{-# 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.EFS.DescribeFileSystems
-- 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 the description of a specific Amazon EFS file system if either
-- the file system @CreationToken@ or the @FileSystemId@ is provided.
-- Otherwise, it returns descriptions of all file systems owned by the
-- caller\'s Amazon Web Services account in the Amazon Web Services Region
-- of the endpoint that you\'re calling.
--
-- When retrieving all file system descriptions, you can optionally specify
-- the @MaxItems@ parameter to limit the number of descriptions in a
-- response. Currently, this number is automatically set to 10. If more
-- file system descriptions remain, Amazon EFS returns a @NextMarker@, an
-- opaque token, in the response. In this case, you should send a
-- subsequent request with the @Marker@ request parameter set to the value
-- of @NextMarker@.
--
-- To retrieve a list of your file system descriptions, this operation is
-- used in an iterative process, where @DescribeFileSystems@ is called
-- first without the @Marker@ and then the operation continues to call it
-- with the @Marker@ parameter set to the value of the @NextMarker@ from
-- the previous response until the response has no @NextMarker@.
--
-- The order of file systems returned in the response of one
-- @DescribeFileSystems@ call and the order of file systems returned across
-- the responses of a multi-call iteration is unspecified.
--
-- This operation requires permissions for the
-- @elasticfilesystem:DescribeFileSystems@ action.
--
-- This operation returns paginated results.
module Amazonka.EFS.DescribeFileSystems
  ( -- * Creating a Request
    DescribeFileSystems (..),
    newDescribeFileSystems,

    -- * Request Lenses
    describeFileSystems_creationToken,
    describeFileSystems_fileSystemId,
    describeFileSystems_marker,
    describeFileSystems_maxItems,

    -- * Destructuring the Response
    DescribeFileSystemsResponse (..),
    newDescribeFileSystemsResponse,

    -- * Response Lenses
    describeFileSystemsResponse_fileSystems,
    describeFileSystemsResponse_marker,
    describeFileSystemsResponse_nextMarker,
    describeFileSystemsResponse_httpStatus,
  )
where

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

-- |
--
-- /See:/ 'newDescribeFileSystems' smart constructor.
data DescribeFileSystems = DescribeFileSystems'
  { -- | (Optional) Restricts the list to the file system with this creation
    -- token (String). You specify a creation token when you create an Amazon
    -- EFS file system.
    creationToken :: Prelude.Maybe Prelude.Text,
    -- | (Optional) ID of the file system whose description you want to retrieve
    -- (String).
    fileSystemId :: Prelude.Maybe Prelude.Text,
    -- | (Optional) Opaque pagination token returned from a previous
    -- @DescribeFileSystems@ operation (String). If present, specifies to
    -- continue the list from where the returning call had left off.
    marker :: Prelude.Maybe Prelude.Text,
    -- | (Optional) Specifies the maximum number of file systems to return in the
    -- response (integer). This number is automatically set to 100. The
    -- response is paginated at 100 per page if you have more than 100 file
    -- systems.
    maxItems :: Prelude.Maybe Prelude.Natural
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'DescribeFileSystems' 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:
--
-- 'creationToken', 'describeFileSystems_creationToken' - (Optional) Restricts the list to the file system with this creation
-- token (String). You specify a creation token when you create an Amazon
-- EFS file system.
--
-- 'fileSystemId', 'describeFileSystems_fileSystemId' - (Optional) ID of the file system whose description you want to retrieve
-- (String).
--
-- 'marker', 'describeFileSystems_marker' - (Optional) Opaque pagination token returned from a previous
-- @DescribeFileSystems@ operation (String). If present, specifies to
-- continue the list from where the returning call had left off.
--
-- 'maxItems', 'describeFileSystems_maxItems' - (Optional) Specifies the maximum number of file systems to return in the
-- response (integer). This number is automatically set to 100. The
-- response is paginated at 100 per page if you have more than 100 file
-- systems.
newDescribeFileSystems ::
  DescribeFileSystems
newDescribeFileSystems =
  DescribeFileSystems'
    { creationToken =
        Prelude.Nothing,
      fileSystemId = Prelude.Nothing,
      marker = Prelude.Nothing,
      maxItems = Prelude.Nothing
    }

-- | (Optional) Restricts the list to the file system with this creation
-- token (String). You specify a creation token when you create an Amazon
-- EFS file system.
describeFileSystems_creationToken :: Lens.Lens' DescribeFileSystems (Prelude.Maybe Prelude.Text)
describeFileSystems_creationToken = Lens.lens (\DescribeFileSystems' {creationToken} -> creationToken) (\s@DescribeFileSystems' {} a -> s {creationToken = a} :: DescribeFileSystems)

-- | (Optional) ID of the file system whose description you want to retrieve
-- (String).
describeFileSystems_fileSystemId :: Lens.Lens' DescribeFileSystems (Prelude.Maybe Prelude.Text)
describeFileSystems_fileSystemId = Lens.lens (\DescribeFileSystems' {fileSystemId} -> fileSystemId) (\s@DescribeFileSystems' {} a -> s {fileSystemId = a} :: DescribeFileSystems)

-- | (Optional) Opaque pagination token returned from a previous
-- @DescribeFileSystems@ operation (String). If present, specifies to
-- continue the list from where the returning call had left off.
describeFileSystems_marker :: Lens.Lens' DescribeFileSystems (Prelude.Maybe Prelude.Text)
describeFileSystems_marker = Lens.lens (\DescribeFileSystems' {marker} -> marker) (\s@DescribeFileSystems' {} a -> s {marker = a} :: DescribeFileSystems)

-- | (Optional) Specifies the maximum number of file systems to return in the
-- response (integer). This number is automatically set to 100. The
-- response is paginated at 100 per page if you have more than 100 file
-- systems.
describeFileSystems_maxItems :: Lens.Lens' DescribeFileSystems (Prelude.Maybe Prelude.Natural)
describeFileSystems_maxItems = Lens.lens (\DescribeFileSystems' {maxItems} -> maxItems) (\s@DescribeFileSystems' {} a -> s {maxItems = a} :: DescribeFileSystems)

instance Core.AWSPager DescribeFileSystems where
  page rq rs
    | Core.stop
        ( rs
            Lens.^? describeFileSystemsResponse_nextMarker
            Prelude.. Lens._Just
        ) =
        Prelude.Nothing
    | Core.stop
        ( rs
            Lens.^? describeFileSystemsResponse_fileSystems
            Prelude.. Lens._Just
        ) =
        Prelude.Nothing
    | Prelude.otherwise =
        Prelude.Just
          Prelude.$ rq
          Prelude.& describeFileSystems_marker
          Lens..~ rs
          Lens.^? describeFileSystemsResponse_nextMarker
          Prelude.. Lens._Just

instance Core.AWSRequest DescribeFileSystems where
  type
    AWSResponse DescribeFileSystems =
      DescribeFileSystemsResponse
  request overrides =
    Request.get (overrides defaultService)
  response =
    Response.receiveJSON
      ( \s h x ->
          DescribeFileSystemsResponse'
            Prelude.<$> (x Data..?> "FileSystems" Core..!@ Prelude.mempty)
            Prelude.<*> (x Data..?> "Marker")
            Prelude.<*> (x Data..?> "NextMarker")
            Prelude.<*> (Prelude.pure (Prelude.fromEnum s))
      )

instance Prelude.Hashable DescribeFileSystems where
  hashWithSalt _salt DescribeFileSystems' {..} =
    _salt
      `Prelude.hashWithSalt` creationToken
      `Prelude.hashWithSalt` fileSystemId
      `Prelude.hashWithSalt` marker
      `Prelude.hashWithSalt` maxItems

instance Prelude.NFData DescribeFileSystems where
  rnf DescribeFileSystems' {..} =
    Prelude.rnf creationToken
      `Prelude.seq` Prelude.rnf fileSystemId
      `Prelude.seq` Prelude.rnf marker
      `Prelude.seq` Prelude.rnf maxItems

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

instance Data.ToPath DescribeFileSystems where
  toPath = Prelude.const "/2015-02-01/file-systems"

instance Data.ToQuery DescribeFileSystems where
  toQuery DescribeFileSystems' {..} =
    Prelude.mconcat
      [ "CreationToken" Data.=: creationToken,
        "FileSystemId" Data.=: fileSystemId,
        "Marker" Data.=: marker,
        "MaxItems" Data.=: maxItems
      ]

-- | /See:/ 'newDescribeFileSystemsResponse' smart constructor.
data DescribeFileSystemsResponse = DescribeFileSystemsResponse'
  { -- | An array of file system descriptions.
    fileSystems :: Prelude.Maybe [FileSystemDescription],
    -- | Present if provided by caller in the request (String).
    marker :: Prelude.Maybe Prelude.Text,
    -- | Present if there are more file systems than returned in the response
    -- (String). You can use the @NextMarker@ in the subsequent request to
    -- fetch the descriptions.
    nextMarker :: 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 'DescribeFileSystemsResponse' 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:
--
-- 'fileSystems', 'describeFileSystemsResponse_fileSystems' - An array of file system descriptions.
--
-- 'marker', 'describeFileSystemsResponse_marker' - Present if provided by caller in the request (String).
--
-- 'nextMarker', 'describeFileSystemsResponse_nextMarker' - Present if there are more file systems than returned in the response
-- (String). You can use the @NextMarker@ in the subsequent request to
-- fetch the descriptions.
--
-- 'httpStatus', 'describeFileSystemsResponse_httpStatus' - The response's http status code.
newDescribeFileSystemsResponse ::
  -- | 'httpStatus'
  Prelude.Int ->
  DescribeFileSystemsResponse
newDescribeFileSystemsResponse pHttpStatus_ =
  DescribeFileSystemsResponse'
    { fileSystems =
        Prelude.Nothing,
      marker = Prelude.Nothing,
      nextMarker = Prelude.Nothing,
      httpStatus = pHttpStatus_
    }

-- | An array of file system descriptions.
describeFileSystemsResponse_fileSystems :: Lens.Lens' DescribeFileSystemsResponse (Prelude.Maybe [FileSystemDescription])
describeFileSystemsResponse_fileSystems = Lens.lens (\DescribeFileSystemsResponse' {fileSystems} -> fileSystems) (\s@DescribeFileSystemsResponse' {} a -> s {fileSystems = a} :: DescribeFileSystemsResponse) Prelude.. Lens.mapping Lens.coerced

-- | Present if provided by caller in the request (String).
describeFileSystemsResponse_marker :: Lens.Lens' DescribeFileSystemsResponse (Prelude.Maybe Prelude.Text)
describeFileSystemsResponse_marker = Lens.lens (\DescribeFileSystemsResponse' {marker} -> marker) (\s@DescribeFileSystemsResponse' {} a -> s {marker = a} :: DescribeFileSystemsResponse)

-- | Present if there are more file systems than returned in the response
-- (String). You can use the @NextMarker@ in the subsequent request to
-- fetch the descriptions.
describeFileSystemsResponse_nextMarker :: Lens.Lens' DescribeFileSystemsResponse (Prelude.Maybe Prelude.Text)
describeFileSystemsResponse_nextMarker = Lens.lens (\DescribeFileSystemsResponse' {nextMarker} -> nextMarker) (\s@DescribeFileSystemsResponse' {} a -> s {nextMarker = a} :: DescribeFileSystemsResponse)

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

instance Prelude.NFData DescribeFileSystemsResponse where
  rnf DescribeFileSystemsResponse' {..} =
    Prelude.rnf fileSystems
      `Prelude.seq` Prelude.rnf marker
      `Prelude.seq` Prelude.rnf nextMarker
      `Prelude.seq` Prelude.rnf httpStatus