/*
 * Copyright Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags and
 * the COPYRIGHT.txt file distributed with this work.
 *
 * Licensed 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.teiid.core.types.basic;

import org.teiid.core.types.NullType;
import org.teiid.core.types.Transform;
import org.teiid.core.types.TransformationException;
import org.teiid.core.util.Assertion;

/**
 * This class can do a simple null-->anything.  
 * Incoming value must be null and outgoing value is the same.  
 * This is purely for type purposes.
 */
public class NullToAnyTransform extends Transform {
	
	public static final NullToAnyTransform INSTANCE = new NullToAnyTransform(Object.class);

	private Class<?> targetType;
	
	public NullToAnyTransform(Class<?> targetType) {
		this.targetType = targetType;
	}
	
	/**
	 * Type of the incoming value.
	 * @return Source type
	 */
	public Class getSourceType() {
        return NullType.class;
    }
    
    /**
     * Type of the outgoing value.
     * @return Target type
     */
    public Class getTargetType() {
    	return targetType;
    }

	/**
	 * This method transforms a value of the source type into a value
	 * of the target type.
	 * @param value Incoming value - Integer
	 * @return Outgoing value - String
	 * @throws TransformationException if value is an incorrect input type or
	 * the transformation fails
	 */
	public Object transformDirect(Object value) throws TransformationException {
		Assertion.isNull(value);
		return null;
	}
	
}
