{-# 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.ApplicationAutoScaling.DescribeScalingPolicies
-- 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)
--
-- Provides descriptive information for scaling policies with a specified service namespace.
--
-- You can filter the results in a service namespace with the 'ResourceId', 'ScalableDimension', and 'PolicyNames' parameters.
--
-- To create a new scaling policy or update an existing one, see < PutScalingPolicy>. If you are no longer using a scaling policy, you can delete it with < DeleteScalingPolicy>.
module Network.AWS.ApplicationAutoScaling.DescribeScalingPolicies
    (
    -- * Creating a Request
      describeScalingPolicies
    , DescribeScalingPolicies
    -- * Request Lenses
    , dPolicyNames
    , dScalableDimension
    , dResourceId
    , dNextToken
    , dMaxResults
    , dServiceNamespace

    -- * Destructuring the Response
    , describeScalingPoliciesResponse
    , DescribeScalingPoliciesResponse
    -- * Response Lenses
    , drsNextToken
    , drsScalingPolicies
    , drsResponseStatus
    ) where

import           Network.AWS.ApplicationAutoScaling.Types
import           Network.AWS.ApplicationAutoScaling.Types.Product
import           Network.AWS.Lens
import           Network.AWS.Prelude
import           Network.AWS.Request
import           Network.AWS.Response

-- | /See:/ 'describeScalingPolicies' smart constructor.
data DescribeScalingPolicies = DescribeScalingPolicies'
    { _dPolicyNames       :: !(Maybe [Text])
    , _dScalableDimension :: !(Maybe ScalableDimension)
    , _dResourceId        :: !(Maybe Text)
    , _dNextToken         :: !(Maybe Text)
    , _dMaxResults        :: !(Maybe Int)
    , _dServiceNamespace  :: !ServiceNamespace
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'DescribeScalingPolicies' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'dPolicyNames'
--
-- * 'dScalableDimension'
--
-- * 'dResourceId'
--
-- * 'dNextToken'
--
-- * 'dMaxResults'
--
-- * 'dServiceNamespace'
describeScalingPolicies
    :: ServiceNamespace -- ^ 'dServiceNamespace'
    -> DescribeScalingPolicies
describeScalingPolicies pServiceNamespace_ =
    DescribeScalingPolicies'
    { _dPolicyNames = Nothing
    , _dScalableDimension = Nothing
    , _dResourceId = Nothing
    , _dNextToken = Nothing
    , _dMaxResults = Nothing
    , _dServiceNamespace = pServiceNamespace_
    }

-- | The names of the scaling policies to describe.
dPolicyNames :: Lens' DescribeScalingPolicies [Text]
dPolicyNames = lens _dPolicyNames (\ s a -> s{_dPolicyNames = a}) . _Default . _Coerce;

-- | The scalable dimension of the scalable target that the scaling policy is associated with. The scalable dimension contains the service namespace, resource type, and scaling property, such as 'ecs:service:DesiredCount' for the desired task count of an Amazon ECS service. If you specify a scalable dimension, you must also specify a resource ID.
dScalableDimension :: Lens' DescribeScalingPolicies (Maybe ScalableDimension)
dScalableDimension = lens _dScalableDimension (\ s a -> s{_dScalableDimension = a});

-- | The unique resource identifier string of the scalable target that the scaling policy is associated with. For Amazon ECS services, this value is the resource type, followed by the cluster name and service name, such as 'service\/default\/sample-webapp'. If you specify a scalable dimension, you must also specify a resource ID.
dResourceId :: Lens' DescribeScalingPolicies (Maybe Text)
dResourceId = lens _dResourceId (\ s a -> s{_dResourceId = a});

-- | The 'NextToken' value returned from a previous paginated 'DescribeScalingPolicies' request. 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.
dNextToken :: Lens' DescribeScalingPolicies (Maybe Text)
dNextToken = lens _dNextToken (\ s a -> s{_dNextToken = a});

-- | The maximum number of scaling policy results returned by 'DescribeScalingPolicies' in paginated output. When this parameter is used, 'DescribeScalingPolicies' returns up to '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 'DescribeScalingPolicies' request with the returned 'NextToken' value. This value can be between 1 and 50. If this parameter is not used, then 'DescribeScalingPolicies' returns up to 50 results and a 'NextToken' value, if applicable.
dMaxResults :: Lens' DescribeScalingPolicies (Maybe Int)
dMaxResults = lens _dMaxResults (\ s a -> s{_dMaxResults = a});

-- | The AWS service namespace of the scalable target that the scaling policy is associated with. For more information, see <http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html#genref-aws-service-namespaces AWS Service Namespaces> in the Amazon Web Services General Reference.
dServiceNamespace :: Lens' DescribeScalingPolicies ServiceNamespace
dServiceNamespace = lens _dServiceNamespace (\ s a -> s{_dServiceNamespace = a});

instance AWSRequest DescribeScalingPolicies where
        type Rs DescribeScalingPolicies =
             DescribeScalingPoliciesResponse
        request = postJSON applicationAutoScaling
        response
          = receiveJSON
              (\ s h x ->
                 DescribeScalingPoliciesResponse' <$>
                   (x .?> "NextToken") <*>
                     (x .?> "ScalingPolicies" .!@ mempty)
                     <*> (pure (fromEnum s)))

instance Hashable DescribeScalingPolicies

instance NFData DescribeScalingPolicies

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

instance ToJSON DescribeScalingPolicies where
        toJSON DescribeScalingPolicies'{..}
          = object
              (catMaybes
                 [("PolicyNames" .=) <$> _dPolicyNames,
                  ("ScalableDimension" .=) <$> _dScalableDimension,
                  ("ResourceId" .=) <$> _dResourceId,
                  ("NextToken" .=) <$> _dNextToken,
                  ("MaxResults" .=) <$> _dMaxResults,
                  Just ("ServiceNamespace" .= _dServiceNamespace)])

instance ToPath DescribeScalingPolicies where
        toPath = const "/"

instance ToQuery DescribeScalingPolicies where
        toQuery = const mempty

-- | /See:/ 'describeScalingPoliciesResponse' smart constructor.
data DescribeScalingPoliciesResponse = DescribeScalingPoliciesResponse'
    { _drsNextToken       :: !(Maybe Text)
    , _drsScalingPolicies :: !(Maybe [ScalingPolicy])
    , _drsResponseStatus  :: !Int
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'DescribeScalingPoliciesResponse' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'drsNextToken'
--
-- * 'drsScalingPolicies'
--
-- * 'drsResponseStatus'
describeScalingPoliciesResponse
    :: Int -- ^ 'drsResponseStatus'
    -> DescribeScalingPoliciesResponse
describeScalingPoliciesResponse pResponseStatus_ =
    DescribeScalingPoliciesResponse'
    { _drsNextToken = Nothing
    , _drsScalingPolicies = Nothing
    , _drsResponseStatus = pResponseStatus_
    }

-- | The 'NextToken' value to include in a future 'DescribeScalingPolicies' request. When the results of a 'DescribeScalingPolicies' 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.
drsNextToken :: Lens' DescribeScalingPoliciesResponse (Maybe Text)
drsNextToken = lens _drsNextToken (\ s a -> s{_drsNextToken = a});

-- | A list of scaling policy objects.
drsScalingPolicies :: Lens' DescribeScalingPoliciesResponse [ScalingPolicy]
drsScalingPolicies = lens _drsScalingPolicies (\ s a -> s{_drsScalingPolicies = a}) . _Default . _Coerce;

-- | The response status code.
drsResponseStatus :: Lens' DescribeScalingPoliciesResponse Int
drsResponseStatus = lens _drsResponseStatus (\ s a -> s{_drsResponseStatus = a});

instance NFData DescribeScalingPoliciesResponse