{-# LANGUAGE GeneralizedNewtypeDeriving #-}

{- |
Copyright : Flipstone Technology Partners 2023
License   : MIT
Stability : Stable

@since 1.0.0.0
-}
module Orville.PostgreSQL.Expr.LimitExpr
  ( LimitExpr
  , limitExpr
  )
where

import qualified Orville.PostgreSQL.Raw.RawSql as RawSql
import qualified Orville.PostgreSQL.Raw.SqlValue as SqlValue

{- |
Type to represent a SQL limit expression. E.G.

> LIMIT 10

'LimitExpr' provides a 'RawSql.SqlExpression' instance. See
'RawSql.unsafeSqlExpression' for how to construct a value with your own custom
SQL.

@since 1.0.0.0
-}
newtype LimitExpr
  = LimitExpr RawSql.RawSql
  deriving
    ( -- | @since 1.0.0.0
      RawSql -> LimitExpr
LimitExpr -> RawSql
(LimitExpr -> RawSql)
-> (RawSql -> LimitExpr) -> SqlExpression LimitExpr
forall a. (a -> RawSql) -> (RawSql -> a) -> SqlExpression a
$ctoRawSql :: LimitExpr -> RawSql
toRawSql :: LimitExpr -> RawSql
$cunsafeFromRawSql :: RawSql -> LimitExpr
unsafeFromRawSql :: RawSql -> LimitExpr
RawSql.SqlExpression
    )

{- | Create a 'LimitExpr' for the given 'Int'. This ensures that the input value is used
as a parameter in the generated SQL.

@since 1.0.0.0
-}
limitExpr :: Int -> LimitExpr
limitExpr :: Int -> LimitExpr
limitExpr Int
limitValue =
  RawSql -> LimitExpr
LimitExpr (RawSql -> LimitExpr) -> RawSql -> LimitExpr
forall a b. (a -> b) -> a -> b
$
    String -> RawSql
RawSql.fromString String
"LIMIT "
      RawSql -> RawSql -> RawSql
forall a. Semigroup a => a -> a -> a
<> SqlValue -> RawSql
RawSql.parameter (Int -> SqlValue
SqlValue.fromInt Int
limitValue)