Select.hs

{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE DeriveGeneric      #-}
{-# LANGUAGE OverloadedStrings  #-}
{-# LANGUAGE RecordWildCards    #-}
{-# LANGUAGE TypeFamilies       #-}

{-# OPTIONS_GHC -fno-warn-unused-imports #-}
{-# OPTIONS_GHC -fno-warn-unused-binds   #-}
{-# OPTIONS_GHC -fno-warn-unused-matches #-}

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

-- |
-- Module      : Network.AWS.SDB.Select
-- Copyright   : (c) 2013-2016 Brendan Hay
-- License     : Mozilla Public License, v. 2.0.
-- Maintainer  : Brendan Hay <brendan.g.hay@gmail.com>
-- 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 Network.AWS.SDB.Select
    (
    -- * Creating a Request
      select
    , Select
    -- * Request Lenses
    , sConsistentRead
    , sNextToken
    , sSelectExpression

    -- * Destructuring the Response
    , selectResponse
    , SelectResponse
    -- * Response Lenses
    , srsItems
    , srsNextToken
    , srsResponseStatus
    ) where

import           Network.AWS.Lens
import           Network.AWS.Pager
import           Network.AWS.Prelude
import           Network.AWS.Request
import           Network.AWS.Response
import           Network.AWS.SDB.Types
import           Network.AWS.SDB.Types.Product

-- | /See:/ 'select' smart constructor.
data Select = Select'
    { _sConsistentRead   :: !(Maybe Bool)
    , _sNextToken        :: !(Maybe Text)
    , _sSelectExpression :: !Text
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'Select' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'sConsistentRead'
--
-- * 'sNextToken'
--
-- * 'sSelectExpression'
select
    :: Text -- ^ 'sSelectExpression'
    -> Select
select pSelectExpression_ =
    Select'
    { _sConsistentRead = Nothing
    , _sNextToken = Nothing
    , _sSelectExpression = 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.
sConsistentRead :: Lens' Select (Maybe Bool)
sConsistentRead = lens _sConsistentRead (\ s a -> s{_sConsistentRead = a});

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

-- | The expression used to query the domain.
sSelectExpression :: Lens' Select Text
sSelectExpression = lens _sSelectExpression (\ s a -> s{_sSelectExpression = a});

instance AWSPager Select where
        page rq rs
          | stop (rs ^. srsNextToken) = Nothing
          | stop (rs ^. srsItems) = Nothing
          | otherwise =
            Just $ rq & sNextToken .~ rs ^. srsNextToken

instance AWSRequest Select where
        type Rs Select = SelectResponse
        request = postQuery sdb
        response
          = receiveXMLWrapper "SelectResult"
              (\ s h x ->
                 SelectResponse' <$>
                   (may (parseXMLList "Item") x) <*> (x .@? "NextToken")
                     <*> (pure (fromEnum s)))

instance Hashable Select

instance NFData Select

instance ToHeaders Select where
        toHeaders = const mempty

instance ToPath Select where
        toPath = const "/"

instance ToQuery Select where
        toQuery Select'{..}
          = mconcat
              ["Action" =: ("Select" :: ByteString),
               "Version" =: ("2009-04-15" :: ByteString),
               "ConsistentRead" =: _sConsistentRead,
               "NextToken" =: _sNextToken,
               "SelectExpression" =: _sSelectExpression]

-- | /See:/ 'selectResponse' smart constructor.
data SelectResponse = SelectResponse'
    { _srsItems          :: !(Maybe [Item])
    , _srsNextToken      :: !(Maybe Text)
    , _srsResponseStatus :: !Int
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'SelectResponse' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'srsItems'
--
-- * 'srsNextToken'
--
-- * 'srsResponseStatus'
selectResponse
    :: Int -- ^ 'srsResponseStatus'
    -> SelectResponse
selectResponse pResponseStatus_ =
    SelectResponse'
    { _srsItems = Nothing
    , _srsNextToken = Nothing
    , _srsResponseStatus = pResponseStatus_
    }

-- | A list of items that match the select expression.
srsItems :: Lens' SelectResponse [Item]
srsItems = lens _srsItems (\ s a -> s{_srsItems = a}) . _Default . _Coerce;

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

-- | The response status code.
srsResponseStatus :: Lens' SelectResponse Int
srsResponseStatus = lens _srsResponseStatus (\ s a -> s{_srsResponseStatus = a});

instance NFData SelectResponse