{-# 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.MergeShards
-- 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)
--
-- Merges two adjacent shards in an Amazon Kinesis stream and combines them into a single shard to reduce the stream\'s capacity to ingest and transport data. Two shards are considered adjacent if the union of the hash key ranges for the two shards form a contiguous set with no gaps. For example, if you have two shards, one with a hash key range of 276...381 and the other with a hash key range of 382...454, then you could merge these two shards into a single shard that would have a hash key range of 276...454. After the merge, the single child shard receives data for all hash key values covered by the two parent shards.
--
-- 'MergeShards' is called when there is a need to reduce the overall capacity of a stream because of excess capacity that is not being used. You must specify the shard to be merged and the adjacent shard for a stream. For more information about merging shards, see <http://docs.aws.amazon.com/kinesis/latest/dev/kinesis-using-sdk-java-resharding-merge.html Merge Two Shards> in the /Amazon Kinesis Streams Developer Guide/.
--
-- If the stream is in the 'ACTIVE' state, you can call 'MergeShards'. If a stream is in the 'CREATING', 'UPDATING', or 'DELETING' state, 'MergeShards' returns a 'ResourceInUseException'. If the specified stream does not exist, 'MergeShards' returns a 'ResourceNotFoundException'.
--
-- You can use < DescribeStream> to check the state of the stream, which is returned in 'StreamStatus'.
--
-- 'MergeShards' is an asynchronous operation. Upon receiving a 'MergeShards' request, Amazon Kinesis immediately returns a response and sets the 'StreamStatus' to 'UPDATING'. After the operation is completed, Amazon Kinesis sets the 'StreamStatus' to 'ACTIVE'. Read and write operations continue to work while the stream is in the 'UPDATING' state.
--
-- You use < DescribeStream> to determine the shard IDs that are specified in the 'MergeShards' request.
--
-- If you try to operate on too many streams in parallel using < CreateStream>, < DeleteStream>, 'MergeShards' or < SplitShard>, you will receive a 'LimitExceededException'.
--
-- 'MergeShards' has limit of 5 transactions per second per account.
module Network.AWS.Kinesis.MergeShards
    (
    -- * Creating a Request
      mergeShards
    , MergeShards
    -- * Request Lenses
    , msStreamName
    , msShardToMerge
    , msAdjacentShardToMerge

    -- * Destructuring the Response
    , mergeShardsResponse
    , MergeShardsResponse
    ) where

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

-- | Represents the input for 'MergeShards'.
--
-- /See:/ 'mergeShards' smart constructor.
data MergeShards = MergeShards'
    { _msStreamName           :: !Text
    , _msShardToMerge         :: !Text
    , _msAdjacentShardToMerge :: !Text
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'MergeShards' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'msStreamName'
--
-- * 'msShardToMerge'
--
-- * 'msAdjacentShardToMerge'
mergeShards
    :: Text -- ^ 'msStreamName'
    -> Text -- ^ 'msShardToMerge'
    -> Text -- ^ 'msAdjacentShardToMerge'
    -> MergeShards
mergeShards pStreamName_ pShardToMerge_ pAdjacentShardToMerge_ =
    MergeShards'
    { _msStreamName = pStreamName_
    , _msShardToMerge = pShardToMerge_
    , _msAdjacentShardToMerge = pAdjacentShardToMerge_
    }

-- | The name of the stream for the merge.
msStreamName :: Lens' MergeShards Text
msStreamName = lens _msStreamName (\ s a -> s{_msStreamName = a});

-- | The shard ID of the shard to combine with the adjacent shard for the merge.
msShardToMerge :: Lens' MergeShards Text
msShardToMerge = lens _msShardToMerge (\ s a -> s{_msShardToMerge = a});

-- | The shard ID of the adjacent shard for the merge.
msAdjacentShardToMerge :: Lens' MergeShards Text
msAdjacentShardToMerge = lens _msAdjacentShardToMerge (\ s a -> s{_msAdjacentShardToMerge = a});

instance AWSRequest MergeShards where
        type Rs MergeShards = MergeShardsResponse
        request = postJSON kinesis
        response = receiveNull MergeShardsResponse'

instance Hashable MergeShards

instance NFData MergeShards

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

instance ToJSON MergeShards where
        toJSON MergeShards'{..}
          = object
              (catMaybes
                 [Just ("StreamName" .= _msStreamName),
                  Just ("ShardToMerge" .= _msShardToMerge),
                  Just
                    ("AdjacentShardToMerge" .= _msAdjacentShardToMerge)])

instance ToPath MergeShards where
        toPath = const "/"

instance ToQuery MergeShards where
        toQuery = const mempty

-- | /See:/ 'mergeShardsResponse' smart constructor.
data MergeShardsResponse =
    MergeShardsResponse'
    deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'MergeShardsResponse' with the minimum fields required to make a request.
--
mergeShardsResponse
    :: MergeShardsResponse
mergeShardsResponse = MergeShardsResponse'

instance NFData MergeShardsResponse