/*
 * 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 java.io.IOException;
import java.io.UncheckedIOException;
import java.util.Collection;
import java.util.Map;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.Term;
import org.neo4j.internal.schema.IndexDescriptor;
import org.neo4j.io.pagecache.context.CursorContext;
import org.neo4j.kernel.api.impl.index.DatabaseIndex;
import org.neo4j.kernel.api.impl.schema.populator.LuceneIndexPopulator;
import org.neo4j.kernel.api.index.IndexSample;
import org.neo4j.kernel.api.index.IndexUpdater;
import org.neo4j.kernel.impl.index.schema.IndexUpdateIgnoreStrategy;
import org.neo4j.storageengine.api.IndexEntryUpdate;
import org.neo4j.storageengine.api.ValueIndexEntryUpdate;
import org.neo4j.values.storable.Value;

public class FulltextIndexPopulator extends LuceneIndexPopulator<DatabaseIndex<FulltextIndexReader>> {
    private final IndexDescriptor descriptor;
    private final String[] propertyNames;

    FulltextIndexPopulator(
            IndexDescriptor descriptor,
            DatabaseIndex<FulltextIndexReader> luceneFulltext,
            String[] propertyNames,
            IndexUpdateIgnoreStrategy ignoreStrategy) {
        super(luceneFulltext, ignoreStrategy);
        this.descriptor = descriptor;
        this.propertyNames = propertyNames;
    }

    @Override
    public void add(Collection<? extends IndexEntryUpdate<?>> updates, CursorContext cursorContext) {
        try {
            for (IndexEntryUpdate<?> update : updates) {
                final var valueUpdate = (ValueIndexEntryUpdate<?>) update;
                if (ignoreStrategy.ignore(valueUpdate.values())) {
                    continue;
                }

                writer.updateOrDeleteDocument(
                        LuceneFulltextDocumentStructure.newTermForChangeOrRemove(valueUpdate.getEntityId()),
                        updateAsDocument(valueUpdate));
            }
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        }
    }

    @Override
    public IndexUpdater newPopulatingUpdater(CursorContext cursorContext) {
        return new PopulatingFulltextIndexUpdater();
    }

    @Override
    public IndexSample sample(CursorContext cursorContext) {
        return new IndexSample();
    }

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

    @Override
    protected Document updateAsDocument(ValueIndexEntryUpdate<?> update) {
        return LuceneFulltextDocumentStructure.documentRepresentingProperties(
                update.getEntityId(), propertyNames, update.values());
    }

    private class PopulatingFulltextIndexUpdater implements IndexUpdater {
        @Override
        public void process(IndexEntryUpdate<?> update) {
            ValueIndexEntryUpdate<?> valueUpdate = asValueUpdate(update);
            if (ignoreStrategy.ignore(valueUpdate)) {
                return;
            }
            try {
                long nodeId = valueUpdate.getEntityId();
                Term term = LuceneFulltextDocumentStructure.newTermForChangeOrRemove(nodeId);
                switch (valueUpdate.updateMode()) {
                    case ADDED, CHANGED -> luceneIndex
                            .getIndexWriter()
                            .updateOrDeleteDocument(
                                    term,
                                    LuceneFulltextDocumentStructure.documentRepresentingProperties(
                                            nodeId, propertyNames, valueUpdate.values()));
                    case REMOVED -> luceneIndex.getIndexWriter().deleteDocuments(term);
                    default -> throw new UnsupportedOperationException();
                }
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        }

        @Override
        public void close() {}
    }
}
