content: /*****************************************************************
   *   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
   *
   *    https://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.apache.cayenne.exp.parser;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * @since 4.0
   */
  public abstract class EvaluatedNode extends SimpleNode {
  
      protected EvaluatedNode(int i) {
          super(i);
      }
  
      @Override
      protected Object evaluateNode(Object o) throws Exception {
          int len = jjtGetNumChildren();
          int requiredLen = getRequiredChildrenCount();
          if (len < requiredLen) {
              return null;
          }
  
          if(requiredLen == 0) {
              return evaluateSubNode(null, null);
          }
  
          final Object[] evaluatedChildren = new Object[len];
          for(int i=0; i<len; i++) {
              evaluatedChildren[i] = evaluateChild(i, o);
          }
  
          Object firstChild = evaluatedChildren[0];
  
          // convert Map, keep Map keys
          if(firstChild instanceof Map) {
              @SuppressWarnings("unchecked")
              Map<Object, Object> child = (Map<Object, Object>) firstChild;
              Map<Object, Object> result = new HashMap<>(child.size());
              for(Map.Entry<Object, Object> entry : child.entrySet()) {
                  result.put(entry.getKey(), evaluateSubNode(entry.getValue(), evaluatedChildren));
              }
              return result;
          }
  
          // convert collection
          if (firstChild instanceof Collection) {
              @SuppressWarnings("unchecked")
              Collection<Object> child = (Collection<Object>) firstChild;
              Collection<Object> result = new ArrayList<>(child.size());
              for(Object c : child) {
                  result.add(evaluateSubNode(c, evaluatedChildren));
              }
              return result;
          }
  
          // convert scalar
          return evaluateSubNode(firstChild, evaluatedChildren);
      }
  
      abstract protected int getRequiredChildrenCount();
  
      abstract protected Object evaluateSubNode(Object o, Object[] evaluatedChildren) throws Exception;
  
  }
  