/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.elasticsearch.action.search.type;

import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.cluster.ClusterService;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.util.concurrent.AtomicArray;
import org.elasticsearch.search.action.SearchServiceListener;
import org.elasticsearch.search.action.SearchServiceTransportAction;
import org.elasticsearch.search.controller.SearchPhaseController;
import org.elasticsearch.search.fetch.FetchSearchResultProvider;
import org.elasticsearch.search.internal.InternalSearchResponse;
import org.elasticsearch.search.internal.ShardSearchRequest;
import org.elasticsearch.search.query.QuerySearchResult;
import org.elasticsearch.search.query.QuerySearchResultProvider;
import org.elasticsearch.threadpool.ThreadPool;

import static org.elasticsearch.action.search.type.TransportSearchHelper.buildScrollId;

/**
 *
 */
public class TransportSearchCountAction extends TransportSearchTypeAction {

    @Inject
    public TransportSearchCountAction(Settings settings, ThreadPool threadPool, ClusterService clusterService,
                                      SearchServiceTransportAction searchService, SearchPhaseController searchPhaseController, ActionFilters actionFilters) {
        super(settings, threadPool, clusterService, searchService, searchPhaseController, actionFilters);
    }

    @Override
    protected void doExecute(SearchRequest searchRequest, ActionListener<SearchResponse> listener) {
        new AsyncAction(searchRequest, listener).start();
    }

    private class AsyncAction extends BaseAsyncAction<QuerySearchResultProvider> {

        private AsyncAction(SearchRequest request, ActionListener<SearchResponse> listener) {
            super(request, listener);
        }

        @Override
        protected String firstPhaseName() {
            return "query";
        }

        @Override
        protected void sendExecuteFirstPhase(DiscoveryNode node, ShardSearchRequest request, SearchServiceListener<QuerySearchResultProvider> listener) {
            searchService.sendExecuteQuery(node, request, listener);
        }

        @Override
        protected void moveToSecondPhase() throws Exception {
            // no need to sort, since we know we have no hits back
            final InternalSearchResponse internalResponse = searchPhaseController.merge(SearchPhaseController.EMPTY_DOCS, firstResults, (AtomicArray<? extends FetchSearchResultProvider>) AtomicArray.empty());
            String scrollId = null;
            if (request.scroll() != null) {
                scrollId = buildScrollId(request.searchType(), firstResults, null);
            }
            listener.onResponse(new SearchResponse(internalResponse, scrollId, expectedSuccessfulOps, successfulOps.get(), buildTookInMillis(), buildShardFailures()));
        }
    }
}
