/*
    * Copyright 2011 - Doxia :: Include Macro - Juergen Kellerer
    *
    *    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.tinyjee.maven.dim.extensions;
  
  import org.apache.maven.doxia.logging.Log;
  import org.tinyjee.maven.dim.spi.Globals;
  import org.tinyjee.maven.dim.spi.RequestParameterTransformer;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import static org.tinyjee.maven.dim.IncludeMacroSignature.PARAM_SOURCE;
  import static org.tinyjee.maven.dim.IncludeMacroSignature.PARAM_SOURCE_CLASS;
  
  /**
   * Implements a base for bundled request parameter transformers.
   *
   * @author Juergen_Kellerer, 2011-11-08
   */
  public abstract class AbstractParameterTransformer implements RequestParameterTransformer {
  
  	protected abstract boolean doTransformParameters(Map<String, Object> requestParams);
  
  	protected boolean isSourceSet(Map<String, Object> requestParams) {
  		return requestParams.containsKey(PARAM_SOURCE) && requestParams.containsKey(PARAM_SOURCE_CLASS);
  	}
  
  	public final void transformParameters(Map<String, Object> requestParams) {
  		final Log log = Globals.getLog();
  		if (!isSourceSet(requestParams)) {
  			final Map<String, Object> originalParams = new HashMap<String, Object>(requestParams);
  			if (doTransformParameters(requestParams)) {
  				if (log.isDebugEnabled()) {
  					log.debug("The parameter transformer " + this + " changed the request parameters from " + originalParams +
  							" to " + requestParams);
  				}
  			} else if (!originalParams.equals(requestParams)) {
  				log.warn("The parameter transformer " + this + " changed the request parameters from " + originalParams +
  						" to " + requestParams + " without reporting it.");
  			}
  		}
  	}
  }