{-# LANGUAGE CPP                #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

{-|
Module:      Instances.System.IO
Copyright:   (C) 2014-2016 Ryan Scott
License:     BSD-style (see the file LICENSE)
Maintainer:  Ryan Scott
Stability:   Provisional
Portability: GHC

'Arbitrary' instances for data types in the "System.IO" module.
-}
module Instances.System.IO () where

#if MIN_VERSION_base(4,4,0)
import GHC.IO.Encoding.Failure (CodingFailureMode(..))
import GHC.IO.Encoding.Types (CodingProgress(..))
#endif

import GHC.IO.Handle (HandlePosn(..))

import Prelude ()
import Prelude.Compat

import System.IO (BufferMode(..), IOMode(..), Newline(..), NewlineMode(..),
                  SeekMode(..), Handle, stdin, stdout, stderr)

import Test.QuickCheck (Arbitrary(..), arbitraryBoundedEnum, oneof)

instance Arbitrary Handle where
    arbitrary = oneof $ map pure [stdin, stdout, stderr]

instance Arbitrary HandlePosn where
    arbitrary = HandlePosn <$> arbitrary <*> arbitrary

deriving instance Bounded IOMode
instance Arbitrary IOMode where
    arbitrary = arbitraryBoundedEnum

instance Arbitrary BufferMode where
    arbitrary = oneof [ pure NoBuffering
                      , pure LineBuffering
                      , BlockBuffering <$> arbitrary
                      ]

deriving instance Bounded SeekMode
instance Arbitrary SeekMode where
    arbitrary = arbitraryBoundedEnum

#if MIN_VERSION_base(4,4,0)
deriving instance Bounded CodingProgress
deriving instance Enum CodingProgress
instance Arbitrary CodingProgress where
    arbitrary = arbitraryBoundedEnum

deriving instance Bounded CodingFailureMode
deriving instance Enum CodingFailureMode
instance Arbitrary CodingFailureMode where
    arbitrary = arbitraryBoundedEnum
#endif

deriving instance Bounded Newline
deriving instance Enum Newline
instance Arbitrary Newline where
    arbitrary = arbitraryBoundedEnum

instance Arbitrary NewlineMode where
    arbitrary = NewlineMode <$> arbitrary <*> arbitrary