{-# 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.CloudWatch.ListMetrics
-- Copyright   : (c) 2013-2015 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 valid metrics stored for the AWS account owner.
-- Returned metrics can be used with GetMetricStatistics to obtain
-- statistical data for a given metric.
--
-- /See:/ <http://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_ListMetrics.html AWS API Reference> for ListMetrics.
--
-- This operation returns paginated results.
module Network.AWS.CloudWatch.ListMetrics
    (
    -- * Creating a Request
      listMetrics
    , ListMetrics
    -- * Request Lenses
    , lmMetricName
    , lmNamespace
    , lmNextToken
    , lmDimensions

    -- * Destructuring the Response
    , listMetricsResponse
    , ListMetricsResponse
    -- * Response Lenses
    , lmrsMetrics
    , lmrsNextToken
    , lmrsResponseStatus
    ) where

import           Network.AWS.CloudWatch.Types
import           Network.AWS.CloudWatch.Types.Product
import           Network.AWS.Pager
import           Network.AWS.Prelude
import           Network.AWS.Request
import           Network.AWS.Response

-- | /See:/ 'listMetrics' smart constructor.
data ListMetrics = ListMetrics'
    { _lmMetricName :: !(Maybe Text)
    , _lmNamespace  :: !(Maybe Text)
    , _lmNextToken  :: !(Maybe Text)
    , _lmDimensions :: !(Maybe [DimensionFilter])
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'ListMetrics' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'lmMetricName'
--
-- * 'lmNamespace'
--
-- * 'lmNextToken'
--
-- * 'lmDimensions'
listMetrics
    :: ListMetrics
listMetrics =
    ListMetrics'
    { _lmMetricName = Nothing
    , _lmNamespace = Nothing
    , _lmNextToken = Nothing
    , _lmDimensions = Nothing
    }

-- | The name of the metric to filter against.
lmMetricName :: Lens' ListMetrics (Maybe Text)
lmMetricName = lens _lmMetricName (\ s a -> s{_lmMetricName = a});

-- | The namespace to filter against.
lmNamespace :: Lens' ListMetrics (Maybe Text)
lmNamespace = lens _lmNamespace (\ s a -> s{_lmNamespace = a});

-- | The token returned by a previous call to indicate that there is more
-- data available.
lmNextToken :: Lens' ListMetrics (Maybe Text)
lmNextToken = lens _lmNextToken (\ s a -> s{_lmNextToken = a});

-- | A list of dimensions to filter against.
lmDimensions :: Lens' ListMetrics [DimensionFilter]
lmDimensions = lens _lmDimensions (\ s a -> s{_lmDimensions = a}) . _Default . _Coerce;

instance AWSPager ListMetrics where
        page rq rs
          | stop (rs ^. lmrsNextToken) = Nothing
          | stop (rs ^. lmrsMetrics) = Nothing
          | otherwise =
            Just $ rq & lmNextToken .~ rs ^. lmrsNextToken

instance AWSRequest ListMetrics where
        type Rs ListMetrics = ListMetricsResponse
        request = postQuery cloudWatch
        response
          = receiveXMLWrapper "ListMetricsResult"
              (\ s h x ->
                 ListMetricsResponse' <$>
                   (x .@? "Metrics" .!@ mempty >>=
                      may (parseXMLList "member"))
                     <*> (x .@? "NextToken")
                     <*> (pure (fromEnum s)))

instance ToHeaders ListMetrics where
        toHeaders = const mempty

instance ToPath ListMetrics where
        toPath = const "/"

instance ToQuery ListMetrics where
        toQuery ListMetrics'{..}
          = mconcat
              ["Action" =: ("ListMetrics" :: ByteString),
               "Version" =: ("2010-08-01" :: ByteString),
               "MetricName" =: _lmMetricName,
               "Namespace" =: _lmNamespace,
               "NextToken" =: _lmNextToken,
               "Dimensions" =:
                 toQuery (toQueryList "member" <$> _lmDimensions)]

-- | The output for the ListMetrics action.
--
-- /See:/ 'listMetricsResponse' smart constructor.
data ListMetricsResponse = ListMetricsResponse'
    { _lmrsMetrics        :: !(Maybe [Metric])
    , _lmrsNextToken      :: !(Maybe Text)
    , _lmrsResponseStatus :: !Int
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'ListMetricsResponse' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'lmrsMetrics'
--
-- * 'lmrsNextToken'
--
-- * 'lmrsResponseStatus'
listMetricsResponse
    :: Int -- ^ 'lmrsResponseStatus'
    -> ListMetricsResponse
listMetricsResponse pResponseStatus_ =
    ListMetricsResponse'
    { _lmrsMetrics = Nothing
    , _lmrsNextToken = Nothing
    , _lmrsResponseStatus = pResponseStatus_
    }

-- | A list of metrics used to generate statistics for an AWS account.
lmrsMetrics :: Lens' ListMetricsResponse [Metric]
lmrsMetrics = lens _lmrsMetrics (\ s a -> s{_lmrsMetrics = a}) . _Default . _Coerce;

-- | A string that marks the start of the next batch of returned results.
lmrsNextToken :: Lens' ListMetricsResponse (Maybe Text)
lmrsNextToken = lens _lmrsNextToken (\ s a -> s{_lmrsNextToken = a});

-- | The response status code.
lmrsResponseStatus :: Lens' ListMetricsResponse Int
lmrsResponseStatus = lens _lmrsResponseStatus (\ s a -> s{_lmrsResponseStatus = a});