{-# LANGUAGE NoMonomorphismRestriction, FlexibleContexts, ScopedTypeVariables, BangPatterns #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE TypeApplications #-}
module Main where

import Control.Monad.IO.Class
import Control.Monad
import Control.Effects.Signal
import Control.Effects.State
import Control.Effects.Early
import Control.Effects.Async
import Control.Effects.List
import Control.Effects.Yield
import Control.Effects.Resource
import Control.Concurrent hiding (yield)
import System.IO

import Data.Function

-- Should infer
ex1 = signal True

-- Should compile
ex2 :: MonadEffect (Throw Bool) m => m ()
ex2 = throwSignal False

ex3 = do
    void $ discardAllExceptions ex1
    void $ showAllExceptions ex2
    handleException (\(_ :: Bool) -> return ()) ex2
    handleSignal (\(_ :: Bool) -> return $ Resume 5) ex1

-- Nested Early
testEarly1 :: Monad m => m Bool
testEarly1 = handleEarly $ do
    return ()
    _ <- earlyReturn True
    _ <- handleEarly $ do
        return ()
        earlyReturn (123 :: Int)
    _ <- testEarly2
    return True

testEarly2 :: Monad m => m Char
testEarly2 = handleEarly $
    earlyReturn 'a'

orderTest :: (MonadEffects '[HandleException Bool, Throw Bool, State Int] m, MonadIO m) => m ()
orderTest = do
    setState (1 :: Int)
    _ :: Either Bool () <- handleToEitherRecursive $ do
        setState (2 :: Int)
        void $ throwSignal True
        setState (3 :: Int)
    st :: Int <- getState
    liftIO (print st)

inc :: Int -> Int
inc !x = x + 1

task :: (MonadEffect (State Int) m) => m Int
task = do
    replicateM_ 10000000 (modifyState inc)
    st <- getState
    st `seq` return st

main :: IO ()
main = do
    orderTest & handleException (\(_ :: Bool) -> return ())
              & implementStateViaStateT (0 :: Int)
    orderTest & implementStateViaStateT (0 :: Int)
              & handleException (\(_ :: Bool) -> return ())
    putStrLn "Starting sequential test"
    replicateM_ 8 (implementStateViaStateT (0 :: Int) task >>= print)
    putStrLn "Sequential test done"
    putStrLn "Starting parallel test"
    implementStateViaStateT (0 :: Int) $ do
        res <- parallelMapM id (replicate 8 task)
        mapM_ (liftIO . print) res
    putStrLn "Parallel test done"

parallelTest ::
    (MonadEffects '[Async thread, NonDeterminism] m, MonadIO m) => m (thread m (Int, Char))
parallelTest = do
    n <- choose [1,2,3,4]
    async $ do
        liftIO $ threadDelay ((5 - n) * 1000000)
        l <- choose "ab"
        return (n, l)

mainAsync :: IO ()
mainAsync = do
    threads <- evaluateToList parallelTest
    forM_ threads $ \thread ->
        evaluateToList (do
            p <- waitAsync thread
            liftIO $ print p
            )

yieldTest ::
    (MonadEffects '[Yield Int, Async thread] m, MonadIO m) => m ()
yieldTest = do
    yield @Int 5
    t <- async $ do
        liftIO $ putStrLn "yielding 6"
        yield @Int 6
        liftIO $ putStrLn "yielding 10"
        yield @Int 10

    t2 <- async $ do
        liftIO $ putStrLn "yielding 8"
        yield @Int 8
        liftIO $ putStrLn "yielding 9"
        yield @Int 9
    yield @Int 7
    waitAsync t
    waitAsync t2
    return ()

mainYield :: IO ()
mainYield = do
    hSetBuffering stdout LineBuffering
    await <- implementYieldViaMVar @Int yieldTest
    traverseYielded_ await $ \res -> do
        print res
        void getLine

-- testResource = evaluateAll $ bracket
--     (choose [True, False] >>= \tf -> liftIO (putStrLn ("acq " ++ show tf)) >> return tf)
--     (\tf _ -> liftIO $ putStrLn ("cleaning " ++ show tf))
--     (\tf -> if tf then liftIO $ putStrLn "true" else error "io err" >> liftIO (putStrLn "false") )