/*
 * 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 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 or the Server
 * Side Public License, v 1.
 */

package org.elasticsearch.node;

import org.elasticsearch.client.internal.node.NodeClient;
import org.elasticsearch.cluster.ClusterInfoService;
import org.elasticsearch.cluster.MockInternalClusterInfoService;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
import org.elasticsearch.common.network.NetworkModule;
import org.elasticsearch.common.settings.ClusterSettings;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.BoundTransportAddress;
import org.elasticsearch.common.util.BigArrays;
import org.elasticsearch.common.util.MockBigArrays;
import org.elasticsearch.common.util.MockPageCacheRecycler;
import org.elasticsearch.common.util.PageCacheRecycler;
import org.elasticsearch.env.Environment;
import org.elasticsearch.http.HttpServerTransport;
import org.elasticsearch.indices.ExecutorSelector;
import org.elasticsearch.indices.IndicesService;
import org.elasticsearch.indices.breaker.CircuitBreakerService;
import org.elasticsearch.indices.recovery.RecoverySettings;
import org.elasticsearch.plugins.MockPluginsService;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.script.MockScriptService;
import org.elasticsearch.script.ScriptContext;
import org.elasticsearch.script.ScriptEngine;
import org.elasticsearch.script.ScriptService;
import org.elasticsearch.search.MockSearchService;
import org.elasticsearch.search.SearchService;
import org.elasticsearch.search.fetch.FetchPhase;
import org.elasticsearch.tasks.TaskManager;
import org.elasticsearch.test.ESTestCase;
import org.elasticsearch.test.MockHttpTransport;
import org.elasticsearch.test.transport.MockTransportService;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.tracing.Tracer;
import org.elasticsearch.transport.Transport;
import org.elasticsearch.transport.TransportInterceptor;
import org.elasticsearch.transport.TransportService;
import org.elasticsearch.transport.TransportSettings;

import java.nio.file.Path;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Map;
import java.util.function.Function;
import java.util.function.LongSupplier;

/**
 * A node for testing which allows:
 * <ul>
 *   <li>Overriding Version.CURRENT</li>
 *   <li>Adding test plugins that exist on the classpath</li>
 *   <li>Swapping in various mock services</li>
 * </ul>
 */
public class MockNode extends Node {

    private final Collection<Class<? extends Plugin>> classpathPlugins;

    public MockNode(final Settings settings, final Collection<Class<? extends Plugin>> classpathPlugins) {
        this(settings, classpathPlugins, true);
    }

    public MockNode(
        final Settings settings,
        final Collection<Class<? extends Plugin>> classpathPlugins,
        final boolean forbidPrivateIndexSettings
    ) {
        this(settings, classpathPlugins, null, forbidPrivateIndexSettings);
    }

    public MockNode(
        final Settings settings,
        final Collection<Class<? extends Plugin>> classpathPlugins,
        final Path configPath,
        final boolean forbidPrivateIndexSettings
    ) {
        this(
            InternalSettingsPreparer.prepareEnvironment(
                Settings.builder().put(TransportSettings.PORT.getKey(), ESTestCase.getPortRange()).put(settings).build(),
                Collections.emptyMap(),
                configPath,
                () -> "mock_ node"
            ),
            classpathPlugins,
            forbidPrivateIndexSettings
        );
    }

    private MockNode(
        final Environment environment,
        final Collection<Class<? extends Plugin>> classpathPlugins,
        final boolean forbidPrivateIndexSettings
    ) {
        super(environment, settings -> new MockPluginsService(settings, environment, classpathPlugins), forbidPrivateIndexSettings);
        this.classpathPlugins = classpathPlugins;
    }

    /**
     * The classpath plugins this node was constructed with.
     */
    public Collection<Class<? extends Plugin>> getClasspathPlugins() {
        return classpathPlugins;
    }

    @Override
    protected BigArrays createBigArrays(PageCacheRecycler pageCacheRecycler, CircuitBreakerService circuitBreakerService) {
        if (getPluginsService().filterPlugins(NodeMocksPlugin.class).isEmpty()) {
            return super.createBigArrays(pageCacheRecycler, circuitBreakerService);
        }
        return new MockBigArrays(pageCacheRecycler, circuitBreakerService);
    }

    @Override
    PageCacheRecycler createPageCacheRecycler(Settings settings) {
        if (getPluginsService().filterPlugins(NodeMocksPlugin.class).isEmpty()) {
            return super.createPageCacheRecycler(settings);
        }
        return new MockPageCacheRecycler(settings);
    }

    @Override
    protected SearchService newSearchService(
        ClusterService clusterService,
        IndicesService indicesService,
        ThreadPool threadPool,
        ScriptService scriptService,
        BigArrays bigArrays,
        FetchPhase fetchPhase,
        ResponseCollectorService responseCollectorService,
        CircuitBreakerService circuitBreakerService,
        ExecutorSelector executorSelector,
        Tracer tracer
    ) {
        if (getPluginsService().filterPlugins(MockSearchService.TestPlugin.class).isEmpty()) {
            return super.newSearchService(
                clusterService,
                indicesService,
                threadPool,
                scriptService,
                bigArrays,
                fetchPhase,
                responseCollectorService,
                circuitBreakerService,
                executorSelector,
                tracer
            );
        }
        return new MockSearchService(
            clusterService,
            indicesService,
            threadPool,
            scriptService,
            bigArrays,
            fetchPhase,
            responseCollectorService,
            circuitBreakerService,
            executorSelector,
            tracer
        );
    }

    @Override
    protected ScriptService newScriptService(
        Settings settings,
        Map<String, ScriptEngine> engines,
        Map<String, ScriptContext<?>> contexts,
        LongSupplier timeProvider
    ) {
        if (getPluginsService().filterPlugins(MockScriptService.TestPlugin.class).isEmpty()) {
            return super.newScriptService(settings, engines, contexts, timeProvider);
        }
        return new MockScriptService(settings, engines, contexts);
    }

    @Override
    protected TransportService newTransportService(
        Settings settings,
        Transport transport,
        ThreadPool threadPool,
        TransportInterceptor interceptor,
        Function<BoundTransportAddress, DiscoveryNode> localNodeFactory,
        ClusterSettings clusterSettings,
        TaskManager taskManager,
        Tracer tracer
    ) {
        // we use the MockTransportService.TestPlugin class as a marker to create a network
        // module with this MockNetworkService. NetworkService is such an integral part of the systme
        // we don't allow to plug it in from plugins or anything. this is a test-only override and
        // can't be done in a production env.
        if (getPluginsService().filterPlugins(MockTransportService.TestPlugin.class).isEmpty()) {
            return super.newTransportService(
                settings,
                transport,
                threadPool,
                interceptor,
                localNodeFactory,
                clusterSettings,
                taskManager,
                tracer
            );
        } else {
            return new MockTransportService(
                settings,
                transport,
                threadPool,
                interceptor,
                localNodeFactory,
                clusterSettings,
                new HashSet<>(taskManager.getTaskHeaders())
            );
        }
    }

    @Override
    protected void processRecoverySettings(ClusterSettings clusterSettings, RecoverySettings recoverySettings) {
        if (false == getPluginsService().filterPlugins(RecoverySettingsChunkSizePlugin.class).isEmpty()) {
            clusterSettings.addSettingsUpdateConsumer(RecoverySettingsChunkSizePlugin.CHUNK_SIZE_SETTING, recoverySettings::setChunkSize);
        }
    }

    @Override
    protected ClusterInfoService newClusterInfoService(
        Settings settings,
        ClusterService clusterService,
        ThreadPool threadPool,
        NodeClient client
    ) {
        if (getPluginsService().filterPlugins(MockInternalClusterInfoService.TestPlugin.class).isEmpty()) {
            return super.newClusterInfoService(settings, clusterService, threadPool, client);
        } else {
            final MockInternalClusterInfoService service = new MockInternalClusterInfoService(settings, clusterService, threadPool, client);
            clusterService.addListener(service);
            return service;
        }
    }

    @Override
    protected HttpServerTransport newHttpTransport(NetworkModule networkModule) {
        if (getPluginsService().filterPlugins(MockHttpTransport.TestPlugin.class).isEmpty()) {
            return super.newHttpTransport(networkModule);
        } else {
            return new MockHttpTransport();
        }
    }

    @Override
    protected void configureNodeAndClusterIdStateListener(ClusterService clusterService) {
        // do not configure this in tests as this is causing SetOnce to throw exceptions when jvm is used for multiple tests
    }

    public NamedWriteableRegistry getNamedWriteableRegistry() {
        return namedWriteableRegistry;
    }
}
