/*
 * 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.
 */

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

package org.opensearch.index.query;

import org.apache.lucene.document.FeatureField;
import org.apache.lucene.search.MatchNoDocsQuery;
import org.apache.lucene.search.Query;
import org.opensearch.action.admin.indices.mapping.put.PutMappingRequest;
import org.opensearch.common.Strings;
import org.opensearch.common.compress.CompressedXContent;
import org.opensearch.index.mapper.MapperExtrasModulePlugin;
import org.opensearch.index.mapper.MapperService;
import org.opensearch.index.query.RankFeatureQueryBuilder.ScoreFunction;
import org.opensearch.plugins.Plugin;
import org.opensearch.test.AbstractQueryTestCase;
import org.opensearch.test.TestGeoShapeFieldMapperPlugin;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;

import static org.hamcrest.CoreMatchers.instanceOf;
import static org.hamcrest.Matchers.either;

public class RankFeatureQueryBuilderTests extends AbstractQueryTestCase<RankFeatureQueryBuilder> {

    @Override
    protected void initializeAdditionalMappings(MapperService mapperService) throws IOException {
        mapperService.merge(
            "_doc",
            new CompressedXContent(
                Strings.toString(
                    PutMappingRequest.simpleMapping(
                        "my_feature_field",
                        "type=rank_feature",
                        "my_negative_feature_field",
                        "type=rank_feature,positive_score_impact=false",
                        "my_feature_vector_field",
                        "type=rank_features"
                    )
                )
            ),
            MapperService.MergeReason.MAPPING_UPDATE
        );
    }

    @Override
    protected Collection<Class<? extends Plugin>> getPlugins() {
        return Arrays.asList(MapperExtrasModulePlugin.class, TestGeoShapeFieldMapperPlugin.class);
    }

    @Override
    protected RankFeatureQueryBuilder doCreateTestQueryBuilder() {
        ScoreFunction function;
        boolean mayUseNegativeField = true;
        switch (random().nextInt(4)) {
            case 0:
                mayUseNegativeField = false;
                function = new ScoreFunction.Log(1 + randomFloat());
                break;
            case 1:
                if (randomBoolean()) {
                    function = new ScoreFunction.Saturation();
                } else {
                    function = new ScoreFunction.Saturation(randomFloat());
                }
                break;
            case 2:
                function = new ScoreFunction.Sigmoid(randomFloat(), randomFloat());
                break;
            case 3:
                function = new ScoreFunction.Linear();
                break;
            default:
                throw new AssertionError();
        }
        List<String> fields = new ArrayList<>();
        fields.add("my_feature_field");
        fields.add("unmapped_field");
        fields.add("my_feature_vector_field.feature");
        if (mayUseNegativeField) {
            fields.add("my_negative_feature_field");
        }

        final String field = randomFrom(fields);
        return new RankFeatureQueryBuilder(field, function);
    }

    @Override
    protected void doAssertLuceneQuery(RankFeatureQueryBuilder queryBuilder, Query query, QueryShardContext context) throws IOException {
        Class<?> expectedClass = FeatureField.newSaturationQuery("", "", 1, 1).getClass();
        assertThat(query, either(instanceOf(MatchNoDocsQuery.class)).or(instanceOf(expectedClass)));
    }

    public void testDefaultScoreFunction() throws IOException {
        String query = "{\n" + "    \"rank_feature\" : {\n" + "        \"field\": \"my_feature_field\"\n" + "    }\n" + "}";
        Query parsedQuery = parseQuery(query).toQuery(createShardContext());
        assertEquals(FeatureField.newSaturationQuery("_feature", "my_feature_field"), parsedQuery);
    }

    public void testIllegalField() throws IOException {
        String query = "{\n" + "    \"rank_feature\" : {\n" + "        \"field\": \"" + TEXT_FIELD_NAME + "\"\n" + "    }\n" + "}";
        IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> parseQuery(query).toQuery(createShardContext()));
        assertEquals(
            "[rank_feature] query only works on [rank_feature] fields and features of [rank_features] fields, not [text]",
            e.getMessage()
        );
    }

    public void testIllegalCombination() throws IOException {
        String query = "{\n"
            + "    \"rank_feature\" : {\n"
            + "        \"field\": \"my_negative_feature_field\",\n"
            + "        \"log\" : {\n"
            + "            \"scaling_factor\": 4.5\n"
            + "        }\n"
            + "    }\n"
            + "}";
        IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> parseQuery(query).toQuery(createShardContext()));
        assertEquals(
            "Cannot use the [log] function with a field that has a negative score impact as it would trigger negative scores",
            e.getMessage()
        );
    }
}