/**
    * Copyright 2005-2012 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.kew.messaging;
  
  import java.util.ArrayList;
  import java.util.List;
  
  
  /**
   * A simple utility class which can handle translated a comma-seperated String
   * into an array of String paramters and vice-versa.
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class ParameterTranslator {
  
  	private static final String SLASH_REGEXP = "\\\\";
      private static final String SLASH_ESCAPE = "\\\\";
      private static final String COMMA_REGEXP = ",";
      private static final String COMMA_ESCAPE = "\\,";
  	
  	private String untranslatedString = "";
  	
  	public ParameterTranslator() {}
  	
  	public ParameterTranslator(String untranslatedString) {
  		this.untranslatedString = untranslatedString;
  	}
  	
  	public void addParameter(String value) {
  		if (!org.apache.commons.lang.StringUtils.isEmpty(untranslatedString)) {
  			untranslatedString += ",";
  		}
  		untranslatedString += escape(value);
  	}
  	
  	private String escape(String value) {
  		if (org.apache.commons.lang.StringUtils.isEmpty(value)) {
  			return "";
  		}
      	// escape '\' and ',' with "\\" and "\,"
      	value = value.replaceAll(SLASH_REGEXP, SLASH_ESCAPE);
      	value = value.replaceAll(COMMA_REGEXP, COMMA_ESCAPE);
      	return value;
      }
  	
  	public String getUntranslatedString() {
  		return untranslatedString;
  	}
  	
  	public String[] getParameters() {
  		List strings = new ArrayList();
  		boolean isEscaped = false;
  		StringBuffer buffer = null;
  		for (int index = 0; index < untranslatedString.length(); index++) {
  			char character = untranslatedString.charAt(index);
  			if (isEscaped) {
  				isEscaped = false;
  				if (buffer == null) {
  					buffer = new StringBuffer();
  				}
  				buffer.append(character);
  			} else {
  				if (character == '\\') {
  					isEscaped = true;
  				} else if (character == ',') {
  					strings.add(buffer.toString());
  					buffer = null;
  				} else {
  					if (buffer == null) {
  						buffer = new StringBuffer();
  					}
  					buffer.append(character);
  				}
  			}
  		}
  		// put whatever is left in the buffer (after the last ',') into the list of strings
  		if (buffer != null) {
  			strings.add(buffer.toString());
  		}
  		return (String[])strings.toArray(new String[0]);
  	}
  	
  }