{-# LANGUAGE DataKinds                   #-}
{-# LANGUAGE DeriveGeneric               #-}
{-# LANGUAGE FlexibleInstances           #-}
{-# LANGUAGE GeneralizedNewtypeDeriving  #-}
{-# LANGUAGE LambdaCase                  #-}
{-# LANGUAGE NoImplicitPrelude           #-}
{-# LANGUAGE OverloadedStrings           #-}
{-# LANGUAGE RecordWildCards             #-}
{-# LANGUAGE TypeFamilies                #-}

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

-- Module      : Network.AWS.Redshift.DescribeReservedNodes
-- Copyright   : (c) 2013-2014 Brendan Hay <brendan.g.hay@gmail.com>
-- License     : This Source Code Form is subject to the terms of
--               the Mozilla Public License, v. 2.0.
--               A copy of the MPL can be found in the LICENSE file or
--               you can obtain it at http://mozilla.org/MPL/2.0/.
-- Maintainer  : Brendan Hay <brendan.g.hay@gmail.com>
-- Stability   : experimental
-- Portability : non-portable (GHC extensions)
--
-- Derived from AWS service descriptions, licensed under Apache 2.0.

-- | Returns the descriptions of the reserved nodes.
--
-- <http://docs.aws.amazon.com/redshift/latest/APIReference/API_DescribeReservedNodes.html>
module Network.AWS.Redshift.DescribeReservedNodes
    (
    -- * Request
      DescribeReservedNodes
    -- ** Request constructor
    , describeReservedNodes
    -- ** Request lenses
    , drnMarker
    , drnMaxRecords
    , drnReservedNodeId

    -- * Response
    , DescribeReservedNodesResponse
    -- ** Response constructor
    , describeReservedNodesResponse
    -- ** Response lenses
    , drnrMarker
    , drnrReservedNodes
    ) where

import Network.AWS.Prelude
import Network.AWS.Request.Query
import Network.AWS.Redshift.Types
import qualified GHC.Exts

data DescribeReservedNodes = DescribeReservedNodes
    { _drnMarker         :: Maybe Text
    , _drnMaxRecords     :: Maybe Int
    , _drnReservedNodeId :: Maybe Text
    } deriving (Eq, Ord, Show)

-- | 'DescribeReservedNodes' constructor.
--
-- The fields accessible through corresponding lenses are:
--
-- * 'drnMarker' @::@ 'Maybe' 'Text'
--
-- * 'drnMaxRecords' @::@ 'Maybe' 'Int'
--
-- * 'drnReservedNodeId' @::@ 'Maybe' 'Text'
--
describeReservedNodes :: DescribeReservedNodes
describeReservedNodes = DescribeReservedNodes
    { _drnReservedNodeId = Nothing
    , _drnMaxRecords     = Nothing
    , _drnMarker         = Nothing
    }

-- | An optional parameter that specifies the starting point to return a set of
-- response records. When the results of a 'DescribeReservedNodes' request exceed
-- the value specified in 'MaxRecords', AWS returns a value in the 'Marker' field of
-- the response. You can retrieve the next set of response records by providing
-- the returned marker value in the 'Marker' parameter and retrying the request.
drnMarker :: Lens' DescribeReservedNodes (Maybe Text)
drnMarker = lens _drnMarker (\s a -> s { _drnMarker = a })

-- | The maximum number of response records to return in each call. If the number
-- of remaining response records exceeds the specified 'MaxRecords' value, a value
-- is returned in a 'marker' field of the response. You can retrieve the next set
-- of records by retrying the command with the returned marker value.
--
-- Default: '100'
--
-- Constraints: minimum 20, maximum 100.
drnMaxRecords :: Lens' DescribeReservedNodes (Maybe Int)
drnMaxRecords = lens _drnMaxRecords (\s a -> s { _drnMaxRecords = a })

-- | Identifier for the node reservation.
drnReservedNodeId :: Lens' DescribeReservedNodes (Maybe Text)
drnReservedNodeId =
    lens _drnReservedNodeId (\s a -> s { _drnReservedNodeId = a })

data DescribeReservedNodesResponse = DescribeReservedNodesResponse
    { _drnrMarker        :: Maybe Text
    , _drnrReservedNodes :: List "member" ReservedNode
    } deriving (Eq, Show)

-- | 'DescribeReservedNodesResponse' constructor.
--
-- The fields accessible through corresponding lenses are:
--
-- * 'drnrMarker' @::@ 'Maybe' 'Text'
--
-- * 'drnrReservedNodes' @::@ ['ReservedNode']
--
describeReservedNodesResponse :: DescribeReservedNodesResponse
describeReservedNodesResponse = DescribeReservedNodesResponse
    { _drnrMarker        = Nothing
    , _drnrReservedNodes = mempty
    }

-- | A value that indicates the starting point for the next set of response
-- records in a subsequent request. If a value is returned in a response, you
-- can retrieve the next set of records by providing this returned marker value
-- in the 'Marker' parameter and retrying the command. If the 'Marker' field is
-- empty, all response records have been retrieved for the request.
drnrMarker :: Lens' DescribeReservedNodesResponse (Maybe Text)
drnrMarker = lens _drnrMarker (\s a -> s { _drnrMarker = a })

-- | The list of reserved nodes.
drnrReservedNodes :: Lens' DescribeReservedNodesResponse [ReservedNode]
drnrReservedNodes =
    lens _drnrReservedNodes (\s a -> s { _drnrReservedNodes = a })
        . _List

instance ToPath DescribeReservedNodes where
    toPath = const "/"

instance ToQuery DescribeReservedNodes where
    toQuery DescribeReservedNodes{..} = mconcat
        [ "Marker"         =? _drnMarker
        , "MaxRecords"     =? _drnMaxRecords
        , "ReservedNodeId" =? _drnReservedNodeId
        ]

instance ToHeaders DescribeReservedNodes

instance AWSRequest DescribeReservedNodes where
    type Sv DescribeReservedNodes = Redshift
    type Rs DescribeReservedNodes = DescribeReservedNodesResponse

    request  = post "DescribeReservedNodes"
    response = xmlResponse

instance FromXML DescribeReservedNodesResponse where
    parseXML = withElement "DescribeReservedNodesResult" $ \x -> DescribeReservedNodesResponse
        <$> x .@? "Marker"
        <*> x .@? "ReservedNodes" .!@ mempty

instance AWSPager DescribeReservedNodes where
    page rq rs
        | stop (rq ^. drnMarker) = Nothing
        | otherwise = (\x -> rq & drnMarker ?~ x)
            <$> (rs ^. drnrMarker)