/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */

package org.elasticsearch.action.search;

import org.elasticsearch.TransportVersion;
import org.elasticsearch.Version;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.ActionListenerResponseHandler;
import org.elasticsearch.action.IndicesRequest;
import org.elasticsearch.action.OriginalIndices;
import org.elasticsearch.action.admin.cluster.node.tasks.cancel.CancelTasksRequest;
import org.elasticsearch.action.admin.cluster.node.tasks.get.GetTaskAction;
import org.elasticsearch.action.support.ChannelActionListener;
import org.elasticsearch.action.support.IndicesOptions;
import org.elasticsearch.client.internal.OriginSettingClient;
import org.elasticsearch.client.internal.node.NodeClient;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.common.util.concurrent.ConcurrentCollections;
import org.elasticsearch.common.util.concurrent.CountDown;
import org.elasticsearch.core.Nullable;
import org.elasticsearch.search.CanMatchShardResponse;
import org.elasticsearch.search.SearchPhaseResult;
import org.elasticsearch.search.SearchService;
import org.elasticsearch.search.dfs.DfsSearchResult;
import org.elasticsearch.search.fetch.FetchSearchResult;
import org.elasticsearch.search.fetch.QueryFetchSearchResult;
import org.elasticsearch.search.fetch.ScrollQueryFetchSearchResult;
import org.elasticsearch.search.fetch.ShardFetchRequest;
import org.elasticsearch.search.fetch.ShardFetchSearchRequest;
import org.elasticsearch.search.internal.InternalScrollSearchRequest;
import org.elasticsearch.search.internal.ShardSearchContextId;
import org.elasticsearch.search.internal.ShardSearchRequest;
import org.elasticsearch.search.query.QuerySearchRequest;
import org.elasticsearch.search.query.QuerySearchResult;
import org.elasticsearch.search.query.ScrollQuerySearchResult;
import org.elasticsearch.tasks.TaskId;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.RemoteClusterService;
import org.elasticsearch.transport.Transport;
import org.elasticsearch.transport.TransportActionProxy;
import org.elasticsearch.transport.TransportException;
import org.elasticsearch.transport.TransportRequest;
import org.elasticsearch.transport.TransportRequestOptions;
import org.elasticsearch.transport.TransportResponse;
import org.elasticsearch.transport.TransportService;

import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicReferenceArray;
import java.util.function.BiFunction;

/**
 * An encapsulation of {@link org.elasticsearch.search.SearchService} operations exposed through
 * transport.
 */
public class SearchTransportService {

    public static final String FREE_CONTEXT_SCROLL_ACTION_NAME = "indices:data/read/search[free_context/scroll]";
    public static final String FREE_CONTEXT_ACTION_NAME = "indices:data/read/search[free_context]";
    public static final String CLEAR_SCROLL_CONTEXTS_ACTION_NAME = "indices:data/read/search[clear_scroll_contexts]";
    public static final String DFS_ACTION_NAME = "indices:data/read/search[phase/dfs]";
    public static final String QUERY_ACTION_NAME = "indices:data/read/search[phase/query]";
    public static final String QUERY_ID_ACTION_NAME = "indices:data/read/search[phase/query/id]";
    public static final String QUERY_SCROLL_ACTION_NAME = "indices:data/read/search[phase/query/scroll]";
    public static final String QUERY_FETCH_SCROLL_ACTION_NAME = "indices:data/read/search[phase/query+fetch/scroll]";
    public static final String FETCH_ID_SCROLL_ACTION_NAME = "indices:data/read/search[phase/fetch/id/scroll]";
    public static final String FETCH_ID_ACTION_NAME = "indices:data/read/search[phase/fetch/id]";
    public static final String QUERY_CAN_MATCH_NAME = "indices:data/read/search[can_match]";
    public static final String QUERY_CAN_MATCH_NODE_NAME = "indices:data/read/search[can_match][n]";

    private final TransportService transportService;
    private final NodeClient client;
    private final BiFunction<
        Transport.Connection,
        SearchActionListener<? super SearchPhaseResult>,
        ActionListener<? super SearchPhaseResult>> responseWrapper;
    private final Map<String, Long> clientConnections = ConcurrentCollections.newConcurrentMapWithAggressiveConcurrency();

    public SearchTransportService(
        TransportService transportService,
        NodeClient client,
        BiFunction<
            Transport.Connection,
            SearchActionListener<? super SearchPhaseResult>,
            ActionListener<? super SearchPhaseResult>> responseWrapper
    ) {
        this.transportService = transportService;
        this.client = client;
        this.responseWrapper = responseWrapper;
    }

    public void sendFreeContext(Transport.Connection connection, final ShardSearchContextId contextId, OriginalIndices originalIndices) {
        transportService.sendRequest(
            connection,
            FREE_CONTEXT_ACTION_NAME,
            new SearchFreeContextRequest(originalIndices, contextId),
            TransportRequestOptions.EMPTY,
            // no need to respond if it was freed or not
            new ActionListenerResponseHandler<>(ActionListener.noop(), SearchFreeContextResponse::new)
        );
    }

    public void sendFreeContext(
        Transport.Connection connection,
        ShardSearchContextId contextId,
        ActionListener<SearchFreeContextResponse> listener
    ) {
        transportService.sendRequest(
            connection,
            FREE_CONTEXT_SCROLL_ACTION_NAME,
            new ScrollFreeContextRequest(contextId),
            TransportRequestOptions.EMPTY,
            new ActionListenerResponseHandler<>(listener, SearchFreeContextResponse::new)
        );
    }

    public void sendCanMatch(
        Transport.Connection connection,
        final ShardSearchRequest request,
        SearchTask task,
        final ActionListener<CanMatchShardResponse> listener
    ) {
        transportService.sendChildRequest(
            connection,
            QUERY_CAN_MATCH_NAME,
            request,
            task,
            TransportRequestOptions.EMPTY,
            new ActionListenerResponseHandler<>(listener, CanMatchShardResponse::new)
        );
    }

    public void sendCanMatch(
        Transport.Connection connection,
        final CanMatchNodeRequest request,
        SearchTask task,
        final ActionListener<CanMatchNodeResponse> listener
    ) {
        if (connection.getTransportVersion().onOrAfter(TransportVersion.V_7_16_0)
            && connection.getNode().getVersion().onOrAfter(Version.V_7_16_0)) {
            transportService.sendChildRequest(
                connection,
                QUERY_CAN_MATCH_NODE_NAME,
                request,
                task,
                TransportRequestOptions.EMPTY,
                new ActionListenerResponseHandler<>(listener, CanMatchNodeResponse::new)
            );
        } else {
            // BWC layer: translate into shard-level requests
            final List<ShardSearchRequest> shardSearchRequests = request.createShardSearchRequests();
            final AtomicReferenceArray<CanMatchNodeResponse.ResponseOrFailure> results = new AtomicReferenceArray<>(
                shardSearchRequests.size()
            );
            final CountDown counter = new CountDown(shardSearchRequests.size());
            final Runnable maybeFinish = () -> {
                if (counter.countDown()) {
                    final CanMatchNodeResponse.ResponseOrFailure[] responses =
                        new CanMatchNodeResponse.ResponseOrFailure[shardSearchRequests.size()];
                    for (int i = 0; i < responses.length; i++) {
                        responses[i] = results.get(i);
                    }
                    final CanMatchNodeResponse response = new CanMatchNodeResponse(Arrays.asList(responses));
                    listener.onResponse(response);
                }
            };
            for (int i = 0; i < shardSearchRequests.size(); i++) {
                final ShardSearchRequest shardSearchRequest = shardSearchRequests.get(i);
                final int finalI = i;
                try {
                    sendCanMatch(connection, shardSearchRequest, task, new ActionListener<>() {
                        @Override
                        public void onResponse(CanMatchShardResponse response) {
                            results.set(finalI, new CanMatchNodeResponse.ResponseOrFailure(response));
                            maybeFinish.run();
                        }

                        @Override
                        public void onFailure(Exception e) {
                            results.set(finalI, new CanMatchNodeResponse.ResponseOrFailure(e));
                            maybeFinish.run();
                        }
                    });
                } catch (Exception e) {
                    results.set(finalI, new CanMatchNodeResponse.ResponseOrFailure(e));
                    maybeFinish.run();
                }
            }
        }
    }

    public void sendClearAllScrollContexts(Transport.Connection connection, final ActionListener<TransportResponse> listener) {
        transportService.sendRequest(
            connection,
            CLEAR_SCROLL_CONTEXTS_ACTION_NAME,
            TransportRequest.Empty.INSTANCE,
            TransportRequestOptions.EMPTY,
            new ActionListenerResponseHandler<>(listener, (in) -> TransportResponse.Empty.INSTANCE)
        );
    }

    public void sendExecuteDfs(
        Transport.Connection connection,
        final ShardSearchRequest request,
        SearchTask task,
        final SearchActionListener<DfsSearchResult> listener
    ) {
        transportService.sendChildRequest(
            connection,
            DFS_ACTION_NAME,
            request,
            task,
            new ConnectionCountingHandler<>(listener, DfsSearchResult::new, clientConnections, connection.getNode().getId())
        );
    }

    public void sendExecuteQuery(
        Transport.Connection connection,
        final ShardSearchRequest request,
        SearchTask task,
        final SearchActionListener<? super SearchPhaseResult> listener
    ) {
        // we optimize this and expect a QueryFetchSearchResult if we only have a single shard in the search request
        // this used to be the QUERY_AND_FETCH which doesn't exist anymore.
        final boolean fetchDocuments = request.numberOfShards() == 1
            && (request.source() == null || request.source().rankBuilder() == null);
        Writeable.Reader<SearchPhaseResult> reader = fetchDocuments ? QueryFetchSearchResult::new : in -> new QuerySearchResult(in, true);

        final ActionListener<? super SearchPhaseResult> handler = responseWrapper.apply(connection, listener);
        transportService.sendChildRequest(
            connection,
            QUERY_ACTION_NAME,
            request,
            task,
            new ConnectionCountingHandler<>(handler, reader, clientConnections, connection.getNode().getId())
        );
    }

    public void sendExecuteQuery(
        Transport.Connection connection,
        final QuerySearchRequest request,
        SearchTask task,
        final SearchActionListener<QuerySearchResult> listener
    ) {
        transportService.sendChildRequest(
            connection,
            QUERY_ID_ACTION_NAME,
            request,
            task,
            new ConnectionCountingHandler<>(listener, QuerySearchResult::new, clientConnections, connection.getNode().getId())
        );
    }

    public void sendExecuteScrollQuery(
        Transport.Connection connection,
        final InternalScrollSearchRequest request,
        SearchTask task,
        final SearchActionListener<ScrollQuerySearchResult> listener
    ) {
        transportService.sendChildRequest(
            connection,
            QUERY_SCROLL_ACTION_NAME,
            request,
            task,
            new ConnectionCountingHandler<>(listener, ScrollQuerySearchResult::new, clientConnections, connection.getNode().getId())
        );
    }

    public void sendExecuteScrollFetch(
        Transport.Connection connection,
        final InternalScrollSearchRequest request,
        SearchTask task,
        final SearchActionListener<ScrollQueryFetchSearchResult> listener
    ) {
        transportService.sendChildRequest(
            connection,
            QUERY_FETCH_SCROLL_ACTION_NAME,
            request,
            task,
            new ConnectionCountingHandler<>(listener, ScrollQueryFetchSearchResult::new, clientConnections, connection.getNode().getId())
        );
    }

    public void sendExecuteFetch(
        Transport.Connection connection,
        final ShardFetchSearchRequest request,
        SearchTask task,
        final SearchActionListener<FetchSearchResult> listener
    ) {
        sendExecuteFetch(connection, FETCH_ID_ACTION_NAME, request, task, listener);
    }

    public void sendExecuteFetchScroll(
        Transport.Connection connection,
        final ShardFetchRequest request,
        SearchTask task,
        final SearchActionListener<FetchSearchResult> listener
    ) {
        sendExecuteFetch(connection, FETCH_ID_SCROLL_ACTION_NAME, request, task, listener);
    }

    private void sendExecuteFetch(
        Transport.Connection connection,
        String action,
        final ShardFetchRequest request,
        SearchTask task,
        final SearchActionListener<FetchSearchResult> listener
    ) {
        transportService.sendChildRequest(
            connection,
            action,
            request,
            task,
            new ConnectionCountingHandler<>(listener, FetchSearchResult::new, clientConnections, connection.getNode().getId())
        );
    }

    /**
     * Used by {@link TransportSearchAction} to send the expand queries (field collapsing).
     */
    void sendExecuteMultiSearch(final MultiSearchRequest request, SearchTask task, final ActionListener<MultiSearchResponse> listener) {
        final Transport.Connection connection = transportService.getConnection(transportService.getLocalNode());
        transportService.sendChildRequest(
            connection,
            MultiSearchAction.NAME,
            request,
            task,
            new ConnectionCountingHandler<>(listener, MultiSearchResponse::new, clientConnections, connection.getNode().getId())
        );
    }

    public RemoteClusterService getRemoteClusterService() {
        return transportService.getRemoteClusterService();
    }

    /**
     * Return a map of nodeId to pending number of search requests.
     * This is a snapshot of the current pending search and not a live map.
     */
    public Map<String, Long> getPendingSearchRequests() {
        return new HashMap<>(clientConnections);
    }

    static class ScrollFreeContextRequest extends TransportRequest {
        private ShardSearchContextId contextId;

        ScrollFreeContextRequest(ShardSearchContextId contextId) {
            this.contextId = Objects.requireNonNull(contextId);
        }

        ScrollFreeContextRequest(StreamInput in) throws IOException {
            super(in);
            contextId = new ShardSearchContextId(in);
        }

        @Override
        public void writeTo(StreamOutput out) throws IOException {
            super.writeTo(out);
            contextId.writeTo(out);
        }

        public ShardSearchContextId id() {
            return this.contextId;
        }

    }

    static class SearchFreeContextRequest extends ScrollFreeContextRequest implements IndicesRequest {
        private OriginalIndices originalIndices;

        SearchFreeContextRequest(OriginalIndices originalIndices, ShardSearchContextId id) {
            super(id);
            this.originalIndices = originalIndices;
        }

        SearchFreeContextRequest(StreamInput in) throws IOException {
            super(in);
            originalIndices = OriginalIndices.readOriginalIndices(in);
        }

        @Override
        public void writeTo(StreamOutput out) throws IOException {
            super.writeTo(out);
            OriginalIndices.writeOriginalIndices(originalIndices, out);
        }

        @Override
        public String[] indices() {
            if (originalIndices == null) {
                return null;
            }
            return originalIndices.indices();
        }

        @Override
        public IndicesOptions indicesOptions() {
            if (originalIndices == null) {
                return null;
            }
            return originalIndices.indicesOptions();
        }

    }

    public static class SearchFreeContextResponse extends TransportResponse {

        private boolean freed;

        SearchFreeContextResponse(StreamInput in) throws IOException {
            freed = in.readBoolean();
        }

        SearchFreeContextResponse(boolean freed) {
            this.freed = freed;
        }

        public boolean isFreed() {
            return freed;
        }

        @Override
        public void writeTo(StreamOutput out) throws IOException {
            out.writeBoolean(freed);
        }
    }

    public static void registerRequestHandler(TransportService transportService, SearchService searchService) {
        transportService.registerRequestHandler(
            FREE_CONTEXT_SCROLL_ACTION_NAME,
            ThreadPool.Names.SAME,
            ScrollFreeContextRequest::new,
            (request, channel, task) -> {
                boolean freed = searchService.freeReaderContext(request.id());
                channel.sendResponse(new SearchFreeContextResponse(freed));
            }
        );
        TransportActionProxy.registerProxyAction(transportService, FREE_CONTEXT_SCROLL_ACTION_NAME, false, SearchFreeContextResponse::new);
        transportService.registerRequestHandler(
            FREE_CONTEXT_ACTION_NAME,
            ThreadPool.Names.SAME,
            SearchFreeContextRequest::new,
            (request, channel, task) -> {
                boolean freed = searchService.freeReaderContext(request.id());
                channel.sendResponse(new SearchFreeContextResponse(freed));
            }
        );
        TransportActionProxy.registerProxyAction(transportService, FREE_CONTEXT_ACTION_NAME, false, SearchFreeContextResponse::new);
        transportService.registerRequestHandler(
            CLEAR_SCROLL_CONTEXTS_ACTION_NAME,
            ThreadPool.Names.SAME,
            TransportRequest.Empty::new,
            (request, channel, task) -> {
                searchService.freeAllScrollContexts();
                channel.sendResponse(TransportResponse.Empty.INSTANCE);
            }
        );
        TransportActionProxy.registerProxyAction(
            transportService,
            CLEAR_SCROLL_CONTEXTS_ACTION_NAME,
            false,
            (in) -> TransportResponse.Empty.INSTANCE
        );

        transportService.registerRequestHandler(
            DFS_ACTION_NAME,
            ThreadPool.Names.SAME,
            ShardSearchRequest::new,
            (request, channel, task) -> searchService.executeDfsPhase(request, (SearchShardTask) task, new ChannelActionListener<>(channel))
        );

        TransportActionProxy.registerProxyAction(transportService, DFS_ACTION_NAME, true, DfsSearchResult::new);

        transportService.registerRequestHandler(
            QUERY_ACTION_NAME,
            ThreadPool.Names.SAME,
            ShardSearchRequest::new,
            (request, channel, task) -> searchService.executeQueryPhase(
                request,
                (SearchShardTask) task,
                new ChannelActionListener<>(channel)
            )
        );
        TransportActionProxy.registerProxyActionWithDynamicResponseType(
            transportService,
            QUERY_ACTION_NAME,
            true,
            (request) -> ((ShardSearchRequest) request).numberOfShards() == 1 ? QueryFetchSearchResult::new : QuerySearchResult::new
        );

        transportService.registerRequestHandler(
            QUERY_ID_ACTION_NAME,
            ThreadPool.Names.SAME,
            QuerySearchRequest::new,
            (request, channel, task) -> {
                searchService.executeQueryPhase(request, (SearchShardTask) task, new ChannelActionListener<>(channel));
            }
        );
        TransportActionProxy.registerProxyAction(transportService, QUERY_ID_ACTION_NAME, true, QuerySearchResult::new);

        transportService.registerRequestHandler(
            QUERY_SCROLL_ACTION_NAME,
            ThreadPool.Names.SAME,
            InternalScrollSearchRequest::new,
            (request, channel, task) -> {
                searchService.executeQueryPhase(request, (SearchShardTask) task, new ChannelActionListener<>(channel));
            }
        );
        TransportActionProxy.registerProxyAction(transportService, QUERY_SCROLL_ACTION_NAME, true, ScrollQuerySearchResult::new);

        transportService.registerRequestHandler(
            QUERY_FETCH_SCROLL_ACTION_NAME,
            ThreadPool.Names.SAME,
            InternalScrollSearchRequest::new,
            (request, channel, task) -> {
                searchService.executeFetchPhase(request, (SearchShardTask) task, new ChannelActionListener<>(channel));
            }
        );
        TransportActionProxy.registerProxyAction(transportService, QUERY_FETCH_SCROLL_ACTION_NAME, true, ScrollQueryFetchSearchResult::new);

        transportService.registerRequestHandler(
            FETCH_ID_SCROLL_ACTION_NAME,
            ThreadPool.Names.SAME,
            ShardFetchRequest::new,
            (request, channel, task) -> {
                searchService.executeFetchPhase(request, (SearchShardTask) task, new ChannelActionListener<>(channel));
            }
        );
        TransportActionProxy.registerProxyAction(transportService, FETCH_ID_SCROLL_ACTION_NAME, true, FetchSearchResult::new);

        transportService.registerRequestHandler(
            FETCH_ID_ACTION_NAME,
            ThreadPool.Names.SAME,
            true,
            true,
            ShardFetchSearchRequest::new,
            (request, channel, task) -> {
                searchService.executeFetchPhase(request, (SearchShardTask) task, new ChannelActionListener<>(channel));
            }
        );
        TransportActionProxy.registerProxyAction(transportService, FETCH_ID_ACTION_NAME, true, FetchSearchResult::new);

        // this is cheap, it does not fetch during the rewrite phase, so we can let it quickly execute on a networking thread
        transportService.registerRequestHandler(
            QUERY_CAN_MATCH_NAME,
            ThreadPool.Names.SAME,
            ShardSearchRequest::new,
            (request, channel, task) -> {
                searchService.canMatch(request, new ChannelActionListener<>(channel));
            }
        );
        TransportActionProxy.registerProxyAction(transportService, QUERY_CAN_MATCH_NAME, true, CanMatchShardResponse::new);

        transportService.registerRequestHandler(
            QUERY_CAN_MATCH_NODE_NAME,
            ThreadPool.Names.SEARCH_COORDINATION,
            CanMatchNodeRequest::new,
            (request, channel, task) -> {
                searchService.canMatch(request, new ChannelActionListener<>(channel));
            }
        );
        TransportActionProxy.registerProxyAction(transportService, QUERY_CAN_MATCH_NODE_NAME, true, CanMatchNodeResponse::new);
    }

    /**
     * Returns a connection to the given node on the provided cluster. If the cluster alias is <code>null</code> the node will be resolved
     * against the local cluster.
     * @param clusterAlias the cluster alias the node should be resolved against
     * @param node the node to resolve
     * @return a connection to the given node belonging to the cluster with the provided alias.
     */
    public Transport.Connection getConnection(@Nullable String clusterAlias, DiscoveryNode node) {
        if (clusterAlias == null) {
            return transportService.getConnection(node);
        } else {
            return transportService.getRemoteClusterService().getConnection(node, clusterAlias);
        }
    }

    static final class ConnectionCountingHandler<Response extends TransportResponse> extends ActionListenerResponseHandler<Response> {
        private final Map<String, Long> clientConnections;
        private final String nodeId;

        ConnectionCountingHandler(
            final ActionListener<? super Response> listener,
            final Writeable.Reader<Response> responseReader,
            final Map<String, Long> clientConnections,
            final String nodeId
        ) {
            super(listener, responseReader);
            this.clientConnections = clientConnections;
            this.nodeId = nodeId;
            // Increment the number of connections for this node by one
            clientConnections.compute(nodeId, (id, conns) -> conns == null ? 1 : conns + 1);
        }

        @Override
        public void handleResponse(Response response) {
            super.handleResponse(response);
            // Decrement the number of connections or remove it entirely if there are no more connections
            // We need to remove the entry here so we don't leak when nodes go away forever
            assert assertNodePresent();
            clientConnections.computeIfPresent(nodeId, (id, conns) -> conns.longValue() == 1 ? null : conns - 1);
        }

        @Override
        public void handleException(TransportException e) {
            super.handleException(e);
            // Decrement the number of connections or remove it entirely if there are no more connections
            // We need to remove the entry here so we don't leak when nodes go away forever
            assert assertNodePresent();
            clientConnections.computeIfPresent(nodeId, (id, conns) -> conns.longValue() == 1 ? null : conns - 1);
        }

        private boolean assertNodePresent() {
            clientConnections.compute(nodeId, (id, conns) -> {
                assert conns != null : "number of connections for " + id + " is null, but should be an integer";
                assert conns >= 1 : "number of connections for " + id + " should be >= 1 but was " + conns;
                return conns;
            });
            // Always return true, there is additional asserting here, the boolean is just so this
            // can be skipped when assertions are not enabled
            return true;
        }
    }

    public void cancelSearchTask(SearchTask task, String reason) {
        CancelTasksRequest req = new CancelTasksRequest().setTargetTaskId(new TaskId(client.getLocalNodeId(), task.getId()))
            .setReason("Fatal failure during search: " + reason);
        // force the origin to execute the cancellation as a system user
        new OriginSettingClient(client, GetTaskAction.TASKS_ORIGIN).admin().cluster().cancelTasks(req, ActionListener.noop());
    }

    public NamedWriteableRegistry getNamedWriteableRegistry() {
        return client.getNamedWriteableRegistry();
    }
}
