aboutsummaryrefslogtreecommitdiff
path: root/hsm-dummy-poller/Main.hs
blob: d3d2f881bd13c5ae252945037c43d4492557db51 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
{-# LANGUAGE OverloadedRecordDot #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell #-}

import Control.Monad (forM_)
import Data.ByteString (ByteString)
import Data.Function ((&))
import Data.Text (Text, pack)
import Effectful (Eff, (:>), runEff)
import Effectful.Concurrent (Concurrent, runConcurrent, threadDelay)
import Effectful.Log (Log, localDomain, logInfo_, runLog)
import Effectful.Reader.Static (Reader, asks, runReader)
import Effectful.Resource (runResource)
import Hsm.Core.App (launch)
import Hsm.Core.Env (deriveFromYaml)
import Hsm.Core.Message (body)
import Hsm.Core.Zmq.Client (poll, runClient)
import Streamly.Data.Fold qualified as S (drain)
import Streamly.Data.Stream qualified as S (Stream, fold, mapM)
import System.IO.Echo (withoutInputEcho)

data Env = Env
  { name :: Text
  , subEps :: [Text]
  , topics :: [Text]
  , period :: Word
  }

$(deriveFromYaml ''Env)

handle ::
     (Concurrent :> es, Log :> es, Reader Env :> es)
  => S.Stream (Eff es) [ByteString]
  -> Eff es ()
handle = S.fold S.drain . S.mapM handler
  where
    receiverDomain = "receiver"
    delay = asks period >>= threadDelay . fromIntegral
    handler [] = do
      localDomain receiverDomain $ logInfo_ "No pulse received yet"
      delay
    handler ps = do
      localDomain receiverDomain
        $ forM_ ps
        $ logInfo_ . mappend "Received pulse #" . pack . show . body @Word
      delay

-- Dummy Poller Service: A proof of concept that polls for "pulses" via ZMQ at
-- a set interval and logs a message each time one is received.
main :: IO ()
main =
  launch @Env "dummy-poller" withoutInputEcho $ \env logger level ->
    (poll & handle)
      & runClient @Env
      & runConcurrent
      & runLog env.name logger level
      & runReader env
      & runResource
      & runEff