{-# 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.StopInstances
-- 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)
--
-- Stops an Amazon EBS-backed instance. Each time you transition an
-- instance from stopped to started, Amazon EC2 charges a full instance
-- hour, even if transitions happen multiple times within a single hour.
--
-- You can\'t start or stop Spot Instances.
--
-- Instances that use Amazon EBS volumes as their root devices can be
-- quickly stopped and started. When an instance is stopped, the compute
-- resources are released and you are not billed for hourly instance usage.
-- However, your root partition Amazon EBS volume remains, continues to
-- persist your data, and you are charged for Amazon EBS volume usage. You
-- can restart your instance at any time.
--
-- Before stopping an instance, make sure it is in a state from which it
-- can be restarted. Stopping an instance does not preserve data stored in
-- RAM.
--
-- Performing this operation on an instance that uses an instance store as
-- its root device returns an error.
--
-- You can stop, start, and terminate EBS-backed instances. You can only
-- terminate instance store-backed instances. What happens to an instance
-- differs if you stop it or terminate it. For example, when you stop an
-- instance, the root device and any other devices attached to the instance
-- persist. When you terminate an instance, the root device and any other
-- devices attached during the instance launch are automatically deleted.
-- For more information about the differences between stopping and
-- terminating instances, see
-- <http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-lifecycle.html Instance Lifecycle>
-- in the /Amazon Elastic Compute Cloud User Guide/.
--
-- For more information about troubleshooting, see
-- <http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/TroubleshootingInstancesStopping.html Troubleshooting Stopping Your Instance>
-- in the /Amazon Elastic Compute Cloud User Guide/.
--
-- /See:/ <http://docs.aws.amazon.com/AWSEC2/latest/APIReference/ApiReference-query-StopInstances.html AWS API Reference> for StopInstances.
module Network.AWS.EC2.StopInstances
    (
    -- * Creating a Request
      stopInstances
    , StopInstances
    -- * Request Lenses
    , siForce
    , siDryRun
    , siInstanceIds

    -- * Destructuring the Response
    , stopInstancesResponse
    , StopInstancesResponse
    -- * Response Lenses
    , sirsStoppingInstances
    , sirsStatus
    ) where

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

-- | /See:/ 'stopInstances' smart constructor.
data StopInstances = StopInstances'
    { _siForce       :: !(Maybe Bool)
    , _siDryRun      :: !(Maybe Bool)
    , _siInstanceIds :: ![Text]
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'StopInstances' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'siForce'
--
-- * 'siDryRun'
--
-- * 'siInstanceIds'
stopInstances
    :: StopInstances
stopInstances =
    StopInstances'
    { _siForce = Nothing
    , _siDryRun = Nothing
    , _siInstanceIds = mempty
    }

-- | Forces the instances to stop. The instances do not have an opportunity
-- to flush file system caches or file system metadata. If you use this
-- option, you must perform file system check and repair procedures. This
-- option is not recommended for Windows instances.
--
-- Default: 'false'
siForce :: Lens' StopInstances (Maybe Bool)
siForce = lens _siForce (\ s a -> s{_siForce = 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'.
siDryRun :: Lens' StopInstances (Maybe Bool)
siDryRun = lens _siDryRun (\ s a -> s{_siDryRun = a});

-- | One or more instance IDs.
siInstanceIds :: Lens' StopInstances [Text]
siInstanceIds = lens _siInstanceIds (\ s a -> s{_siInstanceIds = a}) . _Coerce;

instance AWSRequest StopInstances where
        type Sv StopInstances = EC2
        type Rs StopInstances = StopInstancesResponse
        request = post
        response
          = receiveXML
              (\ s h x ->
                 StopInstancesResponse' <$>
                   (x .@? "instancesSet" .!@ mempty >>=
                      may (parseXMLList "item"))
                     <*> (pure (fromEnum s)))

instance ToHeaders StopInstances where
        toHeaders = const mempty

instance ToPath StopInstances where
        toPath = const "/"

instance ToQuery StopInstances where
        toQuery StopInstances'{..}
          = mconcat
              ["Action" =: ("StopInstances" :: ByteString),
               "Version" =: ("2015-04-15" :: ByteString),
               "Force" =: _siForce, "DryRun" =: _siDryRun,
               toQueryList "InstanceId" _siInstanceIds]

-- | /See:/ 'stopInstancesResponse' smart constructor.
data StopInstancesResponse = StopInstancesResponse'
    { _sirsStoppingInstances :: !(Maybe [InstanceStateChange])
    , _sirsStatus            :: !Int
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'StopInstancesResponse' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'sirsStoppingInstances'
--
-- * 'sirsStatus'
stopInstancesResponse
    :: Int -- ^ 'sirsStatus'
    -> StopInstancesResponse
stopInstancesResponse pStatus_ =
    StopInstancesResponse'
    { _sirsStoppingInstances = Nothing
    , _sirsStatus = pStatus_
    }

-- | Information about one or more stopped instances.
sirsStoppingInstances :: Lens' StopInstancesResponse [InstanceStateChange]
sirsStoppingInstances = lens _sirsStoppingInstances (\ s a -> s{_sirsStoppingInstances = a}) . _Default . _Coerce;

-- | The response status code.
sirsStatus :: Lens' StopInstancesResponse Int
sirsStatus = lens _sirsStatus (\ s a -> s{_sirsStatus = a});