kiroku-metrics-0.4.0.0: app-inspect/Main.hs

module Main (main) where

import Control.Concurrent.MVar (newEmptyMVar, takeMVar, tryPutMVar)
import Control.Exception (SomeAsyncException, SomeException, fromException, tryJust)
import Control.Monad (void)
import Data.Text.IO qualified as TIO
import InspectSignals (withInspectSignals)
import Options.Applicative (execParser)
import System.Environment (getEnvironment)
import System.Exit (ExitCode (..), exitFailure, exitWith)
import System.IO (hFlush, stderr, stdout)

import Kiroku.Metrics.Standalone

main :: IO ()
main = do
  opts <- execParser inspectParserInfo
  env <- getEnvironment
  case resolveInspectOptions env opts of
    Left err -> TIO.hPutStrLn stderr err >> exitWith (ExitFailure 2)
    Right rt -> do
      done <- newEmptyMVar
      let hooks =
            InspectHooks
              { onListening = \port caps -> mapM_ TIO.putStrLn (renderStartupBanner rt port caps) >> hFlush stdout,
                waitForShutdown = takeMVar done >> TIO.putStrLn "kiroku-inspect: shutting down"
              }
      result <- tryJust synchronousException (withInspectSignals (void (tryPutMVar done ())) (runInspect hooks rt))
      case result of
        Left err -> TIO.hPutStrLn stderr (renderInspectFailure (classifyInspectFailure err)) >> exitFailure
        Right () -> pure ()

synchronousException :: SomeException -> Maybe SomeException
synchronousException err = case fromException err :: Maybe SomeAsyncException of
  Just _ -> Nothing
  Nothing -> Just err