{-# 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.DynamoDBStreams.DescribeStream
-- 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 a stream, including the current status of the
-- stream, its Amazon Resource Name (ARN), the composition of its shards,
-- and its corresponding DynamoDB table.
--
-- You can call @DescribeStream@ at a maximum rate of 10 times per second.
--
-- Each shard in the stream has a @SequenceNumberRange@ associated with it.
-- If the @SequenceNumberRange@ has a @StartingSequenceNumber@ but no
-- @EndingSequenceNumber@, then the shard is still open (able to receive
-- more stream records). If both @StartingSequenceNumber@ and
-- @EndingSequenceNumber@ are present, then that shard is closed and can no
-- longer receive more data.
module Amazonka.DynamoDBStreams.DescribeStream
  ( -- * Creating a Request
    DescribeStream (..),
    newDescribeStream,

    -- * Request Lenses
    describeStream_exclusiveStartShardId,
    describeStream_limit,
    describeStream_streamArn,

    -- * Destructuring the Response
    DescribeStreamResponse (..),
    newDescribeStreamResponse,

    -- * Response Lenses
    describeStreamResponse_streamDescription,
    describeStreamResponse_httpStatus,
  )
where

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

-- | Represents the input of a @DescribeStream@ operation.
--
-- /See:/ 'newDescribeStream' smart constructor.
data DescribeStream = DescribeStream'
  { -- | The shard ID of the first item that this operation will evaluate. Use
    -- the value that was returned for @LastEvaluatedShardId@ in the previous
    -- operation.
    exclusiveStartShardId :: Prelude.Maybe Prelude.Text,
    -- | The maximum number of shard objects to return. The upper limit is 100.
    limit :: Prelude.Maybe Prelude.Natural,
    -- | The Amazon Resource Name (ARN) for the stream.
    streamArn :: Prelude.Text
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'DescribeStream' 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:
--
-- 'exclusiveStartShardId', 'describeStream_exclusiveStartShardId' - The shard ID of the first item that this operation will evaluate. Use
-- the value that was returned for @LastEvaluatedShardId@ in the previous
-- operation.
--
-- 'limit', 'describeStream_limit' - The maximum number of shard objects to return. The upper limit is 100.
--
-- 'streamArn', 'describeStream_streamArn' - The Amazon Resource Name (ARN) for the stream.
newDescribeStream ::
  -- | 'streamArn'
  Prelude.Text ->
  DescribeStream
newDescribeStream pStreamArn_ =
  DescribeStream'
    { exclusiveStartShardId =
        Prelude.Nothing,
      limit = Prelude.Nothing,
      streamArn = pStreamArn_
    }

-- | The shard ID of the first item that this operation will evaluate. Use
-- the value that was returned for @LastEvaluatedShardId@ in the previous
-- operation.
describeStream_exclusiveStartShardId :: Lens.Lens' DescribeStream (Prelude.Maybe Prelude.Text)
describeStream_exclusiveStartShardId = Lens.lens (\DescribeStream' {exclusiveStartShardId} -> exclusiveStartShardId) (\s@DescribeStream' {} a -> s {exclusiveStartShardId = a} :: DescribeStream)

-- | The maximum number of shard objects to return. The upper limit is 100.
describeStream_limit :: Lens.Lens' DescribeStream (Prelude.Maybe Prelude.Natural)
describeStream_limit = Lens.lens (\DescribeStream' {limit} -> limit) (\s@DescribeStream' {} a -> s {limit = a} :: DescribeStream)

-- | The Amazon Resource Name (ARN) for the stream.
describeStream_streamArn :: Lens.Lens' DescribeStream Prelude.Text
describeStream_streamArn = Lens.lens (\DescribeStream' {streamArn} -> streamArn) (\s@DescribeStream' {} a -> s {streamArn = a} :: DescribeStream)

instance Core.AWSRequest DescribeStream where
  type
    AWSResponse DescribeStream =
      DescribeStreamResponse
  request overrides =
    Request.postJSON (overrides defaultService)
  response =
    Response.receiveJSON
      ( \s h x ->
          DescribeStreamResponse'
            Prelude.<$> (x Data..?> "StreamDescription")
            Prelude.<*> (Prelude.pure (Prelude.fromEnum s))
      )

instance Prelude.Hashable DescribeStream where
  hashWithSalt _salt DescribeStream' {..} =
    _salt
      `Prelude.hashWithSalt` exclusiveStartShardId
      `Prelude.hashWithSalt` limit
      `Prelude.hashWithSalt` streamArn

instance Prelude.NFData DescribeStream where
  rnf DescribeStream' {..} =
    Prelude.rnf exclusiveStartShardId
      `Prelude.seq` Prelude.rnf limit
      `Prelude.seq` Prelude.rnf streamArn

instance Data.ToHeaders DescribeStream where
  toHeaders =
    Prelude.const
      ( Prelude.mconcat
          [ "X-Amz-Target"
              Data.=# ( "DynamoDBStreams_20120810.DescribeStream" ::
                          Prelude.ByteString
                      ),
            "Content-Type"
              Data.=# ( "application/x-amz-json-1.0" ::
                          Prelude.ByteString
                      )
          ]
      )

instance Data.ToJSON DescribeStream where
  toJSON DescribeStream' {..} =
    Data.object
      ( Prelude.catMaybes
          [ ("ExclusiveStartShardId" Data..=)
              Prelude.<$> exclusiveStartShardId,
            ("Limit" Data..=) Prelude.<$> limit,
            Prelude.Just ("StreamArn" Data..= streamArn)
          ]
      )

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

instance Data.ToQuery DescribeStream where
  toQuery = Prelude.const Prelude.mempty

-- | Represents the output of a @DescribeStream@ operation.
--
-- /See:/ 'newDescribeStreamResponse' smart constructor.
data DescribeStreamResponse = DescribeStreamResponse'
  { -- | A complete description of the stream, including its creation date and
    -- time, the DynamoDB table associated with the stream, the shard IDs
    -- within the stream, and the beginning and ending sequence numbers of
    -- stream records within the shards.
    streamDescription :: Prelude.Maybe StreamDescription,
    -- | The response's http status code.
    httpStatus :: Prelude.Int
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'DescribeStreamResponse' 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:
--
-- 'streamDescription', 'describeStreamResponse_streamDescription' - A complete description of the stream, including its creation date and
-- time, the DynamoDB table associated with the stream, the shard IDs
-- within the stream, and the beginning and ending sequence numbers of
-- stream records within the shards.
--
-- 'httpStatus', 'describeStreamResponse_httpStatus' - The response's http status code.
newDescribeStreamResponse ::
  -- | 'httpStatus'
  Prelude.Int ->
  DescribeStreamResponse
newDescribeStreamResponse pHttpStatus_ =
  DescribeStreamResponse'
    { streamDescription =
        Prelude.Nothing,
      httpStatus = pHttpStatus_
    }

-- | A complete description of the stream, including its creation date and
-- time, the DynamoDB table associated with the stream, the shard IDs
-- within the stream, and the beginning and ending sequence numbers of
-- stream records within the shards.
describeStreamResponse_streamDescription :: Lens.Lens' DescribeStreamResponse (Prelude.Maybe StreamDescription)
describeStreamResponse_streamDescription = Lens.lens (\DescribeStreamResponse' {streamDescription} -> streamDescription) (\s@DescribeStreamResponse' {} a -> s {streamDescription = a} :: DescribeStreamResponse)

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

instance Prelude.NFData DescribeStreamResponse where
  rnf DescribeStreamResponse' {..} =
    Prelude.rnf streamDescription
      `Prelude.seq` Prelude.rnf httpStatus