successful post publishing with MonadState and random relay selection

app/Experiment.hs

@@ -1,3 +1,44 @@
+{-# LANGUAGE OverloadedStrings     #-}
+
 module Main where
 
-main = putStrLn "This gives us ALL the insights!"
+import System.Random
+import Control.Concurrent
+import Control.Monad (forM_)
+import Control.Monad.State.Class
+import Control.Monad.State.Strict (evalStateT)
+import Control.Monad.IO.Class
+import qualified Network.HTTP.Client           as HTTP
+
+import Hash2Pub.PostService     (clientPublishPost, Hashtag)
+
+-- placeholder post data definition
+
+tagsToPostTo = [ "JustSomeTag", "WantAnotherTag234", "HereWeGoAgain", "Oyä", "通信端末" ]
+
+knownRelays :: [(String, Int)]
+knownRelays =
+  [ ("animalliberation.social", 3342)
+  , ("hostux.social", 3343)
+  , ("social.diskseven.com", 3344)
+  , ("social.imirhil.fr", 3345)
+  ]
+
+main :: IO ()
+main = do
+    -- initialise HTTP manager
+    httpMan <- HTTP.newManager HTTP.defaultManagerSettings
+    -- initialise RNG
+    let initRGen = mkStdGen 12
+    -- cycle through tags and post to a random instance
+    evalStateT (forM_ (cycle tagsToPostTo) $ publishPostRandom httpMan) initRGen
+    -- wait for a specified time
+
+publishPostRandom :: (RandomGen g, MonadIO m, MonadState g m) => HTTP.Manager -> Hashtag -> m ()
+publishPostRandom httpman tag = do
+    index <- state $ randomR (0, length knownRelays - 1)
+    let (pubHost, pubPort) = knownRelays !! index
+    _ <- liftIO . forkIO $ do
+        postResult <- liftIO $ clientPublishPost httpman pubHost pubPort ("foobar #" <> tag)
+        either putStrLn (const $ pure ()) postResult
+    liftIO $ threadDelay 500