{-# 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.EC2.DescribeTags
-- 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)
--
-- Describes one or more of the tags for your EC2 resources.
--
-- For more information about tags, see <http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html Tagging Your Resources> in the /Amazon Elastic Compute Cloud User Guide/.
--
-- This operation returns paginated results.
module Network.AWS.EC2.DescribeTags
    (
    -- * Creating a Request
      describeTags
    , DescribeTags
    -- * Request Lenses
    , dtFilters
    , dtNextToken
    , dtDryRun
    , dtMaxResults

    -- * Destructuring the Response
    , describeTagsResponse
    , DescribeTagsResponse
    -- * Response Lenses
    , dtrsNextToken
    , dtrsTags
    , dtrsResponseStatus
    ) where

import           Network.AWS.EC2.Types
import           Network.AWS.EC2.Types.Product
import           Network.AWS.Lens
import           Network.AWS.Pager
import           Network.AWS.Prelude
import           Network.AWS.Request
import           Network.AWS.Response

-- | Contains the parameters for DescribeTags.
--
-- /See:/ 'describeTags' smart constructor.
data DescribeTags = DescribeTags'
    { _dtFilters    :: !(Maybe [Filter])
    , _dtNextToken  :: !(Maybe Text)
    , _dtDryRun     :: !(Maybe Bool)
    , _dtMaxResults :: !(Maybe Int)
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'DescribeTags' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'dtFilters'
--
-- * 'dtNextToken'
--
-- * 'dtDryRun'
--
-- * 'dtMaxResults'
describeTags
    :: DescribeTags
describeTags =
    DescribeTags'
    { _dtFilters = Nothing
    , _dtNextToken = Nothing
    , _dtDryRun = Nothing
    , _dtMaxResults = Nothing
    }

-- | One or more filters.
--
-- -   'key' - The tag key.
--
-- -   'resource-id' - The resource ID.
--
-- -   'resource-type' - The resource type ('customer-gateway' | 'dhcp-options' | 'image' | 'instance' | 'internet-gateway' | 'network-acl' | 'network-interface' | 'reserved-instances' | 'route-table' | 'security-group' | 'snapshot' | 'spot-instances-request' | 'subnet' | 'volume' | 'vpc' | 'vpn-connection' | 'vpn-gateway').
--
-- -   'value' - The tag value.
--
dtFilters :: Lens' DescribeTags [Filter]
dtFilters = lens _dtFilters (\ s a -> s{_dtFilters = a}) . _Default . _Coerce;

-- | The token to retrieve the next page of results.
dtNextToken :: Lens' DescribeTags (Maybe Text)
dtNextToken = lens _dtNextToken (\ s a -> s{_dtNextToken = a});

-- | Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is 'DryRunOperation'. Otherwise, it is 'UnauthorizedOperation'.
dtDryRun :: Lens' DescribeTags (Maybe Bool)
dtDryRun = lens _dtDryRun (\ s a -> s{_dtDryRun = a});

-- | The maximum number of results to return in a single call. This value can be between 5 and 1000. To retrieve the remaining results, make another call with the returned 'NextToken' value.
dtMaxResults :: Lens' DescribeTags (Maybe Int)
dtMaxResults = lens _dtMaxResults (\ s a -> s{_dtMaxResults = a});

instance AWSPager DescribeTags where
        page rq rs
          | stop (rs ^. dtrsNextToken) = Nothing
          | stop (rs ^. dtrsTags) = Nothing
          | otherwise =
            Just $ rq & dtNextToken .~ rs ^. dtrsNextToken

instance AWSRequest DescribeTags where
        type Rs DescribeTags = DescribeTagsResponse
        request = postQuery ec2
        response
          = receiveXML
              (\ s h x ->
                 DescribeTagsResponse' <$>
                   (x .@? "nextToken") <*>
                     (x .@? "tagSet" .!@ mempty >>=
                        may (parseXMLList "item"))
                     <*> (pure (fromEnum s)))

instance Hashable DescribeTags

instance NFData DescribeTags

instance ToHeaders DescribeTags where
        toHeaders = const mempty

instance ToPath DescribeTags where
        toPath = const "/"

instance ToQuery DescribeTags where
        toQuery DescribeTags'{..}
          = mconcat
              ["Action" =: ("DescribeTags" :: ByteString),
               "Version" =: ("2016-04-01" :: ByteString),
               toQuery (toQueryList "Filter" <$> _dtFilters),
               "NextToken" =: _dtNextToken, "DryRun" =: _dtDryRun,
               "MaxResults" =: _dtMaxResults]

-- | Contains the output of DescribeTags.
--
-- /See:/ 'describeTagsResponse' smart constructor.
data DescribeTagsResponse = DescribeTagsResponse'
    { _dtrsNextToken      :: !(Maybe Text)
    , _dtrsTags           :: !(Maybe [TagDescription])
    , _dtrsResponseStatus :: !Int
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'DescribeTagsResponse' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'dtrsNextToken'
--
-- * 'dtrsTags'
--
-- * 'dtrsResponseStatus'
describeTagsResponse
    :: Int -- ^ 'dtrsResponseStatus'
    -> DescribeTagsResponse
describeTagsResponse pResponseStatus_ =
    DescribeTagsResponse'
    { _dtrsNextToken = Nothing
    , _dtrsTags = Nothing
    , _dtrsResponseStatus = pResponseStatus_
    }

-- | The token to use to retrieve the next page of results. This value is 'null' when there are no more results to return..
dtrsNextToken :: Lens' DescribeTagsResponse (Maybe Text)
dtrsNextToken = lens _dtrsNextToken (\ s a -> s{_dtrsNextToken = a});

-- | A list of tags.
dtrsTags :: Lens' DescribeTagsResponse [TagDescription]
dtrsTags = lens _dtrsTags (\ s a -> s{_dtrsTags = a}) . _Default . _Coerce;

-- | The response status code.
dtrsResponseStatus :: Lens' DescribeTagsResponse Int
dtrsResponseStatus = lens _dtrsResponseStatus (\ s a -> s{_dtrsResponseStatus = a});

instance NFData DescribeTagsResponse