/*
    * Copyright 2004-2005, 2008 the original author or authors.
    * 
    * 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 net.sf.morph.transform.converters;
  
  import java.util.Locale;
  
  import net.sf.composite.util.ObjectUtils;
  import net.sf.morph.Defaults;
  import net.sf.morph.transform.Converter;
  import net.sf.morph.transform.DecoratedConverter;
  import net.sf.morph.transform.TransformationException;
  import net.sf.morph.transform.transformers.BaseTransformer;
  import net.sf.morph.util.ContainerUtils;
  
  /**
   * Converts text values to Booleans.  Text values include Characters, Strings and
   * StringBuffers.
   * 
   * @author Matt Sgarlata
   * @since Dec 31, 2004
   */
  public class TextToBooleanConverter extends BaseTransformer implements DecoratedConverter {
  	private Converter textConverter;
  
  	private static final Class[] DESTINATION_TYPES = { Boolean.class,
  		boolean.class };	
  
  	/**
  	 * Default values for the <code>trueText</code> attribute.
  	 */
  	public static final String[] DEFAULT_TRUE_TEXT = { "true", "t", "yes", "y" };
  
  	/**
  	 * Default values for the <code>falseText</code> attribute.
  	 */
  	public static final String[] DEFAULT_FALSE_TEXT = { "false", "f", "no", "n" };
  
  	/**
  	 * Defines the String, StringBuffer, and Character values that will be
  	 * converted to <code>true</code>. The strings are not case-sensitive.
  	 */
  	private String[] trueText;
  	/**
  	 * Defines the String, StringBuffer, and Character values that will be
  	 * converted to <code>false</code>. The strings are not case-sensitive.
  	 */
  	private String[] falseText;
  
  	/**
  	 * {@inheritDoc}
  	 */
  	protected Object convertImpl(Class destinationClass, Object source,
  		Locale locale) throws Exception {
  
  		String str = (String) getTextConverter().convert(String.class, source, locale);
  		if (str != null) {
  			str = str.toLowerCase();
  		}
  		if (ContainerUtils.contains(getTrueText(), str)) {
  			return Boolean.TRUE;
  		}
  		if (ContainerUtils.contains(getFalseText(), str)) {
  			return Boolean.FALSE;
  		}
  		if (ObjectUtils.isEmpty(str) && !destinationClass.isPrimitive()) {
  			return null;
  		}
  		throw new TransformationException(destinationClass, source);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	protected Class[] getSourceClassesImpl() throws Exception {
  		return getTextConverter().getSourceClasses();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	protected Class[] getDestinationClassesImpl() throws Exception {
  		return DESTINATION_TYPES;
  	}
  
  	/**
  	 * Returns the String, StringBuffer, and Character values that will be
 	 * converted to <code>false</code>. The strings are not case-sensitive.
 	 * 
 	 * @return the String, StringBuffer, and Character values that will be
 	 *         converted to <code>false</code>. The strings are not
 	 *         case-sensitive.
 	 */
 	public String[] getFalseText() {
 		if (ObjectUtils.isEmpty(falseText)) {
 			setFalseText(DEFAULT_FALSE_TEXT);
 		}
 		return falseText;
 	}
 
 	/**
 	 * Sets the values that will be converted to <code>false</code>. The
 	 * strings are not case-sensitive.
 	 * 
 	 * @param falseText
 	 *            the values that will be converted to <code>false</code>.
 	 *            The strings are not case-sensitive.
 	 */
 	public void setFalseText(String[] falseStrings) {
 		falseStrings = changeToLowerCase(falseStrings);
 		this.falseText = falseStrings;
 	}
 
 	/**
 	 * Returns the String, StringBuffer, and Character values that will be
 	 * converted to <code>true</code>. The strings are not case-sensitive.
 	 * 
 	 * @return the String, StringBuffer, and Character values that will be
 	 *         converted to <code>true</code>. The strings are not
 	 *         case-sensitive.
 	 */
 	public String[] getTrueText() {
 		if (ObjectUtils.isEmpty(trueText)) {
 			setTrueText(DEFAULT_TRUE_TEXT);
 		}
 		return trueText;
 	}
 
 	/**
 	 * Sets the values that will be converted to <code>true</code>. The
 	 * strings are not case-sensitive.
 	 * 
 	 * @param trueText
 	 *            the values that will be converted to <code>true</code>. The
 	 *            strings are not case-sensitive.
 	 */
 	public void setTrueText(String[] trueStrings) {
 		trueStrings = changeToLowerCase(trueStrings);
 		this.trueText = trueStrings;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	protected boolean isAutomaticallyHandlingNulls() {
 		return false;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	protected boolean isWrappingRuntimeExceptions() {
 	    return true;
     }
 
 	/**
 	 * Get an array of Strings obtained by converting contents of <code>array</code> to lowercase.
 	 * @param array
 	 * @return String[]
 	 */
 	private String[] changeToLowerCase(String[] array) {
 		if (array == null) {
 			return null;
 		}
 
 		String[] lowerCase = new String[array.length];
 		for (int i = 0; i < array.length; i++) {
 			lowerCase[i] = array[i].toLowerCase();
 		}
 		return lowerCase;
 	}
 
 	/**
 	 * Get the text converter of this TextToBooleanConverter.
 	 * @return Converter
 	 */
 	public Converter getTextConverter() {
 		if (textConverter == null) {
 			setTextConverter(Defaults.createTextConverter());
 		}
 		return textConverter;
 	}
 
 	/**
 	 * Set the text converter of this TextToBooleanConverter.
 	 * @param textConverter the Converter to set
 	 */
 	public void setTextConverter(Converter textConverter) {
 		this.textConverter = textConverter;
 	}
 
 }