-- SPDX-FileCopyrightText: 2020 Tocqueville Group
--
-- SPDX-License-Identifier: LicenseRef-MIT-TQ

module Indigo.Internal.Object
  ( IndigoObjectF (..)
  , NamedFieldObj (..)
  , TypedFieldObj (..)
  , FieldTypes
  , Object
  , SomeObject (..)
  , namedToTypedRec
  , typedToNamedRec
  , namedToTypedFieldObj
  , typedToNamedFieldObj

  , IsObject
  , complexObjectDict
  , ComplexObjectC
  , castFieldConstructors
  ) where

import Data.Vinyl (RMap)
import Data.Vinyl.TypeLevel (AllConstrained)
import Data.Constraint (Dict(..))
import qualified GHC.Generics as G

import Indigo.Internal.Var (RefId)
import Indigo.Backend.Prelude
import Indigo.Lorentz
import Michelson.Typed.Haskell.Instr.Product
  ( GetFieldType, ConstructorFieldNames, GetFieldType
  , InstrDeconstructC, FieldConstructor (..), CastFieldConstructors (..))
import Michelson.Typed (IsPrimitiveValue)
import Util.Type (KnownList (..), KList (..))

----------------------------------------------------------------------------
-- IndigoObjectF
----------------------------------------------------------------------------

-- | A object that can be either
-- stored in the single stack cell or split into fields.
-- Fields are identified by their names.
--
-- @f@ is a functor to be applied to each of field names.
data IndigoObjectF f a where
  -- | Value stored on the stack, it might be
  -- either complex product type, like @(a, b)@, Storage, etc,
  -- or sum type like 'Either', or primitive like 'Int', 'Operation', etc.
  Cell :: KnownValue a => RefId -> IndigoObjectF f a
  -- | Decomposed product type, which is NOT stored
  -- as one cell on the stack.
  Decomposed :: ComplexObjectC a => Rec f (ConstructorFieldNames a) -> IndigoObjectF f a

-- | Auxiliary type family to convert list of field names
-- to list of field types
type family MapGFT a rs where
  MapGFT _ '[] = '[]
  MapGFT a (name ': xs) = GetFieldType a name ': MapGFT a xs

-- | Convert a list of fields from name-based list to type-based one
namedToTypedRec
  :: forall a f g .
    (forall name . f name -> g (GetFieldType a name))
  -> Rec f (ConstructorFieldNames a)
  -> Rec g (FieldTypes a)
namedToTypedRec :: (forall (name :: Symbol). f name -> g (GetFieldType a name))
-> Rec f (ConstructorFieldNames a) -> Rec g (FieldTypes a)
namedToTypedRec fun :: forall (name :: Symbol). f name -> g (GetFieldType a name)
fun = Rec f (ConstructorFieldNames a) -> Rec g (FieldTypes a)
forall (rs :: [Symbol]). Rec f rs -> Rec g (MapGFT a rs)
namedToTypedRecImpl
  where
    namedToTypedRecImpl :: Rec f rs -> Rec g (MapGFT a rs)
    namedToTypedRecImpl :: Rec f rs -> Rec g (MapGFT a rs)
namedToTypedRecImpl RNil = Rec g (MapGFT a rs)
forall u (a :: u -> *). Rec a '[]
RNil
    namedToTypedRecImpl (v :: f r
v :& xs :: Rec f rs
xs) = f r -> g (GetFieldType a r)
forall (name :: Symbol). f name -> g (GetFieldType a name)
fun f r
v g (GetFieldType a r)
-> Rec g (MapGFT a rs) -> Rec g (GetFieldType a r : MapGFT a rs)
forall u (a :: u -> *) (r :: u) (rs :: [u]).
a r -> Rec a rs -> Rec a (r : rs)
:& Rec f rs -> Rec g (MapGFT a rs)
forall (rs :: [Symbol]). Rec f rs -> Rec g (MapGFT a rs)
namedToTypedRecImpl Rec f rs
xs

-- | Convert a list of fields from type-based list to named-based one
typedToNamedRec :: forall a f g . KnownList (ConstructorFieldNames a)
  => (forall name . f (GetFieldType a name) -> g name)
  -> Rec f (FieldTypes a)
  -> Rec g (ConstructorFieldNames a)
typedToNamedRec :: (forall (name :: Symbol). f (GetFieldType a name) -> g name)
-> Rec f (FieldTypes a) -> Rec g (ConstructorFieldNames a)
typedToNamedRec fun :: forall (name :: Symbol). f (GetFieldType a name) -> g name
fun = Rec f (FieldTypes a) -> Rec g (ConstructorFieldNames a)
forall (rs :: [Symbol]).
KnownList rs =>
Rec f (MapGFT a rs) -> Rec g rs
typedToNamedRecImpl
  where
    typedToNamedRecImpl :: forall rs . KnownList rs => Rec f (MapGFT a rs) -> Rec g rs
    typedToNamedRecImpl :: Rec f (MapGFT a rs) -> Rec g rs
typedToNamedRecImpl re :: Rec f (MapGFT a rs)
re = case (KnownList rs => KList rs
forall k (l :: [k]). KnownList l => KList l
klist @rs, Rec f (MapGFT a rs)
re) of
      (KNil, RNil)  -> Rec g rs
forall u (a :: u -> *). Rec a '[]
RNil
      (KCons (Proxy x
_ :: Proxy nm) (Proxy xs
_ :: Proxy rs'), v :& vs) -> f (GetFieldType a x) -> g x
forall (name :: Symbol). f (GetFieldType a name) -> g name
fun f r
f (GetFieldType a x)
v g x -> Rec g xs -> Rec g (x : xs)
forall u (a :: u -> *) (r :: u) (rs :: [u]).
a r -> Rec a rs -> Rec a (r : rs)
:& Rec f (MapGFT a xs) -> Rec g xs
forall (rs :: [Symbol]).
KnownList rs =>
Rec f (MapGFT a rs) -> Rec g rs
typedToNamedRecImpl Rec f rs
Rec f (MapGFT a xs)
vs

castFieldConstructors
  :: forall a st . CastFieldConstructors (FieldTypes a) (ConstructorFieldTypes a)
  => Rec (FieldConstructor st) (FieldTypes a) -> Rec (FieldConstructor st) (ConstructorFieldTypes a)
castFieldConstructors :: Rec (FieldConstructor st) (FieldTypes a)
-> Rec (FieldConstructor st) (ConstructorFieldTypes a)
castFieldConstructors = Rec (FieldConstructor st) (FieldTypes a)
-> Rec (FieldConstructor st) (ConstructorFieldTypes a)
forall (xs :: [*]) (ys :: [*]) k (st :: [k]).
CastFieldConstructors xs ys =>
Rec (FieldConstructor st) xs -> Rec (FieldConstructor st) ys
castFieldConstructorsImpl

-- | Auxiliary datatype to define a Objiable.
-- Keeps field name as type param
data NamedFieldObj a name where
  NamedFieldObj
    :: IsObject (GetFieldType a name)
    => { NamedFieldObj a name -> Object (GetFieldType a name)
unFieldObj :: Object (GetFieldType a name)
       }
    -> NamedFieldObj a name

type Object a = IndigoObjectF (NamedFieldObj a) a

data SomeObject where
  SomeObject :: IsObject a => Object a -> SomeObject

-- | Like 'NamedFieldObj', but this one doesn't keep name of a field
data TypedFieldObj a where
  TypedFieldObj :: IsObject a => Object a -> TypedFieldObj a

namedToTypedFieldObj :: forall a name . NamedFieldObj a name -> TypedFieldObj (GetFieldType a name)
namedToTypedFieldObj :: NamedFieldObj a name -> TypedFieldObj (GetFieldType a name)
namedToTypedFieldObj (NamedFieldObj f :: Object (GetFieldType a name)
f) = Object (GetFieldType a name) -> TypedFieldObj (GetFieldType a name)
forall a. IsObject a => Object a -> TypedFieldObj a
TypedFieldObj Object (GetFieldType a name)
f

typedToNamedFieldObj :: forall a name . TypedFieldObj (GetFieldType a name) -> NamedFieldObj a name
typedToNamedFieldObj :: TypedFieldObj (GetFieldType a name) -> NamedFieldObj a name
typedToNamedFieldObj (TypedFieldObj f :: Object (GetFieldType a name)
f) = Object (GetFieldType a name) -> NamedFieldObj a name
forall a (name :: Symbol).
IsObject (GetFieldType a name) =>
Object (GetFieldType a name) -> NamedFieldObj a name
NamedFieldObj Object (GetFieldType a name)
f

----------------------------------------------------------------------------
-- IsObject type class
----------------------------------------------------------------------------

class IsObject' (TypeDecision a) a => IsObject a
instance IsObject' (TypeDecision a) a => IsObject a

type FieldTypes a = MapGFT a (ConstructorFieldNames a)

type ToDeconstructC a =
  ( InstrDeconstructC a
  , KnownList (FieldTypes a)
  , AllConstrained KnownValue (FieldTypes a)
  )

type ToConstructC a =
  ( KnownValue a
  , InstrConstructC a
  , RMap (ConstructorFieldNames a)
  , RMap (ConstructorFieldTypes a)
  , RMap (FieldTypes a)
  , KnownList (ConstructorFieldNames a)
  , CastFieldConstructors (FieldTypes a) (ConstructorFieldTypes a)
  )

type ComplexObjectC a =
  ( ToDeconstructC a
  , ToConstructC a
  , AllConstrained IsObject (FieldTypes a)
  )

-- | Type class instantiated for all possible Indigo types
class KnownValue a => IsObject' (decision :: Decision) a where
  complexObjectDict' :: Maybe (Dict (ComplexObjectC a))

instance KnownValue a => IsObject' 'PrimitiveD a where
  complexObjectDict' :: Maybe (Dict (ComplexObjectC a))
complexObjectDict' = Maybe (Dict (ComplexObjectC a))
forall a. Maybe a
Nothing

instance KnownValue a => IsObject' 'SumTypeD a where
  complexObjectDict' :: Maybe (Dict (ComplexObjectC a))
complexObjectDict' = Maybe (Dict (ComplexObjectC a))
forall a. Maybe a
Nothing

instance ComplexObjectC a => IsObject' 'ProductTypeD a where
  complexObjectDict' :: Maybe (Dict (ComplexObjectC a))
complexObjectDict' = Dict
  ((((IsoValue a, Generic a,
      GValueType (Rep a) ~ GValueType (Rep a)),
     GInstrDeconstruct (Rep a)),
    KnownList (MapGFT a (GFieldNames (Rep a))),
    AllConstrained KnownValue (MapGFT a (GFieldNames (Rep a)))),
   (KnownValue a,
    ((IsoValue a, Generic a, GValueType (Rep a) ~ GValueType (Rep a)),
     GInstrConstruct (Rep a)),
    RMap (GFieldNames (Rep a)), RMap (GFieldTypes (Rep a)),
    RMap (MapGFT a (GFieldNames (Rep a))),
    KnownList (GFieldNames (Rep a)),
    CastFieldConstructors
      (MapGFT a (GFieldNames (Rep a))) (GFieldTypes (Rep a))),
   AllConstrained IsObject (MapGFT a (GFieldNames (Rep a))))
-> Maybe
     (Dict
        ((((IsoValue a, Generic a,
            GValueType (Rep a) ~ GValueType (Rep a)),
           GInstrDeconstruct (Rep a)),
          KnownList (MapGFT a (GFieldNames (Rep a))),
          AllConstrained KnownValue (MapGFT a (GFieldNames (Rep a)))),
         (KnownValue a,
          ((IsoValue a, Generic a, GValueType (Rep a) ~ GValueType (Rep a)),
           GInstrConstruct (Rep a)),
          RMap (GFieldNames (Rep a)), RMap (GFieldTypes (Rep a)),
          RMap (MapGFT a (GFieldNames (Rep a))),
          KnownList (GFieldNames (Rep a)),
          CastFieldConstructors
            (MapGFT a (GFieldNames (Rep a))) (GFieldTypes (Rep a))),
         AllConstrained IsObject (MapGFT a (GFieldNames (Rep a)))))
forall a. a -> Maybe a
Just Dict
  ((((IsoValue a, Generic a,
      GValueType (Rep a) ~ GValueType (Rep a)),
     GInstrDeconstruct (Rep a)),
    KnownList (MapGFT a (GFieldNames (Rep a))),
    AllConstrained KnownValue (MapGFT a (GFieldNames (Rep a)))),
   (KnownValue a,
    ((IsoValue a, Generic a, GValueType (Rep a) ~ GValueType (Rep a)),
     GInstrConstruct (Rep a)),
    RMap (GFieldNames (Rep a)), RMap (GFieldTypes (Rep a)),
    RMap (MapGFT a (GFieldNames (Rep a))),
    KnownList (GFieldNames (Rep a)),
    CastFieldConstructors
      (MapGFT a (GFieldNames (Rep a))) (GFieldTypes (Rep a))),
   AllConstrained IsObject (MapGFT a (GFieldNames (Rep a))))
forall (a :: Constraint). a => Dict a
Dict

complexObjectDict :: forall a . IsObject a => Maybe (Dict (ComplexObjectC a))
complexObjectDict :: Maybe (Dict (ComplexObjectC a))
complexObjectDict = IsObject' (TypeDecision a) a => Maybe (Dict (ComplexObjectC a))
forall (decision :: Decision) a.
IsObject' decision a =>
Maybe (Dict (ComplexObjectC a))
complexObjectDict' @(TypeDecision a) @a

-- | Decide whether type is either primitive or ADT
type TypeDecision a = Decide (IsPrimitiveValue a) (IsSumType (G.Rep a))

data Decision
  = PrimitiveD
  | SumTypeD
  | ProductTypeD

type family Decide flagPrimitive flagSumType where
  Decide 'True _ = 'PrimitiveD
  Decide 'False 'True = 'SumTypeD
  Decide 'False 'False = 'ProductTypeD

type family IsSumType x where
  IsSumType (G.D1 _ x) = IsSumType x
  IsSumType (G.C1 _ x) = IsSumType x
  IsSumType (G.M1 _ _ x) = IsSumType x
  IsSumType (_ G.:*: _) = 'False
  IsSumType (G.Rec0 _) = 'False
  IsSumType G.V1 = 'False
  IsSumType G.U1 = 'False
  IsSumType (_ G.:+: _) = 'True