Select.hs

{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE StrictData #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# OPTIONS_GHC -fno-warn-unused-binds #-}
{-# OPTIONS_GHC -fno-warn-unused-imports #-}
{-# OPTIONS_GHC -fno-warn-unused-matches #-}

-- Derived from AWS service descriptions, licensed under Apache 2.0.

-- |
-- Module      : Amazonka.SDB.Select
-- Copyright   : (c) 2013-2023 Brendan Hay
-- License     : Mozilla Public License, v. 2.0.
-- Maintainer  : Brendan Hay
-- Stability   : auto-generated
-- Portability : non-portable (GHC extensions)
--
-- The @Select@ operation returns a set of attributes for @ItemNames@ that
-- match the select expression. @Select@ is similar to the standard SQL
-- SELECT statement.
--
-- The total size of the response cannot exceed 1 MB in total size. Amazon
-- SimpleDB automatically adjusts the number of items returned per page to
-- enforce this limit. For example, if the client asks to retrieve 2500
-- items, but each individual item is 10 kB in size, the system returns 100
-- items and an appropriate @NextToken@ so the client can access the next
-- page of results.
--
-- For information on how to construct select expressions, see Using Select
-- to Create Amazon SimpleDB Queries in the Developer Guide.
--
-- This operation returns paginated results.
module Amazonka.SDB.Select
  ( -- * Creating a Request
    Select (..),
    newSelect,

    -- * Request Lenses
    select_consistentRead,
    select_nextToken,
    select_selectExpression,

    -- * Destructuring the Response
    SelectResponse (..),
    newSelectResponse,

    -- * Response Lenses
    selectResponse_items,
    selectResponse_nextToken,
    selectResponse_httpStatus,
  )
where

import qualified Amazonka.Core as Core
import qualified Amazonka.Core.Lens.Internal as Lens
import qualified Amazonka.Data as Data
import qualified Amazonka.Prelude as Prelude
import qualified Amazonka.Request as Request
import qualified Amazonka.Response as Response
import Amazonka.SDB.Types

-- | /See:/ 'newSelect' smart constructor.
data Select = Select'
  { -- | Determines whether or not strong consistency should be enforced when
    -- data is read from SimpleDB. If @true@, any data previously written to
    -- SimpleDB will be returned. Otherwise, results will be consistent
    -- eventually, and the client may not see data that was written immediately
    -- before your read.
    consistentRead :: Prelude.Maybe Prelude.Bool,
    -- | A string informing Amazon SimpleDB where to start the next list of
    -- @ItemNames@.
    nextToken :: Prelude.Maybe Prelude.Text,
    -- | The expression used to query the domain.
    selectExpression :: Prelude.Text
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'Select' with all optional fields omitted.
--
-- Use <https://hackage.haskell.org/package/generic-lens generic-lens> or <https://hackage.haskell.org/package/optics optics> to modify other optional fields.
--
-- The following record fields are available, with the corresponding lenses provided
-- for backwards compatibility:
--
-- 'consistentRead', 'select_consistentRead' - Determines whether or not strong consistency should be enforced when
-- data is read from SimpleDB. If @true@, any data previously written to
-- SimpleDB will be returned. Otherwise, results will be consistent
-- eventually, and the client may not see data that was written immediately
-- before your read.
--
-- 'nextToken', 'select_nextToken' - A string informing Amazon SimpleDB where to start the next list of
-- @ItemNames@.
--
-- 'selectExpression', 'select_selectExpression' - The expression used to query the domain.
newSelect ::
  -- | 'selectExpression'
  Prelude.Text ->
  Select
newSelect pSelectExpression_ =
  Select'
    { consistentRead = Prelude.Nothing,
      nextToken = Prelude.Nothing,
      selectExpression = pSelectExpression_
    }

-- | Determines whether or not strong consistency should be enforced when
-- data is read from SimpleDB. If @true@, any data previously written to
-- SimpleDB will be returned. Otherwise, results will be consistent
-- eventually, and the client may not see data that was written immediately
-- before your read.
select_consistentRead :: Lens.Lens' Select (Prelude.Maybe Prelude.Bool)
select_consistentRead = Lens.lens (\Select' {consistentRead} -> consistentRead) (\s@Select' {} a -> s {consistentRead = a} :: Select)

-- | A string informing Amazon SimpleDB where to start the next list of
-- @ItemNames@.
select_nextToken :: Lens.Lens' Select (Prelude.Maybe Prelude.Text)
select_nextToken = Lens.lens (\Select' {nextToken} -> nextToken) (\s@Select' {} a -> s {nextToken = a} :: Select)

-- | The expression used to query the domain.
select_selectExpression :: Lens.Lens' Select Prelude.Text
select_selectExpression = Lens.lens (\Select' {selectExpression} -> selectExpression) (\s@Select' {} a -> s {selectExpression = a} :: Select)

instance Core.AWSPager Select where
  page rq rs
    | Core.stop
        ( rs
            Lens.^? selectResponse_nextToken
            Prelude.. Lens._Just
        ) =
        Prelude.Nothing
    | Core.stop
        ( rs
            Lens.^? selectResponse_items
            Prelude.. Lens._Just
        ) =
        Prelude.Nothing
    | Prelude.otherwise =
        Prelude.Just
          Prelude.$ rq
          Prelude.& select_nextToken
          Lens..~ rs
          Lens.^? selectResponse_nextToken
          Prelude.. Lens._Just

instance Core.AWSRequest Select where
  type AWSResponse Select = SelectResponse
  request overrides =
    Request.postQuery (overrides defaultService)
  response =
    Response.receiveXMLWrapper
      "SelectResult"
      ( \s h x ->
          SelectResponse'
            Prelude.<$> (Core.may (Data.parseXMLList "Item") x)
            Prelude.<*> (x Data..@? "NextToken")
            Prelude.<*> (Prelude.pure (Prelude.fromEnum s))
      )

instance Prelude.Hashable Select where
  hashWithSalt _salt Select' {..} =
    _salt
      `Prelude.hashWithSalt` consistentRead
      `Prelude.hashWithSalt` nextToken
      `Prelude.hashWithSalt` selectExpression

instance Prelude.NFData Select where
  rnf Select' {..} =
    Prelude.rnf consistentRead
      `Prelude.seq` Prelude.rnf nextToken
      `Prelude.seq` Prelude.rnf selectExpression

instance Data.ToHeaders Select where
  toHeaders = Prelude.const Prelude.mempty

instance Data.ToPath Select where
  toPath = Prelude.const "/"

instance Data.ToQuery Select where
  toQuery Select' {..} =
    Prelude.mconcat
      [ "Action" Data.=: ("Select" :: Prelude.ByteString),
        "Version"
          Data.=: ("2009-04-15" :: Prelude.ByteString),
        "ConsistentRead" Data.=: consistentRead,
        "NextToken" Data.=: nextToken,
        "SelectExpression" Data.=: selectExpression
      ]

-- | /See:/ 'newSelectResponse' smart constructor.
data SelectResponse = SelectResponse'
  { -- | A list of items that match the select expression.
    items :: Prelude.Maybe [Item],
    -- | An opaque token indicating that more items than @MaxNumberOfItems@ were
    -- matched, the response size exceeded 1 megabyte, or the execution time
    -- exceeded 5 seconds.
    nextToken :: Prelude.Maybe Prelude.Text,
    -- | The response's http status code.
    httpStatus :: Prelude.Int
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'SelectResponse' with all optional fields omitted.
--
-- Use <https://hackage.haskell.org/package/generic-lens generic-lens> or <https://hackage.haskell.org/package/optics optics> to modify other optional fields.
--
-- The following record fields are available, with the corresponding lenses provided
-- for backwards compatibility:
--
-- 'items', 'selectResponse_items' - A list of items that match the select expression.
--
-- 'nextToken', 'selectResponse_nextToken' - An opaque token indicating that more items than @MaxNumberOfItems@ were
-- matched, the response size exceeded 1 megabyte, or the execution time
-- exceeded 5 seconds.
--
-- 'httpStatus', 'selectResponse_httpStatus' - The response's http status code.
newSelectResponse ::
  -- | 'httpStatus'
  Prelude.Int ->
  SelectResponse
newSelectResponse pHttpStatus_ =
  SelectResponse'
    { items = Prelude.Nothing,
      nextToken = Prelude.Nothing,
      httpStatus = pHttpStatus_
    }

-- | A list of items that match the select expression.
selectResponse_items :: Lens.Lens' SelectResponse (Prelude.Maybe [Item])
selectResponse_items = Lens.lens (\SelectResponse' {items} -> items) (\s@SelectResponse' {} a -> s {items = a} :: SelectResponse) Prelude.. Lens.mapping Lens.coerced

-- | An opaque token indicating that more items than @MaxNumberOfItems@ were
-- matched, the response size exceeded 1 megabyte, or the execution time
-- exceeded 5 seconds.
selectResponse_nextToken :: Lens.Lens' SelectResponse (Prelude.Maybe Prelude.Text)
selectResponse_nextToken = Lens.lens (\SelectResponse' {nextToken} -> nextToken) (\s@SelectResponse' {} a -> s {nextToken = a} :: SelectResponse)

-- | The response's http status code.
selectResponse_httpStatus :: Lens.Lens' SelectResponse Prelude.Int
selectResponse_httpStatus = Lens.lens (\SelectResponse' {httpStatus} -> httpStatus) (\s@SelectResponse' {} a -> s {httpStatus = a} :: SelectResponse)

instance Prelude.NFData SelectResponse where
  rnf SelectResponse' {..} =
    Prelude.rnf items
      `Prelude.seq` Prelude.rnf nextToken
      `Prelude.seq` Prelude.rnf httpStatus