{-# LANGUAGE OverloadedStrings #-}

module LooperSpec
  ( spec
  ) where

import Test.Hspec

import Options.Applicative as AP
import UnliftIO

import Looper

spec :: Spec
spec = do
  describe "getLooperFlags" $ do
    it "parses default values for an empty list of arguments" $ do
      parserSucceedsWith
        (getLooperFlags "test")
        []
        (LooperFlags
           {looperFlagEnabled = Nothing, looperFlagPhase = Nothing, looperFlagPeriod = Nothing})
    it "parses an enable flag correctly" $ do
      parserSucceedsWith
        (getLooperFlags "test")
        ["--enable-test"]
        (LooperFlags
           {looperFlagEnabled = Just True, looperFlagPhase = Nothing, looperFlagPeriod = Nothing})
    it "parses an disable flag correctly" $ do
      parserSucceedsWith
        (getLooperFlags "test")
        ["--disable-test"]
        (LooperFlags
           {looperFlagEnabled = Just False, looperFlagPhase = Nothing, looperFlagPeriod = Nothing})
  describe "runLoopers" $ do
    it "runs one looper as intended" $ do
      v <- newTVarIO (0 :: Int)
      let l =
            LooperDef
              { looperDefName = "l1"
              , looperDefEnabled = True
              , looperDefPeriod = seconds 0.01
              , looperDefPhase = seconds 0
              , looperDefFunc = atomically $ modifyTVar' v succ
              }
      a <- async $ runLoopers [l]
      waitNominalDiffTime $ seconds 0.015
      cancel a
      r <- readTVarIO v
      r `shouldBe` 2
    it "does not run a looper before its phase" $ do
      v <- newTVarIO (0 :: Int)
      let l =
            LooperDef
              { looperDefName = "l"
              , looperDefEnabled = True
              , looperDefPeriod = seconds 0.01
              , looperDefPhase = seconds 0.02
              , looperDefFunc = atomically $ modifyTVar' v succ
              }
      a <- async $ runLoopers [l]
      waitNominalDiffTime $ seconds 0.015
      cancel a
      r <- readTVarIO v
      r `shouldBe` 0
    it "runs two loopers as intended" $ do
      v1 <- newTVarIO (0 :: Int)
      v2 <- newTVarIO (0 :: Int)
      v3 <- newTVarIO (0 :: Int)
      let l1 =
            LooperDef
              { looperDefName = "l1"
              , looperDefEnabled = True
              , looperDefPeriod = seconds 0.01
              , looperDefPhase = seconds 0
              , looperDefFunc =
                  atomically $ do
                    modifyTVar' v1 succ
                    modifyTVar' v2 succ
              }
      let l2 =
            LooperDef
              { looperDefName = "l2"
              , looperDefEnabled = True
              , looperDefPeriod = seconds 0.005
              , looperDefPhase = seconds 0.005
              , looperDefFunc =
                  atomically $ do
                    modifyTVar' v2 succ
                    modifyTVar' v3 succ
              }
      a <- async $ runLoopers [l1, l2]
      waitNominalDiffTime $ seconds 0.0225
      cancel a
      r1 <- readTVarIO v1
      r2 <- readTVarIO v2
      r3 <- readTVarIO v3
      (r1, r2, r3) `shouldBe` (3, 7, 4)
  describe "runLoopersRaw" $ do
    it "runs one looper as intended with a custom runner" $ do
      v1 <- newTVarIO (0 :: Int)
      v2 <- newTVarIO (0 :: Int)
      let inc1 = atomically $ modifyTVar' v1 succ
          inc2 = atomically $ modifyTVar' v2 succ
      let l =
            LooperDef
              { looperDefName = "l"
              , looperDefEnabled = True
              , looperDefPeriod = seconds 0.01
              , looperDefPhase = seconds 0
              , looperDefFunc = inc1
              }
      a <- async $ runLoopersRaw (pure ()) (\ld -> looperDefFunc ld >> inc2) [l]
      waitNominalDiffTime $ seconds 0.015
      cancel a
      r1 <- readTVarIO v1
      r2 <- readTVarIO v2
      (r1, r2) `shouldBe` (2, 2)
    it "runs one looper as intended with a custom overrun hook" $ do
      v1 <- newTVarIO (0 :: Int)
      v2 <- newTVarIO (0 :: Int)
      let inc1 = atomically $ modifyTVar' v1 succ
          inc2 = atomically $ modifyTVar' v2 succ
      let l =
            LooperDef
              { looperDefName = "l"
              , looperDefEnabled = True
              , looperDefPeriod = seconds 0.01
              , looperDefPhase = seconds 0
              , looperDefFunc = inc1 >> waitNominalDiffTime (seconds 0.015)
              }
      a <- async $ runLoopersRaw inc2 looperDefFunc [l]
      waitNominalDiffTime $ seconds 0.035
      cancel a
      r1 <- readTVarIO v1
      r2 <- readTVarIO v2
      (r1, r2) `shouldBe` (3, 2)

parserSucceedsWith :: (Show a, Eq a) => Parser a -> [String] -> a -> Expectation
parserSucceedsWith parser args expectedValue =
  case execParserPure parserPrefs (info parser mempty) args of
    AP.Success r -> r `shouldBe` expectedValue
    AP.Failure fp ->
      let (err, ec) = renderFailure fp "test"
       in expectationFailure $
          unlines ["Failed to parse:", err, "would have resulted in exit code", show ec]
    AP.CompletionInvoked _ -> expectationFailure "Tried to invoke a completion, should not happen"
  where
    parserPrefs :: ParserPrefs
    parserPrefs =
      ParserPrefs
        { prefMultiSuffix = ""
        , prefDisambiguate = True
        , prefShowHelpOnError = True
        , prefShowHelpOnEmpty = True
        , prefBacktrack = True
        , prefColumns = 80
        }