DescribeStream.hs

{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE DeriveGeneric      #-}
{-# LANGUAGE OverloadedStrings  #-}
{-# LANGUAGE RecordWildCards    #-}
{-# LANGUAGE TypeFamilies       #-}

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

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

-- |
-- Module      : Network.AWS.Kinesis.DescribeStream
-- Copyright   : (c) 2013-2016 Brendan Hay
-- License     : Mozilla Public License, v. 2.0.
-- Maintainer  : Brendan Hay <brendan.g.hay@gmail.com>
-- Stability   : auto-generated
-- Portability : non-portable (GHC extensions)
--
-- Describes the specified Amazon Kinesis stream.
--
--
-- The information returned includes the stream name, Amazon Resource Name (ARN), creation time, enhanced metric configuration, and shard map. The shard map is an array of shard objects. For each shard object, there is the hash key and sequence number ranges that the shard spans, and the IDs of any earlier shards that played in a role in creating the shard. Every record ingested in the stream is identified by a sequence number, which is assigned when the record is put into the stream.
--
-- You can limit the number of shards returned by each call. For more information, see <http://docs.aws.amazon.com/kinesis/latest/dev/kinesis-using-sdk-java-retrieve-shards.html Retrieving Shards from a Stream> in the /Amazon Kinesis Streams Developer Guide/ .
--
-- There are no guarantees about the chronological order shards returned. To process shards in chronological order, use the ID of the parent shard to track the lineage to the oldest shard.
--
-- This operation has a limit of 10 transactions per second per account.
--
--
-- This operation returns paginated results.
module Network.AWS.Kinesis.DescribeStream
    (
    -- * Creating a Request
      describeStream
    , DescribeStream
    -- * Request Lenses
    , dExclusiveStartShardId
    , dLimit
    , dStreamName

    -- * Destructuring the Response
    , describeStreamResponse
    , DescribeStreamResponse
    -- * Response Lenses
    , dsrsResponseStatus
    , dsrsStreamDescription
    ) where

import           Network.AWS.Kinesis.Types
import           Network.AWS.Kinesis.Types.Product
import           Network.AWS.Lens
import           Network.AWS.Pager
import           Network.AWS.Prelude
import           Network.AWS.Request
import           Network.AWS.Response

-- | Represents the input for @DescribeStream@ .
--
--
--
-- /See:/ 'describeStream' smart constructor.
data DescribeStream = DescribeStream'
    { _dExclusiveStartShardId :: !(Maybe Text)
    , _dLimit                 :: !(Maybe Nat)
    , _dStreamName            :: !Text
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'DescribeStream' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'dExclusiveStartShardId' - The shard ID of the shard to start with.
--
-- * 'dLimit' - The maximum number of shards to return in a single call. The default value is 100. If you specify a value greater than 100, at most 100 shards are returned.
--
-- * 'dStreamName' - The name of the stream to describe.
describeStream
    :: Text -- ^ 'dStreamName'
    -> DescribeStream
describeStream pStreamName_ =
    DescribeStream'
    { _dExclusiveStartShardId = Nothing
    , _dLimit = Nothing
    , _dStreamName = pStreamName_
    }

-- | The shard ID of the shard to start with.
dExclusiveStartShardId :: Lens' DescribeStream (Maybe Text)
dExclusiveStartShardId = lens _dExclusiveStartShardId (\ s a -> s{_dExclusiveStartShardId = a});

-- | The maximum number of shards to return in a single call. The default value is 100. If you specify a value greater than 100, at most 100 shards are returned.
dLimit :: Lens' DescribeStream (Maybe Natural)
dLimit = lens _dLimit (\ s a -> s{_dLimit = a}) . mapping _Nat;

-- | The name of the stream to describe.
dStreamName :: Lens' DescribeStream Text
dStreamName = lens _dStreamName (\ s a -> s{_dStreamName = a});

instance AWSPager DescribeStream where
        page rq rs
          | stop
              (rs ^. dsrsStreamDescription . sdHasMoreShards)
            = Nothing
          | isNothing
              (rs ^?
                 dsrsStreamDescription . sdShards . _last . sShardId)
            = Nothing
          | otherwise =
            Just $ rq &
              dExclusiveStartShardId .~
                rs ^?
                  dsrsStreamDescription . sdShards . _last . sShardId

instance AWSRequest DescribeStream where
        type Rs DescribeStream = DescribeStreamResponse
        request = postJSON kinesis
        response
          = receiveJSON
              (\ s h x ->
                 DescribeStreamResponse' <$>
                   (pure (fromEnum s)) <*> (x .:> "StreamDescription"))

instance Hashable DescribeStream

instance NFData DescribeStream

instance ToHeaders DescribeStream where
        toHeaders
          = const
              (mconcat
                 ["X-Amz-Target" =#
                    ("Kinesis_20131202.DescribeStream" :: ByteString),
                  "Content-Type" =#
                    ("application/x-amz-json-1.1" :: ByteString)])

instance ToJSON DescribeStream where
        toJSON DescribeStream'{..}
          = object
              (catMaybes
                 [("ExclusiveStartShardId" .=) <$>
                    _dExclusiveStartShardId,
                  ("Limit" .=) <$> _dLimit,
                  Just ("StreamName" .= _dStreamName)])

instance ToPath DescribeStream where
        toPath = const "/"

instance ToQuery DescribeStream where
        toQuery = const mempty

-- | Represents the output for @DescribeStream@ .
--
--
--
-- /See:/ 'describeStreamResponse' smart constructor.
data DescribeStreamResponse = DescribeStreamResponse'
    { _dsrsResponseStatus    :: !Int
    , _dsrsStreamDescription :: !StreamDescription
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'DescribeStreamResponse' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'dsrsResponseStatus' - -- | The response status code.
--
-- * 'dsrsStreamDescription' - The current status of the stream, the stream ARN, an array of shard objects that comprise the stream, and whether there are more shards available.
describeStreamResponse
    :: Int -- ^ 'dsrsResponseStatus'
    -> StreamDescription -- ^ 'dsrsStreamDescription'
    -> DescribeStreamResponse
describeStreamResponse pResponseStatus_ pStreamDescription_ =
    DescribeStreamResponse'
    { _dsrsResponseStatus = pResponseStatus_
    , _dsrsStreamDescription = pStreamDescription_
    }

-- | -- | The response status code.
dsrsResponseStatus :: Lens' DescribeStreamResponse Int
dsrsResponseStatus = lens _dsrsResponseStatus (\ s a -> s{_dsrsResponseStatus = a});

-- | The current status of the stream, the stream ARN, an array of shard objects that comprise the stream, and whether there are more shards available.
dsrsStreamDescription :: Lens' DescribeStreamResponse StreamDescription
dsrsStreamDescription = lens _dsrsStreamDescription (\ s a -> s{_dsrsStreamDescription = a});

instance NFData DescribeStreamResponse