/*
 * 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.index.store;

import org.elasticsearch.action.admin.cluster.node.stats.NodeStats;
import org.elasticsearch.action.admin.cluster.node.stats.NodesStatsResponse;
import org.elasticsearch.action.admin.indices.stats.IndexShardStats;
import org.elasticsearch.action.admin.indices.stats.IndexStats;
import org.elasticsearch.action.admin.indices.stats.IndicesStatsResponse;
import org.elasticsearch.action.admin.indices.stats.ShardStats;
import org.elasticsearch.action.bulk.BulkItemResponse;
import org.elasticsearch.action.bulk.BulkRequestBuilder;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.bulk.TransportShardBulkAction;
import org.elasticsearch.client.internal.Client;
import org.elasticsearch.index.engine.SegmentsStats;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.test.ESIntegTestCase;
import org.elasticsearch.test.transport.MockTransportService;
import org.elasticsearch.transport.ConnectTransportException;
import org.elasticsearch.transport.TransportService;
import org.elasticsearch.xcontent.XContentBuilder;

import java.io.IOException;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.atomic.AtomicBoolean;

import static org.elasticsearch.index.query.QueryBuilders.termQuery;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertHitCount;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertNoFailuresAndResponse;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertResponse;
import static org.elasticsearch.xcontent.XContentFactory.jsonBuilder;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.Matchers.greaterThan;

@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.SUITE, numDataNodes = 2, supportsDedicatedMasters = false, numClientNodes = 1)
public class ExceptionRetryIT extends ESIntegTestCase {

    @Override
    protected Collection<Class<? extends Plugin>> nodePlugins() {
        return Arrays.asList(MockTransportService.TestPlugin.class);
    }

    @Override
    protected void beforeIndexDeletion() {
        // a write operation might still be in flight when the test has finished
        // so we should not check the operation counter here
    }

    /**
     * Tests retry mechanism when indexing. If an exception occurs when indexing then the indexing request is tried again before finally
     * failing. If auto generated ids are used this must not lead to duplicate ids
     * see https://github.com/elastic/elasticsearch/issues/8788
     */
    public void testRetryDueToExceptionOnNetworkLayer() throws ExecutionException, InterruptedException, IOException {
        final AtomicBoolean exceptionThrown = new AtomicBoolean(false);
        int numDocs = scaledRandomIntBetween(100, 1000);
        Client client = internalCluster().coordOnlyNodeClient();
        NodesStatsResponse nodeStats = clusterAdmin().prepareNodesStats().get();
        NodeStats unluckyNode = randomFrom(nodeStats.getNodes().stream().filter((s) -> s.getNode().canContainData()).toList());
        assertAcked(indicesAdmin().prepareCreate("index").setSettings(indexSettings(5, 1)));
        ensureGreen("index");
        logger.info("unlucky node: {}", unluckyNode.getNode());
        // create a transport service that throws a ConnectTransportException for one bulk request and therefore triggers a retry.
        for (NodeStats dataNode : nodeStats.getNodes()) {
            MockTransportService.getInstance(dataNode.getNode().getName())
                .addSendBehavior(
                    internalCluster().getInstance(TransportService.class, unluckyNode.getNode().getName()),
                    (connection, requestId, action, request, options) -> {
                        connection.sendRequest(requestId, action, request, options);
                        if (action.equals(TransportShardBulkAction.ACTION_NAME) && exceptionThrown.compareAndSet(false, true)) {
                            logger.debug("Throw ConnectTransportException");
                            throw new ConnectTransportException(connection.getNode(), action);
                        }
                    }
                );
        }

        BulkRequestBuilder bulkBuilder = client.prepareBulk();
        for (int i = 0; i < numDocs; i++) {
            XContentBuilder doc = null;
            doc = jsonBuilder().startObject().field("foo", "bar").endObject();
            bulkBuilder.add(client.prepareIndex("index").setSource(doc));
        }

        BulkResponse bulkResponse = bulkBuilder.get();
        if (bulkResponse.hasFailures()) {
            for (BulkItemResponse singleIndexRespons : bulkResponse.getItems()) {
                if (singleIndexRespons.isFailed()) {
                    fail("None of the bulk items should fail but got " + singleIndexRespons.getFailureMessage());
                }
            }
        }

        refresh();
        assertNoFailuresAndResponse(prepareSearch("index").setSize(numDocs * 2).addStoredField("_id"), response -> {
            Set<String> uniqueIds = new HashSet<>();
            long dupCounter = 0;
            boolean found_duplicate_already = false;
            for (int i = 0; i < response.getHits().getHits().length; i++) {
                if (uniqueIds.add(response.getHits().getHits()[i].getId()) == false) {
                    if (found_duplicate_already == false) {
                        assertResponse(
                            prepareSearch("index").setQuery(termQuery("_id", response.getHits().getHits()[i].getId())).setExplain(true),
                            dupIdResponse -> {
                                assertThat(dupIdResponse.getHits().getTotalHits().value(), greaterThan(1L));
                                logger.info("found a duplicate id:");
                                for (SearchHit hit : dupIdResponse.getHits()) {
                                    logger.info("Doc {} was found on shard {}", hit.getId(), hit.getShard().getShardId());
                                }
                                logger.info("will not print anymore in case more duplicates are found.");
                            }
                        );
                        found_duplicate_already = true;
                    }
                    dupCounter++;
                }
            }
            assertThat(dupCounter, equalTo(0L));
            assertHitCount(response, numDocs);
            IndicesStatsResponse index = indicesAdmin().prepareStats("index").clear().setSegments(true).get();
            IndexStats indexStats = index.getIndex("index");
            long maxUnsafeAutoIdTimestamp = Long.MIN_VALUE;
            for (IndexShardStats indexShardStats : indexStats) {
                for (ShardStats shardStats : indexShardStats) {
                    SegmentsStats segments = shardStats.getStats().getSegments();
                    maxUnsafeAutoIdTimestamp = Math.max(maxUnsafeAutoIdTimestamp, segments.getMaxUnsafeAutoIdTimestamp());
                }
            }
            assertTrue("exception must have been thrown otherwise setup is broken", exceptionThrown.get());
            assertTrue("maxUnsafeAutoIdTimestamp must be > than 0 we have at least one retry", maxUnsafeAutoIdTimestamp > -1);
        });
    }
}