/*
 * 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.search.aggregations;

import com.carrotsearch.hppc.IntIntHashMap;
import com.carrotsearch.hppc.IntIntMap;
import org.elasticsearch.action.index.IndexRequestBuilder;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
import org.elasticsearch.search.aggregations.bucket.histogram.Histogram;
import org.elasticsearch.search.aggregations.bucket.missing.Missing;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.test.ESIntegTestCase;
import org.hamcrest.Matchers;

import java.util.List;

import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
import static org.elasticsearch.search.aggregations.AggregationBuilders.histogram;
import static org.elasticsearch.search.aggregations.AggregationBuilders.missing;
import static org.elasticsearch.search.aggregations.AggregationBuilders.terms;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertSearchResponse;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.core.IsNull.notNullValue;

public class CombiIT extends ESIntegTestCase {

    /**
     * Making sure that if there are multiple aggregations, working on the same field, yet require different
     * value source type, they can all still work. It used to fail as we used to cache the ValueSource by the
     * field name. If the cached value source was of type "bytes" and another aggregation on the field required to see
     * it as "numeric", it didn't work. Now we cache the Value Sources by a custom key (field name + ValueSource type)
     * so there's no conflict there.
     */
    public void testMultipleAggsOnSameField_WithDifferentRequiredValueSourceType() throws Exception {

        createIndex("idx");
        IndexRequestBuilder[] builders = new IndexRequestBuilder[randomInt(30)];
        IntIntMap values = new IntIntHashMap();
        long missingValues = 0;
        for (int i = 0; i < builders.length; i++) {
            String name = "name_" + randomIntBetween(1, 10);
            if (rarely()) {
                missingValues++;
                builders[i] = client().prepareIndex("idx", "type").setSource(jsonBuilder()
                        .startObject()
                        .field("name", name)
                        .endObject());
            } else {
                int value = randomIntBetween(1, 10);
                values.put(value, values.getOrDefault(value, 0) + 1);
                builders[i] = client().prepareIndex("idx", "type").setSource(jsonBuilder()
                        .startObject()
                        .field("name", name)
                        .field("value", value)
                        .endObject());
            }
        }
        indexRandom(true, builders);
        ensureSearchable();


        SubAggCollectionMode aggCollectionMode = randomFrom(SubAggCollectionMode.values());
        SearchResponse response = client().prepareSearch("idx")
                .addAggregation(missing("missing_values").field("value"))
                .addAggregation(terms("values").field("value")
                        .collectMode(aggCollectionMode ))
                .get();

        assertSearchResponse(response);

        Aggregations aggs = response.getAggregations();

        Missing missing = aggs.get("missing_values");
        assertNotNull(missing);
        assertThat(missing.getDocCount(), equalTo(missingValues));

        Terms terms = aggs.get("values");
        assertNotNull(terms);
        List<? extends Terms.Bucket> buckets = terms.getBuckets();
        assertThat(buckets.size(), equalTo(values.size()));
        for (Terms.Bucket bucket : buckets) {
            values.remove(((Number) bucket.getKey()).intValue());
        }
        assertTrue(values.isEmpty());
    }


    /**
     * Some top aggs (eg. date_/histogram) that are executed on unmapped fields, will generate an estimate count of buckets - zero.
     * when the sub aggregator is then created, it will take this estimation into account. This used to cause
     * and an ArrayIndexOutOfBoundsException...
     */
    public void testSubAggregationForTopAggregationOnUnmappedField() throws Exception {

        prepareCreate("idx").addMapping("type", jsonBuilder()
                .startObject()
                .startObject("type").startObject("properties")
                    .startObject("name").field("type", "keyword").endObject()
                    .startObject("value").field("type", "integer").endObject()
                .endObject().endObject()
                .endObject()).get();

        ensureSearchable("idx");

        SubAggCollectionMode aggCollectionMode = randomFrom(SubAggCollectionMode.values());
        SearchResponse searchResponse = client().prepareSearch("idx")
                .addAggregation(histogram("values").field("value1").interval(1)
                        .subAggregation(terms("names").field("name")
                                .collectMode(aggCollectionMode )))
                .get();

        assertThat(searchResponse.getHits().getTotalHits().value, Matchers.equalTo(0L));
        Histogram values = searchResponse.getAggregations().get("values");
        assertThat(values, notNullValue());
        assertThat(values.getBuckets().isEmpty(), is(true));
    }
}
