{-# LANGUAGE TemplateHaskell #-}

-- |
-- Module      :   Grisette.Internal.TH.Derivation.DeriveHashable
-- Copyright   :   (c) Sirui Lu 2024
-- License     :   BSD-3-Clause (see the LICENSE file)
--
-- Maintainer  :   siruilu@cs.washington.edu
-- Stability   :   Experimental
-- Portability :   GHC only
module Grisette.Internal.TH.Derivation.DeriveHashable
  ( deriveHashable,
    deriveHashable1,
    deriveHashable2,
  )
where

import Data.Hashable (Hashable (hashWithSalt))
import Data.Hashable.Lifted
  ( Hashable1 (liftHashWithSalt),
    Hashable2 (liftHashWithSalt2),
  )
import Grisette.Internal.TH.Derivation.Common (DeriveConfig)
import Grisette.Internal.TH.Derivation.UnaryOpCommon
  ( UnaryOpClassConfig
      ( UnaryOpClassConfig,
        unaryOpAllowExistential,
        unaryOpConfigs,
        unaryOpContextNames,
        unaryOpExtraVars,
        unaryOpInstanceNames,
        unaryOpInstanceTypeFromConfig
      ),
    UnaryOpConfig (UnaryOpConfig),
    UnaryOpFieldConfig
      ( UnaryOpFieldConfig,
        extraLiftedPatNames,
        extraPatNames,
        fieldCombineFun,
        fieldFunExp,
        fieldResFun
      ),
    defaultFieldFunExp,
    defaultUnaryOpInstanceTypeFromConfig,
    genUnaryOpClass,
  )
import Language.Haskell.TH (Dec, Name, Q)

hashableConfig :: UnaryOpClassConfig
hashableConfig :: UnaryOpClassConfig
hashableConfig =
  UnaryOpClassConfig
    { unaryOpConfigs :: [UnaryOpConfig]
unaryOpConfigs =
        [ UnaryOpFieldConfig -> [Name] -> UnaryOpConfig
forall config.
UnaryOpFunConfig config =>
config -> [Name] -> UnaryOpConfig
UnaryOpConfig
            UnaryOpFieldConfig
              { extraPatNames :: [String]
extraPatNames = [String
"salt"],
                extraLiftedPatNames :: Int -> [String]
extraLiftedPatNames = [String] -> Int -> [String]
forall a b. a -> b -> a
const [],
                fieldCombineFun :: Int
-> Int
-> ConstructorVariant
-> Name
-> [Exp]
-> [Exp]
-> Q (Exp, [Bool])
fieldCombineFun =
                  \Int
_ Int
_ ConstructorVariant
_ Name
_ [Exp
salt] [Exp]
exp -> do
                    r <-
                      (Q Exp -> Exp -> Q Exp) -> Q Exp -> [Exp] -> Q Exp
forall b a. (b -> a -> b) -> b -> [a] -> b
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl
                        (\Q Exp
salt Exp
exp -> [|$(Exp -> Q Exp
forall a. a -> Q a
forall (m :: * -> *) a. Monad m => a -> m a
return Exp
exp) $Q Exp
salt|])
                        (Exp -> Q Exp
forall a. a -> Q a
forall (m :: * -> *) a. Monad m => a -> m a
return Exp
salt)
                        [Exp]
exp
                    return (r, [True]),
                fieldResFun :: ConstructorVariant
-> Name -> [Exp] -> Int -> Exp -> Exp -> Q (Exp, [Bool])
fieldResFun = \ConstructorVariant
_ Name
_ [Exp]
_ Int
_ Exp
fieldPat Exp
fieldFun -> do
                  r <- [|\salt -> $(Exp -> Q Exp
forall a. a -> Q a
forall (m :: * -> *) a. Monad m => a -> m a
return Exp
fieldFun) salt $(Exp -> Q Exp
forall a. a -> Q a
forall (m :: * -> *) a. Monad m => a -> m a
return Exp
fieldPat)|]
                  return (r, [False]),
                fieldFunExp :: FieldFunExp
fieldFunExp =
                  [Name] -> FieldFunExp
defaultFieldFunExp
                    ['hashWithSalt, 'liftHashWithSalt, 'liftHashWithSalt2]
              }
            ['hashWithSalt, 'liftHashWithSalt, 'liftHashWithSalt2]
        ],
      unaryOpInstanceNames :: [Name]
unaryOpInstanceNames =
        [''Hashable, ''Hashable1, ''Hashable2],
      unaryOpExtraVars :: DeriveConfig -> Q [(Type, Type)]
unaryOpExtraVars = Q [(Type, Type)] -> DeriveConfig -> Q [(Type, Type)]
forall a b. a -> b -> a
const (Q [(Type, Type)] -> DeriveConfig -> Q [(Type, Type)])
-> Q [(Type, Type)] -> DeriveConfig -> Q [(Type, Type)]
forall a b. (a -> b) -> a -> b
$ [(Type, Type)] -> Q [(Type, Type)]
forall a. a -> Q a
forall (m :: * -> *) a. Monad m => a -> m a
return [],
      unaryOpInstanceTypeFromConfig :: DeriveConfig -> [(Type, Type)] -> [(Type, Type)] -> Name -> Q Type
unaryOpInstanceTypeFromConfig = DeriveConfig -> [(Type, Type)] -> [(Type, Type)] -> Name -> Q Type
defaultUnaryOpInstanceTypeFromConfig,
      unaryOpAllowExistential :: Bool
unaryOpAllowExistential = Bool
True,
      unaryOpContextNames :: Maybe [Name]
unaryOpContextNames = Maybe [Name]
forall a. Maybe a
Nothing
    }

-- | Derive 'Hashable' instance for a data type.
deriveHashable :: DeriveConfig -> Name -> Q [Dec]
deriveHashable :: DeriveConfig -> Name -> Q [Dec]
deriveHashable DeriveConfig
deriveConfig = DeriveConfig -> UnaryOpClassConfig -> Int -> Name -> Q [Dec]
genUnaryOpClass DeriveConfig
deriveConfig UnaryOpClassConfig
hashableConfig Int
0

-- | Derive 'Hashable1' instance for a data type.
deriveHashable1 :: DeriveConfig -> Name -> Q [Dec]
deriveHashable1 :: DeriveConfig -> Name -> Q [Dec]
deriveHashable1 DeriveConfig
deriveConfig = DeriveConfig -> UnaryOpClassConfig -> Int -> Name -> Q [Dec]
genUnaryOpClass DeriveConfig
deriveConfig UnaryOpClassConfig
hashableConfig Int
1

-- | Derive 'Hashable2' instance for a data type.
deriveHashable2 :: DeriveConfig -> Name -> Q [Dec]
deriveHashable2 :: DeriveConfig -> Name -> Q [Dec]
deriveHashable2 DeriveConfig
deriveConfig = DeriveConfig -> UnaryOpClassConfig -> Int -> Name -> Q [Dec]
genUnaryOpClass DeriveConfig
deriveConfig UnaryOpClassConfig
hashableConfig Int
2