/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * 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.
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/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.index.fieldstats;

import org.opensearch.action.admin.indices.refresh.RefreshResponse;
import org.opensearch.action.index.IndexResponse;
import org.opensearch.action.search.SearchResponse;
import org.opensearch.action.search.SearchType;
import org.opensearch.cluster.metadata.IndexMetadata;
import org.opensearch.common.settings.Settings;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.indices.IndicesRequestCache;
import org.opensearch.core.rest.RestStatus;
import org.opensearch.test.OpenSearchSingleNodeTestCase;

import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;
import static org.hamcrest.Matchers.anyOf;
import static org.hamcrest.Matchers.equalTo;

public class FieldStatsProviderRefreshTests extends OpenSearchSingleNodeTestCase {

    public void testQueryRewriteOnRefresh() throws Exception {
        assertAcked(
            client().admin()
                .indices()
                .prepareCreate("index")
                .setMapping("s", "type=text")
                .setSettings(
                    Settings.builder()
                        .put(IndicesRequestCache.INDEX_CACHE_REQUEST_ENABLED_SETTING.getKey(), true)
                        .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
                        .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
                )
                .get()
        );

        // Index some documents
        indexDocument("1", "d");
        indexDocument("2", "e");
        indexDocument("3", "f");
        refreshIndex();

        // check request cache stats are clean
        assertRequestCacheStats(0, 0);

        // Search for a range and check that it missed the cache (since its the
        // first time it has run)
        final SearchResponse r1 = client().prepareSearch("index")
            .setSearchType(SearchType.QUERY_THEN_FETCH)
            .setSize(0)
            .setQuery(QueryBuilders.rangeQuery("s").gte("a").lte("g"))
            .get();
        assertSearchResponse(r1);
        assertThat(r1.getHits().getTotalHits().value, equalTo(3L));
        assertRequestCacheStats(0, 1);

        // Search again and check it hits the cache
        final SearchResponse r2 = client().prepareSearch("index")
            .setSearchType(SearchType.QUERY_THEN_FETCH)
            .setSize(0)
            .setQuery(QueryBuilders.rangeQuery("s").gte("a").lte("g"))
            .get();
        assertSearchResponse(r2);
        assertThat(r2.getHits().getTotalHits().value, equalTo(3L));
        assertRequestCacheStats(1, 1);

        // Index some more documents in the query range and refresh
        indexDocument("4", "c");
        indexDocument("5", "g");
        refreshIndex();

        // Search again and check the request cache for another miss since request cache should be invalidated by refresh
        final SearchResponse r3 = client().prepareSearch("index")
            .setSearchType(SearchType.QUERY_THEN_FETCH)
            .setSize(0)
            .setQuery(QueryBuilders.rangeQuery("s").gte("a").lte("g"))
            .get();
        assertSearchResponse(r3);
        assertThat(r3.getHits().getTotalHits().value, equalTo(5L));
        assertRequestCacheStats(1, 2);
    }

    private void assertRequestCacheStats(long expectedHits, long expectedMisses) {
        assertThat(
            client().admin().indices().prepareStats("index").setRequestCache(true).get().getTotal().getRequestCache().getHitCount(),
            equalTo(expectedHits)
        );
        assertThat(
            client().admin().indices().prepareStats("index").setRequestCache(true).get().getTotal().getRequestCache().getMissCount(),
            equalTo(expectedMisses)
        );
    }

    private void refreshIndex() {
        RefreshResponse refreshResponse = client().admin().indices().prepareRefresh("index").get();
        assertThat(refreshResponse.getSuccessfulShards(), equalTo(refreshResponse.getSuccessfulShards()));
    }

    private void indexDocument(String id, String sValue) {
        IndexResponse response = client().prepareIndex("index").setId(id).setSource("s", sValue).get();
        assertThat(response.status(), anyOf(equalTo(RestStatus.OK), equalTo(RestStatus.CREATED)));
    }
}