ListClusters.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.ECS.ListClusters
-- 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)
--
-- Returns a list of existing clusters.
--
-- This operation returns paginated results.
module Network.AWS.ECS.ListClusters
    (
    -- * Creating a Request
      listClusters
    , ListClusters
    -- * Request Lenses
    , lcNextToken
    , lcMaxResults

    -- * Destructuring the Response
    , listClustersResponse
    , ListClustersResponse
    -- * Response Lenses
    , lcrsClusterARNs
    , lcrsNextToken
    , lcrsResponseStatus
    ) where

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

-- | /See:/ 'listClusters' smart constructor.
data ListClusters = ListClusters'
    { _lcNextToken  :: !(Maybe Text)
    , _lcMaxResults :: !(Maybe Int)
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'ListClusters' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'lcNextToken'
--
-- * 'lcMaxResults'
listClusters
    :: ListClusters
listClusters =
    ListClusters'
    { _lcNextToken = Nothing
    , _lcMaxResults = Nothing
    }

-- | The 'nextToken' value returned from a previous paginated 'ListClusters' request where 'maxResults' was used and the results exceeded the value of that parameter. Pagination continues from the end of the previous results that returned the 'nextToken' value. This value is 'null' when there are no more results to return.
--
-- This token should be treated as an opaque identifier that is only used to retrieve the next items in a list and not for other programmatic purposes.
lcNextToken :: Lens' ListClusters (Maybe Text)
lcNextToken = lens _lcNextToken (\ s a -> s{_lcNextToken = a});

-- | The maximum number of cluster results returned by 'ListClusters' in paginated output. When this parameter is used, 'ListClusters' only returns 'maxResults' results in a single page along with a 'nextToken' response element. The remaining results of the initial request can be seen by sending another 'ListClusters' request with the returned 'nextToken' value. This value can be between 1 and 100. If this parameter is not used, then 'ListClusters' returns up to 100 results and a 'nextToken' value if applicable.
lcMaxResults :: Lens' ListClusters (Maybe Int)
lcMaxResults = lens _lcMaxResults (\ s a -> s{_lcMaxResults = a});

instance AWSPager ListClusters where
        page rq rs
          | stop (rs ^. lcrsNextToken) = Nothing
          | stop (rs ^. lcrsClusterARNs) = Nothing
          | otherwise =
            Just $ rq & lcNextToken .~ rs ^. lcrsNextToken

instance AWSRequest ListClusters where
        type Rs ListClusters = ListClustersResponse
        request = postJSON ecs
        response
          = receiveJSON
              (\ s h x ->
                 ListClustersResponse' <$>
                   (x .?> "clusterArns" .!@ mempty) <*>
                     (x .?> "nextToken")
                     <*> (pure (fromEnum s)))

instance Hashable ListClusters

instance NFData ListClusters

instance ToHeaders ListClusters where
        toHeaders
          = const
              (mconcat
                 ["X-Amz-Target" =#
                    ("AmazonEC2ContainerServiceV20141113.ListClusters" ::
                       ByteString),
                  "Content-Type" =#
                    ("application/x-amz-json-1.1" :: ByteString)])

instance ToJSON ListClusters where
        toJSON ListClusters'{..}
          = object
              (catMaybes
                 [("nextToken" .=) <$> _lcNextToken,
                  ("maxResults" .=) <$> _lcMaxResults])

instance ToPath ListClusters where
        toPath = const "/"

instance ToQuery ListClusters where
        toQuery = const mempty

-- | /See:/ 'listClustersResponse' smart constructor.
data ListClustersResponse = ListClustersResponse'
    { _lcrsClusterARNs    :: !(Maybe [Text])
    , _lcrsNextToken      :: !(Maybe Text)
    , _lcrsResponseStatus :: !Int
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'ListClustersResponse' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'lcrsClusterARNs'
--
-- * 'lcrsNextToken'
--
-- * 'lcrsResponseStatus'
listClustersResponse
    :: Int -- ^ 'lcrsResponseStatus'
    -> ListClustersResponse
listClustersResponse pResponseStatus_ =
    ListClustersResponse'
    { _lcrsClusterARNs = Nothing
    , _lcrsNextToken = Nothing
    , _lcrsResponseStatus = pResponseStatus_
    }

-- | The list of full Amazon Resource Name (ARN) entries for each cluster associated with your account.
lcrsClusterARNs :: Lens' ListClustersResponse [Text]
lcrsClusterARNs = lens _lcrsClusterARNs (\ s a -> s{_lcrsClusterARNs = a}) . _Default . _Coerce;

-- | The 'nextToken' value to include in a future 'ListClusters' request. When the results of a 'ListClusters' request exceed 'maxResults', this value can be used to retrieve the next page of results. This value is 'null' when there are no more results to return.
lcrsNextToken :: Lens' ListClustersResponse (Maybe Text)
lcrsNextToken = lens _lcrsNextToken (\ s a -> s{_lcrsNextToken = a});

-- | The response status code.
lcrsResponseStatus :: Lens' ListClustersResponse Int
lcrsResponseStatus = lens _lcrsResponseStatus (\ s a -> s{_lcrsResponseStatus = a});

instance NFData ListClustersResponse