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.Collection;
  
  import org.apache.cayenne.exp.Expression;
  import org.apache.cayenne.exp.ValueInjector;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * "Equal To" expression.
   * 
   * @since 1.1
   */
  public class ASTEqual extends ConditionNode implements ValueInjector {
  
  	private static final long serialVersionUID = 1211234198602067833L;
  	
  	private static final Logger LOGGER = LoggerFactory.getLogger(ASTEqual.class);
  
  	/**
  	 * Constructor used by expression parser. Do not invoke directly.
  	 */
  	ASTEqual(int id) {
  		super(id);
  	}
  
  	public ASTEqual() {
  		super(ExpressionParserTreeConstants.JJTEQUAL);
  	}
  
  	/**
  	 * Creates "Equal To" expression.
  	 */
  	public ASTEqual(SimpleNode path, Object value) {
  		super(ExpressionParserTreeConstants.JJTEQUAL);
  		jjtAddChild(path, 0);
  		jjtAddChild(new ASTScalar(value), 1);
  		connectChildren();
  	}
  
  	@Override
  	protected int getRequiredChildrenCount() {
  		return 2;
  	}
  
  	@Override
  	protected Boolean evaluateSubNode(Object o, Object[] evaluatedChildren) throws Exception {
  		Object o2 = evaluatedChildren[1];
  		return evaluateImpl(o, o2) ? Boolean.TRUE : Boolean.FALSE;
  	}
  
  	/**
  	 * Compares two objects, if one of them is array, 'in' operation is
  	 * performed
  	 */
  	static boolean evaluateImpl(Object o1, Object o2) {
  		// TODO: maybe we need a comparison "strategy" here, instead of
  		// a switch of all possible cases? ... there were other requests for
  		// more relaxed type-unsafe comparison (e.g. numbers to strings)
  
  		if (o1 == null && o2 == null) {
  			return true;
  		} else if (o1 != null) {
  			// Per CAY-419 we perform 'in' comparison if one object is a list, and other is not
  			if (o2 instanceof Collection) {
  				for (Object element : ((Collection<?>) o2)) {
  					if (element != null && Evaluator.evaluator(element).eq(element, o1)) {
  						return true;
  					}
  				}
  				return false;
  			}
  
  			return Evaluator.evaluator(o1).eq(o1, o2);
  		}
  		return false;
  	}
  
  	/**
  	 * Creates a copy of this expression node, without copying children.
  	 */
  	@Override
  	public Expression shallowCopy() {
  		return new ASTEqual(id);
  	}
  
  	@Override
  	protected String getExpressionOperator(int index) {
  		return "=";
  	}
  
  	@Override
  	protected String getEJBQLExpressionOperator(int index) {
  		if (jjtGetChild(1) instanceof ASTScalar && ((ASTScalar) jjtGetChild(1)).getValue() == null) {
  			// for ejbql, we need "is null" instead of "= null"
  			return "is";
  		}
  		return getExpressionOperator(index);
  	}
  
  	@Override
  	public int getType() {
  		return Expression.EQUAL_TO;
  	}
  
  	public void injectValue(Object o) {
  		// try to inject value, if one of the operands is scalar, and other is a path
  		ASTScalar scalar = null;
  		ASTObjPath path = null;
  
  		for(int i=0; i<=1; i++) {
  			Node node = jjtGetChild(i);
  			if(node instanceof ASTScalar) {
  				scalar = (ASTScalar)node;
  			} else if(node instanceof ASTObjPath) {
  				path = (ASTObjPath) node;
  			}
  		}
  
  		if (scalar != null && path != null) {
  			try {
  				path.injectValue(o, scalar.getValue());
  			} catch (Exception ex) {
  				LOGGER.warn("Failed to inject value " + " on path " + path.getPath() + " to " + o, ex);
  			}
  		}
  	}
  }
  