ nodesFileName netname ++ "."

        ("swarms", s) -> cmd0 $ do
                    let fltr = case s of
                                    ('-':'v':cs) | all isSpace (take 1 cs)
                                      -> const True
                                    _ -> (\(h,c,n) -> c/=0 )
                    ss <- atomically $ Peers.knownSwarms <$> readTVar (Mainline.contactInfo swarms)
                    let r = map (\(h,c,n) -> (unwords [show h,show c], maybe "" show n))
                            $ filter fltr ss
                    hPutClient h $ showReport r

        ("peers", s) -> cmd0 $ case readEither s of
                        Right ih -> do
                            ps <- atomically $ Peers.lookup ih <$> readTVar (Mainline.contactInfo swarms)
                            hPutClient h $ showReport $ map (((,) "") . show . pPrint) ps
                        Left er -> hPutClient h er
        ("toxids", s) -> cmd0 $ do
                        keydb <- atomically $ readTVar toxkeys
                        now <- getPOSIXTime
                        let entries = map mkentry $ PSQ.toList (Tox.keyByAge keydb)
                            mkentry (k :-> Down tm) = [ show cnt, show k, show (now - tm) ]
                                where Just (_,(cnt,_)) = MM.lookup' k (Tox.keyAssoc keydb)
                        hPutClient h $ showColumns entries

        ("c", s) | Just (ConnectionManager mgr) <- connectionManager
                 , "" <- strp s
                 -> cmd0 $ join $ atomically $ do
            cmap <- connections mgr
            cs <- Map.toList <$> mapM connStatus cmap
            let mkrow = Connection.showKey mgr *** Connection.showStatus mgr
                rs    = map mkrow cs
            return $ do
            hPutClient h $ showReport rs

        ("help", s) | Just DHT{..} <- Map.lookup netname dhts
                    -> cmd0 $ do
            let tolist :: a -> [a]
                tolist = (:[])

                dhtkeys, announcables, ks, allcommands :: [[String]]
                dhtkeys = map tolist $ Map.keys dhts
                queries = map (tolist . ("s "++)) $ Map.keys dhtQuery
                xs = map (tolist . ("x "++)) $ Map.keys dhtQuery
                gs = map (tolist . ("g "++)) $ Map.keys dhtQuery
                announcables = map (tolist . ("p "++)) $ Map.keys dhtAnnouncables
                ks = [["k gen"],["k public"],["k secret"]]
                allcommands = sortBy (comparing (take 1)) $ concat [sessionCommands, dhtkeys, announcables, ks, queries, gs,xs]

            hPutClient h ("Available commands:\n" ++ showColumns allcommands)

        _    -> cmd0 $ hPutClient h "error."


readExternals :: (ni -> SockAddr) -> [TVar (BucketList ni)] -> IO [SockAddr]
readExternals nodeAddr vars = do
    as <- atomically $ mapM (fmap (nodeAddr . selfNode) . readTVar) vars
    let unspecified (SockAddrInet _ 0)              = True
        unspecified (SockAddrInet6 _ _ (0,0,0,0) _) = True
        unspecified _                               = False
    -- TODO: Filter to only global addresses?
    return $ filter (not . unspecified) as

data Options = Options
    { portbt    :: String
    , porttox   :: String
    , portxmpp  :: String -- client-to-server
    , portxmppS :: String -- server-to-server
    , ip6bt     :: Bool
    , ip6tox    :: Bool
    , dhtkey    :: Maybe SecretKey
    -- | Currently only relevant to XMPP server code.
    --
    --   [ 0 ] Don't log XMPP stanzas.
    --
    --   [ 1 ] Log non-ping stanzas.
    --
    --   [ 2 ] Log all stanzas, even pings.
    , verbosity :: Int
    }
 deriving (Eq,Show)

sensibleDefaults :: Options
sensibleDefaults = Options
    { portbt    = "6881"
    , porttox   = "33445"
    , portxmpp  = "5222"
    , portxmppS = "5269"
    , ip6bt     = True
    , ip6tox    = True
    , dhtkey    = Nothing
    , verbosity = 2
    }

-- bt=<port>,tox=<port>
-- -4
parseArgs :: [String] -> Options -> Options
parseArgs []                  opts = opts
parseArgs ("--dhtkey":k:args) opts = parseArgs args opts
    { dhtkey = decodeSecret $ B.pack k }
parseArgs ("--dht-key":k:args) opts = parseArgs args opts
    { dhtkey = decodeSecret $ B.pack k }
parseArgs ("-4":args) opts         = parseArgs args opts
    { ip6bt  = False
    , ip6tox = False }
parseArgs (arg:args) opts          = parseArgs args opts
    { portbt    = fromMaybe (portbt opts)  $ Prelude.lookup "bt"  ports
    , porttox   = fromMaybe (porttox opts) $ Prelude.lookup "tox" ports
    , portxmpp  = fromMaybe (portxmpp opts) $ Prelude.lookup "xmpp" ports
    , portxmppS = fromMaybe (portxmppS opts) $ Prelude.lookup "xmpp.s2s" ports }
 where
    ports = map ( (dropWhile (==',') *** dropWhile (=='='))
                . break (=='=') )
                $ groupBy (const (/= ',')) arg

noArgPing :: (x -> IO (Maybe r)) -> [String] -> x -> IO (Maybe r)
noArgPing f [] x = f x
noArgPing _ _  _ = return Nothing

-- | Create a Conduit Source by repeatedly calling an IO action.
ioToSource :: IO (Maybe x) -> IO () -> C.Source IO x
ioToSource !action !onEOF = liftIO action >>= \case
        Nothing   -> liftIO onEOF
        Just item -> do C.yield item
                        ioToSource action onEOF

newXmmpSink :: Tox.NetCryptoSession -> C.Sink (Flush Tox.CryptoMessage) IO ()
newXmmpSink session@(Tox.NCrypto { ncOutgoingQueue, ncPacketQueue }) = C.awaitForever $ \flush_cyptomessage -> do
    let sendit :: Tox.NetCryptoSession -> Flush Tox.CryptoMessage -> IO ()
        sendit session (Chunk msg) = do
            extra <- readyOutGoing ncOutgoingQueue
            r <- atomically $ do
                rTry <- tryAppendQueueOutgoing extra ncOutgoingQueue msg
                case rTry of
                    OGFull -> retry
                    OGSuccess -> return OGSuccess
                    OGEncodeFail -> return OGEncodeFail
            when (r == OGEncodeFail) $
                hPutStrLn stderr ("FAILURE to Encode Outgoing: " ++ show msg)
        sendit session Flush = return ()
    liftIO $ sendit session flush_cyptomessage


toxAnnounceSendData :: Tox.Tox -> PublicKey
                               -> Nonce32
                               -> Maybe Tox.NodeInfo
                               -> IO (Maybe (Tox.Rendezvous, Tox.AnnounceResponse))
toxAnnounceSendData tox pubkey token = \case
    Just ni -> Tox.putRendezvous (Tox.onionTimeout tox)
                                 (Tox.toxCryptoKeys tox)
                                 (Tox.toxOnion tox)
                                 (pubkey :: PublicKey)
                                 (token :: Nonce32)
                                 ni
    Nothing -> return Nothing

toxQSearch :: Tox.Tox -> Search Tox.NodeId (IP, PortNumber) Nonce32 Tox.NodeInfo Tox.Rendezvous
toxQSearch tox = Tox.toxidSearch (Tox.onionTimeout tox) (Tox.toxCryptoKeys tox) (Tox.toxOnion tox)

toxAnnounceInterval :: POSIXTime
toxAnnounceInterval = 15

-- |
--
-- These hooks will be invoked in order to connect to *.tox hosts in a user's
-- XMPP roster.
toxman :: Announcer -> [(String,TVar (BucketList Tox.NodeInfo))] -> Tox.Tox -> ToxManager ConnectionKey
toxman announcer toxbkts tox = ToxManager
    { activateAccount        = \k pubname seckey -> do
        hPutStrLn stderr $ "toxman ACTIVATE " ++ show (Tox.key2id $ toPublic seckey)
        let ContactInfo{ accounts } = Tox.toxContactInfo tox
            pub = toPublic seckey
            pubid = Tox.key2id pub
        newlyActive <- atomically $ do
            macnt <- HashMap.lookup pubid <$> readTVar accounts
            acnt <- maybe (newAccount seckey) return macnt
            rs <- readTVar $ clientRefs acnt
            writeTVar (clientRefs acnt) $! Set.insert k rs
            modifyTVar accounts (HashMap.insert pubid acnt)
            if not (Set.null rs)
                then return []
                else do
                    forM toxbkts $ \(nm,bkts) -> do
                        akey <- packAnnounceKey announcer (nm ++ "id:" ++ show pubid)
                        return (akey,bkts)
        forM_ newlyActive $ \(akey,bkts) -> do
            -- Schedule recurring announce.
            --
            schedule announcer
                     akey
                     (AnnounceMethod (toxQSearch tox)
                                     (Right $ toxAnnounceSendData tox)
                                     bkts
                                     pubid
                                     toxAnnounceInterval)
                     pub
            --
            -- Schedule recurring search for all non-connected contacts.
            return ()
    , deactivateAccount      = \k pubname -> do
       bStopped <- fmap (fromMaybe False) $ atomically $ do
        let ContactInfo{ accounts } = Tox.toxContactInfo tox
            mpubid = readMaybe $ T.unpack $ T.take 43 pubname
        forM mpubid $ \pubid -> do
        refs <- do
            macnt <- HashMap.lookup pubid <$> readTVar accounts
            rs <- fromMaybe Set.empty <$> mapM (readTVar . clientRefs) macnt
            forM_ macnt $ \acnt -> do
                modifyTVar' (clientRefs acnt) $ Set.delete k
            return rs
        if (not $ Set.null $ refs Set.\\ Set.singleton k) then do
            --   Stop recurring announce.
            --   If this is the last reference to a non-connected contact:
            --      Stop the recurring search for that contact
            return True
        else return False
       when bStopped $ hPutStrLn stderr $ "toxman DECTIVATE (todo) " ++ show pubname
    , setToxConnectionPolicy = \me them p -> do
       hPutStrLn stderr $ "toxman ConnectionPolicy " ++ show (me,them,p)
       case p of
        TryingToConnect -> do
            let db@ContactInfo{ accounts } = Tox.toxContactInfo tox
            sequence_ $ do
            meid   <- readMaybe $ T.unpack $ T.take 43 me
            themid <- readMaybe $ T.unpack $ T.take 43 them
            Just $ atomically $ do
            accs <- readTVar accounts
            case HashMap.lookup meid accs of
                Nothing  -> return () -- Unknown account.
                Just acc -> modifyTVar' (contacts acc)
                    $ HashMap.alter (mergeContact nullContact { contactPolicy = Just TryingToConnect })
                                    themid
            -- If unscheduled and unconnected, schedule recurring search for this contact.
        _ -> return () -- Remove contact.
    }

#ifdef XMPP

-- | Called upon a new Tox friend-connection session with a remote peer in
-- order to set up translating conduits that simulate a remote XMPP server.
announceToxJabberPeer :: TChan ((ConnectionKey,SockAddr), Tcp.ConnectionEvent XML.Event)
                      -> SockAddr -- ^ Local bind address for incoming Tox packets.
                      -> SockAddr -- ^ Remote address for this connection.
                      -> STM Bool
                      -> C.Source IO Tox.CryptoMessage
                      -> C.Sink (Flush Tox.CryptoMessage) IO ()
                      -> IO (Maybe (Tox.NetCryptoSession -> Tox.NetCryptoSession))
announceToxJabberPeer echan laddr saddr pingflag tsrc tsnk
    = do
     atomically $ writeTChan echan
        ( (PeerKey saddr, laddr )
        , Tcp.Connection pingflag xsrc xsnk )
     return Nothing
 where
    xsrc = tsrc =$= toxToXmpp
    xsnk = flushPassThrough xmppToTox =$= tsnk

#endif

data PerSession = PerSession { perSessionMsgs :: PacketQueue (Bool{-Handled?-},Tox.CryptoMessage)
                             , perSessionPublicKey :: PublicKey
                             , perSessionAddr :: SockAddr
                             , perSessionNumVar    :: TVar Word32
                             , perSessionDropCount :: TVar Word32
                             }

main :: IO ()
main = runResourceT $ liftBaseWith $ \resT -> do
    args <- getArgs
    let opts = parseArgs args sensibleDefaults
    print opts

    swarms <- Mainline.newSwarmsDatabase
    -- Restore peer database before forking the listener thread.
    peerdb <- left show <$> tryIOError (L.readFile "bt-peers.dat")
    either (hPutStrLn stderr . ("bt-peers.dat: "++))
           (atomically . writeTVar (Mainline.contactInfo swarms))
           (peerdb >>= S.decodeLazy)

    announcer <- forkAnnouncer


    (quitBt,btdhts,btips,baddrs) <- case portbt opts of
        "" -> return (return (), Map.empty,return [],[])
        p  -> do
            addr <- getBindAddress p (ip6bt opts)
            (bt,btR,btBootstrap4, btBootstrap6) <- Mainline.newClient swarms addr
            quitBt <- forkListener "bt" (clientNet bt)
            mainlineSearches <- atomically $ newTVar Map.empty
            peerPort <- atomically $ newTVar 6881 -- BitTorrent client TCP port.
            let mainlineDHT bkts wantip = DHT
                    { dhtBuckets = bkts btR
                    , dhtPing    = Map.singleton "ping" $ DHTPing
                                        { pingQuery = noArgPing $ fmap (bool Nothing (Just ())) . Mainline.ping bt
                                        , pingShowResult = show
                                        }
                    , dhtQuery   = Map.fromList
                                    [ ("node", DHTQuery
                                        { qsearch = (Mainline.nodeSearch bt)
                                        , qhandler = (\ni -> fmap Mainline.unwrapNodes
                                                                . Mainline.findNodeH btR ni
                                                                . flip Mainline.FindNode (Just Want_Both))
                                        , qshowR = show
                                        , qshowTok = (const Nothing)
                                        })
                                    -- Maybe (sr :~: pr, stok :~: ptok, sni :~: pni )
                                    -- sr = InfoHash
                                    -- stok = Token
                                    -- sni = NodeInfo
                                    , ("peer", DHTQuery
                                        { qsearch = (Mainline.peerSearch bt)
                                        , qhandler = (\ni -> fmap Mainline.unwrapPeers
                                                                . Mainline.getPeersH btR swarms ni
                                                                . flip Mainline.GetPeers (Just Want_Both)
                                                                . (read . show)) -- TODO: InfoHash -> NodeId
                                        , qshowR = (show . pPrint)
                                        , qshowTok = (Just . show)
                                        })
                                    ]
                    , dhtParseId  = readEither :: String -> Either String Mainline.NodeId
                    , dhtSearches = mainlineSearches
                    , dhtFallbackNodes = Mainline.bootstrapNodes wantip
                    , dhtAnnouncables = Map.fromList
                                    -- Maybe (sr :~: pr, stok :~: ptok, sni :~: pni )
                                    -- dta = Announce
                                    -- pr = Announced
                                    -- ptok = Token
                                    -- pni = NodeInfo
                                    [ ("peer", DHTAnnouncable { announceSendData = Right $ \ih tok -> \case
                                                                    Just ni -> do
                                                                        port <- atomically $ readTVar peerPort
                                                                        let dta = Mainline.mkAnnounce port ih tok
                                                                        Mainline.announce bt dta ni
                                                                    Nothing -> return Nothing
                                                              , announceParseAddress = readEither
                                                              , announceParseData = readEither
                                                              , announceParseToken = const $ readEither
                                                              , announceInterval = 60 -- TODO: Is one minute good?
                                                              , announceTarget = (read . show) -- TODO: InfoHash -> NodeId -- peer
                                                              })
                                    , ("port", DHTAnnouncable { announceParseData = readEither
                                                              , announceParseToken = \_ _ -> return ()
                                                              , announceParseAddress = const $ Right ()
                                                              , announceSendData = Right $ \dta () -> \case
                                                                    Nothing -> do atomically $ writeTVar peerPort (dta :: PortNumber)
                                                                                  return $ Just dta
                                                                    Just _ -> return Nothing
                                                              , announceInterval = 0 -- TODO: The "port" setting should probably
                                                                                     -- be a command rather than an announcement.
                                                              , announceTarget = const $ Mainline.zeroID
                                                              })]

                    , dhtSecretKey = return Nothing
                    , dhtBootstrap = case wantip of
                                        Want_IP4 -> btBootstrap4
                                        Want_IP6 -> btBootstrap6
                    }
                dhts = Map.fromList $
                        ("bt4", mainlineDHT Mainline.routing4 Want_IP4)
                        : if ip6bt opts
                            then [ ("bt6", mainlineDHT Mainline.routing6 Want_IP6) ]
                            else []
                ips :: IO [SockAddr]
                ips = readExternals Mainline.nodeAddr
                                        [ Mainline.routing4 btR
                                        , Mainline.routing6 btR
                                        ]
            return (quitBt,dhts,ips, [addr])

    keysdb <- Tox.newKeysDatabase

    crypto <- Tox.newCrypto
    netCryptoSessionsState <- Tox.newSessionsState crypto Tox.defaultUnRecHook Tox.defaultCryptoDataHooks
    sessions <- atomically (newTVar []) :: IO (TVar [PerSession])
    (mbtox,quitTox,toxdhts,toxips,(taddrs::[SockAddr])) <- case porttox opts of
        "" -> return (Nothing,return (), Map.empty, return [],[])
        toxport -> do
            addrTox <- getBindAddress toxport (ip6tox opts)
            hPutStrLn stderr $ "Supplied key: " ++ show (fmap (Tox.key2id . toPublic) (dhtkey opts))
            tox <- Tox.newTox keysdb
                              addrTox
                              (Just netCryptoSessionsState)
                              (dhtkey opts)
            (quitTox, toxStrap4, toxStrap6) <- Tox.forkTox tox

            toxSearches <- atomically $ newTVar Map.empty

            let toxDHT bkts wantip = DHT
                    { dhtBuckets = bkts (Tox.toxRouting tox)
                    , dhtPing    = Map.fromList
                                    [ ("ping", DHTPing
                                            { pingQuery = noArgPing $ fmap (bool Nothing (Just ())) . Tox.ping (Tox.toxDHT tox)
                                            , pingShowResult = show
                                            })
                                    , ("cookie", DHTPing
                                            { pingQuery = \case
                                                [keystr] | Just mykey <- readMaybe keystr
                                                         -> Tox.cookieRequest (Tox.toxCryptoKeys tox)
                                                                              (Tox.toxDHT tox)
                                                                              (Tox.id2key mykey)
                                                _        -> const $ return Nothing
                                            , pingShowResult = show
                                            })]
                    , dhtQuery   = Map.fromList
                                    [ ("node", DHTQuery
                                        { qsearch = (Tox.nodeSearch $ Tox.toxDHT tox)
                                        , qhandler = (\ni -> fmap Tox.unwrapNodes
                                                                . Tox.getNodesH (Tox.toxRouting tox) ni
                                                                . Tox.GetNodes)
                                        , qshowR = show -- NodeInfo
                                        , qshowTok = (const Nothing)
                                        })
                                    , ("toxid", DHTQuery
                                        { qsearch = toxQSearch tox
                                        , qhandler = -- qhandler :: ni -> nid -> IO ([ni], [r], tok)
                                                         (\ni nid ->
                                                            Tox.unwrapAnnounceResponse Nothing
                                                                <$> clientAddress (Tox.toxDHT tox) Nothing
                                                                <*> Tox.announceH (Tox.toxRouting tox)
                                                                                  (Tox.toxTokens tox)
                                                                                  (Tox.toxAnnouncedKeys tox)
                                                                                  (Tox.OnionDestination Tox.SearchingAlias ni Nothing)
                                                                                  (Tox.AnnounceRequest zeros32 nid Tox.zeroID))
                                        , qshowR  = show -- Rendezvous
                                        , qshowTok = Just . show -- Nonce32
                                        })
                                    ]
                    , dhtParseId  = readEither :: String -> Either String Tox.NodeId
                    , dhtSearches = toxSearches
                    , dhtFallbackNodes = return []
                    , dhtAnnouncables = Map.fromList
                                    [ ("toxid", DHTAnnouncable { announceSendData = Right (toxAnnounceSendData tox)
                                                               , announceParseAddress = readEither
                                                               , announceParseToken = const $ readEither
                                                               , announceParseData = fmap Tox.id2key . readEither
                                                               , announceTarget = Tox.key2id -- toxid

                    -- For peers we are announcing ourselves to, if we are not
                    -- announced to them toxcore tries every 3 seconds to
                    -- announce ourselves to them until they return that we
                    -- have announced ourselves to, then toxcore sends an
                    -- announce request packet every 15 seconds to see if we
                    -- are still announced and re announce ourselves at the
                    -- same time. The timeout of 15 seconds means a `ping_id`
                    -- received in the last packet will not have had time to
                    -- expire (20 second minimum timeout) before it is resent
                    -- 15 seconds later. Toxcore sends every announce packet
                    -- with the `ping_id` previously received from that peer
                    -- with the same path (if possible).
                                                               , announceInterval = toxAnnounceInterval

                                                               })
                                    -- dhtkey parameters:
                                    --
                                    -- ni  = NodeInfo
                                    -- r   = Rendezvous
                                    -- tok = Nonce32
                                    -- dta = PublicKey{-them-}
                                    , ("dhtkey", DHTAnnouncable { announceSendData = Left ("toxid", readEither, \me them addr -> do
                                                                        dkey <- Tox.getContactInfo tox
                                                                        sendMessage
                                                                            (Tox.toxToRoute tox)
                                                                            (Tox.AnnouncedRendezvous them addr)
                                                                            (me,Tox.OnionDHTPublicKey dkey))
                                                                , announceParseAddress = \str -> do
                                                                        ni <- readEither str
                                                                        return ( ni :: Tox.NodeInfo )
                                                                , announceParseToken = \_ str -> do
                                                                        tok <- readEither str
                                                                        return ( tok :: Nonce32 )
                                                                , announceParseData = fmap Tox.id2key . readEither
                                                                , announceTarget = Tox.key2id

                    -- We send this packet every 30 seconds if there is more
                    -- than one peer (in the 8) that says they our friend is
                    -- announced on them. This packet can also be sent through
                    -- the DHT module as a DHT request packet (see DHT) if we
                    -- know the DHT public key of the friend and are looking
                    -- for them in the DHT but have not connected to them yet.
                    -- 30 second is a reasonable timeout to not flood the
                    -- network with too many packets while making sure the
                    -- other will eventually receive the packet. Since packets
                    -- are sent through every peer that knows the friend,
                    -- resending it right away without waiting has a high
                    -- likelihood of failure as the chances of packet loss
                    -- happening to all (up to to 8) packets sent is low.
                    --
                                                               , announceInterval = 30

                                                               })
                                    -- "friend" parameters
                                    --
                                    -- ni  = NodeInfo
                                    -- r   = Rendezvous
                                    -- tok = Nonce32
                                    -- dta = (NoSpamId{-them-},String)
                                    , ("friend", DHTAnnouncable { announceSendData = Left ("toxid", readEither, \me them0 addr -> do
                                                                        let (Tox.NoSpamId sum them,txt) = them0
                                                                            Tox.NoSpam nospam _ = sum
                                                                            fr = Tox.FriendRequest nospam (T.encodeUtf8 $ T.pack txt)
                                                                        sendMessage
                                                                            (Tox.toxToRoute tox)
                                                                            (Tox.AnnouncedRendezvous them addr)
                                                                            (me,Tox.OnionFriendRequest fr))
                                                                , announceParseAddress = \str -> do
                                                                        ni <- readEither str
                                                                        return ( ni :: Tox.NodeInfo )
                                                                , announceParseToken = \_ str -> do
                                                                        tok <- readEither str
                                                                        return ( tok :: Nonce32 )
                                                                , announceParseData = \str -> do
                                                                        let (jidstr,txt) = break isSpace str
                                                                        jid <- readEither jidstr
                                                                        return (jid, drop 1 txt)
                                                                , announceTarget = \(Tox.NoSpamId _ pub,_) -> Tox.key2id pub

                    -- Friend requests are sent with exponentially increasing
                    -- interval of 2 seconds, 4 seconds, 8 seconds, etc... in
                    -- toxcore. This is so friend requests get resent but
                    -- eventually get resent in intervals that are so big that
                    -- they essentially expire. The sender has no way of
                    -- knowing if a peer refuses a friend requests which is why
                    -- friend requests need to expire in some way.  Note that
                    -- the interval is the minimum timeout, if toxcore cannot
                    -- send that friend request it will try again until it
                    -- manages to send it. One reason for not being able to
                    -- send the friend request would be that the onion has not
                    -- found the friend in the onion and so cannot send an
                    -- onion data packet to them.
                    --
                    -- TODO: Support exponential backoff behavior.  For now, setting
                    -- interval to 8 seconds.

                                                               , announceInterval = 8
                                                               })]
                    , dhtSecretKey = return $ Just $ transportSecret (Tox.toxCryptoKeys tox)
                    , dhtBootstrap = case wantip of
                                        Want_IP4 -> toxStrap4
                                        Want_IP6 -> toxStrap6
                    }
                dhts = Map.fromList $
                        ("tox4", toxDHT Tox.routing4 Want_IP4)
                        : if ip6tox opts
                            then [ ("tox6", toxDHT Tox.routing6 Want_IP6) ]
                            else []
                ips :: IO [SockAddr]
                ips = readExternals Tox.nodeAddr [ Tox.routing4 $ Tox.toxRouting tox
                                                 , Tox.routing6 $ Tox.toxRouting tox ]
            return (Just tox, quitTox, dhts, ips, [addrTox])

    _ <- UPNP.requestPorts "dht-client" $ map (Datagram,) $ baddrs ++ taddrs

    (msv,mconns,mstate) <- case portxmpp opts of
        "" -> return (Nothing,Nothing,Nothing)
        p  -> do
            cport <- getBindAddress p True{-IPv6 supported-}
            -- TODO: Allow running without an XMPP server-to-server port.
            --       This should probably be default for toxmpp use.
            sport <- getBindAddress (portxmppS opts) True{-IPv6 supported-}

            -- XMPP initialization
            cw        <- newConsoleWriter
            serverVar <- atomically $ newEmptyTMVar
            let lookupBkts :: String -> Map.Map String DHT -> Maybe (String,TVar (BucketList Tox.NodeInfo))
                lookupBkts name m = case Map.lookup name m of
                    Nothing              -> Nothing
                    Just DHT{dhtBuckets} -> cast (name, dhtBuckets)
            let toxbkts = catMaybes
                            [ lookupBkts "tox4" toxdhts
                            , lookupBkts "tox6" toxdhts
                            ]
            state     <- newPresenceState cw (toxman announcer toxbkts <$> mbtox) serverVar

            sv    <- resT $ xmppServer (presenceHooks state (verbosity opts) (Just cport) (Just sport))
            -- We now have a server object but it's not ready to use until
            -- we put it into the 'server' field of our /state/ record.
            conns     <- xmppConnections  sv
            atomically $ do
                putTMVar serverVar  (sv,conns) -- Okay, now it's ready. :)
                                               -- FIXME: This is error prone.
            return (Just sv, Just conns, Just state)

    forM_ (take 1 taddrs) $ \addrTox -> do
        atomically $ Tox.addNewSessionHook netCryptoSessionsState $ \mbNoSpam netcrypto -> do
            -- allsessionsMap <- atomically $ readTVar (netCryptoSessions netCryptoSessionsState)
            let sockAddr = Tox.ncSockAddr netcrypto
                pubKey   = Tox.ncTheirPublicKey netcrypto
            msgQ <- atomically (Data.PacketQueue.newOverwrite 10 0 :: STM (PacketQueue (Bool,Tox.CryptoMessage)))
            msgNumVar <- atomically (newTVar 0)
            dropCntVar <- atomically (newTVar 0)
            let perSession = PerSession { perSessionMsgs = msgQ
                                        , perSessionPublicKey = pubKey
                                        , perSessionAddr = sockAddr
                                        , perSessionNumVar = msgNumVar
                                        , perSessionDropCount = dropCntVar
                                        }
            atomically $ modifyTVar' sessions (perSession:)
            tmchan <- atomically newTMChan
            let Just pingMachine = Tox.ncPingMachine netcrypto
                pingflag         = readTVar (pingFlag pingMachine)
                receiveCrypto    = atomically $ readTMChan tmchan
#ifdef XMPP
                onEOF            = return () -- TODO: Update toxContactInfo, not connected.
                xmppSrc          = ioToSource receiveCrypto onEOF
                xmppSink         = newXmmpSink netcrypto
            forM_ msv $ \sv -> do
                announceToxJabberPeer (xmppEventChannel sv) addrTox (Tox.ncSockAddr netcrypto) pingflag xmppSrc xmppSink
            -- TODO: Update toxContactInfo, connected.
#endif
            let handleIncoming typ session cm | any ($ typ) [Tox.isKillPacket, Tox.isOFFLINE] = atomically $ do
                    closeTMChan tmchan
                    Tox.forgetCrypto crypto netCryptoSessionsState netcrypto
                    return Nothing
                handleIncoming mTyp session cm = do
                    atomically $ do
                        num <- readTVar msgNumVar
                        (wraps,offset) <- enqueue msgQ num (False,cm)
                        capacity <- getCapacity msgQ
                        let dropped = wraps * capacity + offset
                        modifyTVar' msgNumVar (+1)
                        writeTVar dropCntVar dropped
                    atomically $ writeTMChan tmchan cm -- (Tox.bufferData cd)
                    return Nothing
            atomically $ writeTVar (Tox.ncUnrecognizedHook netcrypto) handleIncoming
            return Nothing

    let dhts = Map.union btdhts toxdhts

    (waitForSignal, checkQuit) <- do
        signalQuit <- atomically $ newTVar False
        let quitCommand = atomically $ writeTVar signalQuit True
        installHandler sigTERM (CatchOnce (atomically $ writeTVar signalQuit True)) Nothing
        installHandler sigINT (CatchOnce (atomically $ writeTVar signalQuit True)) Nothing
        let defaultToxData = do
                toxids <- atomically $ newTVar []
                rster <- Tox.newContactInfo
                orouter <- newOnionRouter (hPutStrLn stderr)
                return (toxids, rster, orouter)
        (toxids,rstr,orouter) <- fromMaybe defaultToxData $ do
            tox <- mbtox
            return $ return ( userKeys (Tox.toxCryptoKeys tox), Tox.toxContactInfo tox, Tox.toxOnionRoutes tox )
        let session = clientSession0 $ Session
                { netname           = concat $ take 1 $ Map.keys dhts -- initial default DHT
                , selectedKey       = Nothing
                , dhts              = dhts  -- all DHTs
                , signalQuit        = quitCommand
                , swarms            = swarms
                , cryptosessions    = netCryptoSessionsState
                , toxkeys           = keysdb
                , userkeys          = toxids
                , roster            = rstr
                , announceToLan     = fromMaybe (return ()) $ Tox.toxAnnounceToLan <$> mbtox
                , sessions          = sessions
                , connectionManager = ConnectionManager <$> mconns
                , onionRouter       = orouter
                , externalAddresses = liftM2 (++) btips toxips
                , announcer         = announcer
                }
        srv <- streamServer (withSession session) (SockAddrUnix "dht.sock")
        return ( do atomically $ readTVar signalQuit >>= check
                    quitListening srv
               , readTVar signalQuit >>= check
               )


    forM_ (Map.toList dhts)
          $ \(netname, dht@DHT { dhtBuckets = bkts
                               , dhtQuery = qrys
                               , dhtPing = pings
                               , dhtFallbackNodes = getBootstrapNodes
                               , dhtBootstrap = bootstrap }) -> do
        btSaved <- loadNodes netname --  :: IO [Mainline.NodeInfo]
        putStrLn $ "Loaded "++show (length btSaved)++" nodes for "++netname++"."
        fallbackNodes <- getBootstrapNodes
        let isNodesSearch :: ni :~: r -> Search nid addr tok ni r -> Search nid addr tok ni ni
            isNodesSearch Refl sch = sch
            ping = maybe (const $ return False)
                         (\DHTPing{pingQuery} -> fmap (maybe False (const True)) . pingQuery [])
                         $ Map.lookup "ping" pings
        fork $ do
            myThreadId >>= flip labelThread ("bootstrap."++netname)
            bootstrap btSaved fallbackNodes
        return ()

    forkIO $ do
        myThreadId >>= flip labelThread "XMPP.stanzas"
        let console = cwPresenceChan <$> (mstate >>= consoleWriter)
        fix $ \loop -> do
        what <- atomically
            $ orElse (do (client,stanza) <- maybe retry takeTMVar console
                         return $ forM_ mstate $ \state -> do
                                     informClientPresence0 state Nothing client stanza
                                     loop)
                     (checkQuit >> return (return ()))
        what

    forM msv $ \_ -> hPutStrLn stderr "Started XMPP server."

    -- Wait for DHT and XMPP threads to finish.
    -- Use ResourceT to clean-up XMPP server.
    waitForSignal

    stopAnnouncer announcer
    quitBt
    quitTox

    swarmsdb <- atomically $ readTVar (Mainline.contactInfo swarms)
    L.writeFile "bt-peers.dat" $ S.encodeLazy swarmsdb