ntf-server: carry retry reason in PPRetryLater, log retries

Change PPRetryLater from nullary to PPRetryLater Text so the cause
(503 / 410-reason) propagates to the retry call site. Log a warning
at every retry attempt with provider, token id and reason.

src/Simplex/Messaging/Notifications/Server.hs

@@ -672,8 +672,8 @@ ntfPush s@NtfPushServer {pushQ} = forever $ do
       runExceptT (deliver tkn ntf) >>= \case
         Right _ -> pure $ Right ()
         Left e -> case e of
-          PPConnection _ -> retryDeliver
-          PPRetryLater -> retryDeliver
+          PPConnection ce -> retryDeliver $ "connection " <> tshow ce
+          PPRetryLater r -> retryDeliver r
           PPCryptoError _ -> err e
           PPResponseError {} -> err e
           PPTokenInvalid r -> do
@@ -681,8 +681,9 @@ ntfPush s@NtfPushServer {pushQ} = forever $ do
             err e
           PPPermanentError -> err e
       where
-        retryDeliver :: IO (Either PushProviderError ())
-        retryDeliver = do
+        retryDeliver :: Text -> IO (Either PushProviderError ())
+        retryDeliver reason = do
+          logWarn $ "retrying push (" <> tshow pp <> ", " <> tshow ntfTknId <> "): " <> reason
           deliver <- newPushClient s pp
           runExceptT (deliver tkn ntf) >>= \case
             Right _ -> pure $ Right ()

src/Simplex/Messaging/Notifications/Server/Push/APNS.hs

@@ -326,7 +326,7 @@ data PushProviderError
   | PPCryptoError C.CryptoError
   | PPResponseError (Maybe Status) Text
   | PPTokenInvalid NTInvalidReason
-  | PPRetryLater
+  | PPRetryLater Text
   | PPPermanentError
   deriving (Show, Exception)
 
@@ -373,8 +373,8 @@ apnsPushProviderClient c@APNSPushClient {nonceDrg, apnsCfg} tkn@NtfTknRec {token
       | status == Just N.gone410 = throwE $ case reason' of
           "ExpiredToken" -> PPTokenInvalid NTIRExpiredToken
           "Unregistered" -> PPTokenInvalid NTIRUnregistered
-          _ -> PPRetryLater
-      | status == Just N.serviceUnavailable503 = liftIO (disconnectApnsHTTP2Client c) >> throwE PPRetryLater
+          _ -> PPRetryLater $ "410 " <> reason'
+      | status == Just N.serviceUnavailable503 = liftIO (disconnectApnsHTTP2Client c) >> throwE (PPRetryLater "503")
       -- Just tooManyRequests429 -> TooManyRequests - too many requests for the same token
       | otherwise = throwE $ PPResponseError status reason'
     liftHTTPS2 a = ExceptT $ first PPConnection <$> a