1 files changed, 59 insertions, 0 deletions
diff --git a/fig-monitor-twitch/src/Fig/Monitor/Twitch/LiveChecker.hs b/fig-monitor-twitch/src/Fig/Monitor/Twitch/LiveChecker.hs
new file mode 100644
index 0000000..cf0389a
--- /dev/null
+++ b/fig-monitor-twitch/src/Fig/Monitor/Twitch/LiveChecker.hs
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+module Fig.Monitor.Twitch.LiveChecker
+  ( twitchChannelLiveChecker
+  ) where
+
+import Fig.Prelude
+
+import Control.Concurrent (threadDelay)
+
+import qualified Data.Text as Text
+import qualified Data.Set as Set
+
+import Data.Aeson ((.:))
+import qualified Data.Aeson as Aeson
+import qualified Data.Aeson.Types as Aeson
+
+import Fig.Bus.Binary.Client
+import Fig.Monitor.Twitch.Auth.AppToken
+import Fig.Monitor.Twitch.Utils
+
+twitchChannelLiveChecker :: Config -> (Text, Text) -> IO ()
+twitchChannelLiveChecker cfg busAddr = do
+  busClient busAddr
+    (\cmds -> do
+        let
+          loop :: IO ()
+          loop = do
+            log "Updating liveness..."
+            live <- runAuthed cfg $ usersAreLive cfg.monitor
+            if null live
+              then log "Update complete! No users live"
+              else log $ "Update complete! Live users: " <> Text.unwords (Set.toList live)
+            cmds.publish "fig monitor twitch stream online" . encodeUtf8 . Text.unwords $ Set.toList live
+            threadDelay $ 5 * 60 * 1000000 -- wait 5 minutes
+            loop
+        loop
+    )
+    (\_cmds _ev _d -> pure ())
+    (pure ())
+
+usersAreLive :: [Text] -> Authed (Set.Set Text)
+usersAreLive users = do
+  log $ "Checking liveness for: " <> Text.intercalate " " users
+  res <- authedRequestJSON @()
+    "GET"
+    ( mconcat
+      [ "https://api.twitch.tv/helix/streams?type=live"
+      , mconcat $ ("&user_login="<>) <$> users
+      ]
+    )
+    Nothing
+  let mos = flip Aeson.parseEither res \obj -> do
+        obj .: "data" >>= \case
+          Aeson.Array os -> catMaybes . toList <$> forM os \case
+            Aeson.Object o -> Just <$> o .: "user_login"
+            _else -> pure Nothing
+          _else -> mempty
+  case mos of
+    Left err -> throwM $ FigMonitorTwitchException $ "Failed to check liveness: " <> pack err <> "\nResponse was: " <> tshow res
+    Right os -> pure . Set.fromList $ filter (`elem` os) users