/*
 * 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.search;

import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.TimestampParsingException;
import org.elasticsearch.common.ParsingException;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.bytes.BytesReference;
import org.elasticsearch.common.util.concurrent.EsRejectedExecutionException;
import org.elasticsearch.common.xcontent.XContentHelper;
import org.elasticsearch.index.shard.IndexShardClosedException;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.indices.InvalidIndexTemplateException;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.SearchShardTarget;
import org.elasticsearch.test.ESTestCase;
import org.elasticsearch.transport.NodeDisconnectedException;
import org.elasticsearch.xcontent.ToXContent;
import org.elasticsearch.xcontent.XContent;
import org.elasticsearch.xcontent.XContentParser;
import org.elasticsearch.xcontent.XContentType;

import java.io.IOException;

import static org.hamcrest.CoreMatchers.hasItem;
import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.is;

public class SearchPhaseExecutionExceptionTests extends ESTestCase {

    public void testToXContent() throws IOException {
        SearchPhaseExecutionException exception = new SearchPhaseExecutionException(
            "test",
            "all shards failed",
            new ShardSearchFailure[] {
                new ShardSearchFailure(
                    new ParsingException(1, 2, "foobar", null),
                    new SearchShardTarget("node_1", new ShardId("foo", "_na_", 0), null)
                ),
                new ShardSearchFailure(
                    new IndexShardClosedException(new ShardId("foo", "_na_", 1)),
                    new SearchShardTarget("node_2", new ShardId("foo", "_na_", 1), null)
                ),
                new ShardSearchFailure(
                    new ParsingException(5, 7, "foobar", null),
                    new SearchShardTarget("node_3", new ShardId("foo", "_na_", 2), null)
                ), }
        );

        // Failures are grouped (by default)
        final String expectedJson = XContentHelper.stripWhitespace("""
            {
              "type": "search_phase_execution_exception",
              "reason": "all shards failed",
              "phase": "test",
              "grouped": true,
              "failed_shards": [
                {
                  "shard": 0,
                  "index": "foo",
                  "node": "node_1",
                  "reason": {
                    "type": "parsing_exception",
                    "reason": "foobar",
                    "line": 1,
                    "col": 2
                  }
                },
                {
                  "shard": 1,
                  "index": "foo",
                  "node": "node_2",
                  "reason": {
                    "type": "index_shard_closed_exception",
                    "reason": "CurrentState[CLOSED] Closed",
                    "index_uuid": "_na_",
                    "shard": "1",
                    "index": "foo"
                  }
                }
              ]
            }""");
        assertEquals(XContentHelper.stripWhitespace(expectedJson), Strings.toString(exception));
    }

    public void testToAndFromXContent() throws IOException {
        final XContent xContent = randomFrom(XContentType.values()).xContent();

        ShardSearchFailure[] shardSearchFailures = new ShardSearchFailure[randomIntBetween(1, 5)];
        for (int i = 0; i < shardSearchFailures.length; i++) {
            Exception cause = randomFrom(
                new ParsingException(1, 2, "foobar", null),
                new InvalidIndexTemplateException("foo", "bar"),
                new TimestampParsingException("foo", null),
                new NullPointerException()
            );
            shardSearchFailures[i] = new ShardSearchFailure(
                cause,
                new SearchShardTarget("node_" + i, new ShardId("test", "_na_", i), null)
            );
        }

        final String phase = randomFrom("query", "search", "other");
        SearchPhaseExecutionException actual = new SearchPhaseExecutionException(phase, "unexpected failures", shardSearchFailures);

        BytesReference exceptionBytes = toShuffledXContent(actual, xContent.type(), ToXContent.EMPTY_PARAMS, randomBoolean());

        ElasticsearchException parsedException;
        try (XContentParser parser = createParser(xContent, exceptionBytes)) {
            assertEquals(XContentParser.Token.START_OBJECT, parser.nextToken());
            parsedException = ElasticsearchException.fromXContent(parser);
            assertEquals(XContentParser.Token.END_OBJECT, parser.currentToken());
            assertNull(parser.nextToken());
        }

        assertNotNull(parsedException);
        assertThat(parsedException.getHeaderKeys(), hasSize(0));
        assertThat(parsedException.getMetadataKeys(), hasSize(1));
        assertThat(parsedException.getMetadata("es.phase"), hasItem(phase));
        // SearchPhaseExecutionException has no cause field
        assertNull(parsedException.getCause());
    }

    public void testPhaseFailureWithoutSearchShardFailure() {
        final ShardSearchFailure[] searchShardFailures = new ShardSearchFailure[0];
        final String phase = randomFrom("fetch", "search", "other");
        SearchPhaseExecutionException actual = new SearchPhaseExecutionException(
            phase,
            "unexpected failures",
            new EsRejectedExecutionException("ES rejected execution of fetch phase"),
            searchShardFailures
        );

        assertEquals(actual.status(), RestStatus.TOO_MANY_REQUESTS);
    }

    public void testPhaseFailureWithoutSearchShardFailureAndCause() {
        final ShardSearchFailure[] searchShardFailures = new ShardSearchFailure[0];
        final String phase = randomFrom("fetch", "search", "other");
        SearchPhaseExecutionException actual = new SearchPhaseExecutionException(phase, "unexpected failures", null, searchShardFailures);

        assertEquals(actual.status(), RestStatus.SERVICE_UNAVAILABLE);
    }

    public void testPhaseFailureWithSearchShardFailure() {
        final ShardSearchFailure[] shardSearchFailures = new ShardSearchFailure[randomIntBetween(1, 5)];
        for (int i = 0; i < shardSearchFailures.length; i++) {
            Exception cause = randomFrom(new ParsingException(1, 2, "foobar", null), new InvalidIndexTemplateException("foo", "bar"));
            shardSearchFailures[i] = new ShardSearchFailure(
                cause,
                new SearchShardTarget("node_" + i, new ShardId("test", "_na_", i), null)
            );
        }

        final String phase = randomFrom("fetch", "search", "other");
        SearchPhaseExecutionException actual = new SearchPhaseExecutionException(
            phase,
            "unexpected failures",
            new EsRejectedExecutionException("ES rejected execution of fetch phase"),
            shardSearchFailures
        );

        assertEquals(actual.status(), RestStatus.BAD_REQUEST);
    }

    public void testOnlyWithCodesThatDoNotRequirePrecedence() {
        int pickedIndex = randomIntBetween(0, 1);

        // Pick one of these exceptions randomly.
        var searchExceptions = new ElasticsearchException[] {
            new ElasticsearchException("simulated"),
            new NodeDisconnectedException(null, "unused message", "unused action", null) };

        // Status codes that map to searchExceptions.
        var expectedStatusCodes = new RestStatus[] { RestStatus.INTERNAL_SERVER_ERROR, RestStatus.BAD_GATEWAY };

        ShardSearchFailure shardFailure1 = new ShardSearchFailure(
            searchExceptions[pickedIndex],
            new SearchShardTarget("nodeID", new ShardId("someIndex", "someUUID", 1), null)
        );

        ShardSearchFailure shardFailure2 = new ShardSearchFailure(
            searchExceptions[pickedIndex],
            new SearchShardTarget("nodeID", new ShardId("someIndex", "someUUID", 2), null)
        );

        SearchPhaseExecutionException ex = new SearchPhaseExecutionException(
            "search",
            "all shards failed",
            new ShardSearchFailure[] { shardFailure1, shardFailure2 }
        );

        assertThat(ex.status(), is(expectedStatusCodes[pickedIndex]));
    }

    public void testWithRetriableCodesThatTakePrecedence() {
        // Maps to a 500.
        ShardSearchFailure shardFailure1 = new ShardSearchFailure(
            new ElasticsearchException("simulated"),
            new SearchShardTarget("nodeID", new ShardId("someIndex", "someUUID", 1), null)
        );

        // Maps to a 502.
        ShardSearchFailure shardFailure2 = new ShardSearchFailure(
            new NodeDisconnectedException(null, "unused message", "unused action", null),
            new SearchShardTarget("nodeID", new ShardId("someIndex", "someUUID", 2), null)
        );

        SearchPhaseExecutionException ex = new SearchPhaseExecutionException(
            "search",
            "all shards failed",
            new ShardSearchFailure[] { shardFailure1, shardFailure2 }
        );

        // The 502 takes precedence over 500.
        assertThat(ex.status(), is(RestStatus.BAD_GATEWAY));
    }
}