/*
 * 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.indices.recovery;

import org.elasticsearch.cluster.metadata.IndexMetadata;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.util.CollectionUtils;
import org.elasticsearch.index.IndexSettings;
import org.elasticsearch.index.engine.EngineFactory;
import org.elasticsearch.index.engine.InternalEngine;
import org.elasticsearch.plugins.EnginePlugin;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.plugins.PluginsService;
import org.elasticsearch.tasks.TaskInfo;
import org.elasticsearch.test.ESIntegTestCase;

import java.util.Collection;
import java.util.List;
import java.util.Optional;
import java.util.concurrent.CountDownLatch;
import java.util.stream.StreamSupport;

import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
import static org.hamcrest.Matchers.equalTo;

@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
public class TaskRecoveryIT extends ESIntegTestCase {

    @Override
    protected boolean addMockInternalEngine() {
        return false;
    }

    @Override
    protected Collection<Class<? extends Plugin>> nodePlugins() {
        return CollectionUtils.appendToCopy(super.nodePlugins(), TaskRecoveryIT.EngineTestPlugin.class);
    }

    public void testTaskForOngoingRecovery() throws Exception {
        String indexName = "test";
        internalCluster().startMasterOnlyNode();
        String nodeWithPrimary = internalCluster().startDataOnlyNode();
        assertAcked(
            client().admin()
                .indices()
                .prepareCreate(indexName)
                .setSettings(
                    Settings.builder()
                        .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
                        .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
                        .put("index.routing.allocation.include._name", nodeWithPrimary)
                )
        );
        try {
            String nodeWithReplica = internalCluster().startDataOnlyNode();
            assertAcked(
                client().admin()
                    .indices()
                    .prepareUpdateSettings(indexName)
                    .setSettings(
                        Settings.builder()
                            .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1)
                            .put("index.routing.allocation.include._name", nodeWithPrimary + "," + nodeWithReplica)
                    )
            );
            assertBusy(() -> {
                List<TaskInfo> primaryTasks = client().admin().cluster().prepareListTasks(nodeWithPrimary).setActions(PeerRecoverySourceService.Actions.START_RECOVERY).get().getTasks();
                assertThat(primaryTasks.size(), equalTo(1));
                List<TaskInfo> replicaTasks =
                    client().admin().cluster().prepareListTasks(nodeWithReplica).setActions(PeerRecoveryTargetService.Actions.PREPARE_TRANSLOG).get().getTasks();
                assertThat(replicaTasks.size(), equalTo(1));
                assertThat(replicaTasks.get(0).parentTaskId(), equalTo(primaryTasks.get(0).taskId()));
            });
        } finally {
            StreamSupport.stream(internalCluster().getInstances(PluginsService.class).spliterator(), false).flatMap(ps -> ps.filterPlugins(EnginePlugin.class).stream()).map(EngineTestPlugin.class::cast).forEach(EngineTestPlugin::release);
        }
        ensureGreen(indexName);
    }

    public static class EngineTestPlugin extends Plugin implements EnginePlugin {
        private final CountDownLatch latch = new CountDownLatch(1);

        public EngineTestPlugin() {

        }
        public void release() {
            latch.countDown();
        }

        @Override
        public Optional<EngineFactory> getEngineFactory(IndexSettings indexSettings) {
            return Optional.of(config -> new InternalEngine(config) {

                @Override
                public void skipTranslogRecovery() {
                    try {
                        latch.await();
                    } catch (InterruptedException e) {
                        throw new AssertionError(e);
                    }
                    super.skipTranslogRecovery();
                }
            });
        }
    }
}