/*
 * 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.ingest;

import org.elasticsearch.action.DocWriteResponse;
import org.elasticsearch.action.bulk.BulkItemResponse;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.plugins.IngestPlugin;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.test.ESSingleNodeTestCase;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.xcontent.XContentType;

import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.function.BiConsumer;

import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.equalTo;

/**
 * The purpose of this test is to verify that when a processor executes an operation asynchronously that
 * the expected result is the same as if the same operation happens synchronously.
 * <p>
 * In this test two test processors are defined that basically do the same operation, but a single processor
 * executes asynchronously. The result of the operation should be the same and also the order in which the
 * bulk responses are returned should be the same as how the corresponding index requests were defined.
 * <p>
 * As a further test, one document is dropped by the synchronous processor, and one document causes
 * the asynchronous processor throw an exception.
 */
public class IngestAsyncProcessorIT extends ESSingleNodeTestCase {

    private static final int DROPPED = 3;

    private static final int ERROR = 7;

    @Override
    protected Collection<Class<? extends Plugin>> getPlugins() {
        return List.of(TestPlugin.class);
    }

    public void testAsyncProcessorImplementation() {
        // A pipeline with 2 processors: the test async processor and sync test processor.
        putJsonPipeline("_id", "{\"processors\": [{\"test-async\": {}, \"test\": {}}]}");

        BulkRequest bulkRequest = new BulkRequest();
        int numDocs = randomIntBetween(8, 256);
        for (int i = 0; i < numDocs; i++) {
            bulkRequest.add(new IndexRequest("foobar").id(Integer.toString(i)).source("{}", XContentType.JSON).setPipeline("_id"));
        }
        BulkResponse bulkResponse = client().bulk(bulkRequest).actionGet();
        assertThat(bulkResponse.getItems().length, equalTo(numDocs));
        for (int i = 0; i < numDocs; i++) {
            String id = Integer.toString(i);
            assertThat(bulkResponse.getItems()[i].getId(), equalTo(id));
            if (i == DROPPED) {
                UpdateResponse dropped = bulkResponse.getItems()[i].getResponse();
                assertThat(dropped.getId(), equalTo(id));
                assertThat(dropped.getResult(), equalTo(DocWriteResponse.Result.NOOP));
            } else if (i == ERROR) {
                BulkItemResponse failure = bulkResponse.getItems()[i];
                assertThat(failure.getFailure().getId(), equalTo(id));
                assertThat(failure.getFailure().getMessage(), containsString("lucky number seven"));
            } else {
                GetResponse getResponse = client().get(new GetRequest("foobar", id)).actionGet();
                // The expected result of async test processor:
                assertThat(getResponse.getSource().get("foo"), equalTo("bar-" + id));
                // The expected result of sync test processor:
                assertThat(getResponse.getSource().get("bar"), equalTo("baz-" + id));
            }
        }
    }

    public static class TestPlugin extends Plugin implements IngestPlugin {

        private ThreadPool threadPool;

        @Override
        public Collection<?> createComponents(PluginServices services) {
            this.threadPool = services.threadPool();
            return List.of();
        }

        @Override
        public Map<String, Processor.Factory> getProcessors(Processor.Parameters parameters) {
            return Map.of("test-async", (factories, tag, description, config, projectId) -> new AbstractProcessor(tag, description) {

                @Override
                public void execute(IngestDocument ingestDocument, BiConsumer<IngestDocument, Exception> handler) {
                    threadPool.generic().execute(() -> {
                        String id = (String) ingestDocument.getSourceAndMetadata().get("_id");
                        if (id.equals(String.valueOf(ERROR))) {
                            // lucky number seven always fails
                            handler.accept(ingestDocument, new RuntimeException("lucky number seven"));
                        } else {
                            if (usually()) {
                                try {
                                    Thread.sleep(10);
                                } catch (InterruptedException e) {
                                    // ignore
                                }
                            }
                            ingestDocument.setFieldValue("foo", "bar-" + id);
                            handler.accept(ingestDocument, null);
                        }
                    });
                }

                @Override
                public String getType() {
                    return "test-async";
                }

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

            }, "test", (processorFactories, tag, description, config, projectId) -> new AbstractProcessor(tag, description) {
                @Override
                public IngestDocument execute(IngestDocument ingestDocument) throws Exception {
                    String id = (String) ingestDocument.getSourceAndMetadata().get("_id");
                    if (id.equals(String.valueOf(DROPPED))) {
                        // lucky number three is always dropped
                        return null;
                    } else {
                        ingestDocument.setFieldValue("bar", "baz-" + id);
                        return ingestDocument;
                    }
                }

                @Override
                public String getType() {
                    return "test";
                }
            });
        }
    }
}