module Hasql.Private.Encoders.Params where

import Hasql.Private.Prelude
import qualified Database.PostgreSQL.LibPQ as A
import qualified PostgreSQL.Binary.Encoding as B
import qualified Hasql.Private.Encoders.Value as C
import qualified Hasql.Private.PTI as D
import qualified Text.Builder as E


-- |
-- Encoder of some representation of a parameters product.
newtype Params a =
  Params (Op (DList (A.Oid, A.Format, Bool -> Maybe ByteString, Text)) a)
  deriving (Contravariant, Divisible, Decidable, Semigroup, Monoid)

value :: C.Value a -> Params a
value =
  contramap Just . nullableValue

nullableValue :: C.Value a -> Params (Maybe a)
nullableValue (C.Value valueOID arrayOID encode render) =
  Params $ Op $ \ input ->
  let
    D.OID _ pqOid format =
      valueOID
    encoder env =
      fmap (B.encodingBytes . encode env) input
    rendering =
      maybe "null" (E.run . render) input
    in pure (pqOid, format, encoder, rendering)