/*
 * 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", the "GNU Affero General Public License v3.0 only", 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", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */
package org.elasticsearch.search.aggregations.metrics;

import org.elasticsearch.action.index.IndexRequestBuilder;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.script.Script;
import org.elasticsearch.script.ScriptType;
import org.elasticsearch.search.aggregations.BucketOrder;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.search.aggregations.bucket.SingleBucketAggregation;
import org.elasticsearch.search.aggregations.bucket.histogram.Histogram;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.hamcrest.core.IsNull;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

import static org.elasticsearch.index.query.QueryBuilders.matchAllQuery;
import static org.elasticsearch.index.query.QueryBuilders.termQuery;
import static org.elasticsearch.search.aggregations.AggregationBuilders.filter;
import static org.elasticsearch.search.aggregations.AggregationBuilders.global;
import static org.elasticsearch.search.aggregations.AggregationBuilders.histogram;
import static org.elasticsearch.search.aggregations.AggregationBuilders.sum;
import static org.elasticsearch.search.aggregations.AggregationBuilders.terms;
import static org.elasticsearch.search.aggregations.metrics.MetricAggScriptPlugin.METRIC_SCRIPT_ENGINE;
import static org.elasticsearch.search.aggregations.metrics.MetricAggScriptPlugin.RANDOM_SCRIPT;
import static org.elasticsearch.search.aggregations.metrics.MetricAggScriptPlugin.VALUE_SCRIPT;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertHitCount;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertNoFailures;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertNoFailuresAndResponse;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertResponse;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.notNullValue;

public class SumIT extends AbstractNumericTestCase {

    @Override
    protected Collection<Class<? extends Plugin>> nodePlugins() {
        return Collections.singleton(MetricAggScriptPlugin.class);
    }

    @Override
    public void setupSuiteScopeCluster() throws Exception {
        super.setupSuiteScopeCluster();

        // Create two indices and add the field 'route_length_miles' as an alias in
        // one, and a concrete field in the other.
        prepareCreate("old_index").setMapping(
            "transit_mode",
            "type=keyword",
            "distance",
            "type=double",
            "route_length_miles",
            "type=alias,path=distance"
        ).get();
        prepareCreate("new_index").setMapping("transit_mode", "type=keyword", "route_length_miles", "type=double").get();

        List<IndexRequestBuilder> builders = new ArrayList<>();
        builders.add(prepareIndex("old_index").setSource("transit_mode", "train", "distance", 42.0));
        builders.add(prepareIndex("old_index").setSource("transit_mode", "bus", "distance", 50.5));
        builders.add(prepareIndex("new_index").setSource("transit_mode", "train", "route_length_miles", 100.2));

        indexRandom(true, builders);
        ensureSearchable();
    }

    @Override
    public void testEmptyAggregation() throws Exception {

        assertResponse(
            prepareSearch("empty_bucket_idx").setQuery(matchAllQuery())
                .addAggregation(histogram("histo").field("value").interval(1L).minDocCount(0).subAggregation(sum("sum").field("value"))),
            response -> {
                assertThat(response.getHits().getTotalHits().value(), equalTo(2L));
                Histogram histo = response.getAggregations().get("histo");
                assertThat(histo, notNullValue());
                Histogram.Bucket bucket = histo.getBuckets().get(1);
                assertThat(bucket, notNullValue());

                Sum sum = bucket.getAggregations().get("sum");
                assertThat(sum, notNullValue());
                assertThat(sum.getName(), equalTo("sum"));
                assertThat(sum.value(), equalTo(0.0));
            }
        );
    }

    /** This test has been moved to {@link SumAggregatorTests#testUnmapped()} */
    @Override
    public void testUnmapped() throws Exception {}

    @Override
    public void testSingleValuedField() throws Exception {
        assertResponse(prepareSearch("idx").setQuery(matchAllQuery()).addAggregation(sum("sum").field("value")), response -> {
            assertHitCount(response, 10);

            Sum sum = response.getAggregations().get("sum");
            assertThat(sum, notNullValue());
            assertThat(sum.getName(), equalTo("sum"));
            assertThat(sum.value(), equalTo((double) 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10));
        });
    }

    public void testSingleValuedFieldWithFormatter() throws Exception {
        assertResponse(
            prepareSearch("idx").setQuery(matchAllQuery()).addAggregation(sum("sum").format("0000.0").field("value")),
            response -> {
                assertHitCount(response, 10);

                Sum sum = response.getAggregations().get("sum");
                assertThat(sum, notNullValue());
                assertThat(sum.getName(), equalTo("sum"));
                assertThat(sum.value(), equalTo((double) 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10));
                assertThat(sum.getValueAsString(), equalTo("0055.0"));
            }
        );
    }

    @Override
    public void testSingleValuedFieldGetProperty() throws Exception {

        assertResponse(
            prepareSearch("idx").setQuery(matchAllQuery()).addAggregation(global("global").subAggregation(sum("sum").field("value"))),
            response -> {
                assertHitCount(response, 10);

                SingleBucketAggregation global = response.getAggregations().get("global");
                assertThat(global, notNullValue());
                assertThat(global.getName(), equalTo("global"));
                assertThat(global.getDocCount(), equalTo(10L));
                assertThat(global.getAggregations(), notNullValue());
                assertThat(global.getAggregations().asList().size(), equalTo(1));

                Sum sum = global.getAggregations().get("sum");
                assertThat(sum, notNullValue());
                assertThat(sum.getName(), equalTo("sum"));
                double expectedSumValue = (double) 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10;
                assertThat(sum.value(), equalTo(expectedSumValue));
                assertThat((Sum) ((InternalAggregation) global).getProperty("sum"), equalTo(sum));
                assertThat((double) ((InternalAggregation) global).getProperty("sum.value"), equalTo(expectedSumValue));
                assertThat((double) ((InternalAggregation) sum).getProperty("value"), equalTo(expectedSumValue));
            }
        );
    }

    @Override
    public void testMultiValuedField() throws Exception {

        assertResponse(prepareSearch("idx").setQuery(matchAllQuery()).addAggregation(sum("sum").field("values")), response -> {
            assertHitCount(response, 10);

            Sum sum = response.getAggregations().get("sum");
            assertThat(sum, notNullValue());
            assertThat(sum.getName(), equalTo("sum"));
            assertThat(sum.value(), equalTo((double) 2 + 3 + 3 + 4 + 4 + 5 + 5 + 6 + 6 + 7 + 7 + 8 + 8 + 9 + 9 + 10 + 10 + 11 + 11 + 12));
        });
    }

    @Override
    public void testOrderByEmptyAggregation() throws Exception {
        assertResponse(
            prepareSearch("idx").setQuery(matchAllQuery())
                .addAggregation(
                    terms("terms").field("value")
                        .order(BucketOrder.compound(BucketOrder.aggregation("filter>sum", true)))
                        .subAggregation(filter("filter", termQuery("value", 100)).subAggregation(sum("sum").field("value")))
                ),
            response -> {
                assertHitCount(response, 10);

                Terms terms = response.getAggregations().get("terms");
                assertThat(terms, notNullValue());
                List<? extends Terms.Bucket> buckets = terms.getBuckets();
                assertThat(buckets, notNullValue());
                assertThat(buckets.size(), equalTo(10));

                for (int i = 0; i < 10; i++) {
                    Terms.Bucket bucket = buckets.get(i);
                    assertThat(bucket, notNullValue());
                    assertThat(bucket.getKeyAsNumber(), equalTo((long) i + 1));
                    assertThat(bucket.getDocCount(), equalTo(1L));
                    SingleBucketAggregation filter = bucket.getAggregations().get("filter");
                    assertThat(filter, notNullValue());
                    assertThat(filter.getDocCount(), equalTo(0L));
                    Sum sum = filter.getAggregations().get("sum");
                    assertThat(sum, notNullValue());
                    assertThat(sum.value(), equalTo(0.0));

                }
            }
        );
    }

    /**
     * Make sure that a request using a deterministic script or not using a script get cached.
     * Ensure requests using nondeterministic scripts do not get cached.
     */
    public void testScriptCaching() throws Exception {
        assertAcked(
            prepareCreate("cache_test_idx").setMapping("d", "type=long").setSettings(indexSettings(1, 1).put("requests.cache.enable", true))
        );
        indexRandom(
            true,
            prepareIndex("cache_test_idx").setId("1").setSource("s", 1),
            prepareIndex("cache_test_idx").setId("2").setSource("s", 2)
        );

        // Make sure we are starting with a clear cache
        assertThat(
            indicesAdmin().prepareStats("cache_test_idx").setRequestCache(true).get().getTotal().getRequestCache().getHitCount(),
            equalTo(0L)
        );
        assertThat(
            indicesAdmin().prepareStats("cache_test_idx").setRequestCache(true).get().getTotal().getRequestCache().getMissCount(),
            equalTo(0L)
        );

        // Test that a request using a nondeterministic script does not get cached
        assertNoFailures(
            prepareSearch("cache_test_idx").setSize(0)
                .addAggregation(
                    sum("foo").field("d").script(new Script(ScriptType.INLINE, METRIC_SCRIPT_ENGINE, RANDOM_SCRIPT, Collections.emptyMap()))
                )
        );

        assertThat(
            indicesAdmin().prepareStats("cache_test_idx").setRequestCache(true).get().getTotal().getRequestCache().getHitCount(),
            equalTo(0L)
        );
        assertThat(
            indicesAdmin().prepareStats("cache_test_idx").setRequestCache(true).get().getTotal().getRequestCache().getMissCount(),
            equalTo(0L)
        );

        // Test that a request using a deterministic script gets cached
        assertNoFailures(
            prepareSearch("cache_test_idx").setSize(0)
                .addAggregation(
                    sum("foo").field("d").script(new Script(ScriptType.INLINE, METRIC_SCRIPT_ENGINE, VALUE_SCRIPT, Collections.emptyMap()))
                )
        );

        assertThat(
            indicesAdmin().prepareStats("cache_test_idx").setRequestCache(true).get().getTotal().getRequestCache().getHitCount(),
            equalTo(0L)
        );
        assertThat(
            indicesAdmin().prepareStats("cache_test_idx").setRequestCache(true).get().getTotal().getRequestCache().getMissCount(),
            equalTo(1L)
        );

        // Ensure that non-scripted requests are cached as normal
        assertNoFailures(prepareSearch("cache_test_idx").setSize(0).addAggregation(sum("foo").field("d")));

        assertThat(
            indicesAdmin().prepareStats("cache_test_idx").setRequestCache(true).get().getTotal().getRequestCache().getHitCount(),
            equalTo(0L)
        );
        assertThat(
            indicesAdmin().prepareStats("cache_test_idx").setRequestCache(true).get().getTotal().getRequestCache().getMissCount(),
            equalTo(2L)
        );
    }

    public void testFieldAlias() {
        assertNoFailuresAndResponse(
            prepareSearch("old_index", "new_index").addAggregation(sum("sum").field("route_length_miles")),
            response -> {
                Sum sum = response.getAggregations().get("sum");
                assertThat(sum, IsNull.notNullValue());
                assertThat(sum.getName(), equalTo("sum"));
                assertThat(sum.value(), equalTo(192.7));
            }
        );
    }

    public void testFieldAliasInSubAggregation() {
        assertNoFailuresAndResponse(
            prepareSearch("old_index", "new_index").addAggregation(
                terms("terms").field("transit_mode").subAggregation(sum("sum").field("route_length_miles"))
            ),
            response -> {
                Terms terms = response.getAggregations().get("terms");
                assertThat(terms, notNullValue());
                assertThat(terms.getName(), equalTo("terms"));

                List<? extends Terms.Bucket> buckets = terms.getBuckets();
                assertThat(buckets.size(), equalTo(2));

                Terms.Bucket bucket = buckets.get(0);
                assertThat(bucket, notNullValue());
                assertThat(bucket.getKey(), equalTo("train"));
                assertThat(bucket.getDocCount(), equalTo(2L));

                Sum sum = bucket.getAggregations().get("sum");
                assertThat(sum, notNullValue());
                assertThat(sum.value(), equalTo(142.2));

                bucket = buckets.get(1);
                assertThat(bucket, notNullValue());
                assertThat(bucket.getKey(), equalTo("bus"));
                assertThat(bucket.getDocCount(), equalTo(1L));

                sum = bucket.getAggregations().get("sum");
                assertThat(sum, notNullValue());
                assertThat(sum.value(), equalTo(50.5));
            }
        );
    }
}