{-# 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.RDS.DescribeDBParameters
-- Copyright   : (c) 2013-2015 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)
--
-- Returns the detailed parameter list for a particular DB parameter group.
--
-- /See:/ <http://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DescribeDBParameters.html AWS API Reference> for DescribeDBParameters.
--
-- This operation returns paginated results.
module Network.AWS.RDS.DescribeDBParameters
    (
    -- * Creating a Request
      describeDBParameters
    , DescribeDBParameters
    -- * Request Lenses
    , ddpFilters
    , ddpMaxRecords
    , ddpMarker
    , ddpSource
    , ddpDBParameterGroupName

    -- * Destructuring the Response
    , describeDBParametersResponse
    , DescribeDBParametersResponse
    -- * Response Lenses
    , ddprsParameters
    , ddprsMarker
    , ddprsStatus
    ) where

import           Network.AWS.Pager
import           Network.AWS.Prelude
import           Network.AWS.RDS.Types
import           Network.AWS.RDS.Types.Product
import           Network.AWS.Request
import           Network.AWS.Response

-- | /See:/ 'describeDBParameters' smart constructor.
data DescribeDBParameters = DescribeDBParameters'
    { _ddpFilters              :: !(Maybe [Filter])
    , _ddpMaxRecords           :: !(Maybe Int)
    , _ddpMarker               :: !(Maybe Text)
    , _ddpSource               :: !(Maybe Text)
    , _ddpDBParameterGroupName :: !Text
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'DescribeDBParameters' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'ddpFilters'
--
-- * 'ddpMaxRecords'
--
-- * 'ddpMarker'
--
-- * 'ddpSource'
--
-- * 'ddpDBParameterGroupName'
describeDBParameters
    :: Text -- ^ 'ddpDBParameterGroupName'
    -> DescribeDBParameters
describeDBParameters pDBParameterGroupName_ =
    DescribeDBParameters'
    { _ddpFilters = Nothing
    , _ddpMaxRecords = Nothing
    , _ddpMarker = Nothing
    , _ddpSource = Nothing
    , _ddpDBParameterGroupName = pDBParameterGroupName_
    }

-- | This parameter is not currently supported.
ddpFilters :: Lens' DescribeDBParameters [Filter]
ddpFilters = lens _ddpFilters (\ s a -> s{_ddpFilters = a}) . _Default . _Coerce;

-- | The maximum number of records to include in the response. If more
-- records exist than the specified 'MaxRecords' value, a pagination token
-- called a marker is included in the response so that the remaining
-- results can be retrieved.
--
-- Default: 100
--
-- Constraints: Minimum 20, maximum 100.
ddpMaxRecords :: Lens' DescribeDBParameters (Maybe Int)
ddpMaxRecords = lens _ddpMaxRecords (\ s a -> s{_ddpMaxRecords = a});

-- | An optional pagination token provided by a previous
-- 'DescribeDBParameters' request. If this parameter is specified, the
-- response includes only records beyond the marker, up to the value
-- specified by 'MaxRecords'.
ddpMarker :: Lens' DescribeDBParameters (Maybe Text)
ddpMarker = lens _ddpMarker (\ s a -> s{_ddpMarker = a});

-- | The parameter types to return.
--
-- Default: All parameter types returned
--
-- Valid Values: 'user | system | engine-default'
ddpSource :: Lens' DescribeDBParameters (Maybe Text)
ddpSource = lens _ddpSource (\ s a -> s{_ddpSource = a});

-- | The name of a specific DB parameter group to return details for.
--
-- Constraints:
--
-- -   Must be 1 to 255 alphanumeric characters
-- -   First character must be a letter
-- -   Cannot end with a hyphen or contain two consecutive hyphens
ddpDBParameterGroupName :: Lens' DescribeDBParameters Text
ddpDBParameterGroupName = lens _ddpDBParameterGroupName (\ s a -> s{_ddpDBParameterGroupName = a});

instance AWSPager DescribeDBParameters where
        page rq rs
          | stop (rs ^. ddprsMarker) = Nothing
          | stop (rs ^. ddprsParameters) = Nothing
          | otherwise =
            Just $ rq & ddpMarker .~ rs ^. ddprsMarker

instance AWSRequest DescribeDBParameters where
        type Rs DescribeDBParameters =
             DescribeDBParametersResponse
        request = postQuery rDS
        response
          = receiveXMLWrapper "DescribeDBParametersResult"
              (\ s h x ->
                 DescribeDBParametersResponse' <$>
                   (x .@? "Parameters" .!@ mempty >>=
                      may (parseXMLList "Parameter"))
                     <*> (x .@? "Marker")
                     <*> (pure (fromEnum s)))

instance ToHeaders DescribeDBParameters where
        toHeaders = const mempty

instance ToPath DescribeDBParameters where
        toPath = const "/"

instance ToQuery DescribeDBParameters where
        toQuery DescribeDBParameters'{..}
          = mconcat
              ["Action" =: ("DescribeDBParameters" :: ByteString),
               "Version" =: ("2014-10-31" :: ByteString),
               "Filters" =:
                 toQuery (toQueryList "Filter" <$> _ddpFilters),
               "MaxRecords" =: _ddpMaxRecords,
               "Marker" =: _ddpMarker, "Source" =: _ddpSource,
               "DBParameterGroupName" =: _ddpDBParameterGroupName]

-- | Contains the result of a successful invocation of the
-- DescribeDBParameters action.
--
-- /See:/ 'describeDBParametersResponse' smart constructor.
data DescribeDBParametersResponse = DescribeDBParametersResponse'
    { _ddprsParameters :: !(Maybe [Parameter])
    , _ddprsMarker     :: !(Maybe Text)
    , _ddprsStatus     :: !Int
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'DescribeDBParametersResponse' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'ddprsParameters'
--
-- * 'ddprsMarker'
--
-- * 'ddprsStatus'
describeDBParametersResponse
    :: Int -- ^ 'ddprsStatus'
    -> DescribeDBParametersResponse
describeDBParametersResponse pStatus_ =
    DescribeDBParametersResponse'
    { _ddprsParameters = Nothing
    , _ddprsMarker = Nothing
    , _ddprsStatus = pStatus_
    }

-- | A list of Parameter values.
ddprsParameters :: Lens' DescribeDBParametersResponse [Parameter]
ddprsParameters = lens _ddprsParameters (\ s a -> s{_ddprsParameters = a}) . _Default . _Coerce;

-- | An optional pagination token provided by a previous request. If this
-- parameter is specified, the response includes only records beyond the
-- marker, up to the value specified by 'MaxRecords'.
ddprsMarker :: Lens' DescribeDBParametersResponse (Maybe Text)
ddprsMarker = lens _ddprsMarker (\ s a -> s{_ddprsMarker = a});

-- | The response status code.
ddprsStatus :: Lens' DescribeDBParametersResponse Int
ddprsStatus = lens _ddprsStatus (\ s a -> s{_ddprsStatus = a});