/*
* 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.
*/
package org.elasticsearch.rest.action.explain;
import org.apache.lucene.search.Explanation;
import org.elasticsearch.action.explain.ExplainRequest;
import org.elasticsearch.action.explain.ExplainResponse;
import org.elasticsearch.action.support.QuerySourceBuilder;
import org.elasticsearch.client.Client;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentBuilderString;
import org.elasticsearch.index.get.GetResult;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.QueryStringQueryBuilder;
import org.elasticsearch.rest.*;
import org.elasticsearch.rest.action.support.RestActions;
import org.elasticsearch.rest.action.support.RestBuilderListener;
import org.elasticsearch.search.fetch.source.FetchSourceContext;
import java.io.IOException;
import static org.elasticsearch.rest.RestRequest.Method.GET;
import static org.elasticsearch.rest.RestRequest.Method.POST;
import static org.elasticsearch.rest.RestStatus.NOT_FOUND;
import static org.elasticsearch.rest.RestStatus.OK;
/**
* Rest action for computing a score explanation for specific documents.
*/
public class RestExplainAction extends BaseRestHandler {
@Inject
public RestExplainAction(Settings settings, RestController controller, Client client) {
super(settings, controller, client);
controller.registerHandler(GET, "/{index}/{type}/{id}/_explain", this);
controller.registerHandler(POST, "/{index}/{type}/{id}/_explain", this);
}
@Override
public void handleRequest(final RestRequest request, final RestChannel channel, final Client client) {
final ExplainRequest explainRequest = new ExplainRequest(request.param("index"), request.param("type"), request.param("id"));
explainRequest.parent(request.param("parent"));
explainRequest.routing(request.param("routing"));
explainRequest.preference(request.param("preference"));
String queryString = request.param("q");
if (RestActions.hasBodyContent(request)) {
explainRequest.source(RestActions.getRestContent(request));
} else if (queryString != null) {
QueryStringQueryBuilder queryStringBuilder = QueryBuilders.queryStringQuery(queryString);
queryStringBuilder.defaultField(request.param("df"));
queryStringBuilder.analyzer(request.param("analyzer"));
queryStringBuilder.analyzeWildcard(request.paramAsBoolean("analyze_wildcard", false));
queryStringBuilder.lowercaseExpandedTerms(request.paramAsBoolean("lowercase_expanded_terms", true));
queryStringBuilder.lenient(request.paramAsBoolean("lenient", null));
String defaultOperator = request.param("default_operator");
if (defaultOperator != null) {
if ("OR".equals(defaultOperator)) {
queryStringBuilder.defaultOperator(QueryStringQueryBuilder.Operator.OR);
} else if ("AND".equals(defaultOperator)) {
queryStringBuilder.defaultOperator(QueryStringQueryBuilder.Operator.AND);
} else {
throw new IllegalArgumentException("Unsupported defaultOperator [" + defaultOperator + "], can either be [OR] or [AND]");
}
}
QuerySourceBuilder querySourceBuilder = new QuerySourceBuilder();
querySourceBuilder.setQuery(queryStringBuilder);
explainRequest.source(querySourceBuilder);
}
String sField = request.param("fields");
if (sField != null) {
String[] sFields = Strings.splitStringByCommaToArray(sField);
if (sFields != null) {
explainRequest.fields(sFields);
}
}
explainRequest.fetchSourceContext(FetchSourceContext.parseFromRestRequest(request));
client.explain(explainRequest, new RestBuilderListener<ExplainResponse>(channel) {
@Override
public RestResponse buildResponse(ExplainResponse response, XContentBuilder builder) throws Exception {
builder.startObject();
builder.field(Fields._INDEX, response.getIndex())
.field(Fields._TYPE, response.getType())
.field(Fields._ID, response.getId())
.field(Fields.MATCHED, response.isMatch());
if (response.hasExplanation()) {
builder.startObject(Fields.EXPLANATION);
buildExplanation(builder, response.getExplanation());
builder.endObject();
}
GetResult getResult = response.getGetResult();
if (getResult != null) {
builder.startObject(Fields.GET);
response.getGetResult().toXContentEmbedded(builder, request);
builder.endObject();
}
builder.endObject();
return new BytesRestResponse(response.isExists() ? OK : NOT_FOUND, builder);
}
private void buildExplanation(XContentBuilder builder, Explanation explanation) throws IOException {
builder.field(Fields.VALUE, explanation.getValue());
builder.field(Fields.DESCRIPTION, explanation.getDescription());
Explanation[] innerExps = explanation.getDetails();
if (innerExps != null) {
builder.startArray(Fields.DETAILS);
for (Explanation exp : innerExps) {
builder.startObject();
buildExplanation(builder, exp);
builder.endObject();
}
builder.endArray();
}
}
});
}
static class Fields {
static final XContentBuilderString _INDEX = new XContentBuilderString("_index");
static final XContentBuilderString _TYPE = new XContentBuilderString("_type");
static final XContentBuilderString _ID = new XContentBuilderString("_id");
static final XContentBuilderString MATCHED = new XContentBuilderString("matched");
static final XContentBuilderString EXPLANATION = new XContentBuilderString("explanation");
static final XContentBuilderString VALUE = new XContentBuilderString("value");
static final XContentBuilderString DESCRIPTION = new XContentBuilderString("description");
static final XContentBuilderString DETAILS = new XContentBuilderString("details");
static final XContentBuilderString GET = new XContentBuilderString("get");
}
}