-- XXX We are using head/tail at one place
#if __GLASGOW_HASKELL__ >= 908
{-# OPTIONS_GHC -Wno-x-partial #-}
#endif

-- |
-- Module      : Streamly.Test.Data.Stream
-- Copyright   : (c) 2019 Composewell technologies
-- License     : BSD-3-Clause
-- Maintainer  : streamly@composewell.com
-- Stability   : experimental
-- Portability : GHC

module Streamly.Test.Data.Stream.Time (main) where

#ifdef DEVBUILD
import Control.Concurrent ( threadDelay )
import Control.Monad ( when)
import Data.Int (Int64)
import Streamly.Internal.Data.Time.Clock (Clock(Monotonic), getTime)
import Streamly.Internal.Data.Time.Units
       (AbsTime, NanoSecond64(..), toRelTime64, diffAbsTime64)

import qualified Streamly.Internal.Data.Fold as Fold
import qualified Streamly.Internal.Data.Stream as Stream
import qualified Streamly.Internal.Data.Stream.Prelude as Stream

#endif

import Test.Hspec as H

#ifdef DEVBUILD
tenPow8 :: Int64
tenPow8 = 10^(8 :: Int)

tenPow7 :: Int64
tenPow7 = 10^(7 :: Int)

takeDropTime :: NanoSecond64
takeDropTime = NanoSecond64 $ 5 * tenPow8

checkTakeDropTime :: (Maybe AbsTime, Maybe AbsTime) -> IO Bool
checkTakeDropTime (mt0, mt1) = do
    let graceTime = NanoSecond64 $ 8 * tenPow7
    case mt0 of
        Nothing -> return True
        Just t0 ->
            case mt1 of
                Nothing -> return True
                Just t1 -> do
                    let tMax = toRelTime64 (takeDropTime + graceTime)
                    let tMin = toRelTime64 (takeDropTime - graceTime)
                    let t = diffAbsTime64 t1 t0
                    let r = t >= tMin && t <= tMax
                    when (not r) $ putStrLn $
                        "t = " ++ show t ++
                        " tMin = " ++ show tMin ++
                        " tMax = " ++ show tMax
                    return r

testTakeInterval :: IO Bool
testTakeInterval = do
    r <-
         Stream.fold (Fold.tee Fold.one Fold.latest)
        $ Stream.takeInterval (fromIntegral takeDropTime * 10**(-9))
        $ Stream.repeatM (threadDelay 1000 >> getTime Monotonic)
    checkTakeDropTime r

testDropInterval :: IO Bool
testDropInterval = do
    t0 <- getTime Monotonic
    mt1 <-
         Stream.fold Fold.one
        $ Stream.dropInterval (fromIntegral takeDropTime * 10**(-9))
        $ Stream.repeatM (threadDelay 1000 >> getTime Monotonic)
    checkTakeDropTime (Just t0, mt1)
#endif

moduleName :: String
moduleName = "Data.Stream.Time"

main :: IO ()
main = hspec
  $ H.parallel
#ifdef COVERAGE_BUILD
  $ modifyMaxSuccess (const 10)
#endif
  $ describe moduleName $ do
#ifdef DEVBUILD
        describe "Filtering" $ do
            it "takeInterval" (testTakeInterval `shouldReturn` True)
            it "dropInterval" (testDropInterval `shouldReturn` True)
#endif
        it "dummy" (return () `shouldReturn` ())