feat: Run in a loop

package.yaml

@@ -19,6 +19,7 @@ dependencies:
   - text
   - bytestring
   - optparse-applicative
+  - time
 
 ghc-options:
   - -Wall

src/TK2MQTT.hs

@@ -7,16 +7,20 @@ module TK2MQTT
   )
 where
 
+import Control.Concurrent (threadDelay)
 import Control.Exception (catch)
-import Control.Monad (void)
-import Control.Monad.IO.Class
+import Control.Monad (forever, void)
 import Data.Aeson
+import Data.ByteString.Lazy qualified as BL
 import Data.List qualified as L
 import Data.Maybe (fromMaybe)
 import Data.Text qualified as T
+import Data.Text.IO qualified as T
+import Data.Time (getCurrentTime)
+import Data.Time.Format.ISO8601 (iso8601Show)
 import Network.HTTP.Req
 import Network.MQTT.Client qualified as MQTT
-import Network.MQTT.Topic (mkTopic)
+import Network.MQTT.Topic (Topic (..), mkTopic)
 import Network.URI (URI, parseURI, pathSegments)
 import Options.Applicative (eitherReader, (<**>))
 import Options.Applicative qualified as O
@@ -45,16 +49,22 @@ pConfig =
 runTK2MQTT :: Config -> IO ()
 runTK2MQTT Config {..} = do
   mc <- MQTT.connectURI MQTT.mqttConfig brokerUrl
+  T.putStrLn $ "Publishing to " <> unTopic topic
+  forever $ do
+    now <- iso8601Show <$> getCurrentTime
     result <- runReq defaultHttpConfig $ do
       r <- req GET (https "creativecommons.tankerkoenig.de" /: "json" /: "prices.php") NoReqBody jsonResponse ("apikey" =: apiKey <> "ids" =: stationId)
       pure (responseBody r :: Value)
-  void $ liftIO $ MQTT.publish mc topic (encode result) True
-  void $ liftIO $ print topic
-  void $ liftIO $ print $ encode result
+    void $ MQTT.publish mc topic (encode result) True
+    putStr $ now <> " = "
+    BL.putStr $ encode result
+    putStrLn ""
+    threadDelay oneHour
   where
     topic = fromMaybe "home/fuel" $ case L.intercalate "/" (pathSegments brokerUrl) of
       "" -> Nothing
       t -> mkTopic (T.pack t)
+    oneHour = 60 * 60 * 1_000_000
 
 handleError :: IOError -> IO ()
 handleError e = do

tk2mqtt.cabal

@@ -38,6 +38,7 @@ library
     , optparse-applicative
     , req
     , text
+    , time
   default-language: GHC2021
 
 executable tk2mqtt
@@ -61,6 +62,7 @@ executable tk2mqtt
     , optparse-applicative
     , req
     , text
+    , time
     , tk2mqtt
   default-language: GHC2021
 
@@ -89,6 +91,7 @@ test-suite doctest
     , process
     , req
     , text
+    , time
   default-language: Haskell2010
 
 test-suite spec
@@ -120,5 +123,6 @@ test-suite spec
     , quickcheck-instances
     , req
     , text
+    , time
     , tk2mqtt
   default-language: GHC2021