{-# 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.DynamoDBStreams.ListStreams
-- Copyright   : (c) 2013-2015 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)
--
-- Returns an array of stream ARNs associated with the current account and
-- endpoint. If the 'TableName' parameter is present, then /ListStreams/
-- will return only the streams ARNs for that table.
--
-- You can call /ListStreams/ at a maximum rate of 5 times per second.
--
-- /See:/ <http://dynamodb-preview.s3-website-us-west-2.amazonaws.com/docs/streams-api/API_ListStreams.html AWS API Reference> for ListStreams.
module Network.AWS.DynamoDBStreams.ListStreams
    (
    -- * Creating a Request
      listStreams
    , ListStreams
    -- * Request Lenses
    , lsExclusiveStartStreamARN
    , lsLimit
    , lsTableName

    -- * Destructuring the Response
    , listStreamsResponse
    , ListStreamsResponse
    -- * Response Lenses
    , lsrsLastEvaluatedStreamARN
    , lsrsStreams
    , lsrsStatus
    ) where

import           Network.AWS.DynamoDBStreams.Types
import           Network.AWS.DynamoDBStreams.Types.Product
import           Network.AWS.Prelude
import           Network.AWS.Request
import           Network.AWS.Response

-- | Represents the input of a /ListStreams/ operation.
--
-- /See:/ 'listStreams' smart constructor.
data ListStreams = ListStreams'
    { _lsExclusiveStartStreamARN :: !(Maybe Text)
    , _lsLimit                   :: !(Maybe Nat)
    , _lsTableName               :: !(Maybe Text)
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'ListStreams' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'lsExclusiveStartStreamARN'
--
-- * 'lsLimit'
--
-- * 'lsTableName'
listStreams
    :: ListStreams
listStreams =
    ListStreams'
    { _lsExclusiveStartStreamARN = Nothing
    , _lsLimit = Nothing
    , _lsTableName = Nothing
    }

-- | The ARN (Amazon Resource Name) of the first item that this operation
-- will evaluate. Use the value that was returned for
-- 'LastEvaluatedStreamArn' in the previous operation.
lsExclusiveStartStreamARN :: Lens' ListStreams (Maybe Text)
lsExclusiveStartStreamARN = lens _lsExclusiveStartStreamARN (\ s a -> s{_lsExclusiveStartStreamARN = a});

-- | The maximum number of streams to return. The upper limit is 100.
lsLimit :: Lens' ListStreams (Maybe Natural)
lsLimit = lens _lsLimit (\ s a -> s{_lsLimit = a}) . mapping _Nat;

-- | If this parameter is provided, then only the streams associated with
-- this table name are returned.
lsTableName :: Lens' ListStreams (Maybe Text)
lsTableName = lens _lsTableName (\ s a -> s{_lsTableName = a});

instance AWSRequest ListStreams where
        type Rs ListStreams = ListStreamsResponse
        request = postJSON dynamoDBStreams
        response
          = receiveJSON
              (\ s h x ->
                 ListStreamsResponse' <$>
                   (x .?> "LastEvaluatedStreamArn") <*>
                     (x .?> "Streams" .!@ mempty)
                     <*> (pure (fromEnum s)))

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

instance ToJSON ListStreams where
        toJSON ListStreams'{..}
          = object
              (catMaybes
                 [("ExclusiveStartStreamArn" .=) <$>
                    _lsExclusiveStartStreamARN,
                  ("Limit" .=) <$> _lsLimit,
                  ("TableName" .=) <$> _lsTableName])

instance ToPath ListStreams where
        toPath = const "/"

instance ToQuery ListStreams where
        toQuery = const mempty

-- | Represents the output of a /ListStreams/ operation.
--
-- /See:/ 'listStreamsResponse' smart constructor.
data ListStreamsResponse = ListStreamsResponse'
    { _lsrsLastEvaluatedStreamARN :: !(Maybe Text)
    , _lsrsStreams                :: !(Maybe [Stream])
    , _lsrsStatus                 :: !Int
    } deriving (Eq,Read,Show,Data,Typeable,Generic)

-- | Creates a value of 'ListStreamsResponse' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'lsrsLastEvaluatedStreamARN'
--
-- * 'lsrsStreams'
--
-- * 'lsrsStatus'
listStreamsResponse
    :: Int -- ^ 'lsrsStatus'
    -> ListStreamsResponse
listStreamsResponse pStatus_ =
    ListStreamsResponse'
    { _lsrsLastEvaluatedStreamARN = Nothing
    , _lsrsStreams = Nothing
    , _lsrsStatus = pStatus_
    }

-- | The stream ARN of the item where the operation stopped, inclusive of the
-- previous result set. Use this value to start a new operation, excluding
-- this value in the new request.
--
-- If 'LastEvaluatedStreamArn' is empty, then the \"last page\" of results
-- has been processed and there is no more data to be retrieved.
--
-- If 'LastEvaluatedStreamArn' is not empty, it does not necessarily mean
-- that there is more data in the result set. The only way to know when you
-- have reached the end of the result set is when 'LastEvaluatedStreamArn'
-- is empty.
lsrsLastEvaluatedStreamARN :: Lens' ListStreamsResponse (Maybe Text)
lsrsLastEvaluatedStreamARN = lens _lsrsLastEvaluatedStreamARN (\ s a -> s{_lsrsLastEvaluatedStreamARN = a});

-- | A list of stream descriptors associated with the current account and
-- endpoint.
lsrsStreams :: Lens' ListStreamsResponse [Stream]
lsrsStreams = lens _lsrsStreams (\ s a -> s{_lsrsStreams = a}) . _Default . _Coerce;

-- | The response status code.
lsrsStatus :: Lens' ListStreamsResponse Int
lsrsStatus = lens _lsrsStatus (\ s a -> s{_lsrsStatus = a});