Supervise workers and make auth failures fatal

src/HomeAssistant/Runtime.hs

@@ -14,15 +14,16 @@ module HomeAssistant.Runtime
   ) where
 
 import AFRP (Event (..), Mealy (..))
-import Control.Concurrent.Async (mapConcurrently_)
+import Control.Concurrent.Async (async, waitAny)
 import Control.Concurrent.STM (atomically, dupTChan, readTChan)
 import Data.Aeson (Value)
 import qualified Data.Text as T
 import Data.Time (getCurrentTime)
-import Data.Void (Void)
+import Data.Void (Void, absurd)
 import HomeAssistant.Controller (HASS, HASSEff (..), lightController)
 import HomeAssistant.Runtime.Bus
 import HomeAssistant.Runtime.Connection (readerAction, writerAction)
+import HomeAssistant.Runtime.Supervisor (defaultBackoff, supervised)
 import Network.Socket (withSocketsDo)
 import System.Environment (getEnv)
 
@@ -53,10 +54,13 @@ defaultMain :: IO ()
 defaultMain = withSocketsDo $ do
   token <- getEnv "HA_TOKEN"
   bus <- newBus 0
-  mapConcurrently_ id $
-    [ readerAction "last-resort-redux" 8123 token bus
-    , writerAction bus
-    ] ++ map (runController bus) controllers
+  let workers =
+        [ ("reader", readerAction "last-resort-redux" 8123 token bus)
+        , ("writer", writerAction bus)
+        ] ++ [ (name, runController bus c) | c@(Controller name _) <- controllers ]
+  as <- mapM (\(name, act) -> async (supervised name defaultBackoff act)) workers
+  (_, v) <- waitAny as
+  absurd v
 
 dryRunHassEval :: CallIdGen -> HASSEff a -> IO a
 dryRunHassEval gen = \case

src/HomeAssistant/Runtime/Connection.hs

@@ -15,6 +15,7 @@ import Control.Concurrent.STM
   , writeTChan
   , writeTVar
   )
+import Control.Exception.Annotated (throw)
 import Control.Lens ((^?))
 import Control.Monad (forever)
 import Data.Aeson (Value, eitherDecode, encode, object, (.=))
@@ -24,6 +25,7 @@ import qualified Data.Text as T
 import Data.Void (Void)
 import HomeAssistant.Controller (Service (..))
 import HomeAssistant.Runtime.Bus
+import HomeAssistant.Runtime.Supervisor (Fatal (..))
 import qualified Network.WebSockets as WS
 
 -- | Connect, authenticate, subscribe, then receive and broadcast forever.
@@ -53,7 +55,7 @@ expectType :: T.Text -> Value -> IO ()
 expectType expected msg =
   case msg ^? key "type" . _String of
     Just t | t == expected -> pure ()
-    _ -> fail $ "expected " <> T.unpack expected <> ", got: " <> show msg
+    _ -> throw (Fatal $ "expected " <> expected <> ", got: " <> T.pack (show msg))
 
 subscribe :: Bus -> WS.Connection -> IO ()
 subscribe bus conn = do
@@ -77,7 +79,7 @@ receiveJSON :: WS.Connection -> IO Value
 receiveJSON conn = do
   msg <- WS.receiveData conn
   case eitherDecode msg of
-    Left err -> fail $ "Invalid JSON from Home Assistant: " ++ err
+    Left err -> throw (Fatal $ "Invalid JSON from Home Assistant: " <> T.pack err)
     Right x  -> pure x
 
 writerAction :: Bus -> IO Void