/*
 * 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.index.reindex;

import org.elasticsearch.action.index.IndexRequestBuilder;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import static org.elasticsearch.index.query.QueryBuilders.termQuery;
import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertHitCount;
import static org.hamcrest.Matchers.greaterThanOrEqualTo;
import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.lessThanOrEqualTo;

public class ReindexBasicTests extends ReindexTestCase {
    public void testFiltering() throws Exception {
        indexRandom(true, client().prepareIndex("source", "test", "1").setSource("foo", "a"),
                client().prepareIndex("source", "test", "2").setSource("foo", "a"),
                client().prepareIndex("source", "test", "3").setSource("foo", "b"),
                client().prepareIndex("source", "test", "4").setSource("foo", "c"));
        assertHitCount(client().prepareSearch("source").setSize(0).get(), 4);

        // Copy all the docs
        ReindexRequestBuilder copy = reindex().source("source").destination("dest", "type").refresh(true);
        assertThat(copy.get(), matcher().created(4));
        assertHitCount(client().prepareSearch("dest").setSize(0).get(), 4);

        // Now none of them
        createIndex("none");
        copy = reindex().source("source").destination("none", "type").filter(termQuery("foo", "no_match")).refresh(true);
        assertThat(copy.get(), matcher().created(0));
        assertHitCount(client().prepareSearch("none").setSize(0).get(), 0);

        // Now half of them
        copy = reindex().source("source").destination("dest_half", "type").filter(termQuery("foo", "a")).refresh(true);
        assertThat(copy.get(), matcher().created(2));
        assertHitCount(client().prepareSearch("dest_half").setSize(0).get(), 2);

        // Limit with maxDocs
        copy = reindex().source("source").destination("dest_size_one", "type").maxDocs(1).refresh(true);
        assertThat(copy.get(), matcher().created(1));
        assertHitCount(client().prepareSearch("dest_size_one").setSize(0).get(), 1);
    }

    public void testCopyMany() throws Exception {
        List<IndexRequestBuilder> docs = new ArrayList<>();
        int max = between(150, 500);
        for (int i = 0; i < max; i++) {
            docs.add(client().prepareIndex("source", "test", Integer.toString(i)).setSource("foo", "a"));
        }

        indexRandom(true, docs);
        assertHitCount(client().prepareSearch("source").setSize(0).get(), max);

        // Copy all the docs
        ReindexRequestBuilder copy = reindex().source("source").destination("dest", "type").refresh(true);
        // Use a small batch size so we have to use more than one batch
        copy.source().setSize(5);
        assertThat(copy.get(), matcher().created(max).batches(max, 5));
        assertHitCount(client().prepareSearch("dest").setSize(0).get(), max);

        // Copy some of the docs
        int half = max / 2;
        copy = reindex().source("source").destination("dest_half", "type").refresh(true);
        // Use a small batch size so we have to use more than one batch
        copy.source().setSize(5);
        copy.maxDocs(half);
        assertThat(copy.get(), matcher().created(half).batches(half, 5));
        assertHitCount(client().prepareSearch("dest_half").setSize(0).get(), half);
    }

    public void testCopyManyWithSlices() throws Exception {
        List<IndexRequestBuilder> docs = new ArrayList<>();
        int max = between(150, 500);
        for (int i = 0; i < max; i++) {
            docs.add(client().prepareIndex("source", "test", Integer.toString(i)).setSource("foo", "a"));
        }

        indexRandom(true, docs);
        assertHitCount(client().prepareSearch("source").setSize(0).get(), max);

        int slices = randomSlices();
        int expectedSlices = expectedSliceStatuses(slices, "source");

        // Copy all the docs
        ReindexRequestBuilder copy = reindex().source("source").destination("dest", "type").refresh(true).setSlices(slices);
        // Use a small batch size so we have to use more than one batch
        copy.source().setSize(5);
        assertThat(copy.get(), matcher().created(max).batches(greaterThanOrEqualTo(max / 5)).slices(hasSize(expectedSlices)));
        assertHitCount(client().prepareSearch("dest").setTypes("type").setSize(0).get(), max);

        // Copy some of the docs
        int half = max / 2;
        copy = reindex().source("source").destination("dest_half", "type").refresh(true).setSlices(slices);
        // Use a small batch size so we have to use more than one batch
        copy.source().setSize(5);
        copy.maxDocs(half);
        BulkByScrollResponse response = copy.get();
        assertThat(response, matcher().created(lessThanOrEqualTo((long) half)).slices(hasSize(expectedSlices)));
        assertHitCount(client().prepareSearch("dest_half").setSize(0).get(), response.getCreated());
    }

    public void testMultipleSources() throws Exception {
        int sourceIndices = between(2, 5);

        Map<String, List<IndexRequestBuilder>> docs = new HashMap<>();
        for (int sourceIndex = 0; sourceIndex < sourceIndices; sourceIndex++) {
            String indexName = "source" + sourceIndex;
            String typeName = "test" + sourceIndex;
            docs.put(indexName, new ArrayList<>());
            int numDocs = between(50, 200);
            for (int i = 0; i < numDocs; i++) {
                docs.get(indexName).add(client().prepareIndex(indexName, typeName, "id_" + sourceIndex + "_" + i).setSource("foo", "a"));
            }
        }

        List<IndexRequestBuilder> allDocs = docs.values().stream().flatMap(Collection::stream).collect(Collectors.toList());
        indexRandom(true, allDocs);
        for (Map.Entry<String, List<IndexRequestBuilder>> entry : docs.entrySet()) {
            assertHitCount(client().prepareSearch(entry.getKey()).setSize(0).get(), entry.getValue().size());
        }

        int slices = randomSlices(1, 10);
        int expectedSlices = expectedSliceStatuses(slices, docs.keySet());

        String[] sourceIndexNames = docs.keySet().toArray(new String[docs.size()]);
        ReindexRequestBuilder request = reindex()
            .source(sourceIndexNames)
            .destination("dest", "type")
            .refresh(true)
            .setSlices(slices);

        BulkByScrollResponse response = request.get();
        assertThat(response, matcher().created(allDocs.size()).slices(hasSize(expectedSlices)));
        assertHitCount(client().prepareSearch("dest").setSize(0).get(), allDocs.size());
    }

    public void testMissingSources() {
        BulkByScrollResponse response = updateByQuery()
            .source("missing-index-*")
            .refresh(true)
            .setSlices(AbstractBulkByScrollRequest.AUTO_SLICES)
            .get();
        assertThat(response, matcher().created(0).slices(hasSize(0)));
    }

}
