{-# LANGUAGE DataKinds                   #-}
{-# LANGUAGE DeriveGeneric               #-}
{-# LANGUAGE FlexibleInstances           #-}
{-# LANGUAGE GeneralizedNewtypeDeriving  #-}
{-# LANGUAGE LambdaCase                  #-}
{-# LANGUAGE NoImplicitPrelude           #-}
{-# LANGUAGE OverloadedStrings           #-}
{-# LANGUAGE RecordWildCards             #-}
{-# LANGUAGE TypeFamilies                #-}

{-# OPTIONS_GHC -fno-warn-unused-imports #-}

-- Module      : Network.AWS.EC2.StopInstances
-- Copyright   : (c) 2013-2014 Brendan Hay <brendan.g.hay@gmail.com>
-- License     : This Source Code Form is subject to the terms of
--               the Mozilla Public License, v. 2.0.
--               A copy of the MPL can be found in the LICENSE file or
--               you can obtain it at http://mozilla.org/MPL/2.0/.
-- Maintainer  : Brendan Hay <brendan.g.hay@gmail.com>
-- Stability   : experimental
-- Portability : non-portable (GHC extensions)
--
-- Derived from AWS service descriptions, licensed under Apache 2.0.

-- | 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 UserGuide/.
--
-- For more information about troubleshooting, see <http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/TroubleshootingInstancesStopping.html Troubleshooting StoppingYour Instance> in the /Amazon Elastic Compute Cloud User Guide/.
--
-- <http://docs.aws.amazon.com/AWSEC2/latest/APIReference/ApiReference-query-StopInstances.html>
module Network.AWS.EC2.StopInstances
    (
    -- * Request
      StopInstances
    -- ** Request constructor
    , stopInstances
    -- ** Request lenses
    , siDryRun
    , siForce
    , siInstanceIds

    -- * Response
    , StopInstancesResponse
    -- ** Response constructor
    , stopInstancesResponse
    -- ** Response lenses
    , sirStoppingInstances
    ) where

import Network.AWS.Prelude
import Network.AWS.Request.Query
import Network.AWS.EC2.Types
import qualified GHC.Exts

data StopInstances = StopInstances
    { _siDryRun      :: Maybe Bool
    , _siForce       :: Maybe Bool
    , _siInstanceIds :: List "InstanceId" Text
    } deriving (Eq, Ord, Show)

-- | 'StopInstances' constructor.
--
-- The fields accessible through corresponding lenses are:
--
-- * 'siDryRun' @::@ 'Maybe' 'Bool'
--
-- * 'siForce' @::@ 'Maybe' 'Bool'
--
-- * 'siInstanceIds' @::@ ['Text']
--
stopInstances :: StopInstances
stopInstances = StopInstances
    { _siDryRun      = Nothing
    , _siInstanceIds = mempty
    , _siForce       = Nothing
    }

siDryRun :: Lens' StopInstances (Maybe Bool)
siDryRun = lens _siDryRun (\s a -> s { _siDryRun = a })

-- | 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 })

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

newtype StopInstancesResponse = StopInstancesResponse
    { _sirStoppingInstances :: List "item" InstanceStateChange
    } deriving (Eq, Show, Monoid, Semigroup)

-- | 'StopInstancesResponse' constructor.
--
-- The fields accessible through corresponding lenses are:
--
-- * 'sirStoppingInstances' @::@ ['InstanceStateChange']
--
stopInstancesResponse :: StopInstancesResponse
stopInstancesResponse = StopInstancesResponse
    { _sirStoppingInstances = mempty
    }

-- | Information about one or more stopped instances.
sirStoppingInstances :: Lens' StopInstancesResponse [InstanceStateChange]
sirStoppingInstances =
    lens _sirStoppingInstances (\s a -> s { _sirStoppingInstances = a })
        . _List

instance ToPath StopInstances where
    toPath = const "/"

instance ToQuery StopInstances where
    toQuery StopInstances{..} = mconcat
        [ "dryRun"     =? _siDryRun
        , "force"      =? _siForce
        , toQuery     _siInstanceIds
        ]

instance ToHeaders StopInstances

instance AWSRequest StopInstances where
    type Sv StopInstances = EC2
    type Rs StopInstances = StopInstancesResponse

    request  = post "StopInstances"
    response = xmlResponse

instance FromXML StopInstancesResponse where
    parseXML x = StopInstancesResponse
        <$> parseXML x