{-# 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.Glue.GetCrawlers
-- Copyright   : (c) 2013-2018 Brendan Hay
-- License     : Mozilla Public License, v. 2.0.
-- Maintainer  : Brendan Hay <brendan.g.hay+amazonka@gmail.com>
-- Stability   : auto-generated
-- Portability : non-portable (GHC extensions)
--
-- Retrieves metadata for all crawlers defined in the customer account.
--
--
--
-- This operation returns paginated results.
module Network.AWS.Glue.GetCrawlers
    (
    -- * Creating a Request
      getCrawlers
    , GetCrawlers
    -- * Request Lenses
    , gNextToken
    , gMaxResults

    -- * Destructuring the Response
    , getCrawlersResponse
    , GetCrawlersResponse
    -- * Response Lenses
    , grsNextToken
    , grsCrawlers
    , grsResponseStatus
    ) where

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

-- | /See:/ 'getCrawlers' smart constructor.
data GetCrawlers = GetCrawlers'
  { _gNextToken  :: !(Maybe Text)
  , _gMaxResults :: !(Maybe Nat)
  } deriving (Eq, Read, Show, Data, Typeable, Generic)


-- | Creates a value of 'GetCrawlers' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'gNextToken' - A continuation token, if this is a continuation request.
--
-- * 'gMaxResults' - The number of crawlers to return on each call.
getCrawlers
    :: GetCrawlers
getCrawlers = GetCrawlers' {_gNextToken = Nothing, _gMaxResults = Nothing}


-- | A continuation token, if this is a continuation request.
gNextToken :: Lens' GetCrawlers (Maybe Text)
gNextToken = lens _gNextToken (\ s a -> s{_gNextToken = a})

-- | The number of crawlers to return on each call.
gMaxResults :: Lens' GetCrawlers (Maybe Natural)
gMaxResults = lens _gMaxResults (\ s a -> s{_gMaxResults = a}) . mapping _Nat

instance AWSPager GetCrawlers where
        page rq rs
          | stop (rs ^. grsNextToken) = Nothing
          | stop (rs ^. grsCrawlers) = Nothing
          | otherwise =
            Just $ rq & gNextToken .~ rs ^. grsNextToken

instance AWSRequest GetCrawlers where
        type Rs GetCrawlers = GetCrawlersResponse
        request = postJSON glue
        response
          = receiveJSON
              (\ s h x ->
                 GetCrawlersResponse' <$>
                   (x .?> "NextToken") <*> (x .?> "Crawlers" .!@ mempty)
                     <*> (pure (fromEnum s)))

instance Hashable GetCrawlers where

instance NFData GetCrawlers where

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

instance ToJSON GetCrawlers where
        toJSON GetCrawlers'{..}
          = object
              (catMaybes
                 [("NextToken" .=) <$> _gNextToken,
                  ("MaxResults" .=) <$> _gMaxResults])

instance ToPath GetCrawlers where
        toPath = const "/"

instance ToQuery GetCrawlers where
        toQuery = const mempty

-- | /See:/ 'getCrawlersResponse' smart constructor.
data GetCrawlersResponse = GetCrawlersResponse'
  { _grsNextToken      :: !(Maybe Text)
  , _grsCrawlers       :: !(Maybe [Crawler])
  , _grsResponseStatus :: !Int
  } deriving (Eq, Read, Show, Data, Typeable, Generic)


-- | Creates a value of 'GetCrawlersResponse' with the minimum fields required to make a request.
--
-- Use one of the following lenses to modify other fields as desired:
--
-- * 'grsNextToken' - A continuation token, if the returned list has not reached the end of those defined in this customer account.
--
-- * 'grsCrawlers' - A list of crawler metadata.
--
-- * 'grsResponseStatus' - -- | The response status code.
getCrawlersResponse
    :: Int -- ^ 'grsResponseStatus'
    -> GetCrawlersResponse
getCrawlersResponse pResponseStatus_ =
  GetCrawlersResponse'
    { _grsNextToken = Nothing
    , _grsCrawlers = Nothing
    , _grsResponseStatus = pResponseStatus_
    }


-- | A continuation token, if the returned list has not reached the end of those defined in this customer account.
grsNextToken :: Lens' GetCrawlersResponse (Maybe Text)
grsNextToken = lens _grsNextToken (\ s a -> s{_grsNextToken = a})

-- | A list of crawler metadata.
grsCrawlers :: Lens' GetCrawlersResponse [Crawler]
grsCrawlers = lens _grsCrawlers (\ s a -> s{_grsCrawlers = a}) . _Default . _Coerce

-- | -- | The response status code.
grsResponseStatus :: Lens' GetCrawlersResponse Int
grsResponseStatus = lens _grsResponseStatus (\ s a -> s{_grsResponseStatus = a})

instance NFData GetCrawlersResponse where