/*
 * 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.indices;

import org.elasticsearch.Version;
import org.elasticsearch.cluster.metadata.IndexMetadata;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.xcontent.XContentBuilder;

import java.io.IOException;
import java.io.UncheckedIOException;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;

import static org.elasticsearch.xcontent.XContentFactory.jsonBuilder;

/**
 * A special kind of {@link SystemIndexDescriptor} that can toggle what kind of mappings it
 * expects. A real descriptor is immutable.
 */
public class TestSystemIndexDescriptor extends SystemIndexDescriptor {

    public static final String INDEX_NAME = ".test-index";
    public static final String PRIMARY_INDEX_NAME = INDEX_NAME + "-1";

    public static final AtomicBoolean useNewMappings = new AtomicBoolean(false);

    public static final Settings SETTINGS = Settings.builder()
        .put(IndexMetadata.INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), 1)
        .put(IndexMetadata.INDEX_AUTO_EXPAND_REPLICAS_SETTING.getKey(), "0-1")
        .put(IndexMetadata.SETTING_PRIORITY, Integer.MAX_VALUE)
        .build();
    private static final int NEW_MAPPINGS_VERSION = 1;
    private static final int OLD_MAPPINGS_VERSION = 0;

    TestSystemIndexDescriptor() {
        super(
            INDEX_NAME + "*",
            PRIMARY_INDEX_NAME,
            "Test system index",
            getOldMappings(),
            SETTINGS,
            INDEX_NAME,
            0,
            "stack",
            null,
            Type.INTERNAL_MANAGED,
            List.of(),
            List.of(),
            null,
            false,
            false
        );
    }

    TestSystemIndexDescriptor(String name, String primaryName, boolean allowsTemplates) {
        super(
            name + "*",
            primaryName,
            "Test system index",
            getOldMappings(),
            SETTINGS,
            name,
            0,
            "stack",
            null,
            Type.INTERNAL_MANAGED,
            List.of(),
            List.of(),
            null,
            false,
            allowsTemplates
        );
    }

    @Override
    public boolean isAutomaticallyManaged() {
        return true;
    }

    @Override
    public String getMappings() {
        return useNewMappings.get() ? getNewMappings() : getOldMappings();
    }

    @Override
    public MappingsVersion getMappingsVersion() {
        return useNewMappings.get() ? new MappingsVersion(NEW_MAPPINGS_VERSION, 0) : new MappingsVersion(OLD_MAPPINGS_VERSION, 0);
    }

    public static String getOldMappings() {
        try {
            final XContentBuilder builder = jsonBuilder();

            builder.startObject();
            {
                builder.startObject("_meta");
                builder.field(SystemIndexDescriptor.VERSION_META_KEY, OLD_MAPPINGS_VERSION);
                builder.field("version", Version.CURRENT.previousMajor().toString());
                builder.endObject();

                builder.startObject("properties");
                {
                    builder.startObject("foo");
                    builder.field("type", "text");
                    builder.endObject();
                }
                builder.endObject();
            }

            builder.endObject();
            return Strings.toString(builder);
        } catch (IOException e) {
            throw new UncheckedIOException("Failed to build .test-index-1 index mappings", e);
        }
    }

    public static String getNewMappings() {
        try {
            final XContentBuilder builder = jsonBuilder();

            builder.startObject();
            {
                builder.startObject("_meta");
                builder.field(SystemIndexDescriptor.VERSION_META_KEY, NEW_MAPPINGS_VERSION);
                builder.field("version", Version.CURRENT.toString());
                builder.endObject();

                builder.startObject("properties");
                {
                    builder.startObject("bar");
                    builder.field("type", "text");
                    builder.endObject();
                    builder.startObject("foo");
                    builder.field("type", "text");
                    builder.endObject();
                }
                builder.endObject();
            }

            builder.endObject();
            return Strings.toString(builder);
        } catch (IOException e) {
            throw new UncheckedIOException("Failed to build .test-index-1 index mappings", e);
        }
    }
}