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.
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 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});