/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.jackrabbit.oak.plugins.index.lucene.hybrid;

import static org.apache.jackrabbit.guava.common.util.concurrent.MoreExecutors.newDirectExecutorService;
import static org.apache.jackrabbit.oak.plugins.index.search.FulltextIndexConstants.PROP_FACETS;
import static org.apache.jackrabbit.oak.plugins.index.search.FulltextIndexConstants.STATISTICAL_FACET_SAMPLE_SIZE_DEFAULT;
import static org.apache.jackrabbit.oak.spi.mount.Mounts.defaultMountInfoProvider;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.File;
import java.io.IOException;
import java.util.Properties;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.function.Predicate;

import javax.jcr.GuestCredentials;
import javax.jcr.Repository;
import javax.jcr.RepositoryException;
import javax.jcr.Session;
import javax.jcr.query.Query;
import javax.jcr.query.QueryManager;
import javax.jcr.query.QueryResult;
import javax.jcr.query.Row;
import javax.jcr.query.RowIterator;

import org.apache.jackrabbit.oak.InitialContent;
import org.apache.jackrabbit.oak.Oak;
import org.apache.jackrabbit.oak.api.ContentRepository;
import org.apache.jackrabbit.oak.api.Tree;
import org.apache.jackrabbit.oak.api.Type;
import org.apache.jackrabbit.oak.commons.PathUtils;
import org.apache.jackrabbit.oak.commons.concurrent.ExecutorCloser;
import org.apache.jackrabbit.oak.commons.json.JsonObject;
import org.apache.jackrabbit.oak.jcr.Jcr;
import org.apache.jackrabbit.oak.plugins.index.AsyncIndexUpdate;
import org.apache.jackrabbit.oak.plugins.index.counter.NodeCounterEditorProvider;
import org.apache.jackrabbit.oak.plugins.index.lucene.IndexCopier;
import org.apache.jackrabbit.oak.plugins.index.lucene.IndexTracker;
import org.apache.jackrabbit.oak.plugins.index.lucene.LuceneIndexEditorProvider;
import org.apache.jackrabbit.oak.plugins.index.lucene.LuceneIndexProvider;
import org.apache.jackrabbit.oak.plugins.index.lucene.LucenePropertyIndex;
import org.apache.jackrabbit.oak.plugins.index.lucene.TestUtil;
import org.apache.jackrabbit.oak.plugins.index.lucene.TestUtil.OptionalEditorProvider;
import org.apache.jackrabbit.oak.plugins.index.lucene.reader.DefaultIndexReaderFactory;
import org.apache.jackrabbit.oak.plugins.index.lucene.reader.LuceneIndexReaderFactory;
import org.apache.jackrabbit.oak.plugins.index.lucene.util.LuceneIndexDefinitionBuilder;
import org.apache.jackrabbit.oak.plugins.index.nodetype.NodeTypeIndexProvider;
import org.apache.jackrabbit.oak.plugins.index.property.PropertyIndexEditorProvider;
import org.apache.jackrabbit.oak.plugins.index.search.FulltextIndexConstants;
import org.apache.jackrabbit.oak.plugins.index.search.util.IndexDefinitionBuilder.PropertyRule;
import org.apache.jackrabbit.oak.plugins.memory.MemoryNodeStore;
import org.apache.jackrabbit.oak.query.AbstractQueryTest;
import org.apache.jackrabbit.oak.spi.commit.Observer;
import org.apache.jackrabbit.oak.spi.mount.MountInfoProvider;
import org.apache.jackrabbit.oak.spi.query.QueryIndexProvider;
import org.apache.jackrabbit.oak.spi.security.OpenSecurityProvider;
import org.apache.jackrabbit.oak.spi.state.NodeStore;
import org.apache.jackrabbit.oak.spi.whiteboard.Whiteboard;
import org.apache.jackrabbit.oak.spi.whiteboard.WhiteboardUtils;
import org.apache.jackrabbit.oak.stats.Clock;
import org.apache.jackrabbit.oak.stats.StatisticsProvider;
import org.jetbrains.annotations.Nullable;
import org.junit.After;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;

public class ManyFacetsTest extends AbstractQueryTest {

    @Rule
    public TemporaryFolder temporaryFolder = new TemporaryFolder(new File("target"));

    private static final int NUM_LABELS = 4;
    private static final int NUM_LEAF_NODES = STATISTICAL_FACET_SAMPLE_SIZE_DEFAULT;
    private static final String FACET_PROP = "facets";
    private static final long REFRESH_DELTA = TimeUnit.SECONDS.toMillis(1);
    
    private static final int FACET_COUNT = 10;

    private ExecutorService executorService = Executors.newFixedThreadPool(2);
    private OptionalEditorProvider optionalEditorProvider = new OptionalEditorProvider();
    private NRTIndexFactory nrtIndexFactory;
    private LuceneIndexProvider luceneIndexProvider;
    private NodeStore nodeStore;
    private DocumentQueue queue;
    private Clock clock = new Clock.Virtual();
    private Whiteboard wb;
    private QueryManager qm;
    private Repository jcrRepo;
    private Jcr jcr;
    private Oak oak;
    // backup original system properties i.e. before test started
    private final Properties backupProperties = (Properties) System.getProperties().clone();

    @After
    public void tearDown() throws IOException {
        luceneIndexProvider.close();
        new ExecutorCloser(executorService).close();
        nrtIndexFactory.close();
        // restore original system properties i.e. before test started
        System.setProperties(backupProperties);
    }

    @Override
    protected ContentRepository createRepository() {
        IndexCopier copier;
        try {
            copier = new IndexCopier(executorService, temporaryFolder.getRoot());
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        MountInfoProvider mip = defaultMountInfoProvider();
        nrtIndexFactory = new NRTIndexFactory(copier, clock, TimeUnit.MILLISECONDS.toSeconds(REFRESH_DELTA), StatisticsProvider.NOOP);
        nrtIndexFactory.setAssertAllResourcesClosed(true);
        LuceneIndexReaderFactory indexReaderFactory = new DefaultIndexReaderFactory(mip, copier);
        IndexTracker tracker = new IndexTracker(indexReaderFactory, nrtIndexFactory);
        luceneIndexProvider = new LuceneIndexProvider(tracker);
        queue = new DocumentQueue(100, tracker, newDirectExecutorService());
        LuceneIndexEditorProvider editorProvider = new LuceneIndexEditorProvider(copier,
                tracker,
                null,
                null,
                mip);
        editorProvider.setIndexingQueue(queue);
        LocalIndexObserver localIndexObserver = new LocalIndexObserver(queue, StatisticsProvider.NOOP);
        nodeStore = new MemoryNodeStore();
        oak = new Oak(nodeStore)
                .with(new InitialContent())
                .with(new OpenSecurityProvider())
                .with((QueryIndexProvider) luceneIndexProvider)
                .with((Observer) luceneIndexProvider)
                .with(localIndexObserver)
                .with(editorProvider)
                .with(new PropertyIndexEditorProvider())
                .with(new NodeTypeIndexProvider())
                .with(optionalEditorProvider)
                .with(new NodeCounterEditorProvider())
                //Effectively disable async indexing auto run
                //such that we can control run timing as per test requirement
                .withAsyncIndexing("async", TimeUnit.DAYS.toSeconds(1));

        wb = oak.getWhiteboard();
        ContentRepository repo = oak.createContentRepository();
        return repo;
    }
    
    private void createSmallDataset(int k) throws RepositoryException {
        Random random = new Random(42);
        Tree par = createPath("/parent" + k);
        par.setProperty("foo", "bar");
        for (int i = 0; i < NUM_LABELS * 2; i++) {
            Tree subPar = par.addChild("par" + i);
            for (int j = 0; j < NUM_LEAF_NODES / (2 * NUM_LABELS); j++) {
                Tree child = subPar.addChild("c" + j);
                child.setProperty("cons", "val");
                for (int f = 0; f < FACET_COUNT; f++) {
                    int labelNum = random.nextInt(NUM_LABELS);
                    child.setProperty("foo" + f, "foo"  + f + "x" + labelNum);
                }
            }
        }
    }
    
    private Tree createPath(String path) {
        Tree base = root.getTree("/");
        for (String e : PathUtils.elements(path)) {
            base = base.addChild(e);
        }
        return base;
    }
    
    private void runAsyncIndex() {
        AsyncIndexUpdate async = (AsyncIndexUpdate) WhiteboardUtils.getService(wb, Runnable.class, new Predicate<Runnable>() {
            @Override
            public boolean test(@Nullable Runnable input) {
                return input instanceof AsyncIndexUpdate;
            }
        });
        assertNotNull(async);
        async.run();
        if (async.isFailing()) {
            fail("AsyncIndexUpdate failed");
        }
        root.refresh();
    }
    
    @Test
    public void facet() throws Exception {
        // Explicitly setting following configs to run DelayedLuceneFacetProvider and a thread sleep of 50 ms in refresh readers. Refer: OAK-8898
        System.setProperty(LucenePropertyIndex.OLD_FACET_PROVIDER_CONFIG_NAME, "false");
        // The variable is static final so once set it remains same for all tests and which will lead to slow execution
        // of other tests as this add a sleep of specified milliseconds in refresh reader method in LuceneIndexNodeManager.
        // System.setProperty(LuceneIndexNodeManager.OLD_FACET_PROVIDER_TEST_FAILURE_SLEEP_INSTRUMENT_NAME, "40");
        Thread.currentThread().setName("main");
        String idxName = "hybridtest";
        Tree idx = createIndex(root.getTree("/"), idxName);
        TestUtil.enableIndexingMode(idx, FulltextIndexConstants.IndexingMode.NRT);
        setTraversalEnabled(false);
        root.commit();
        jcr = new Jcr(oak);
        jcrRepo = jcr.createRepository();
        createSmallDataset(0);
        clock.waitUntil(clock.getTime() + REFRESH_DELTA + 1);
        root.commit();
        runAsyncIndex();
        createSmallDataset(2);
        clock.waitUntil(clock.getTime() + REFRESH_DELTA + 1);
        root.commit();
        Session anonSession = jcrRepo.login(new GuestCredentials());
        qm = anonSession.getWorkspace().getQueryManager();
        String facetList = "";
        for (int i = 0; i < FACET_COUNT; i++) {
            if (i > 0) {
                facetList += ", ";
            }
            facetList += "[rep:facet(foo" + i + ")]";
        }
        String queryString = "SELECT " + facetList + 
                " FROM [nt:base] WHERE [cons] = 'val'";
        Query q = qm.createQuery(queryString, SQL2);
        QueryResult qr = q.execute();
        try {
            RowIterator it = qr.getRows();
            assertTrue(it.hasNext());
            while (it.hasNext()) {
                Row r = it.nextRow();
                for (int i = 0; i < qr.getColumnNames().length; i++) {
                    String columnName = qr.getColumnNames()[i];
                    String v = r.getValue(columnName).getString();
                    JsonObject json = JsonObject.fromJson(v, true);
                    for (int j = 0; j < NUM_LABELS; j++) {
                        String n = json.getProperties().get("foo" + i + "x" + j);
                        assertNotNull(n);
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw e;
        }
    }
    
    private Tree createIndex(Tree index, String name) throws RepositoryException {
        LuceneIndexDefinitionBuilder idxBuilder = new LuceneIndexDefinitionBuilder();
        PropertyRule pr = idxBuilder.noAsync()
                .indexRule("nt:base")
                .property("cons").propertyIndex();
        for (int i = 0; i < FACET_COUNT; i++) {
            pr.property("foo" + i).propertyIndex().getBuilderTree().setProperty(PROP_FACETS, true);
        }
        Tree facetConfig = idxBuilder.getBuilderTree().addChild(FACET_PROP);
        facetConfig.setProperty("jcr:primaryType", "nt:unstructured", Type.NAME);
        facetConfig.setProperty("secure", "statistical");
        facetConfig.setProperty("topChildren", "100");
        Tree idxTree = index.getChild("oak:index").addChild(name);
        idxBuilder.build(idxTree);
        return idxTree;
    }
    
}
