/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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.
 */

/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.index.mapper;

import org.apache.lucene.document.Field.Store;
import org.apache.lucene.document.StringField;

import java.io.IOException;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

public class ExternalMetadataMapper extends MetadataFieldMapper {

    static final String CONTENT_TYPE = "_external_root";
    static final String FIELD_NAME = "_is_external";
    static final String FIELD_VALUE = "true";

    protected ExternalMetadataMapper() {
        super(new BooleanFieldMapper.BooleanFieldType(FIELD_NAME));
    }

    @Override
    public Iterator<Mapper> iterator() {
        return Collections.emptyIterator();
    }

    @Override
    protected String contentType() {
        return CONTENT_TYPE;
    }

    @Override
    public void postParse(ParseContext context) throws IOException {
        context.doc().add(new StringField(FIELD_NAME, FIELD_VALUE, Store.YES));
    }

    public static class Builder extends MetadataFieldMapper.Builder {

        protected Builder() {
            super(FIELD_NAME);
        }

        @Override
        protected List<Parameter<?>> getParameters() {
            return Collections.emptyList();
        }

        @Override
        public ExternalMetadataMapper build(BuilderContext context) {
            return new ExternalMetadataMapper();
        }

    }

    public static final TypeParser PARSER = new ConfigurableTypeParser(c -> new ExternalMetadataMapper(), c -> new Builder());

}