{-# 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.DescribeEventSubscriptions
-- 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.

-- | Lists descriptions of all the Amazon Redshift event notifications
-- subscription for a customer account. If you specify a subscription name,
-- lists the description for that subscription.
--
-- <http://docs.aws.amazon.com/redshift/latest/APIReference/API_DescribeEventSubscriptions.html>
module Network.AWS.Redshift.DescribeEventSubscriptions
    (
    -- * Request
      DescribeEventSubscriptions
    -- ** Request constructor
    , describeEventSubscriptions
    -- ** Request lenses
    , des1Marker
    , des1MaxRecords
    , des1SubscriptionName

    -- * Response
    , DescribeEventSubscriptionsResponse
    -- ** Response constructor
    , describeEventSubscriptionsResponse
    -- ** Response lenses
    , desrEventSubscriptionsList
    , desrMarker
    ) where

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

data DescribeEventSubscriptions = DescribeEventSubscriptions
    { _des1Marker           :: Maybe Text
    , _des1MaxRecords       :: Maybe Int
    , _des1SubscriptionName :: Maybe Text
    } deriving (Eq, Ord, Show)

-- | 'DescribeEventSubscriptions' constructor.
--
-- The fields accessible through corresponding lenses are:
--
-- * 'des1Marker' @::@ 'Maybe' 'Text'
--
-- * 'des1MaxRecords' @::@ 'Maybe' 'Int'
--
-- * 'des1SubscriptionName' @::@ 'Maybe' 'Text'
--
describeEventSubscriptions :: DescribeEventSubscriptions
describeEventSubscriptions = DescribeEventSubscriptions
    { _des1SubscriptionName = Nothing
    , _des1MaxRecords       = Nothing
    , _des1Marker           = Nothing
    }

-- | An optional parameter that specifies the starting point to return a set of
-- response records. When the results of a 'DescribeEventSubscriptions' 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.
des1Marker :: Lens' DescribeEventSubscriptions (Maybe Text)
des1Marker = lens _des1Marker (\s a -> s { _des1Marker = 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.
des1MaxRecords :: Lens' DescribeEventSubscriptions (Maybe Int)
des1MaxRecords = lens _des1MaxRecords (\s a -> s { _des1MaxRecords = a })

-- | The name of the Amazon Redshift event notification subscription to be
-- described.
des1SubscriptionName :: Lens' DescribeEventSubscriptions (Maybe Text)
des1SubscriptionName =
    lens _des1SubscriptionName (\s a -> s { _des1SubscriptionName = a })

data DescribeEventSubscriptionsResponse = DescribeEventSubscriptionsResponse
    { _desrEventSubscriptionsList :: List "member" EventSubscription
    , _desrMarker                 :: Maybe Text
    } deriving (Eq, Show)

-- | 'DescribeEventSubscriptionsResponse' constructor.
--
-- The fields accessible through corresponding lenses are:
--
-- * 'desrEventSubscriptionsList' @::@ ['EventSubscription']
--
-- * 'desrMarker' @::@ 'Maybe' 'Text'
--
describeEventSubscriptionsResponse :: DescribeEventSubscriptionsResponse
describeEventSubscriptionsResponse = DescribeEventSubscriptionsResponse
    { _desrMarker                 = Nothing
    , _desrEventSubscriptionsList = mempty
    }

-- | A list of event subscriptions.
desrEventSubscriptionsList :: Lens' DescribeEventSubscriptionsResponse [EventSubscription]
desrEventSubscriptionsList =
    lens _desrEventSubscriptionsList
        (\s a -> s { _desrEventSubscriptionsList = a })
            . _List

-- | 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.
desrMarker :: Lens' DescribeEventSubscriptionsResponse (Maybe Text)
desrMarker = lens _desrMarker (\s a -> s { _desrMarker = a })

instance ToPath DescribeEventSubscriptions where
    toPath = const "/"

instance ToQuery DescribeEventSubscriptions where
    toQuery DescribeEventSubscriptions{..} = mconcat
        [ "Marker"           =? _des1Marker
        , "MaxRecords"       =? _des1MaxRecords
        , "SubscriptionName" =? _des1SubscriptionName
        ]

instance ToHeaders DescribeEventSubscriptions

instance AWSRequest DescribeEventSubscriptions where
    type Sv DescribeEventSubscriptions = Redshift
    type Rs DescribeEventSubscriptions = DescribeEventSubscriptionsResponse

    request  = post "DescribeEventSubscriptions"
    response = xmlResponse

instance FromXML DescribeEventSubscriptionsResponse where
    parseXML = withElement "DescribeEventSubscriptionsResult" $ \x -> DescribeEventSubscriptionsResponse
        <$> x .@? "EventSubscriptionsList" .!@ mempty
        <*> x .@? "Marker"

instance AWSPager DescribeEventSubscriptions where
    page rq rs
        | stop (rq ^. des1Marker) = Nothing
        | otherwise = (\x -> rq & des1Marker ?~ x)
            <$> (rs ^. desrMarker)