src: init

14 files changed, 1005 insertions, 0 deletions

diff --git a/src/Reaktor.hs b/src/Reaktor.hs
new file mode 100644
index 0000000..110485f
--- /dev/null
+++ b/src/Reaktor.hs
@@ -0,0 +1,236 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor (run) where
+
+import           Blessings (Blessings(Append,Empty,Plain,SGR),pp)
+import           Control.Arrow
+import           Control.Concurrent (forkIO,killThread,threadDelay)
+import           Control.Concurrent (newEmptyMVar,putMVar,takeMVar)
+import           Control.Exception (finally)
+import           Control.Monad (foldM,forever,unless)
+import           Control.Monad.Trans.State.Lazy
+import           Data.Aeson
+import           Data.Attoparsec.ByteString.Char8 (IResult(Done,Fail,Partial))
+import           Data.Attoparsec.ByteString.Char8 (feed,parse)
+import qualified Data.ByteString.Char8 as BS
+import           Data.Foldable (toList)
+import qualified Data.Text as T
+import           Data.Time.Clock.System
+import           Data.Time.Format
+import qualified Network.Simple.TCP as TCP
+import qualified Network.Simple.TCP.TLS as TLS
+import           Reaktor.Config
+import           Reaktor.Parser (message)
+import qualified Reaktor.Plugins
+import           Reaktor.Types
+import           System.IO (BufferMode(LineBuffering),hSetBuffering)
+import           System.IO (Handle)
+import           System.IO (hIsTerminalDevice)
+import           System.IO (hPutStr,hPutStrLn,stderr)
+import           System.Posix.Signals
+
+
+run :: Config -> IO ()
+run cfg0 = do
+
+    let logh = stderr
+
+    let cfg1 = addPlugin "ping" (Reaktor.Plugins.get "ping" Null) cfg0
+
+    cfg <- initPlugins cfg1
+
+    let tlsPlugins =
+          T.unpack $
+          T.intercalate ", " $
+          map pi_name $
+          filter (requireTLS . either undefined id . pi_plugin)
+                 (pluginInstances cfg)
+
+    unless (useTLS cfg || null tlsPlugins) $ do
+      error $ "Not using TLS, but following plugins require it: " <> tlsPlugins
+
+    -- TODO reset when done?
+    hSetBuffering logh LineBuffering
+    logToTTY <- hIsTerminalDevice logh
+    let logFilter = if logToTTY then id else stripSGR
+
+    connect cfg $ \send_ recv_ -> do
+      (putLog, takeLog) <- newRelay
+      (putMsg, takeMsg) <- newRelay
+      (shutdown, awaitShutdown) <- newSemaphore
+
+      mapM_ (\(s, f) -> installHandler s (Catch f) Nothing) [
+          (sigINT, shutdown)
+        ]
+
+      let prefixTimestamp s = do
+              t <- SGR [38,5,239] . Plain . BS.pack <$> getTimestamp
+              return (t <> " " <> s)
+
+          takeLog' =
+            if logTime cfg
+              then takeLog >>= prefixTimestamp
+              else takeLog
+
+      threadIds <- mapM (\f -> forkIO $ f `finally` shutdown) [
+          driver cfg putLog putMsg recv_,
+          logger logFilter takeLog' logh,
+          pinger putLog putMsg,
+          sender takeMsg send_
+        ]
+
+      awaitShutdown
+      mapM_ killThread threadIds
+      hPutStrLn logh ""
+  where
+
+    pinger :: (Blessings BS.ByteString -> IO ()) -> (Message -> IO ()) -> IO ()
+    pinger putLog putMsg = forever $ do
+        threadDelay time
+        sendIO putLog putMsg (Message Nothing "PING" ["heartbeat"])
+      where
+        time = 300 * 1000000
+
+    sender :: IO Message -> (BS.ByteString -> IO ()) -> IO ()
+    sender takeMsg send_ =
+        forever $ takeMsg >>= send_ . formatMessage
+
+    logger :: (Blessings BS.ByteString -> Blessings BS.ByteString)
+           -> IO (Blessings BS.ByteString)
+           -> Handle
+           -> IO ()
+    logger f takeLog h = forever $ do
+        s <- takeLog
+        let s' = if lastChar s == '\n' then s else s <> Plain "\n"
+        hPutStr h $ pp $ fmap BS.unpack (f s')
+      where
+        lastChar :: Blessings BS.ByteString -> Char
+        lastChar = BS.last . last . toList
+
+    stripSGR :: Blessings a -> Blessings a
+    stripSGR = \case
+        Append t1 t2 -> Append (stripSGR t1) (stripSGR t2)
+        SGR _ t -> stripSGR t
+        Plain x -> Plain x
+        Empty -> Empty
+
+
+connect :: Config
+        -> ((BS.ByteString -> IO ()) -> IO (Maybe BS.ByteString) -> IO ())
+        -> IO ()
+connect cfg action = do
+    if useTLS cfg then do
+      s <- TLS.getDefaultClientSettings (hostname cfg, BS.pack (port cfg))
+      TLS.connect s (hostname cfg) (port cfg) $ \(ctx, _sockAddr) -> do
+        let send = TLS.send ctx
+            recv = TLS.recv ctx
+        action send recv
+    else do
+      TCP.connect (hostname cfg) (port cfg) $ \(sock, _sockAddr) -> do
+        let send = TCP.send sock
+            recv = TCP.recv sock 512
+        action send recv
+
+driver :: Config
+          -> (Blessings BS.ByteString -> IO ())
+          -> (Message -> IO ())
+          -> IO (Maybe BS.ByteString)
+          -> IO ()
+
+driver cfg putLog putMsg recv_ = do
+    cfg' <- handleMessage cfg putMsg putLog (Message Nothing "<start>" [])
+    drive cfg' putMsg putLog recv_ ""
+
+drive :: Config
+      -> (Message -> IO ())
+      -> (Blessings BS.ByteString -> IO ())
+      -> IO (Maybe BS.ByteString)
+      -> BS.ByteString
+      -> IO ()
+drive cfg putMsg putLog recv_ "" =
+    recv_ >>= \case
+      Nothing -> putLog $ SGR [34,1] (Plain "# EOL")
+      Just msg -> drive cfg putMsg putLog recv_ msg
+
+drive cfg putMsg putLog recv_ buf =
+    go (parse message buf)
+  where
+    go :: IResult BS.ByteString Message -> IO ()
+    go = \case
+        Done rest msg -> do
+          -- TODO log message only if h hasn't disabled logging for it
+          let s = formatMessage msg
+          putLog $ SGR [38,5,235] "< " <> SGR [38,5,244] (Plain s)
+          cfg' <- handleMessage cfg putMsg putLog msg
+          drive cfg' putMsg putLog recv_ rest
+
+        p@(Partial _) -> do
+          recv_ >>= \case
+            Nothing -> do
+              putLog $ SGR [34,1] (Plain "# EOL")
+            Just msg ->
+              go (feed p msg)
+
+        f@(Fail _i _errorContexts _errMessage) ->
+          putLog $ SGR [31,1] (Plain (BS.pack $ show f))
+
+handleMessage :: Config
+              -> (Message -> IO ())
+              -> (Blessings BS.ByteString -> IO ())
+              -> Message
+              -> IO Config
+handleMessage cfg putMsg putLog msg = do
+    let
+        q0 = PluginState {
+              s_putLog = putLog,
+              s_nick = nick cfg,
+              s_sendMsg = sendIO putLog putMsg,
+              s_sendMsg' = sendIO' putLog putMsg
+            }
+
+        f q i =
+          execStateT (pluginFunc (either undefined id (pi_plugin i)) msg) q
+
+    q' <- foldM f q0 (pluginInstances cfg)
+
+    return cfg { nick = s_nick q' }
+
+
+formatMessage :: Message -> BS.ByteString
+formatMessage (Message mb_prefix cmd params) =
+    maybe "" (\x -> ":" <> x <> " ") mb_prefix
+        <> cmd
+        <> BS.concat (map (" "<>) (init params))
+        <> if null params then "" else " :" <> last params
+        <> "\r\n"
+
+
+getTimestamp :: IO String
+getTimestamp =
+    formatTime defaultTimeLocale (iso8601DateFormat $ Just "%H:%M:%SZ")
+    . systemToUTCTime <$> getSystemTime
+
+
+newRelay :: IO (a -> IO (), IO a)
+newRelay = (putMVar &&& takeMVar) <$> newEmptyMVar
+
+
+newSemaphore :: IO (IO (), IO ())
+newSemaphore = first ($()) <$> newRelay
+
+
+sendIO :: (Blessings BS.ByteString -> IO ())
+       -> (Message -> IO ())
+       -> Message
+       -> IO ()
+sendIO putLog putMsg msg =
+    sendIO' putLog putMsg msg msg
+
+sendIO' :: (Blessings BS.ByteString -> IO ())
+       -> (Message -> IO ())
+       -> Message
+       -> Message
+       -> IO ()
+sendIO' putLog putMsg msg logMsg = do
+    putLog $ SGR [38,5,235] "> " <> SGR [35,1] (Plain $ formatMessage logMsg)
+    putMsg msg
diff --git a/src/Reaktor/Config.hs b/src/Reaktor/Config.hs
new file mode 100644
index 0000000..8330be9
--- /dev/null
+++ b/src/Reaktor/Config.hs
@@ -0,0 +1,76 @@
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor.Config where
+
+import           Data.Aeson
+import qualified Data.HashMap.Lazy as HML
+import qualified Data.Text as T
+import qualified Reaktor.Plugins
+import           Reaktor.Types
+
+
+instance FromJSON Config where
+  parseJSON (Object v) = do
+      p <- v .:? "port" .!= defaultPort
+
+      Config
+        <$> v .: "hostname"
+        <*> pure p
+        <*> v .: "nick"
+        <*> v .:? "useTLS" .!= (p == tlsPort)
+        <*> v .:? "logTime" .!= True
+        <*> v .:? "plugins" .!= []
+  parseJSON _ = pure undefined
+
+
+data Config = Config {
+      hostname :: HostName,
+      port :: ServiceName,
+      nick :: Nickname,
+      useTLS :: Bool,
+      logTime :: Bool,
+      pluginInstances :: [PluginInstance]
+    }
+
+
+addPlugin :: T.Text -> IO Plugin -> Config -> Config
+addPlugin name p r =
+    r { pluginInstances = pluginInstances r <> [PluginInstance name (Left p)] }
+
+
+defaultPort :: ServiceName
+defaultPort = tlsPort
+
+tlsPort :: ServiceName
+tlsPort = "6697"
+
+
+data PluginInstance = PluginInstance {
+      pi_name :: T.Text,
+      pi_plugin :: Either (IO Plugin) Plugin
+    }
+
+instance FromJSON PluginInstance where
+  parseJSON o@(Object v) =
+      case HML.lookup "plugin" v of
+        Just (String name) -> do
+          let p = Reaktor.Plugins.get name
+              c = HML.lookupDefault (Object HML.empty) "config" v
+          pure $ PluginInstance name (Left $ p c)
+        Just _ -> error ("bad plugin object: " <> show o)
+        _ -> error ("mising 'plugin' attribute: " <> show o)
+  parseJSON x =
+      error ("bad plugin type: " <> show x)
+
+
+initPlugins :: Config -> IO Config
+initPlugins cfg = do
+    plugins' <- mapM initPlugin (pluginInstances cfg)
+    return cfg { pluginInstances = plugins' }
+  where
+    initPlugin :: PluginInstance -> IO PluginInstance
+    initPlugin i = do
+      p <-
+        case pi_plugin i of
+          Right p -> return p
+          Left f -> f
+      return i { pi_plugin = Right p }
diff --git a/src/Reaktor/Message.hs b/src/Reaktor/Message.hs
new file mode 100644
index 0000000..f929471
--- /dev/null
+++ b/src/Reaktor/Message.hs
@@ -0,0 +1,14 @@
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor.Message where
+
+import qualified Data.ByteString.Char8 as BS
+import           Reaktor.Types
+
+
+privmsg :: BS.ByteString -> [BS.ByteString] -> Message
+privmsg msgtarget xs =
+    Message Nothing "PRIVMSG" (msgtarget:BS.intercalate " " xs:[])
+
+notice :: BS.ByteString -> [BS.ByteString] -> Message
+notice msgtarget xs =
+    Message Nothing "NOTICE" (msgtarget:BS.intercalate " " xs:[])
diff --git a/src/Reaktor/Parser.hs b/src/Reaktor/Parser.hs
new file mode 100644
index 0000000..bdd2f98
--- /dev/null
+++ b/src/Reaktor/Parser.hs
@@ -0,0 +1,45 @@
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor.Parser where
+
+import           Control.Applicative
+import           Data.Attoparsec.ByteString.Char8
+import qualified Data.ByteString.Char8 as BS
+import qualified Data.Char
+import           Reaktor.Types
+
+
+prefix :: Parser Prefix
+prefix = BS.pack <$> many (satisfy Data.Char.isAlphaNum <|>
+                           satisfy (flip elem (":.-@/!~[]\\`_^{|}" :: String)))
+
+command :: Parser Command
+command = BS.pack <$> many1 (satisfy Data.Char.isAlphaNum)
+
+nospcrlfcl :: Parser Char
+nospcrlfcl =
+  satisfy (flip notElem ("\NUL\CR\LF :" :: String)) <?> "nospcrlfcl"
+
+middle :: Parser Param
+middle =
+    BS.pack <$> ((:) <$> nospcrlfcl <*> many (char ':' <|> nospcrlfcl))
+    <?> "middle"
+
+trailing :: Parser Param
+trailing =
+    BS.pack <$> many (char ':' <|> char ' ' <|> nospcrlfcl)
+    <?> "trailing"
+
+params :: Parser [Param]
+params = (do
+    a <- many (char ' ' *> middle)
+    b <- optional (char ' ' *> char ':' *> trailing)
+    return $ a <> (maybe [] (:[]) b))
+    <?> "params"
+
+message :: Parser Message
+message =
+    Message
+      <$> optional (char ':' *> prefix <* char ' ')
+      <*> command
+      <*> params
+      <* string "\r\n"
diff --git a/src/Reaktor/Plugins.hs b/src/Reaktor/Plugins.hs
new file mode 100644
index 0000000..83677bb
--- /dev/null
+++ b/src/Reaktor/Plugins.hs
@@ -0,0 +1,28 @@
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor.Plugins (get,registry) where
+
+import           Data.Aeson (Value)
+import qualified Data.Map as M
+import qualified Data.Text as T
+import qualified Reaktor.Plugins.Mention
+import qualified Reaktor.Plugins.NickServ
+import qualified Reaktor.Plugins.Ping
+import qualified Reaktor.Plugins.Register
+import qualified Reaktor.Plugins.System
+import           Reaktor.Types (Plugin)
+
+
+get :: T.Text -> Value -> IO Plugin
+get name =
+    case M.lookup name registry of
+      Just p -> p
+      Nothing -> error ("unknown plugin: " <> T.unpack name)
+
+registry :: M.Map T.Text (Value -> IO Plugin)
+registry = M.fromList [
+    ("mention", Reaktor.Plugins.Mention.plugin),
+    ("NickServ", Reaktor.Plugins.NickServ.plugin),
+    ("ping", Reaktor.Plugins.Ping.plugin),
+    ("register", Reaktor.Plugins.Register.plugin),
+    ("system", Reaktor.Plugins.System.plugin)
+  ]
diff --git a/src/Reaktor/Plugins/Mention.hs b/src/Reaktor/Plugins/Mention.hs
new file mode 100644
index 0000000..0c86d74
--- /dev/null
+++ b/src/Reaktor/Plugins/Mention.hs
@@ -0,0 +1,27 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor.Plugins.Mention (plugin) where
+
+import           Control.Monad (when)
+import           Data.Aeson
+import qualified Data.ByteString.Char8 as BS
+import qualified Data.Char
+import           Reaktor.Message
+import           Reaktor.Types
+
+
+plugin :: Value -> IO Plugin
+plugin _ = return (Plugin run False)
+
+
+run :: PluginFunc
+run = \case
+    Message _ "PRIVMSG" (msgtarget:text:[]) -> do
+        nick <- getNick
+        when (isMention nick text) $ do
+          sendMsg (privmsg msgtarget ["I'm famous!"])
+    _ -> return ()
+  where
+    isMention nick text =
+      not (BS.isPrefixOf (nick <> ":") text) &&
+      any (==nick) (BS.splitWith (not . Data.Char.isAlphaNum) text)
diff --git a/src/Reaktor/Plugins/NickServ.hs b/src/Reaktor/Plugins/NickServ.hs
new file mode 100644
index 0000000..3987774
--- /dev/null
+++ b/src/Reaktor/Plugins/NickServ.hs
@@ -0,0 +1,92 @@
+{-# LANGUAGE DeriveGeneric, DeriveAnyClass #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE MultiWayIf #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor.Plugins.NickServ (plugin) where
+
+import           Control.Monad (when)
+import           Data.Aeson
+import           Data.Aeson.Types (parseEither)
+import qualified Data.ByteString.Char8 as BS
+import           GHC.Generics
+import           Reaktor.Message
+import           Reaktor.Types
+import           Reaktor.Utils (randomNick)
+
+
+data NickServConfig = NickServConfig {
+      passFile :: FilePath,
+      prefix :: BS.ByteString,
+      channels :: [BS.ByteString]
+    }
+  deriving (FromJSON,Generic)
+
+
+plugin :: Value -> IO Plugin
+plugin v =
+    case parseEither parseJSON v of
+      Right cfg -> do
+        pass <- do
+          [pass] <- lines <$> readFile (passFile cfg)
+          return (BS.pack pass)
+
+        return $ Plugin (run pass cfg) True
+      Left err ->
+        error err
+
+
+run :: BS.ByteString -> NickServConfig -> PluginFunc
+run pass cfg msg = do
+    nick_ <- getNick
+    case msg of
+
+      Message _ "<start>" _ -> do
+        nick0 <- lift randomNick
+        sendMsg (Message Nothing "NICK" [nick0])
+        sendMsg (Message Nothing "USER" [nick_, "*", "0", nick_])
+
+      -- TODO structured prefix, and check just for "NickServ"
+      Message (Just _prefix@"NickServ!NickServ@services.")
+                       "NOTICE"
+                       (_msgtarget:text:[]) -> do
+       if
+         | text == "You are now identified for \STX" <> nick_ <> "\STX." -> do
+           sendMsg (Message Nothing "NICK" [nick_])
+         | text == "\STX" <> nick_ <> "\STX has been released." -> do
+           sendMsg (Message Nothing "NICK" [nick_])
+         | text == "Invalid password for \STX" <> nick_ <> "\STX." -> do
+           error (BS.unpack text)
+         | text == "\STX" <> nick_ <> "\STX is not a registered nickname." -> do
+           error (BS.unpack text)
+         | otherwise ->
+           return ()
+
+
+      Message (Just _self) "NICK" (newnick:[]) -> do
+        when (newnick == nick_) $ do
+          -- TODO JOIN only if not already joined
+          --      i.e. not during subsequent nick changes
+          sendMsg (Message Nothing "JOIN" [ BS.intercalate "," (channels cfg) ])
+
+
+      -- RFC1459 ERR_NICKNAMEINUSE
+      Message (Just _servername) "433" (_msgtarget:nickinuse:_reason:[]) -> do
+        if nickinuse == nick_
+          then do
+            sendMsg (privmsg "NickServ" ["RELEASE", nickinuse])
+          else do
+            nick0 <- lift randomNick
+            sendMsg (Message Nothing "NICK" [nick0])
+
+      --RFC2812 ERR_UNAVAILRESOURCE
+      Message (Just _servername) "437" (_msgtarget:nickunavail:_reason:[]) -> do
+        when (nickunavail == nick_) $ do
+          sendMsg (privmsg "NickServ" ["RELEASE", nickunavail])
+
+      --RFC2812 RPL_WELCOME
+      Message _ "001" [_nick,_s] -> do
+        sendMsg' (privmsg "NickServ" ["IDENTIFY", nick_, pass])
+                 (privmsg "NickServ" ["IDENTIFY", nick_, "<password>"])
+
+
+      _ -> return ()
diff --git a/src/Reaktor/Plugins/Ping.hs b/src/Reaktor/Plugins/Ping.hs
new file mode 100644
index 0000000..83b3ac4
--- /dev/null
+++ b/src/Reaktor/Plugins/Ping.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor.Plugins.Ping (plugin) where
+
+import           Control.Monad (when)
+import           Data.Aeson (Value(Null))
+import           Reaktor.Types
+
+
+plugin :: Value -> IO Plugin
+plugin = simplePlugin (\Null -> run)
+
+run :: PluginFunc
+run (Message _ ircCommand args) =
+    when (ircCommand == "PING") $
+      sendMsg (Message Nothing "PONG" args)
diff --git a/src/Reaktor/Plugins/Register.hs b/src/Reaktor/Plugins/Register.hs
new file mode 100644
index 0000000..fd17f48
--- /dev/null
+++ b/src/Reaktor/Plugins/Register.hs
@@ -0,0 +1,65 @@
+{-# LANGUAGE DeriveGeneric, DeriveAnyClass #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE MultiWayIf #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor.Plugins.Register (plugin) where
+
+import           Control.Monad (when)
+import           Data.Aeson
+import qualified Data.ByteString.Char8 as BS
+import           GHC.Generics
+import           Reaktor.Types
+import           Reaktor.Utils (nextNick,randomNick)
+
+
+data RegisterConfig = RegisterConfig {
+      channels :: [BS.ByteString]
+    }
+  deriving (FromJSON,Generic)
+
+
+plugin :: Value -> IO Plugin
+plugin = simplePlugin run
+
+
+run :: RegisterConfig -> PluginFunc
+run cfg msg = do
+    nick_ <- getNick
+    case msg of
+
+      Message _ "<start>" _ -> do
+        sendMsg (Message Nothing "NICK" [nick_])
+        sendMsg (Message Nothing "USER" [nick_, "*", "0", nick_])
+
+      Message (Just _self) "NICK" (newnick:[]) -> do
+        when (newnick == nick_) $ do
+          -- TODO JOIN only if not already joined
+          --      i.e. not during subsequent nick changes
+          sendMsg (Message Nothing "JOIN" [ BS.intercalate "," (channels cfg) ])
+
+      -- RFC1459 ERR_NICKNAMEINUSE
+      Message (Just _servername) "433" (_msgtarget:nickinuse:_reason:[]) -> do
+        if nickinuse == nick_ then do
+          let nick' = nextNick nickinuse
+          sendMsg (Message Nothing "NICK" [nick'])
+          -- TODO change state on "NICK"
+          setNick nick'
+
+        -- TODO is this just for NickServ? (also check that module if it has
+        -- stuff only for "Register")
+        else do
+          nick' <- lift randomNick
+          sendMsg (Message Nothing "NICK" [nick'])
+          -- TODO set nick on "NICK" message
+          setNick nick'
+
+      -- RFC2812 ERR_UNAVAILRESOURCE
+      --Message (Just _servername) "437" (_msgtarget:nickunavail:_reason:[]) -> do
+
+      -- RFC2812 RPL_WELCOME
+      Message _ "001" [_nick,_s] -> do
+        --logStrLn $ SGR [32,1] (Plain s)
+        sendMsg (Message Nothing "JOIN" [ BS.intercalate "," (channels cfg) ])
+
+
+      _ -> return ()
diff --git a/src/Reaktor/Plugins/System.hs b/src/Reaktor/Plugins/System.hs
new file mode 100644
index 0000000..c8d40be
--- /dev/null
+++ b/src/Reaktor/Plugins/System.hs
@@ -0,0 +1,213 @@
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE MultiWayIf #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor.Plugins.System (plugin) where
+
+import           Blessings
+import           Control.Applicative
+import           Control.Concurrent (forkIO)
+import           Control.Exception (finally)
+import           Data.Aeson
+import qualified Data.ByteString.Char8 as BS
+import qualified Data.Map as M
+import           Reaktor.Message
+import           Reaktor.Plugins.System.Types
+import           Reaktor.Types
+import           System.Environment (getEnvironment)
+import           System.FilePath.Posix (takeBaseName)
+import           System.IO (Handle,hClose,hPutStr,hIsEOF)
+import           System.IO (BufferMode(LineBuffering),hSetBuffering)
+import           System.Process (StdStream(CreatePipe),waitForProcess)
+import           System.Process (createProcess,CreateProcess(..),proc)
+import qualified Text.Regex.PCRE.Heavy as RE
+import qualified Text.Regex.PCRE.Light as RE
+
+
+plugin :: Value -> IO Plugin
+plugin = simplePlugin run
+
+
+-- TODO indicated whether other plugins should run
+run :: SystemConfig -> PluginFunc
+
+run cfg (Message (Just prefix) "PRIVMSG" (msgtarget:text:[])) = do
+    nick_ <- getNick
+    let hs = maybe [] id (M.lookup "PRIVMSG" (hooks cfg))
+    mapM_ (\h -> run1 cfg nick_ h prefix msgtarget text) hs
+
+run cfg (Message (Just prefix) "JOIN" (channel:[])) = do
+    nick_ <- getNick
+    let hs = maybe [] id (M.lookup "JOIN" (hooks cfg))
+    mapM_ (\h -> run1 cfg nick_ h prefix channel "") hs
+
+-- TODO warning?
+run _ _ = return ()
+
+
+run1 ::
+    SystemConfig
+    -> Nickname
+    -> SystemParams
+    -> BS.ByteString
+    -> BS.ByteString
+    -> BS.ByteString
+    -> PluginIO ()
+run1 cfg nick_ params prefix msgtarget text = do
+    let
+        isActivated =
+          case activate params of
+            Always -> Just ""
+            Match ->
+              case pattern params of
+                Nothing -> Nothing
+                Just pat ->
+                  let
+                      result = RE.scan patternRE text
+                      patternRE = RE.compile pat []
+                  in
+                    if null result
+                      then Nothing
+                      else Just ""
+            Query ->
+              if
+                | BS.isPrefixOf (nick_ <> ":") text ->
+                  Just (nick_ <> ":")
+                | BS.isPrefixOf "*:" text ->
+                  Just "*:"
+                | isQuery ->
+                  Just ""
+                | otherwise ->
+                  Nothing
+
+        audience = if isQuery then from else msgtarget
+
+        -- TODO check if msgtarget is one of our channels?
+        --      what if our nick has changed?
+        isQuery = msgtarget == nick_
+
+        from = BS.takeWhile (/='!') prefix
+          --maybe prefix (flip BS.take prefix) $ BS.findIndex (=='!') prefix
+    case isActivated of
+      Just trigger -> do
+        let cmdline = BS.dropWhile (==' ') $ BS.drop (BS.length trigger) text
+            resultPrefix = if isQuery then [] else [from <> ":"]
+
+            parseCommandLine' pat s =
+                if null result then [] else snd (head result)
+              where
+                result = RE.scan patternRE s
+                patternRE = RE.compile pat []
+
+            parse' =
+              case pattern params of
+                Nothing -> [] -- TODO everything
+                Just pat -> parseCommandLine' pat cmdline
+
+            headMaybe x = if null x then Nothing else Just (head x)
+
+            -- TODO rename "command" to something like "commandSpec"
+            command' = case command params of
+              Capture i ->
+                case headMaybe (drop (fromIntegral i - 1) parse') of
+                  Nothing -> Nothing
+                  Just k -> M.lookup k (commands params)
+
+              CaptureOr c -> Just c
+
+            cmdName = case command params of
+              Capture i ->
+                case headMaybe (drop (fromIntegral i - 1) parse') of
+                  Nothing -> "<CMDERP>"
+                  Just k -> k
+
+              CaptureOr c -> BS.pack (takeBaseName $ commandPath c)
+
+            args' =
+                map BS.unpack $
+                map (maybe "" id) $
+                reverse $
+                dropWhile (==Nothing) $
+                reverse $
+                map f (arguments params)
+              where
+                f arg = case arg of
+                  Capture i ->
+                    case headMaybe (drop (fromIntegral i - 1) parse') of
+                      Nothing -> Nothing
+                      Just k -> Just k
+
+                  CaptureOr x -> Just x
+
+        case command' of
+          Just c -> do
+            sendMsg_ <- gets s_sendMsg
+            putLog_ <- gets s_putLog
+            let onErrLine s =
+                  putLog_ $ SGR [31,1] $
+                    Plain (BS.pack (takeBaseName $ commandPath c) <> ": "<> s)
+
+                onOutLine s =
+                  sendMsg_ (privmsg audience [s])
+
+                extraEnv = [("_prefix", BS.unpack prefix),
+                            ("_from", BS.unpack from)]
+
+            lift $ fork cfg c args' (Just extraEnv) "" onOutLine onErrLine
+
+          Nothing -> do
+            sendMsg (privmsg audience (resultPrefix <> [cmdName <> ": command not found"]))
+
+      Nothing -> return ()
+
+
+
+fork :: SystemConfig
+     -> SystemCommand
+     -> [String]
+     -> Maybe [(String, String)]
+     -> String
+     -> (BS.ByteString -> IO ())
+     -> (BS.ByteString -> IO ())
+     -> IO ()
+fork cfg cmd args extraEnv input onOutLine onErrLine = do
+
+    baseEnv <- getEnvironment
+
+    let procEnv = M.toList $ mconcat [
+                    maybe mempty M.fromList extraEnv,
+                    maybe mempty id (commandEnv cmd),
+                    M.fromList baseEnv
+                  ]
+
+    (inh, outh, errh) <- do
+      (Just inh, Just outh, Just errh, ph) <-
+        createProcess (proc (commandPath cmd) args) {
+          cwd = commandWorkDir cmd <|> defaultWorkDir cfg,
+          env = Just procEnv,
+          std_in = CreatePipe,
+          std_out = CreatePipe,
+          std_err = CreatePipe,
+          close_fds = True,
+          create_group = True,
+          new_session = True
+        }
+      _ <- forkIO $ waitForProcess ph >> return ()
+      return (inh, outh, errh)
+
+    mapM_ forkIO [
+        hPutStr inh input `finally` hClose inh,
+        hWithLines outh onOutLine,
+        hWithLines errh onErrLine
+      ]
+
+
+hWithLines :: Handle -> (BS.ByteString -> IO ()) -> IO ()
+hWithLines h f = do
+    hSetBuffering h LineBuffering
+    go `finally` hClose h
+  where
+    go =
+      hIsEOF h >>= \case
+        True -> return ()
+        False -> BS.hGetLine h >>= f >> go
diff --git a/src/Reaktor/Plugins/System/Types.hs b/src/Reaktor/Plugins/System/Types.hs
new file mode 100644
index 0000000..48ec51a
--- /dev/null
+++ b/src/Reaktor/Plugins/System/Types.hs
@@ -0,0 +1,75 @@
+{-# LANGUAGE OverloadedStrings #-}
+module Reaktor.Plugins.System.Types where
+
+import           Data.Aeson
+import qualified Data.ByteString.Char8 as BS
+import qualified Data.Map as M
+import           Reaktor.Types ()
+
+
+-- TODO this needs better names :)
+data CaptureOr a = Capture Integer | CaptureOr a
+  deriving Show -- TODO killme
+
+instance FromJSON a => FromJSON (CaptureOr a) where
+  parseJSON o@(Number _) = Capture <$> parseJSON o -- TODO don't parse twice
+  parseJSON o = CaptureOr <$> parseJSON o
+
+-- TODO query means via direct privmsg and <nick>:
+data Activate = Always | Match | Query
+
+instance FromJSON Activate where
+  parseJSON (String "always") = pure Always
+  parseJSON (String "match") = pure Match
+  parseJSON (String "query") = pure Query
+  parseJSON _ = undefined
+
+data SystemConfig = SystemConfig {
+  defaultWorkDir :: Maybe FilePath,
+  -- TODO IrcCommand as key for map
+  hooks :: M.Map BS.ByteString [SystemParams]
+}
+
+instance FromJSON SystemConfig where
+  parseJSON (Object v) =
+    SystemConfig
+      <$> v .:? "workdir"
+      <*> v .:? "hooks" .!= M.empty
+  parseJSON _ = pure undefined
+
+data SystemParams = SystemParams {
+  activate :: Activate,
+  pattern :: Maybe BS.ByteString, -- TODO RE
+  command :: CaptureOr SystemCommand,
+  arguments :: [CaptureOr BS.ByteString],
+  workDir :: Maybe FilePath,
+  commands :: M.Map BS.ByteString SystemCommand
+}
+
+instance FromJSON SystemParams where
+  parseJSON (Object v) =
+      SystemParams
+        <$> v .:? "activate" .!= Query
+        <*> v .:? "pattern"
+        <*> v .: "command"
+        <*> v .:? "arguments" .!= []
+        <*> v .:? "workdir"
+        <*> v .:? "commands" .!= M.empty
+  parseJSON _ = pure undefined
+
+
+data SystemCommand = SystemCommand {
+    commandPath :: FilePath,
+    commandWorkDir :: Maybe FilePath,
+    commandEnv :: Maybe (M.Map String String)
+  }
+  deriving Show -- TODO killme
+
+instance FromJSON SystemCommand where
+  parseJSON (Object v) =
+      SystemCommand
+        <$> v .: "filename"
+        <*> v .:? "workdir"
+        <*> v .:? "env"
+  parseJSON _ = pure undefined
+
diff --git a/src/Reaktor/Types.hs b/src/Reaktor/Types.hs
new file mode 100644
index 0000000..f2115be
--- /dev/null
+++ b/src/Reaktor/Types.hs
@@ -0,0 +1,68 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+module Reaktor.Types (module Reaktor.Types, module X) where
+
+import           Blessings (Blessings)
+import           Control.Monad.Trans.Class as X (lift)
+import           Control.Monad.Trans.State as X (gets,modify)
+import           Control.Monad.Trans.State (StateT)
+import           Data.Aeson
+import           Data.Aeson.Types
+import qualified Data.ByteString.Char8 as BS
+import qualified Data.Text.Encoding as T
+import           Network.Socket as X (HostName,ServiceName)
+
+
+type Prefix = BS.ByteString
+
+type Nickname = BS.ByteString
+type Password = BS.ByteString
+type MsgTarget = BS.ByteString
+type Channel = MsgTarget
+
+data PluginState = PluginState {
+      s_putLog :: Blessings BS.ByteString -> IO (),
+      s_nick :: BS.ByteString,
+      s_sendMsg :: Message -> IO (),
+      s_sendMsg' :: Message -> Message -> IO ()
+    }
+
+setNick :: Nickname -> PluginIO ()
+setNick newnick = modify (\q -> q { s_nick = newnick })
+
+getNick :: PluginIO Nickname
+getNick = gets s_nick
+
+sendMsg :: Message -> PluginIO ()
+sendMsg msg = gets s_sendMsg >>= \f -> lift $ f msg
+
+sendMsg' :: Message -> Message -> PluginIO ()
+sendMsg' msg logMsg = gets s_sendMsg' >>= \f -> lift $ f msg logMsg
+
+
+type PluginIO = StateT PluginState IO
+
+type PluginFunc = Message -> PluginIO ()