/*
* 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.search.suggest;
import org.elasticsearch.action.support.ToXContentToBytes;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.ParsingException;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.common.lucene.BytesRefs;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.query.QueryShardContext;
import org.elasticsearch.search.suggest.SuggestionSearchContext.SuggestionContext;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Objects;
/**
* Defines how to perform suggesting. This builders allows a number of global options to be specified and
* an arbitrary number of {@link SuggestionBuilder} instances.
* <p>
* Suggesting works by suggesting terms/phrases that appear in the suggest text that are similar compared
* to the terms in provided text. These suggestions are based on several options described in this class.
*/
public class SuggestBuilder extends ToXContentToBytes implements Writeable {
protected static final ParseField GLOBAL_TEXT_FIELD = new ParseField("text");
private String globalText;
private final Map<String, SuggestionBuilder<?>> suggestions = new HashMap<>();
/**
* Build an empty SuggestBuilder.
*/
public SuggestBuilder() {
}
/**
* Read from a stream.
*/
public SuggestBuilder(StreamInput in) throws IOException {
globalText = in.readOptionalString();
final int size = in.readVInt();
for (int i = 0; i < size; i++) {
suggestions.put(in.readString(), in.readNamedWriteable(SuggestionBuilder.class));
}
}
@Override
public void writeTo(StreamOutput out) throws IOException {
out.writeOptionalString(globalText);
final int size = suggestions.size();
out.writeVInt(size);
for (Entry<String, SuggestionBuilder<?>> suggestion : suggestions.entrySet()) {
out.writeString(suggestion.getKey());
out.writeNamedWriteable(suggestion.getValue());
}
}
/**
* Sets the text to provide suggestions for. The suggest text is a required option that needs
* to be set either via this setter or via the {@link org.elasticsearch.search.suggest.SuggestionBuilder#text(String)} method.
* <p>
* The suggest text gets analyzed by the suggest analyzer or the suggest field search analyzer.
* For each analyzed token, suggested terms are suggested if possible.
*/
public SuggestBuilder setGlobalText(@Nullable String globalText) {
this.globalText = globalText;
return this;
}
/**
* Gets the global suggest text
*/
@Nullable
public String getGlobalText() {
return globalText;
}
/**
* Adds an {@link org.elasticsearch.search.suggest.SuggestionBuilder} instance under a user defined name.
* The order in which the <code>Suggestions</code> are added, is the same as in the response.
* @throws IllegalArgumentException if two suggestions added have the same name
*/
public SuggestBuilder addSuggestion(String name, SuggestionBuilder<?> suggestion) {
Objects.requireNonNull(name, "every suggestion needs a name");
if (suggestions.get(name) == null) {
suggestions.put(name, suggestion);
} else {
throw new IllegalArgumentException("already added another suggestion with name [" + name + "]");
}
return this;
}
/**
* Get all the <code>Suggestions</code> that were added to the global {@link SuggestBuilder},
* together with their names
*/
public Map<String, SuggestionBuilder<?>> getSuggestions() {
return suggestions;
}
@Override
public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
builder.startObject();
if (globalText != null) {
builder.field("text", globalText);
}
for (Entry<String, SuggestionBuilder<?>> suggestion : suggestions.entrySet()) {
builder.startObject(suggestion.getKey());
suggestion.getValue().toXContent(builder, params);
builder.endObject();
}
builder.endObject();
return builder;
}
public static SuggestBuilder fromXContent(XContentParser parser) throws IOException {
SuggestBuilder suggestBuilder = new SuggestBuilder();
String fieldName = null;
if (parser.currentToken() == null) {
// when we parse from RestSuggestAction the current token is null, advance the token
parser.nextToken();
}
assert parser.currentToken() == XContentParser.Token.START_OBJECT : "current token must be a start object";
XContentParser.Token token;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
fieldName = parser.currentName();
} else if (token.isValue()) {
if (GLOBAL_TEXT_FIELD.match(fieldName)) {
suggestBuilder.setGlobalText(parser.text());
} else {
throw new IllegalArgumentException("[suggest] does not support [" + fieldName + "]");
}
} else if (token == XContentParser.Token.START_OBJECT) {
String suggestionName = fieldName;
if (suggestionName == null) {
throw new IllegalArgumentException("suggestion must have name");
}
suggestBuilder.addSuggestion(suggestionName, SuggestionBuilder.fromXContent(parser));
} else {
throw new ParsingException(parser.getTokenLocation(), "unexpected token [" + token + "] after [" + fieldName + "]");
}
}
return suggestBuilder;
}
public SuggestionSearchContext build(QueryShardContext context) throws IOException {
SuggestionSearchContext suggestionSearchContext = new SuggestionSearchContext();
for (Entry<String, SuggestionBuilder<?>> suggestion : suggestions.entrySet()) {
SuggestionContext suggestionContext = suggestion.getValue().build(context);
if (suggestionContext.getText() == null) {
if (globalText == null) {
throw new IllegalArgumentException("The required text option is missing");
}
suggestionContext.setText(BytesRefs.toBytesRef(globalText));
}
suggestionSearchContext.addSuggestion(suggestion.getKey(), suggestionContext);
}
return suggestionSearchContext;
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (other == null || getClass() != other.getClass()) {
return false;
}
SuggestBuilder o = (SuggestBuilder) other;
return Objects.equals(globalText, o.globalText) &&
Objects.equals(suggestions, o.suggestions);
}
@Override
public int hashCode() {
return Objects.hash(globalText, suggestions);
}
}