/*
 * 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.rest.action.admin.indices;

import org.elasticsearch.action.admin.indices.mapping.get.GetFieldMappingsRequest;
import org.elasticsearch.action.admin.indices.mapping.get.GetFieldMappingsResponse;
import org.elasticsearch.action.admin.indices.mapping.get.GetFieldMappingsResponse.FieldMappingMetadata;
import org.elasticsearch.action.support.IndicesOptions;
import org.elasticsearch.client.internal.node.NodeClient;
import org.elasticsearch.common.Strings;
import org.elasticsearch.rest.BaseRestHandler;
import org.elasticsearch.rest.RestRequest;
import org.elasticsearch.rest.RestResponse;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.rest.action.RestBuilderListener;
import org.elasticsearch.xcontent.XContentBuilder;

import java.io.IOException;
import java.util.List;
import java.util.Map;

import static org.elasticsearch.rest.RestRequest.Method.GET;
import static org.elasticsearch.rest.RestStatus.NOT_FOUND;
import static org.elasticsearch.rest.RestStatus.OK;

public class RestGetFieldMappingAction extends BaseRestHandler {

    @Override
    public List<Route> routes() {
        return List.of(new Route(GET, "/_mapping/field/{fields}"), new Route(GET, "/{index}/_mapping/field/{fields}"));
    }

    @Override
    public String getName() {
        return "get_field_mapping_action";
    }

    @Override
    public RestChannelConsumer prepareRequest(final RestRequest request, final NodeClient client) throws IOException {
        final String[] indices = Strings.splitStringByCommaToArray(request.param("index"));
        final String[] fields = Strings.splitStringByCommaToArray(request.param("fields"));

        GetFieldMappingsRequest getMappingsRequest = new GetFieldMappingsRequest();
        getMappingsRequest.indices(indices).fields(fields).includeDefaults(request.paramAsBoolean("include_defaults", false));
        getMappingsRequest.indicesOptions(IndicesOptions.fromRequest(request, getMappingsRequest.indicesOptions()));
        return channel -> client.admin().indices().getFieldMappings(getMappingsRequest, new RestBuilderListener<>(channel) {
            @Override
            public RestResponse buildResponse(GetFieldMappingsResponse response, XContentBuilder builder) throws Exception {
                Map<String, Map<String, FieldMappingMetadata>> mappingsByIndex = response.mappings();

                RestStatus status = OK;
                if (mappingsByIndex.isEmpty() && fields.length > 0) {
                    status = NOT_FOUND;
                }
                response.toXContent(builder, request);
                return new RestResponse(status, builder);
            }
        });
    }

}