/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.kernel.api.impl.fulltext;

import static org.neo4j.kernel.api.impl.fulltext.FulltextIndexSettings.isEventuallyConsistent;
import static org.neo4j.kernel.api.impl.fulltext.LuceneFulltextDocumentStructure.documentRepresentingProperties;
import static org.neo4j.kernel.api.impl.fulltext.LuceneFulltextDocumentStructure.newTermForChangeOrRemove;

import java.io.IOException;
import java.io.UncheckedIOException;
import java.util.Map;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.Term;
import org.neo4j.internal.helpers.collection.BoundedIterable;
import org.neo4j.internal.schema.IndexDescriptor;
import org.neo4j.io.pagecache.context.CursorContext;
import org.neo4j.kernel.api.impl.index.AbstractLuceneIndexAccessor;
import org.neo4j.kernel.api.impl.index.DatabaseIndex;
import org.neo4j.kernel.api.index.IndexEntriesReader;
import org.neo4j.kernel.api.index.IndexUpdater;
import org.neo4j.kernel.impl.api.index.IndexUpdateMode;
import org.neo4j.kernel.impl.index.schema.IndexUpdateIgnoreStrategy;
import org.neo4j.values.storable.Value;

public class FulltextIndexAccessor
        extends AbstractLuceneIndexAccessor<FulltextIndexReader, DatabaseIndex<FulltextIndexReader>> {

    private final IndexUpdateSink indexUpdateSink;
    private final IndexDescriptor index;
    private final String[] propertyNames;

    FulltextIndexAccessor(
            IndexUpdateSink indexUpdateSink,
            DatabaseIndex<FulltextIndexReader> luceneIndex,
            IndexDescriptor index,
            String[] propertyNames,
            IndexUpdateIgnoreStrategy ignoreStrategy) {
        super(luceneIndex, index, ignoreStrategy);
        this.indexUpdateSink = indexUpdateSink;
        this.index = index;
        this.propertyNames = propertyNames;
    }

    @Override
    public IndexUpdater getIndexUpdater(IndexUpdateMode mode) {
        IndexUpdater indexUpdater = new FulltextIndexUpdater(mode.requiresIdempotency(), mode.requiresRefresh());
        if (isEventuallyConsistent(index)) {
            indexUpdater = new EventuallyConsistentIndexUpdater(luceneIndex, indexUpdater, indexUpdateSink);
        }
        return indexUpdater;
    }

    @Override
    public void close() {
        if (isEventuallyConsistent(index)) {
            indexUpdateSink.awaitUpdateApplication();
        }
        super.close();
    }

    @Override
    public BoundedIterable<Long> newAllEntriesValueReader(
            long fromIdInclusive, long toIdExclusive, CursorContext cursorContext) {
        return super.newAllEntriesReader(LuceneFulltextDocumentStructure::getNodeId, fromIdInclusive, toIdExclusive);
    }

    @Override
    public IndexEntriesReader[] newAllEntriesValueReader(int partitions, CursorContext cursorContext) {
        return super.newAllEntriesValueReader(LuceneFulltextDocumentStructure::getNodeId, partitions);
    }

    @Override
    public Map<String, Value> indexConfig() {
        return index.getIndexConfig().asMap();
    }

    public class FulltextIndexUpdater extends AbstractLuceneIndexUpdater {
        private FulltextIndexUpdater(boolean idempotent, boolean refresh) {
            super(idempotent, refresh);
        }

        @Override
        protected void addIdempotent(long entityId, Value[] values) {
            try {
                Document document = documentRepresentingProperties(entityId, propertyNames, values);
                writer.updateOrDeleteDocument(newTermForChangeOrRemove(entityId), document);
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        }

        @Override
        public void add(long entityId, Value[] values) {
            try {
                Document document = documentRepresentingProperties(entityId, propertyNames, values);
                writer.nullableAddDocument(document);
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        }

        @Override
        protected void change(long entityId, Value[] values) {
            try {
                Term term = newTermForChangeOrRemove(entityId);
                Document document = documentRepresentingProperties(entityId, propertyNames, values);
                // If the property types have changed away from TEXT we may no longer
                // have any properties that should be indexed and the old document should be removed.
                writer.updateOrDeleteDocument(term, document);
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        }

        @Override
        protected void remove(long entityId) {
            try {
                Term term = newTermForChangeOrRemove(entityId);
                writer.deleteDocuments(term);
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        }
    }
}
