{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE StrictData #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# OPTIONS_GHC -fno-warn-unused-binds #-}
{-# OPTIONS_GHC -fno-warn-unused-imports #-}
{-# OPTIONS_GHC -fno-warn-unused-matches #-}

-- Derived from AWS service descriptions, licensed under Apache 2.0.

-- |
-- Module      : Amazonka.AutoScaling.DescribeLoadBalancerTargetGroups
-- Copyright   : (c) 2013-2023 Brendan Hay
-- License     : Mozilla Public License, v. 2.0.
-- Maintainer  : Brendan Hay
-- Stability   : auto-generated
-- Portability : non-portable (GHC extensions)
--
-- Gets information about the Elastic Load Balancing target groups for the
-- specified Auto Scaling group.
--
-- To determine the attachment status of the target group, use the @State@
-- element in the response. When you attach a target group to an Auto
-- Scaling group, the initial @State@ value is @Adding@. The state
-- transitions to @Added@ after all Auto Scaling instances are registered
-- with the target group. If Elastic Load Balancing health checks are
-- enabled for the Auto Scaling group, the state transitions to @InService@
-- after at least one Auto Scaling instance passes the health check. When
-- the target group is in the @InService@ state, Amazon EC2 Auto Scaling
-- can terminate and replace any instances that are reported as unhealthy.
-- If no registered instances pass the health checks, the target group
-- doesn\'t enter the @InService@ state.
--
-- Target groups also have an @InService@ state if you attach them in the
-- CreateAutoScalingGroup API call. If your target group state is
-- @InService@, but it is not working properly, check the scaling
-- activities by calling DescribeScalingActivities and take any corrective
-- actions necessary.
--
-- For help with failed health checks, see
-- <https://docs.aws.amazon.com/autoscaling/ec2/userguide/ts-as-healthchecks.html Troubleshooting Amazon EC2 Auto Scaling: Health checks>
-- in the /Amazon EC2 Auto Scaling User Guide/. For more information, see
-- <https://docs.aws.amazon.com/autoscaling/ec2/userguide/autoscaling-load-balancer.html Use Elastic Load Balancing to distribute traffic across the instances in your Auto Scaling group>
-- in the /Amazon EC2 Auto Scaling User Guide/.
--
-- You can use this operation to describe target groups that were attached
-- by using AttachLoadBalancerTargetGroups, but not for target groups that
-- were attached by using AttachTrafficSources.
--
-- This operation returns paginated results.
module Amazonka.AutoScaling.DescribeLoadBalancerTargetGroups
  ( -- * Creating a Request
    DescribeLoadBalancerTargetGroups (..),
    newDescribeLoadBalancerTargetGroups,

    -- * Request Lenses
    describeLoadBalancerTargetGroups_maxRecords,
    describeLoadBalancerTargetGroups_nextToken,
    describeLoadBalancerTargetGroups_autoScalingGroupName,

    -- * Destructuring the Response
    DescribeLoadBalancerTargetGroupsResponse (..),
    newDescribeLoadBalancerTargetGroupsResponse,

    -- * Response Lenses
    describeLoadBalancerTargetGroupsResponse_loadBalancerTargetGroups,
    describeLoadBalancerTargetGroupsResponse_nextToken,
    describeLoadBalancerTargetGroupsResponse_httpStatus,
  )
where

import Amazonka.AutoScaling.Types
import qualified Amazonka.Core as Core
import qualified Amazonka.Core.Lens.Internal as Lens
import qualified Amazonka.Data as Data
import qualified Amazonka.Prelude as Prelude
import qualified Amazonka.Request as Request
import qualified Amazonka.Response as Response

-- | /See:/ 'newDescribeLoadBalancerTargetGroups' smart constructor.
data DescribeLoadBalancerTargetGroups = DescribeLoadBalancerTargetGroups'
  { -- | The maximum number of items to return with this call. The default value
    -- is @100@ and the maximum value is @100@.
    maxRecords :: Prelude.Maybe Prelude.Int,
    -- | The token for the next set of items to return. (You received this token
    -- from a previous call.)
    nextToken :: Prelude.Maybe Prelude.Text,
    -- | The name of the Auto Scaling group.
    autoScalingGroupName :: Prelude.Text
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'DescribeLoadBalancerTargetGroups' with all optional fields omitted.
--
-- Use <https://hackage.haskell.org/package/generic-lens generic-lens> or <https://hackage.haskell.org/package/optics optics> to modify other optional fields.
--
-- The following record fields are available, with the corresponding lenses provided
-- for backwards compatibility:
--
-- 'maxRecords', 'describeLoadBalancerTargetGroups_maxRecords' - The maximum number of items to return with this call. The default value
-- is @100@ and the maximum value is @100@.
--
-- 'nextToken', 'describeLoadBalancerTargetGroups_nextToken' - The token for the next set of items to return. (You received this token
-- from a previous call.)
--
-- 'autoScalingGroupName', 'describeLoadBalancerTargetGroups_autoScalingGroupName' - The name of the Auto Scaling group.
newDescribeLoadBalancerTargetGroups ::
  -- | 'autoScalingGroupName'
  Prelude.Text ->
  DescribeLoadBalancerTargetGroups
newDescribeLoadBalancerTargetGroups
  pAutoScalingGroupName_ =
    DescribeLoadBalancerTargetGroups'
      { maxRecords =
          Prelude.Nothing,
        nextToken = Prelude.Nothing,
        autoScalingGroupName =
          pAutoScalingGroupName_
      }

-- | The maximum number of items to return with this call. The default value
-- is @100@ and the maximum value is @100@.
describeLoadBalancerTargetGroups_maxRecords :: Lens.Lens' DescribeLoadBalancerTargetGroups (Prelude.Maybe Prelude.Int)
describeLoadBalancerTargetGroups_maxRecords = Lens.lens (\DescribeLoadBalancerTargetGroups' {maxRecords} -> maxRecords) (\s@DescribeLoadBalancerTargetGroups' {} a -> s {maxRecords = a} :: DescribeLoadBalancerTargetGroups)

-- | The token for the next set of items to return. (You received this token
-- from a previous call.)
describeLoadBalancerTargetGroups_nextToken :: Lens.Lens' DescribeLoadBalancerTargetGroups (Prelude.Maybe Prelude.Text)
describeLoadBalancerTargetGroups_nextToken = Lens.lens (\DescribeLoadBalancerTargetGroups' {nextToken} -> nextToken) (\s@DescribeLoadBalancerTargetGroups' {} a -> s {nextToken = a} :: DescribeLoadBalancerTargetGroups)

-- | The name of the Auto Scaling group.
describeLoadBalancerTargetGroups_autoScalingGroupName :: Lens.Lens' DescribeLoadBalancerTargetGroups Prelude.Text
describeLoadBalancerTargetGroups_autoScalingGroupName = Lens.lens (\DescribeLoadBalancerTargetGroups' {autoScalingGroupName} -> autoScalingGroupName) (\s@DescribeLoadBalancerTargetGroups' {} a -> s {autoScalingGroupName = a} :: DescribeLoadBalancerTargetGroups)

instance
  Core.AWSPager
    DescribeLoadBalancerTargetGroups
  where
  page rq rs
    | Core.stop
        ( rs
            Lens.^? describeLoadBalancerTargetGroupsResponse_nextToken
            Prelude.. Lens._Just
        ) =
        Prelude.Nothing
    | Core.stop
        ( rs
            Lens.^? describeLoadBalancerTargetGroupsResponse_loadBalancerTargetGroups
            Prelude.. Lens._Just
        ) =
        Prelude.Nothing
    | Prelude.otherwise =
        Prelude.Just
          Prelude.$ rq
          Prelude.& describeLoadBalancerTargetGroups_nextToken
          Lens..~ rs
          Lens.^? describeLoadBalancerTargetGroupsResponse_nextToken
          Prelude.. Lens._Just

instance
  Core.AWSRequest
    DescribeLoadBalancerTargetGroups
  where
  type
    AWSResponse DescribeLoadBalancerTargetGroups =
      DescribeLoadBalancerTargetGroupsResponse
  request overrides =
    Request.postQuery (overrides defaultService)
  response =
    Response.receiveXMLWrapper
      "DescribeLoadBalancerTargetGroupsResult"
      ( \s h x ->
          DescribeLoadBalancerTargetGroupsResponse'
            Prelude.<$> ( x
                            Data..@? "LoadBalancerTargetGroups"
                            Core..!@ Prelude.mempty
                            Prelude.>>= Core.may (Data.parseXMLList "member")
                        )
            Prelude.<*> (x Data..@? "NextToken")
            Prelude.<*> (Prelude.pure (Prelude.fromEnum s))
      )

instance
  Prelude.Hashable
    DescribeLoadBalancerTargetGroups
  where
  hashWithSalt
    _salt
    DescribeLoadBalancerTargetGroups' {..} =
      _salt
        `Prelude.hashWithSalt` maxRecords
        `Prelude.hashWithSalt` nextToken
        `Prelude.hashWithSalt` autoScalingGroupName

instance
  Prelude.NFData
    DescribeLoadBalancerTargetGroups
  where
  rnf DescribeLoadBalancerTargetGroups' {..} =
    Prelude.rnf maxRecords
      `Prelude.seq` Prelude.rnf nextToken
      `Prelude.seq` Prelude.rnf autoScalingGroupName

instance
  Data.ToHeaders
    DescribeLoadBalancerTargetGroups
  where
  toHeaders = Prelude.const Prelude.mempty

instance Data.ToPath DescribeLoadBalancerTargetGroups where
  toPath = Prelude.const "/"

instance
  Data.ToQuery
    DescribeLoadBalancerTargetGroups
  where
  toQuery DescribeLoadBalancerTargetGroups' {..} =
    Prelude.mconcat
      [ "Action"
          Data.=: ( "DescribeLoadBalancerTargetGroups" ::
                      Prelude.ByteString
                  ),
        "Version"
          Data.=: ("2011-01-01" :: Prelude.ByteString),
        "MaxRecords" Data.=: maxRecords,
        "NextToken" Data.=: nextToken,
        "AutoScalingGroupName" Data.=: autoScalingGroupName
      ]

-- | /See:/ 'newDescribeLoadBalancerTargetGroupsResponse' smart constructor.
data DescribeLoadBalancerTargetGroupsResponse = DescribeLoadBalancerTargetGroupsResponse'
  { -- | Information about the target groups.
    loadBalancerTargetGroups :: Prelude.Maybe [LoadBalancerTargetGroupState],
    -- | A string that indicates that the response contains more items than can
    -- be returned in a single response. To receive additional items, specify
    -- this string for the @NextToken@ value when requesting the next set of
    -- items. This value is null when there are no more items to return.
    nextToken :: Prelude.Maybe Prelude.Text,
    -- | The response's http status code.
    httpStatus :: Prelude.Int
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'DescribeLoadBalancerTargetGroupsResponse' with all optional fields omitted.
--
-- Use <https://hackage.haskell.org/package/generic-lens generic-lens> or <https://hackage.haskell.org/package/optics optics> to modify other optional fields.
--
-- The following record fields are available, with the corresponding lenses provided
-- for backwards compatibility:
--
-- 'loadBalancerTargetGroups', 'describeLoadBalancerTargetGroupsResponse_loadBalancerTargetGroups' - Information about the target groups.
--
-- 'nextToken', 'describeLoadBalancerTargetGroupsResponse_nextToken' - A string that indicates that the response contains more items than can
-- be returned in a single response. To receive additional items, specify
-- this string for the @NextToken@ value when requesting the next set of
-- items. This value is null when there are no more items to return.
--
-- 'httpStatus', 'describeLoadBalancerTargetGroupsResponse_httpStatus' - The response's http status code.
newDescribeLoadBalancerTargetGroupsResponse ::
  -- | 'httpStatus'
  Prelude.Int ->
  DescribeLoadBalancerTargetGroupsResponse
newDescribeLoadBalancerTargetGroupsResponse
  pHttpStatus_ =
    DescribeLoadBalancerTargetGroupsResponse'
      { loadBalancerTargetGroups =
          Prelude.Nothing,
        nextToken = Prelude.Nothing,
        httpStatus = pHttpStatus_
      }

-- | Information about the target groups.
describeLoadBalancerTargetGroupsResponse_loadBalancerTargetGroups :: Lens.Lens' DescribeLoadBalancerTargetGroupsResponse (Prelude.Maybe [LoadBalancerTargetGroupState])
describeLoadBalancerTargetGroupsResponse_loadBalancerTargetGroups = Lens.lens (\DescribeLoadBalancerTargetGroupsResponse' {loadBalancerTargetGroups} -> loadBalancerTargetGroups) (\s@DescribeLoadBalancerTargetGroupsResponse' {} a -> s {loadBalancerTargetGroups = a} :: DescribeLoadBalancerTargetGroupsResponse) Prelude.. Lens.mapping Lens.coerced

-- | A string that indicates that the response contains more items than can
-- be returned in a single response. To receive additional items, specify
-- this string for the @NextToken@ value when requesting the next set of
-- items. This value is null when there are no more items to return.
describeLoadBalancerTargetGroupsResponse_nextToken :: Lens.Lens' DescribeLoadBalancerTargetGroupsResponse (Prelude.Maybe Prelude.Text)
describeLoadBalancerTargetGroupsResponse_nextToken = Lens.lens (\DescribeLoadBalancerTargetGroupsResponse' {nextToken} -> nextToken) (\s@DescribeLoadBalancerTargetGroupsResponse' {} a -> s {nextToken = a} :: DescribeLoadBalancerTargetGroupsResponse)

-- | The response's http status code.
describeLoadBalancerTargetGroupsResponse_httpStatus :: Lens.Lens' DescribeLoadBalancerTargetGroupsResponse Prelude.Int
describeLoadBalancerTargetGroupsResponse_httpStatus = Lens.lens (\DescribeLoadBalancerTargetGroupsResponse' {httpStatus} -> httpStatus) (\s@DescribeLoadBalancerTargetGroupsResponse' {} a -> s {httpStatus = a} :: DescribeLoadBalancerTargetGroupsResponse)

instance
  Prelude.NFData
    DescribeLoadBalancerTargetGroupsResponse
  where
  rnf DescribeLoadBalancerTargetGroupsResponse' {..} =
    Prelude.rnf loadBalancerTargetGroups
      `Prelude.seq` Prelude.rnf nextToken
      `Prelude.seq` Prelude.rnf httpStatus