/*
 * Licensed to Elastic Search and Shay Banon under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Elastic Search 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.search.facet.query;

import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.QueryWrapperFilter;
import org.elasticsearch.common.lucene.docset.DocSet;
import org.elasticsearch.common.lucene.docset.DocSets;
import org.elasticsearch.index.cache.filter.FilterCache;
import org.elasticsearch.search.facet.AbstractFacetCollector;
import org.elasticsearch.search.facet.Facet;

import java.io.IOException;

/**
 * @author kimchy (shay.banon)
 */
public class QueryFacetCollector extends AbstractFacetCollector {

    private final Filter filter;

    private DocSet docSet;

    private int count = 0;

    public QueryFacetCollector(String facetName, Query query, FilterCache filterCache) {
        super(facetName);
        this.filter = filterCache.cache(new QueryWrapperFilter(query));
    }

    @Override protected void doSetNextReader(IndexReader reader, int docBase) throws IOException {
        docSet = DocSets.convert(reader, filter.getDocIdSet(reader));
    }

    @Override protected void doCollect(int doc) throws IOException {
        if (docSet.get(doc)) {
            count++;
        }
    }

    @Override public Facet facet() {
        return new InternalQueryFacet(facetName, count);
    }
}

@@ -929,105 +929,9 @@
 rch.
-Filter;%0Aimport org.apache.lucene.search.Query;%0Aimport org.apache.lucene.search.QueryWrapperFilter
+*
 ;%0Aim
@@ -1037,16 +1037,82 @@
 ocSets;%0A
+import org.elasticsearch.common.lucene.search.MatchAllDocsFilter;%0A
 import o
@@ -1608,16 +1608,202 @@
 tName);%0A
+        Filter possibleFilter = extractFilterIfApplicable(query);%0A        if (possibleFilter != null) %7B%0A            this.filter = filterCache.cache(possibleFilter);%0A        %7D else %7B%0A    
         
@@ -1862,24 +1862,34 @@
 er(query));%0A
+        %7D%0A
     %7D%0A%0A    @
@@ -2230,24 +2230,24 @@
 t facet() %7B%0A
-
         retu
@@ -2296,11 +2296,786 @@
 );%0A    %7D
+%0A%0A    /**%0A     * If its a filtered query with a match all, then we just need the inner filter.%0A     */%0A    private Filter extractFilterIfApplicable(Query query) %7B%0A        if (query instanceof FilteredQuery) %7B%0A            FilteredQuery fQuery = (FilteredQuery) query;%0A            if (fQuery.getQuery() instanceof MatchAllDocsQuery) %7B%0A                return fQuery.getFilter();%0A            %7D%0A            if (fQuery.getQuery() instanceof DeletionAwareConstantScoreQuery) %7B%0A                DeletionAwareConstantScoreQuery scoreQuery = (DeletionAwareConstantScoreQuery) fQuery.getQuery();%0A                if (scoreQuery.getFilter() instanceof MatchAllDocsFilter) %7B%0A                    return fQuery.getFilter();%0A                %7D%0A            %7D%0A        %7D%0A        return null;%0A    %7D
 %0A%7D%0A

optimize query facet in case the query is a filtered query with match_all query to use just the filter