package org.apache.lucene.queryParser.spans;

/**
 * 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.
 */

import java.util.List;

import org.apache.lucene.messages.MessageImpl;
import org.apache.lucene.queryParser.core.QueryNodeException;
import org.apache.lucene.queryParser.core.messages.QueryParserMessages;
import org.apache.lucene.queryParser.core.nodes.AndQueryNode;
import org.apache.lucene.queryParser.core.nodes.BooleanQueryNode;
import org.apache.lucene.queryParser.core.nodes.FieldQueryNode;
import org.apache.lucene.queryParser.core.nodes.OrQueryNode;
import org.apache.lucene.queryParser.core.nodes.QueryNode;
import org.apache.lucene.queryParser.core.processors.QueryNodeProcessorImpl;

/**
 * Validates every query node in a query node tree. This processor will pass
 * fine if the query nodes are only {@link BooleanQueryNode}s,
 * {@link OrQueryNode}s or {@link FieldQueryNode}s, otherwise an exception will
 * be thrown. <br/>
 * <br/>
 * 
 * If they are {@link AndQueryNode} or an instance of anything else that
 * implements {@link FieldQueryNode} the exception will also be thrown.
 */
public class SpansValidatorQueryNodeProcessor extends QueryNodeProcessorImpl {

  @Override
  protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException {

    return node;

  }

  @Override
  protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {

    if (!((node instanceof BooleanQueryNode && !(node instanceof AndQueryNode)) || node
        .getClass() == FieldQueryNode.class)) {
      throw new QueryNodeException(new MessageImpl(
          QueryParserMessages.NODE_ACTION_NOT_SUPPORTED));
    }

    return node;

  }

  @Override
  protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
      throws QueryNodeException {

    return children;

  }

}