{-# language AllowAmbiguousTypes #-}
{-# language DataKinds #-}
{-# language FlexibleContexts #-}
{-# language FlexibleInstances #-}
{-# language MultiParamTypeClasses #-}
{-# language RankNTypes #-}
{-# language ScopedTypeVariables #-}
{-# language StandaloneKindSignatures #-}
{-# language TypeApplications #-}
{-# language TypeFamilies #-}
{-# language UndecidableInstances #-}
{-# language UndecidableSuperClasses #-}

module Rel8.Table.HKD
  ( HKD( HKD )
  , HKDable
  , BuildableHKD
  , BuildHKD, buildHKD
  , ConstructableHKD
  , ConstructHKD, constructHKD
  , DeconstructHKD, deconstructHKD
  , NameHKD, nameHKD
  , AggregateHKD, aggregateHKD
  , HKDRep
  )
where

-- base
import Data.Kind ( Constraint, Type )
import GHC.Generics ( Generic, Rep, from, to )
import GHC.TypeLits ( Symbol )
import Prelude

-- rel8
import Rel8.Aggregate ( Aggregate )
import Rel8.Column ( TColumn )
import Rel8.Expr ( Expr )
import Rel8.FCF ( Eval, Exp )
import Rel8.Kind.Algebra ( KnownAlgebra )
import Rel8.Generic.Construction
  ( GGBuildable
  , GGBuild, ggbuild
  , GGConstructable
  , GGConstruct, ggconstruct
  , GGDeconstruct, ggdeconstruct
  , GGName, ggname
  , GGAggregate, ggaggregate
  )
import Rel8.Generic.Map ( GMap )
import Rel8.Generic.Record
  ( GRecord, GRecordable, grecord, gunrecord
  , Record( Record ), unrecord
  )
import Rel8.Generic.Rel8able
  ( Rel8able
  , GColumns, gfromColumns, gtoColumns
  , GFromExprs, gfromResult, gtoResult
  )
import Rel8.Generic.Table
  ( GGSerialize, GGColumns, GAlgebra, ggfromResult, ggtoResult
  )
import Rel8.Generic.Table.Record ( GTable, GContext )
import qualified Rel8.Generic.Table.Record as G
import qualified Rel8.Schema.Kind as K
import Rel8.Schema.HTable ( HTable )
import Rel8.Schema.Name ( Name )
import Rel8.Schema.Result ( Result )
import Rel8.Table
  ( Table, fromColumns, toColumns, fromResult, toResult
  , TTable, TColumns, TContext
  , TSerialize
  )


type GColumnsHKD :: Type -> K.HTable
type GColumnsHKD a =
  Eval (GGColumns (GAlgebra (Rep a)) TColumns (GRecord (GMap (TColumn Expr) (Rep a))))


type HKD :: Type -> K.Rel8able
newtype HKD a f = HKD (GColumnsHKD a f)


instance HKDable a => Rel8able (HKD a) where
  type GColumns (HKD a) = GColumnsHKD a
  type GFromExprs (HKD a) = a

  gfromColumns _ = HKD
  gtoColumns _ (HKD a) = a

  gfromResult =
    unrecord .
    to .
    ggfromResult
      @(GAlgebra (Rep a))
      @TSerialize
      @TColumns
      @(Eval (HKDRep a Expr))
      @(Eval (HKDRep a Result))
      (\(_ :: proxy x) -> fromResult @_ @x)

  gtoResult =
    ggtoResult
      @(GAlgebra (Rep a))
      @TSerialize
      @TColumns
      @(Eval (HKDRep a Expr))
      @(Eval (HKDRep a Result))
      (\(_ :: proxy x) -> toResult @_ @x) .
    from .
    Record


instance
  ( GTable (TTable f) TColumns (GRecord (GMap (TColumn f) (Rep a)))
  , G.GColumns TColumns (GRecord (GMap (TColumn f) (Rep a))) ~ GColumnsHKD a
  , GContext TContext (GRecord (GMap (TColumn f) (Rep a))) ~ f
  , GRecordable (GMap (TColumn f) (Rep a))
  )
  => Generic (HKD a f)
 where
  type Rep (HKD a f) = GMap (TColumn f) (Rep a)

  from =
    gunrecord @(GMap (TColumn f) (Rep a)) .
    G.gfromColumns
      @(TTable f)
      @TColumns
      fromColumns .
    (\(HKD a) -> a)

  to =
    HKD .
    G.gtoColumns
      @(TTable f)
      @TColumns
      toColumns .
    grecord @(GMap (TColumn f) (Rep a))


type HKDable :: Type -> Constraint
class
  ( Generic (Record a)
  , HTable (GColumns (HKD a))
  , KnownAlgebra (GAlgebra (Rep a))
  , Eval (GGSerialize (GAlgebra (Rep a)) TSerialize TColumns (Eval (HKDRep a Expr)) (Eval (HKDRep a Result)))
  , GRecord (GMap (TColumn Result) (Rep a)) ~ Rep (Record a)
  )
  => HKDable a
instance
  ( Generic (Record a)
  , HTable (GColumns (HKD a))
  , KnownAlgebra (GAlgebra (Rep a))
  , Eval (GGSerialize (GAlgebra (Rep a)) TSerialize TColumns (Eval (HKDRep a Expr)) (Eval (HKDRep a Result)))
  , GRecord (GMap (TColumn Result) (Rep a)) ~ Rep (Record a)
  )
  => HKDable a


type Top_ :: Constraint
class Top_
instance Top_


data Top :: Type -> Exp Constraint
type instance Eval (Top _) = Top_


type BuildableHKD :: Type -> Symbol -> Constraint
class GGBuildable (GAlgebra (Rep a)) name (HKDRep a) => BuildableHKD a name
instance GGBuildable (GAlgebra (Rep a)) name (HKDRep a) => BuildableHKD a name


type BuildHKD :: Type -> Symbol -> Type
type BuildHKD a name = GGBuild (GAlgebra (Rep a)) name (HKDRep a) (HKD a Expr)


buildHKD :: forall a name. BuildableHKD a name => BuildHKD a name
buildHKD =
  ggbuild @(GAlgebra (Rep a)) @name @(HKDRep a) @(HKD a Expr) HKD


type ConstructableHKD :: Type -> Constraint
class GGConstructable (GAlgebra (Rep a)) (HKDRep a) => ConstructableHKD a
instance GGConstructable (GAlgebra (Rep a)) (HKDRep a) => ConstructableHKD a


type ConstructHKD :: Type -> Type
type ConstructHKD a = forall r. GGConstruct (GAlgebra (Rep a)) (HKDRep a) r


constructHKD :: forall a. ConstructableHKD a => ConstructHKD a -> HKD a Expr
constructHKD f =
  ggconstruct @(GAlgebra (Rep a)) @(HKDRep a) @(HKD a Expr) HKD
    (f @(HKD a Expr))


type DeconstructHKD :: Type -> Type -> Type
type DeconstructHKD a r = GGDeconstruct (GAlgebra (Rep a)) (HKDRep a) (HKD a Expr) r


deconstructHKD :: forall a r. (ConstructableHKD a, Table Expr r)
  => DeconstructHKD a r
deconstructHKD = ggdeconstruct @(GAlgebra (Rep a)) @(HKDRep a) @(HKD a Expr) @r (\(HKD a) -> a)


type NameHKD :: Type -> Type
type NameHKD a = GGName (GAlgebra (Rep a)) (HKDRep a) (HKD a Name)


nameHKD :: forall a. ConstructableHKD a => NameHKD a
nameHKD = ggname @(GAlgebra (Rep a)) @(HKDRep a) @(HKD a Name) HKD


type AggregateHKD :: Type -> Type
type AggregateHKD a = forall r. GGAggregate (GAlgebra (Rep a)) (HKDRep a) r


aggregateHKD :: forall a. ConstructableHKD a
  => AggregateHKD a -> HKD a Expr -> HKD a Aggregate
aggregateHKD f =
  ggaggregate @(GAlgebra (Rep a)) @(HKDRep a) @(HKD a Expr) @(HKD a Aggregate) HKD (\(HKD a) -> a)
    (f @(HKD a Aggregate))


data HKDRep :: Type -> K.Context -> Exp (Type -> Type)
type instance Eval (HKDRep a context) =
  GRecord (GMap (TColumn context) (Rep a))