/*
 * 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.action.explain;

import org.opensearch.action.ActionRequestValidationException;
import org.opensearch.common.io.stream.BytesStreamOutput;
import org.opensearch.core.common.io.stream.NamedWriteableAwareStreamInput;
import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
import org.opensearch.core.common.io.stream.StreamInput;
import org.opensearch.common.settings.Settings;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.indices.IndicesModule;
import org.opensearch.search.SearchModule;
import org.opensearch.search.fetch.subphase.FetchSourceContext;
import org.opensearch.search.internal.AliasFilter;
import org.opensearch.test.OpenSearchTestCase;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import static org.hamcrest.CoreMatchers.hasItems;
import static org.hamcrest.CoreMatchers.not;
import static org.hamcrest.CoreMatchers.nullValue;

public class ExplainRequestTests extends OpenSearchTestCase {
    private NamedWriteableRegistry namedWriteableRegistry;

    public void setUp() throws Exception {
        super.setUp();
        IndicesModule indicesModule = new IndicesModule(Collections.emptyList());
        SearchModule searchModule = new SearchModule(Settings.EMPTY, Collections.emptyList());
        List<NamedWriteableRegistry.Entry> entries = new ArrayList<>();
        entries.addAll(indicesModule.getNamedWriteables());
        entries.addAll(searchModule.getNamedWriteables());
        namedWriteableRegistry = new NamedWriteableRegistry(entries);
    }

    public void testSerialize() throws IOException {
        try (BytesStreamOutput output = new BytesStreamOutput()) {
            ExplainRequest request = new ExplainRequest("index", "id");
            request.fetchSourceContext(new FetchSourceContext(true, new String[] { "field1.*" }, new String[] { "field2.*" }));
            request.filteringAlias(new AliasFilter(QueryBuilders.termQuery("filter_field", "value"), "alias0", "alias1"));
            request.preference("the_preference");
            request.query(QueryBuilders.termQuery("field", "value"));
            request.storedFields(new String[] { "field1", "field2" });
            request.routing("some_routing");
            request.writeTo(output);
            try (StreamInput in = new NamedWriteableAwareStreamInput(output.bytes().streamInput(), namedWriteableRegistry)) {
                ExplainRequest readRequest = new ExplainRequest(in);
                assertEquals(request.filteringAlias(), readRequest.filteringAlias());
                assertArrayEquals(request.storedFields(), readRequest.storedFields());
                assertEquals(request.preference(), readRequest.preference());
                assertEquals(request.query(), readRequest.query());
                assertEquals(request.routing(), readRequest.routing());
                assertEquals(request.fetchSourceContext(), readRequest.fetchSourceContext());
            }
        }
    }

    public void testValidation() {
        {
            final ExplainRequest request = new ExplainRequest("index4", "0");
            request.query(QueryBuilders.termQuery("field", "value"));

            final ActionRequestValidationException validate = request.validate();

            assertThat(validate, nullValue());
        }

        {
            final ExplainRequest request = new ExplainRequest("index4", randomBoolean() ? "" : null);
            request.query(QueryBuilders.termQuery("field", "value"));
            final ActionRequestValidationException validate = request.validate();

            assertThat(validate, not(nullValue()));
            assertThat(validate.validationErrors(), hasItems("id is missing"));
        }
    }
}