/*
 * 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.action.admin.cluster.settings;

import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.common.settings.ClusterSettings;
import org.elasticsearch.common.settings.Setting;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.settings.Settings.Builder;
import org.elasticsearch.test.AbstractXContentSerializingTestCase;
import org.elasticsearch.test.rest.TestResponseParsers;
import org.elasticsearch.xcontent.ConstructingObjectParser;
import org.elasticsearch.xcontent.XContentParser;

import java.util.List;
import java.util.Set;
import java.util.function.Predicate;

import static org.elasticsearch.xcontent.ConstructingObjectParser.constructorArg;

public class ClusterUpdateSettingsResponseTests extends AbstractXContentSerializingTestCase<ClusterUpdateSettingsResponse> {

    private static final ConstructingObjectParser<ClusterUpdateSettingsResponse, Void> PARSER = new ConstructingObjectParser<>(
        "cluster_update_settings_response",
        true,
        args -> new ClusterUpdateSettingsResponse((boolean) args[0], (Settings) args[1], (Settings) args[2])
    );
    static {
        TestResponseParsers.declareAcknowledgedField(PARSER);
        PARSER.declareObject(constructorArg(), (p, c) -> Settings.fromXContent(p), ClusterUpdateSettingsResponse.TRANSIENT);
        PARSER.declareObject(constructorArg(), (p, c) -> Settings.fromXContent(p), ClusterUpdateSettingsResponse.PERSISTENT);
    }

    @Override
    protected ClusterUpdateSettingsResponse doParseInstance(XContentParser parser) {
        return PARSER.apply(parser, null);
    }

    @Override
    protected ClusterUpdateSettingsResponse mutateInstance(ClusterUpdateSettingsResponse response) {
        int i = randomIntBetween(0, 2);
        return switch (i) {
            case 0 -> new ClusterUpdateSettingsResponse(
                response.isAcknowledged() == false,
                response.transientSettings,
                response.persistentSettings
            );
            case 1 -> new ClusterUpdateSettingsResponse(
                response.isAcknowledged(),
                mutateSettings(response.transientSettings),
                response.persistentSettings
            );
            case 2 -> new ClusterUpdateSettingsResponse(
                response.isAcknowledged(),
                response.transientSettings,
                mutateSettings(response.persistentSettings)
            );
            default -> throw new UnsupportedOperationException();
        };
    }

    private static Settings mutateSettings(Settings settings) {
        if (settings.isEmpty()) {
            return randomClusterSettings(1, 3);
        }
        Set<String> allKeys = settings.keySet();
        List<String> keysToBeModified = randomSubsetOf(randomIntBetween(1, allKeys.size()), allKeys);
        Builder builder = Settings.builder();
        for (String key : allKeys) {
            String value = settings.get(key);
            if (keysToBeModified.contains(key)) {
                value += randomAlphaOfLengthBetween(2, 5);
            }
            builder.put(key, value);
        }
        return builder.build();
    }

    @Override
    protected Predicate<String> getRandomFieldsExcludeFilter() {
        return p -> p.startsWith("transient") || p.startsWith("persistent");
    }

    public static Settings randomClusterSettings(int min, int max) {
        int num = randomIntBetween(min, max);
        Builder builder = Settings.builder();
        for (int i = 0; i < num; i++) {
            Setting<?> setting = randomFrom(ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
            builder.put(setting.getKey(), randomAlphaOfLengthBetween(2, 10));
        }
        return builder.build();
    }

    @Override
    protected ClusterUpdateSettingsResponse createTestInstance() {
        return new ClusterUpdateSettingsResponse(randomBoolean(), randomClusterSettings(0, 2), randomClusterSettings(0, 2));
    }

    @Override
    protected Writeable.Reader<ClusterUpdateSettingsResponse> instanceReader() {
        return ClusterUpdateSettingsResponse::new;
    }
}