package org.apache.lucene.queryparser.xml;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.queryparser.xml.builders.*;
import org.apache.lucene.search.Query;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.InputStream;

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.
 */

/**
 * Assembles a QueryBuilder which uses only core Lucene Query objects
 */
public class CoreParser implements QueryBuilder {

  protected Analyzer analyzer;
  protected QueryParser parser;
  protected QueryBuilderFactory queryFactory;
  protected FilterBuilderFactory filterFactory;
  //Controls the max size of the LRU cache used for QueryFilter objects parsed.
  public static int maxNumCachedFilters = 20;


  /**
   * Construct an XML parser that uses a single instance QueryParser for handling
   * UserQuery tags - all parse operations are synchronised on this parser
   *
   * @param parser A QueryParser which will be synchronized on during parse calls.
   */
  public CoreParser(Analyzer analyzer, QueryParser parser) {
    this(null, analyzer, parser);
  }

  /**
   * Constructs an XML parser that creates a QueryParser for each UserQuery request.
   *
   * @param defaultField The default field name used by QueryParsers constructed for UserQuery tags
   */
  public CoreParser(String defaultField, Analyzer analyzer) {
    this(defaultField, analyzer, null);
  }

  protected CoreParser(String defaultField, Analyzer analyzer, QueryParser parser) {
    this.analyzer = analyzer;
    this.parser = parser;
    filterFactory = new FilterBuilderFactory();
    filterFactory.addBuilder("RangeFilter", new RangeFilterBuilder());
    filterFactory.addBuilder("NumericRangeFilter", new NumericRangeFilterBuilder());

    queryFactory = new QueryBuilderFactory();
    queryFactory.addBuilder("TermQuery", new TermQueryBuilder());
    queryFactory.addBuilder("TermsQuery", new TermsQueryBuilder(analyzer));
    queryFactory.addBuilder("MatchAllDocsQuery", new MatchAllDocsQueryBuilder());
    queryFactory.addBuilder("BooleanQuery", new BooleanQueryBuilder(queryFactory));
    queryFactory.addBuilder("NumericRangeQuery", new NumericRangeQueryBuilder());
    queryFactory.addBuilder("DisjunctionMaxQuery", new DisjunctionMaxQueryBuilder(queryFactory));
    if (parser != null) {
      queryFactory.addBuilder("UserQuery", new UserInputQueryBuilder(parser));
    } else {
      queryFactory.addBuilder("UserQuery", new UserInputQueryBuilder(defaultField, analyzer));
    }
    queryFactory.addBuilder("FilteredQuery", new FilteredQueryBuilder(filterFactory, queryFactory));
    queryFactory.addBuilder("ConstantScoreQuery", new ConstantScoreQueryBuilder(filterFactory));

    filterFactory.addBuilder("CachedFilter", new CachedFilterBuilder(queryFactory,
        filterFactory, maxNumCachedFilters));


    SpanQueryBuilderFactory sqof = new SpanQueryBuilderFactory();

    SpanNearBuilder snb = new SpanNearBuilder(sqof);
    sqof.addBuilder("SpanNear", snb);
    queryFactory.addBuilder("SpanNear", snb);

    BoostingTermBuilder btb = new BoostingTermBuilder();
    sqof.addBuilder("BoostingTermQuery", btb);
    queryFactory.addBuilder("BoostingTermQuery", btb);

    SpanTermBuilder snt = new SpanTermBuilder();
    sqof.addBuilder("SpanTerm", snt);
    queryFactory.addBuilder("SpanTerm", snt);

    SpanOrBuilder sot = new SpanOrBuilder(sqof);
    sqof.addBuilder("SpanOr", sot);
    queryFactory.addBuilder("SpanOr", sot);

    SpanOrTermsBuilder sots = new SpanOrTermsBuilder(analyzer);
    sqof.addBuilder("SpanOrTerms", sots);
    queryFactory.addBuilder("SpanOrTerms", sots);

    SpanFirstBuilder sft = new SpanFirstBuilder(sqof);
    sqof.addBuilder("SpanFirst", sft);
    queryFactory.addBuilder("SpanFirst", sft);

    SpanNotBuilder snot = new SpanNotBuilder(sqof);
    sqof.addBuilder("SpanNot", snot);
    queryFactory.addBuilder("SpanNot", snot);
  }

  public Query parse(InputStream xmlStream) throws ParserException {
    return getQuery(parseXML(xmlStream).getDocumentElement());
  }

  public void addQueryBuilder(String nodeName, QueryBuilder builder) {
    queryFactory.addBuilder(nodeName, builder);
  }

  public void addFilterBuilder(String nodeName, FilterBuilder builder) {
    filterFactory.addBuilder(nodeName, builder);
  }

  private static Document parseXML(InputStream pXmlFile) throws ParserException {
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = null;
    try {
      db = dbf.newDocumentBuilder();
    }
    catch (Exception se) {
      throw new ParserException("XML Parser configuration error", se);
    }
    org.w3c.dom.Document doc = null;
    try {
      doc = db.parse(pXmlFile);
    }
    catch (Exception se) {
      throw new ParserException("Error parsing XML stream:" + se, se);
    }
    return doc;
  }


  @Override
  public Query getQuery(Element e) throws ParserException {
    return queryFactory.getQuery(e);
  }
}