{-# 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.Neptune.DescribeDBInstances
-- Copyright   : (c) 2013-2023 Brendan Hay
-- License     : Mozilla Public License, v. 2.0.
-- Maintainer  : Brendan Hay
-- Stability   : auto-generated
-- Portability : non-portable (GHC extensions)
--
-- Returns information about provisioned instances, and supports
-- pagination.
--
-- This operation can also return information for Amazon RDS instances and
-- Amazon DocDB instances.
--
-- This operation returns paginated results.
module Amazonka.Neptune.DescribeDBInstances
  ( -- * Creating a Request
    DescribeDBInstances (..),
    newDescribeDBInstances,

    -- * Request Lenses
    describeDBInstances_dbInstanceIdentifier,
    describeDBInstances_filters,
    describeDBInstances_marker,
    describeDBInstances_maxRecords,

    -- * Destructuring the Response
    DescribeDBInstancesResponse (..),
    newDescribeDBInstancesResponse,

    -- * Response Lenses
    describeDBInstancesResponse_dbInstances,
    describeDBInstancesResponse_marker,
    describeDBInstancesResponse_httpStatus,
  )
where

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

-- | /See:/ 'newDescribeDBInstances' smart constructor.
data DescribeDBInstances = DescribeDBInstances'
  { -- | The user-supplied instance identifier. If this parameter is specified,
    -- information from only the specific DB instance is returned. This
    -- parameter isn\'t case-sensitive.
    --
    -- Constraints:
    --
    -- -   If supplied, must match the identifier of an existing DBInstance.
    dbInstanceIdentifier :: Prelude.Maybe Prelude.Text,
    -- | A filter that specifies one or more DB instances to describe.
    --
    -- Supported filters:
    --
    -- -   @db-cluster-id@ - Accepts DB cluster identifiers and DB cluster
    --     Amazon Resource Names (ARNs). The results list will only include
    --     information about the DB instances associated with the DB clusters
    --     identified by these ARNs.
    --
    -- -   @engine@ - Accepts an engine name (such as @neptune@), and restricts
    --     the results list to DB instances created by that engine.
    --
    -- For example, to invoke this API from the Amazon CLI and filter so that
    -- only Neptune DB instances are returned, you could use the following
    -- command:
    filters :: Prelude.Maybe [Filter],
    -- | An optional pagination token provided by a previous
    -- @DescribeDBInstances@ request. If this parameter is specified, the
    -- response includes only records beyond the marker, up to the value
    -- specified by @MaxRecords@.
    marker :: Prelude.Maybe Prelude.Text,
    -- | The maximum number of records to include in the response. If more
    -- records exist than the specified @MaxRecords@ value, a pagination token
    -- called a marker is included in the response so that the remaining
    -- results can be retrieved.
    --
    -- Default: 100
    --
    -- Constraints: Minimum 20, maximum 100.
    maxRecords :: Prelude.Maybe Prelude.Int
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'DescribeDBInstances' 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:
--
-- 'dbInstanceIdentifier', 'describeDBInstances_dbInstanceIdentifier' - The user-supplied instance identifier. If this parameter is specified,
-- information from only the specific DB instance is returned. This
-- parameter isn\'t case-sensitive.
--
-- Constraints:
--
-- -   If supplied, must match the identifier of an existing DBInstance.
--
-- 'filters', 'describeDBInstances_filters' - A filter that specifies one or more DB instances to describe.
--
-- Supported filters:
--
-- -   @db-cluster-id@ - Accepts DB cluster identifiers and DB cluster
--     Amazon Resource Names (ARNs). The results list will only include
--     information about the DB instances associated with the DB clusters
--     identified by these ARNs.
--
-- -   @engine@ - Accepts an engine name (such as @neptune@), and restricts
--     the results list to DB instances created by that engine.
--
-- For example, to invoke this API from the Amazon CLI and filter so that
-- only Neptune DB instances are returned, you could use the following
-- command:
--
-- 'marker', 'describeDBInstances_marker' - An optional pagination token provided by a previous
-- @DescribeDBInstances@ request. If this parameter is specified, the
-- response includes only records beyond the marker, up to the value
-- specified by @MaxRecords@.
--
-- 'maxRecords', 'describeDBInstances_maxRecords' - The maximum number of records to include in the response. If more
-- records exist than the specified @MaxRecords@ value, a pagination token
-- called a marker is included in the response so that the remaining
-- results can be retrieved.
--
-- Default: 100
--
-- Constraints: Minimum 20, maximum 100.
newDescribeDBInstances ::
  DescribeDBInstances
newDescribeDBInstances =
  DescribeDBInstances'
    { dbInstanceIdentifier =
        Prelude.Nothing,
      filters = Prelude.Nothing,
      marker = Prelude.Nothing,
      maxRecords = Prelude.Nothing
    }

-- | The user-supplied instance identifier. If this parameter is specified,
-- information from only the specific DB instance is returned. This
-- parameter isn\'t case-sensitive.
--
-- Constraints:
--
-- -   If supplied, must match the identifier of an existing DBInstance.
describeDBInstances_dbInstanceIdentifier :: Lens.Lens' DescribeDBInstances (Prelude.Maybe Prelude.Text)
describeDBInstances_dbInstanceIdentifier = Lens.lens (\DescribeDBInstances' {dbInstanceIdentifier} -> dbInstanceIdentifier) (\s@DescribeDBInstances' {} a -> s {dbInstanceIdentifier = a} :: DescribeDBInstances)

-- | A filter that specifies one or more DB instances to describe.
--
-- Supported filters:
--
-- -   @db-cluster-id@ - Accepts DB cluster identifiers and DB cluster
--     Amazon Resource Names (ARNs). The results list will only include
--     information about the DB instances associated with the DB clusters
--     identified by these ARNs.
--
-- -   @engine@ - Accepts an engine name (such as @neptune@), and restricts
--     the results list to DB instances created by that engine.
--
-- For example, to invoke this API from the Amazon CLI and filter so that
-- only Neptune DB instances are returned, you could use the following
-- command:
describeDBInstances_filters :: Lens.Lens' DescribeDBInstances (Prelude.Maybe [Filter])
describeDBInstances_filters = Lens.lens (\DescribeDBInstances' {filters} -> filters) (\s@DescribeDBInstances' {} a -> s {filters = a} :: DescribeDBInstances) Prelude.. Lens.mapping Lens.coerced

-- | An optional pagination token provided by a previous
-- @DescribeDBInstances@ request. If this parameter is specified, the
-- response includes only records beyond the marker, up to the value
-- specified by @MaxRecords@.
describeDBInstances_marker :: Lens.Lens' DescribeDBInstances (Prelude.Maybe Prelude.Text)
describeDBInstances_marker = Lens.lens (\DescribeDBInstances' {marker} -> marker) (\s@DescribeDBInstances' {} a -> s {marker = a} :: DescribeDBInstances)

-- | The maximum number of records to include in the response. If more
-- records exist than the specified @MaxRecords@ value, a pagination token
-- called a marker is included in the response so that the remaining
-- results can be retrieved.
--
-- Default: 100
--
-- Constraints: Minimum 20, maximum 100.
describeDBInstances_maxRecords :: Lens.Lens' DescribeDBInstances (Prelude.Maybe Prelude.Int)
describeDBInstances_maxRecords = Lens.lens (\DescribeDBInstances' {maxRecords} -> maxRecords) (\s@DescribeDBInstances' {} a -> s {maxRecords = a} :: DescribeDBInstances)

instance Core.AWSPager DescribeDBInstances where
  page rq rs
    | Core.stop
        ( rs
            Lens.^? describeDBInstancesResponse_marker
            Prelude.. Lens._Just
        ) =
        Prelude.Nothing
    | Core.stop
        ( rs
            Lens.^? describeDBInstancesResponse_dbInstances
            Prelude.. Lens._Just
        ) =
        Prelude.Nothing
    | Prelude.otherwise =
        Prelude.Just
          Prelude.$ rq
          Prelude.& describeDBInstances_marker
          Lens..~ rs
          Lens.^? describeDBInstancesResponse_marker
          Prelude.. Lens._Just

instance Core.AWSRequest DescribeDBInstances where
  type
    AWSResponse DescribeDBInstances =
      DescribeDBInstancesResponse
  request overrides =
    Request.postQuery (overrides defaultService)
  response =
    Response.receiveXMLWrapper
      "DescribeDBInstancesResult"
      ( \s h x ->
          DescribeDBInstancesResponse'
            Prelude.<$> ( x
                            Data..@? "DBInstances"
                            Core..!@ Prelude.mempty
                            Prelude.>>= Core.may (Data.parseXMLList "DBInstance")
                        )
            Prelude.<*> (x Data..@? "Marker")
            Prelude.<*> (Prelude.pure (Prelude.fromEnum s))
      )

instance Prelude.Hashable DescribeDBInstances where
  hashWithSalt _salt DescribeDBInstances' {..} =
    _salt
      `Prelude.hashWithSalt` dbInstanceIdentifier
      `Prelude.hashWithSalt` filters
      `Prelude.hashWithSalt` marker
      `Prelude.hashWithSalt` maxRecords

instance Prelude.NFData DescribeDBInstances where
  rnf DescribeDBInstances' {..} =
    Prelude.rnf dbInstanceIdentifier
      `Prelude.seq` Prelude.rnf filters
      `Prelude.seq` Prelude.rnf marker
      `Prelude.seq` Prelude.rnf maxRecords

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

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

instance Data.ToQuery DescribeDBInstances where
  toQuery DescribeDBInstances' {..} =
    Prelude.mconcat
      [ "Action"
          Data.=: ("DescribeDBInstances" :: Prelude.ByteString),
        "Version"
          Data.=: ("2014-10-31" :: Prelude.ByteString),
        "DBInstanceIdentifier" Data.=: dbInstanceIdentifier,
        "Filters"
          Data.=: Data.toQuery
            (Data.toQueryList "Filter" Prelude.<$> filters),
        "Marker" Data.=: marker,
        "MaxRecords" Data.=: maxRecords
      ]

-- | /See:/ 'newDescribeDBInstancesResponse' smart constructor.
data DescribeDBInstancesResponse = DescribeDBInstancesResponse'
  { -- | A list of DBInstance instances.
    dbInstances :: Prelude.Maybe [DBInstance],
    -- | An optional pagination token provided by a previous request. If this
    -- parameter is specified, the response includes only records beyond the
    -- marker, up to the value specified by @MaxRecords@ .
    marker :: 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 'DescribeDBInstancesResponse' 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:
--
-- 'dbInstances', 'describeDBInstancesResponse_dbInstances' - A list of DBInstance instances.
--
-- 'marker', 'describeDBInstancesResponse_marker' - An optional pagination token provided by a previous request. If this
-- parameter is specified, the response includes only records beyond the
-- marker, up to the value specified by @MaxRecords@ .
--
-- 'httpStatus', 'describeDBInstancesResponse_httpStatus' - The response's http status code.
newDescribeDBInstancesResponse ::
  -- | 'httpStatus'
  Prelude.Int ->
  DescribeDBInstancesResponse
newDescribeDBInstancesResponse pHttpStatus_ =
  DescribeDBInstancesResponse'
    { dbInstances =
        Prelude.Nothing,
      marker = Prelude.Nothing,
      httpStatus = pHttpStatus_
    }

-- | A list of DBInstance instances.
describeDBInstancesResponse_dbInstances :: Lens.Lens' DescribeDBInstancesResponse (Prelude.Maybe [DBInstance])
describeDBInstancesResponse_dbInstances = Lens.lens (\DescribeDBInstancesResponse' {dbInstances} -> dbInstances) (\s@DescribeDBInstancesResponse' {} a -> s {dbInstances = a} :: DescribeDBInstancesResponse) Prelude.. Lens.mapping Lens.coerced

-- | An optional pagination token provided by a previous request. If this
-- parameter is specified, the response includes only records beyond the
-- marker, up to the value specified by @MaxRecords@ .
describeDBInstancesResponse_marker :: Lens.Lens' DescribeDBInstancesResponse (Prelude.Maybe Prelude.Text)
describeDBInstancesResponse_marker = Lens.lens (\DescribeDBInstancesResponse' {marker} -> marker) (\s@DescribeDBInstancesResponse' {} a -> s {marker = a} :: DescribeDBInstancesResponse)

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

instance Prelude.NFData DescribeDBInstancesResponse where
  rnf DescribeDBInstancesResponse' {..} =
    Prelude.rnf dbInstances
      `Prelude.seq` Prelude.rnf marker
      `Prelude.seq` Prelude.rnf httpStatus