{-# LANGUAGE TemplateHaskell #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

module Database.Persist.Sql.Extra (
  module Sql,
  entityPair,
) where

import Data.Currency (Alpha (..))
import Data.Scientific
import Database.Persist.Postgresql
import Database.Persist.Sql as Sql
import Database.Persist.TH
import Refined
import Universum

entityPair :: Entity record -> (Sql.Key record, record)
entityPair = entityKey &&& entityVal

instance (PersistField a, Predicate p a) => PersistField (Refined p a) where
  toPersistValue = toPersistValue . unrefine
  fromPersistValue = (first show . refine) <=< fromPersistValue

instance (PersistFieldSql a, Predicate p a) => PersistFieldSql (Refined p a) where
  sqlType _ = sqlType (Proxy :: Proxy a)

instance PersistField Scientific where
  toPersistValue = PersistRational . toRational
  fromPersistValue (PersistRational r) = Right $ fromRational r
  fromPersistValue (PersistDouble d) = Right $ fromFloatDigits d
  fromPersistValue (PersistInt64 i) = Right $ fromIntegral i
  fromPersistValue x = Left $ "PersistField Scientific: Expected Scientific, received: " <> show x

instance PersistFieldSql Scientific where
  sqlType _ = SqlNumeric 32 20

derivePersistField "Alpha"