/*
 * 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.fielddata;

import org.apache.lucene.analysis.core.KeywordAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field.Store;
import org.apache.lucene.document.StringField;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.store.ByteBuffersDirectory;
import org.apache.lucene.util.Accountable;
import org.apache.lucene.util.SetOnce;
import org.elasticsearch.common.lucene.index.ElasticsearchDirectoryReader;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.index.IndexService;
import org.elasticsearch.index.fielddata.plain.SortedDoublesIndexFieldData;
import org.elasticsearch.index.fielddata.plain.SortedNumericIndexFieldData;
import org.elasticsearch.index.fielddata.plain.SortedSetOrdinalsIndexFieldData;
import org.elasticsearch.index.mapper.BooleanFieldMapper;
import org.elasticsearch.index.mapper.IndexType;
import org.elasticsearch.index.mapper.KeywordFieldMapper;
import org.elasticsearch.index.mapper.MappedFieldType;
import org.elasticsearch.index.mapper.MapperBuilderContext;
import org.elasticsearch.index.mapper.NumberFieldMapper;
import org.elasticsearch.index.mapper.NumberFieldMapper.NumberType;
import org.elasticsearch.index.mapper.TextFieldMapper;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.indices.IndicesService;
import org.elasticsearch.indices.fielddata.cache.IndicesFieldDataCache;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.script.ScriptCompiler;
import org.elasticsearch.search.lookup.SearchLookup;
import org.elasticsearch.test.ESSingleNodeTestCase;
import org.elasticsearch.test.IndexSettingsModule;
import org.elasticsearch.test.InternalSettingsPlugin;
import org.mockito.ArgumentMatchers;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Supplier;

import static org.elasticsearch.index.mapper.NumberFieldMapper.NumberType.BYTE;
import static org.elasticsearch.index.mapper.NumberFieldMapper.NumberType.DOUBLE;
import static org.elasticsearch.index.mapper.NumberFieldMapper.NumberType.INTEGER;
import static org.elasticsearch.index.mapper.NumberFieldMapper.NumberType.LONG;
import static org.elasticsearch.index.mapper.NumberFieldMapper.NumberType.SHORT;
import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.equalTo;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

public class IndexFieldDataServiceTests extends ESSingleNodeTestCase {

    @Override
    protected Collection<Class<? extends Plugin>> getPlugins() {
        return pluginList(InternalSettingsPlugin.class);
    }

    public void testGetForFieldDefaults() {
        final IndexService indexService = createIndex("test");
        final IndicesService indicesService = getInstanceFromNode(IndicesService.class);
        final IndexFieldDataService ifdService = new IndexFieldDataService(
            indexService.getIndexSettings(),
            indicesService.getIndicesFieldDataCache(),
            indicesService.getCircuitBreakerService()
        );
        MapperBuilderContext context = MapperBuilderContext.root(false, false);
        final MappedFieldType stringMapper = new KeywordFieldMapper.Builder("string", defaultIndexSettings()).build(context).fieldType();
        ifdService.clear();
        IndexFieldData<?> fd = ifdService.getForField(stringMapper, FieldDataContext.noRuntimeFields("test", "test"));
        assertTrue(fd instanceof SortedSetOrdinalsIndexFieldData);

        for (MappedFieldType mapper : Arrays.asList(
            new NumberFieldMapper.Builder("int", BYTE, ScriptCompiler.NONE, defaultIndexSettings()).build(context).fieldType(),
            new NumberFieldMapper.Builder("int", SHORT, ScriptCompiler.NONE, defaultIndexSettings()).build(context).fieldType(),
            new NumberFieldMapper.Builder("int", INTEGER, ScriptCompiler.NONE, defaultIndexSettings()).build(context).fieldType(),
            new NumberFieldMapper.Builder("long", LONG, ScriptCompiler.NONE, defaultIndexSettings()).build(context).fieldType()
        )) {
            ifdService.clear();
            fd = ifdService.getForField(mapper, FieldDataContext.noRuntimeFields("test", "test"));
            assertTrue(fd instanceof SortedNumericIndexFieldData);
        }

        final MappedFieldType floatMapper = new NumberFieldMapper.Builder(
            "float",
            NumberType.FLOAT,
            ScriptCompiler.NONE,
            defaultIndexSettings()
        ).build(context).fieldType();
        ifdService.clear();
        fd = ifdService.getForField(floatMapper, FieldDataContext.noRuntimeFields("test", "test"));
        assertTrue(fd instanceof SortedDoublesIndexFieldData);

        final MappedFieldType doubleMapper = new NumberFieldMapper.Builder("double", DOUBLE, ScriptCompiler.NONE, defaultIndexSettings())
            .build(context)
            .fieldType();
        ifdService.clear();
        fd = ifdService.getForField(doubleMapper, FieldDataContext.noRuntimeFields("test", "test"));
        assertTrue(fd instanceof SortedDoublesIndexFieldData);
    }

    public void testGetForFieldRuntimeField() {
        final IndexService indexService = createIndex("test");
        final IndicesService indicesService = getInstanceFromNode(IndicesService.class);
        final IndexFieldDataService ifdService = new IndexFieldDataService(
            indexService.getIndexSettings(),
            indicesService.getIndicesFieldDataCache(),
            indicesService.getCircuitBreakerService()
        );
        final SetOnce<Supplier<SearchLookup>> searchLookupSetOnce = new SetOnce<>();
        MappedFieldType ft = mock(MappedFieldType.class);
        when(ft.fielddataBuilder(ArgumentMatchers.any())).thenAnswer(invocationOnMock -> {
            @SuppressWarnings("unchecked")
            FieldDataContext fdc = (FieldDataContext) invocationOnMock.getArguments()[0];
            searchLookupSetOnce.set(fdc.lookupSupplier());
            return (IndexFieldData.Builder) (cache, breakerService) -> null;
        });
        SearchLookup searchLookup = new SearchLookup(null, null, (ctx, doc) -> null);
        ifdService.getForField(
            ft,
            new FieldDataContext("qualified", null, () -> searchLookup, null, MappedFieldType.FielddataOperation.SEARCH)
        );
        assertSame(searchLookup, searchLookupSetOnce.get().get());
    }

    public void testClearField() throws Exception {
        final IndexService indexService = createIndex("test");
        final IndicesService indicesService = getInstanceFromNode(IndicesService.class);
        // copy the ifdService since we can set the listener only once.
        final IndexFieldDataService ifdService = new IndexFieldDataService(
            indexService.getIndexSettings(),
            indicesService.getIndicesFieldDataCache(),
            indicesService.getCircuitBreakerService()
        );

        final MapperBuilderContext context = MapperBuilderContext.root(false, false);
        final MappedFieldType mapper1 = new TextFieldMapper.Builder("field_1", createDefaultIndexAnalyzers()).fielddata(true)
            .build(context)
            .fieldType();
        final MappedFieldType mapper2 = new TextFieldMapper.Builder("field_2", createDefaultIndexAnalyzers()).fielddata(true)
            .build(context)
            .fieldType();
        final IndexWriter writer = new IndexWriter(new ByteBuffersDirectory(), new IndexWriterConfig(new KeywordAnalyzer()));
        Document doc = new Document();
        doc.add(new StringField("field_1", "thisisastring", Store.NO));
        doc.add(new StringField("field_2", "thisisanotherstring", Store.NO));
        writer.addDocument(doc);
        final IndexReader reader = DirectoryReader.open(writer);
        final AtomicInteger onCacheCalled = new AtomicInteger();
        final AtomicInteger onRemovalCalled = new AtomicInteger();
        ifdService.setListener(new IndexFieldDataCache.Listener() {
            @Override
            public void onCache(ShardId shardId, String fieldName, Accountable ramUsage) {
                onCacheCalled.incrementAndGet();
            }

            @Override
            public void onRemoval(ShardId shardId, String fieldName, boolean wasEvicted, long sizeInBytes) {
                onRemovalCalled.incrementAndGet();
            }
        });
        IndexFieldData<?> ifd1 = ifdService.getForField(mapper1, FieldDataContext.noRuntimeFields("test", "test"));
        IndexFieldData<?> ifd2 = ifdService.getForField(mapper2, FieldDataContext.noRuntimeFields("test", "test"));
        LeafReaderContext leafReaderContext = reader.getContext().leaves().get(0);
        LeafFieldData loadField1 = ifd1.load(leafReaderContext);
        LeafFieldData loadField2 = ifd2.load(leafReaderContext);

        assertEquals(2, onCacheCalled.get());
        assertEquals(0, onRemovalCalled.get());

        ifdService.clearField("field_1");

        assertEquals(2, onCacheCalled.get());
        assertEquals(1, onRemovalCalled.get());

        ifdService.clearField("field_1");

        assertEquals(2, onCacheCalled.get());
        assertEquals(1, onRemovalCalled.get());

        ifdService.clearField("field_2");

        assertEquals(2, onCacheCalled.get());
        assertEquals(2, onRemovalCalled.get());

        reader.close();
        writer.close();
        ifdService.clear();
    }

    public void testFieldDataCacheListener() throws Exception {
        final IndexService indexService = createIndex("test");
        final IndicesService indicesService = getInstanceFromNode(IndicesService.class);
        // copy the ifdService since we can set the listener only once.
        final IndexFieldDataService ifdService = new IndexFieldDataService(
            indexService.getIndexSettings(),
            indicesService.getIndicesFieldDataCache(),
            indicesService.getCircuitBreakerService()
        );

        final MapperBuilderContext context = MapperBuilderContext.root(false, false);
        final MappedFieldType mapper1 = new TextFieldMapper.Builder("s", createDefaultIndexAnalyzers()).fielddata(true)
            .build(context)
            .fieldType();
        final IndexWriter writer = new IndexWriter(new ByteBuffersDirectory(), new IndexWriterConfig(new KeywordAnalyzer()));
        Document doc = new Document();
        doc.add(new StringField("s", "thisisastring", Store.NO));
        writer.addDocument(doc);
        DirectoryReader open = DirectoryReader.open(writer);
        final boolean wrap = randomBoolean();
        final IndexReader reader = wrap ? ElasticsearchDirectoryReader.wrap(open, new ShardId("test", "_na_", 1)) : open;
        final AtomicInteger onCacheCalled = new AtomicInteger();
        final AtomicInteger onRemovalCalled = new AtomicInteger();
        ifdService.setListener(new IndexFieldDataCache.Listener() {
            @Override
            public void onCache(ShardId shardId, String fieldName, Accountable ramUsage) {
                if (wrap) {
                    assertEquals(new ShardId("test", "_na_", 1), shardId);
                } else {
                    assertNull(shardId);
                }
                onCacheCalled.incrementAndGet();
            }

            @Override
            public void onRemoval(ShardId shardId, String fieldName, boolean wasEvicted, long sizeInBytes) {
                if (wrap) {
                    assertEquals(new ShardId("test", "_na_", 1), shardId);
                } else {
                    assertNull(shardId);
                }
                onRemovalCalled.incrementAndGet();
            }
        });
        IndexFieldData<?> ifd = ifdService.getForField(mapper1, FieldDataContext.noRuntimeFields("test", "test"));
        LeafReaderContext leafReaderContext = reader.getContext().leaves().get(0);
        LeafFieldData load = ifd.load(leafReaderContext);
        assertEquals(1, onCacheCalled.get());
        assertEquals(0, onRemovalCalled.get());
        reader.close();
        writer.close();
        assertEquals(1, onCacheCalled.get());
        assertEquals(1, onRemovalCalled.get());
        ifdService.clear();
    }

    public void testSetCacheListenerTwice() {
        final IndexService indexService = createIndex("test");
        final IndicesService indicesService = getInstanceFromNode(IndicesService.class);
        final IndexFieldDataService shardPrivateService = new IndexFieldDataService(
            indexService.getIndexSettings(),
            indicesService.getIndicesFieldDataCache(),
            indicesService.getCircuitBreakerService()
        );
        // set it the first time...
        shardPrivateService.setListener(new IndexFieldDataCache.Listener() {

        });
        // now set it again and make sure we fail
        try {
            shardPrivateService.setListener(new IndexFieldDataCache.Listener() {

            });
            fail("listener already set");
        } catch (IllegalStateException ex) {
            // all well
        }
    }

    private void doTestRequireDocValues(MappedFieldType ft) {
        Settings settings = Settings.EMPTY;
        IndicesFieldDataCache cache = new IndicesFieldDataCache(settings, null);
        IndexFieldDataService ifds = new IndexFieldDataService(IndexSettingsModule.newIndexSettings("test", settings), cache, null);
        if (ft.hasDocValues()) {
            ifds.getForField(ft, FieldDataContext.noRuntimeFields("test", "test")); // no exception
        } else {
            IllegalArgumentException e = expectThrows(
                IllegalArgumentException.class,
                () -> ifds.getForField(ft, FieldDataContext.noRuntimeFields("test", "test"))
            );
            assertThat(e.getMessage(), containsString("doc values"));
        }
    }

    public void testRequireDocValuesOnLongs() {
        doTestRequireDocValues(new NumberFieldMapper.NumberFieldType("field", LONG));
        doTestRequireDocValues(
            new NumberFieldMapper.NumberFieldType(
                "field",
                LONG,
                IndexType.points(true, false),
                false,
                false,
                null,
                Collections.emptyMap(),
                null,
                false,
                null,
                null,
                false
            )
        );
    }

    public void testRequireDocValuesOnDoubles() {
        doTestRequireDocValues(new NumberFieldMapper.NumberFieldType("field", NumberType.DOUBLE));
        doTestRequireDocValues(
            new NumberFieldMapper.NumberFieldType(
                "field",
                NumberType.DOUBLE,
                IndexType.points(true, false),
                false,
                false,
                null,
                Collections.emptyMap(),
                null,
                false,
                null,
                null,
                false
            )
        );
    }

    public void testRequireDocValuesOnBools() {
        doTestRequireDocValues(new BooleanFieldMapper.BooleanFieldType("field"));
        doTestRequireDocValues(
            new BooleanFieldMapper.BooleanFieldType(
                "field",
                IndexType.terms(true, false),
                false,
                null,
                null,
                Collections.emptyMap(),
                false,
                false
            )
        );
    }

    public void testFieldDataCacheExpire() {
        {
            Settings settings = Settings.EMPTY;
            IndicesFieldDataCache cache = new IndicesFieldDataCache(settings, new IndexFieldDataCache.Listener() {
            });
            assertThat(cache.getCache().getExpireAfterAccessNanos(), equalTo(3_600_000_000_000L));
        }
        {
            Settings settings = Settings.builder().put(IndicesFieldDataCache.INDICES_FIELDDATA_CACHE_EXPIRE.getKey(), "5s").build();
            IndicesFieldDataCache cache = new IndicesFieldDataCache(settings, new IndexFieldDataCache.Listener() {
            });
            assertThat(cache.getCache().getExpireAfterAccessNanos(), equalTo(5_000_000_000L));
        }
    }
}