{-# language FlexibleContexts #-}
{-# language NamedFieldPuns #-}
{-# language ScopedTypeVariables #-}
{-# language TypeFamilies #-}

{-# options_ghc -fno-warn-redundant-constraints #-}

module Rel8.Expr.Opaleye
  ( castExpr, unsafeCastExpr
  , scastExpr, sunsafeCastExpr
  , unsafeLiteral
  , fromPrimExpr, toPrimExpr, mapPrimExpr, zipPrimExprsWith, traversePrimExpr
  , toColumn, fromColumn, traverseFieldP
  )
where

-- base
import Prelude

-- opaleye
import qualified Opaleye.Internal.Column as Opaleye
import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye

-- rel8
import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )
import Rel8.Schema.Null ( Unnullify, Sql )
import Rel8.Type ( DBType, typeInformation )
import Rel8.Type.Information ( TypeInformation(..) )

-- profunctors
import Data.Profunctor ( Profunctor, dimap )


castExpr :: Sql DBType a => Expr a -> Expr a
castExpr :: forall a. Sql DBType a => Expr a -> Expr a
castExpr = forall a. TypeInformation (Unnullify a) -> Expr a -> Expr a
scastExpr forall a. DBType a => TypeInformation a
typeInformation


-- | Cast an expression to a different type. Corresponds to a @CAST()@ function
-- call.
unsafeCastExpr :: Sql DBType b => Expr a -> Expr b
unsafeCastExpr :: forall b a. Sql DBType b => Expr a -> Expr b
unsafeCastExpr = forall b a. TypeInformation (Unnullify b) -> Expr a -> Expr b
sunsafeCastExpr forall a. DBType a => TypeInformation a
typeInformation


scastExpr :: TypeInformation (Unnullify a) -> Expr a -> Expr a
scastExpr :: forall a. TypeInformation (Unnullify a) -> Expr a -> Expr a
scastExpr = forall b a. TypeInformation (Unnullify b) -> Expr a -> Expr b
sunsafeCastExpr


sunsafeCastExpr :: ()
  => TypeInformation (Unnullify b) -> Expr a -> Expr b
sunsafeCastExpr :: forall b a. TypeInformation (Unnullify b) -> Expr a -> Expr b
sunsafeCastExpr TypeInformation {String
typeName :: forall a. TypeInformation a -> String
typeName :: String
typeName} =
  forall a. PrimExpr -> Expr a
fromPrimExpr forall b c a. (b -> c) -> (a -> b) -> a -> c
. String -> PrimExpr -> PrimExpr
Opaleye.CastExpr String
typeName forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Expr a -> PrimExpr
toPrimExpr


-- | Unsafely construct an expression from literal SQL.
--
-- This is an escape hatch, and can be used if Rel8 can not adequately express
-- the query you need. If you find yourself using this function, please let us
-- know, as it may indicate that something is missing from Rel8!
unsafeLiteral :: String -> Expr a
unsafeLiteral :: forall a. String -> Expr a
unsafeLiteral = forall a. PrimExpr -> Expr a
Expr forall b c a. (b -> c) -> (a -> b) -> a -> c
. Literal -> PrimExpr
Opaleye.ConstExpr forall b c a. (b -> c) -> (a -> b) -> a -> c
. String -> Literal
Opaleye.OtherLit


fromPrimExpr :: Opaleye.PrimExpr -> Expr a
fromPrimExpr :: forall a. PrimExpr -> Expr a
fromPrimExpr = forall a. PrimExpr -> Expr a
Expr


toPrimExpr :: Expr a -> Opaleye.PrimExpr
toPrimExpr :: forall a. Expr a -> PrimExpr
toPrimExpr (Expr PrimExpr
a) = PrimExpr
a


mapPrimExpr :: (Opaleye.PrimExpr -> Opaleye.PrimExpr) -> Expr a -> Expr b
mapPrimExpr :: forall a b. (PrimExpr -> PrimExpr) -> Expr a -> Expr b
mapPrimExpr PrimExpr -> PrimExpr
f = forall a. PrimExpr -> Expr a
fromPrimExpr forall b c a. (b -> c) -> (a -> b) -> a -> c
. PrimExpr -> PrimExpr
f forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Expr a -> PrimExpr
toPrimExpr


zipPrimExprsWith :: ()
  => (Opaleye.PrimExpr -> Opaleye.PrimExpr -> Opaleye.PrimExpr)
  -> Expr a -> Expr b -> Expr c
zipPrimExprsWith :: forall a b c.
(PrimExpr -> PrimExpr -> PrimExpr) -> Expr a -> Expr b -> Expr c
zipPrimExprsWith PrimExpr -> PrimExpr -> PrimExpr
f Expr a
a Expr b
b = forall a. PrimExpr -> Expr a
fromPrimExpr (PrimExpr -> PrimExpr -> PrimExpr
f (forall a. Expr a -> PrimExpr
toPrimExpr Expr a
a) (forall a. Expr a -> PrimExpr
toPrimExpr Expr b
b))


traversePrimExpr :: Functor f
  => (Opaleye.PrimExpr -> f Opaleye.PrimExpr) -> Expr a -> f (Expr b)
traversePrimExpr :: forall (f :: * -> *) a b.
Functor f =>
(PrimExpr -> f PrimExpr) -> Expr a -> f (Expr b)
traversePrimExpr PrimExpr -> f PrimExpr
f = forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a. PrimExpr -> Expr a
fromPrimExpr forall b c a. (b -> c) -> (a -> b) -> a -> c
. PrimExpr -> f PrimExpr
f forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Expr a -> PrimExpr
toPrimExpr


traverseFieldP :: Profunctor p
  => p (Opaleye.Field_ n x) (Opaleye.Field_ m y)
  -> p (Expr a) (Expr b)
traverseFieldP :: forall (p :: * -> * -> *) (n :: Nullability) x (m :: Nullability) y
       a b.
Profunctor p =>
p (Field_ n x) (Field_ m y) -> p (Expr a) (Expr b)
traverseFieldP =  forall (p :: * -> * -> *) a b c d.
Profunctor p =>
(a -> b) -> (c -> d) -> p b c -> p a d
dimap (forall (n :: Nullability) b. PrimExpr -> Field_ n b
toColumn forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Expr a -> PrimExpr
toPrimExpr) (forall a. PrimExpr -> Expr a
fromPrimExpr forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (n :: Nullability) b. Field_ n b -> PrimExpr
fromColumn)


toColumn :: Opaleye.PrimExpr -> Opaleye.Field_ n b
toColumn :: forall (n :: Nullability) b. PrimExpr -> Field_ n b
toColumn = forall (n :: Nullability) b. PrimExpr -> Field_ n b
Opaleye.Column


fromColumn :: Opaleye.Field_ n b -> Opaleye.PrimExpr
fromColumn :: forall (n :: Nullability) b. Field_ n b -> PrimExpr
fromColumn (Opaleye.Column PrimExpr
a) = PrimExpr
a