/*******************************************************************************
 * Copyright (c) 2008 Sonatype, Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *******************************************************************************/

package org.eclipse.m2e.wtp;

import org.codehaus.plexus.util.StringUtils;
import org.codehaus.plexus.util.xml.Xpp3Dom;
import org.eclipse.core.runtime.Assert;

/**
 * Utility class for {@link Xpp3Dom} manipulations.
 * 
 * @provisional This class has been added as part of a work in progress. It is not guaranteed to work or remain the same
 *              in future releases. For more information contact <a
 *              href="mailto:m2e-wtp-dev@eclipse.org">m2e-wtp-dev@eclipse.org</a>.
 * @author Fred Bricon
 */
public class DomUtils {

  /**
   * Return the value of a child node.
   * 
   * @param parent - the parent node.
   * @param childName - the child node name.
   * @return the child node value or null if it doesn't exist.
   */
  public static final String getChildValue(Xpp3Dom parent, String childName) {
    String result = null;
    if(parent != null && childName != null) {
      Xpp3Dom dom = parent.getChild(childName);
      if(dom != null && dom.getValue() != null) {//MNGECLIPSE-2328 add null-safety in case of <somenode/> 
        result = dom.getValue().trim();
      }
    }
    return result;
  }

  public static final String getChildValue(Xpp3Dom parent, String childName, String defaultValue) {
    String result = getChildValue(parent, childName);
    return StringUtils.defaultString(result, defaultValue);
  }

  public static final boolean getBooleanChildValue(Xpp3Dom parent, String childName) {
    return Boolean.valueOf(getChildValue(parent, childName));
  }

  public static final boolean getBooleanChildValue(Xpp3Dom parent, String childName, boolean defaultValue) {
	  String result = getChildValue(parent, childName);
	  if (result == null) {
		  return defaultValue;
	  }
	  return Boolean.valueOf(result);
  }

  /**
   * @param node
   */
  public static final void removeChildren(Xpp3Dom node) {
    if(node == null)
      return;
    for(int i = node.getChildCount() - 1; i > -1; i-- ) {
      node.removeChild(i);
    }
  }

  public static String[] getChildrenAsStringArray(Xpp3Dom root, String childName) {
    String[] values = null;
    if(root != null) {
      Xpp3Dom[] children = root.getChildren(childName);
      if(children != null) {
        values = new String[children.length];
        int i = 0;
        for(Xpp3Dom child : children) {
          values[i++ ] = child.getValue();
        }
      }
    }
    return values;
  }

  public static String[] getPatternsAsArray(Xpp3Dom config, String patternParameterName) {
    if(config != null) {
      Xpp3Dom excl = config.getChild(patternParameterName);
      if(excl != null) {
        return org.eclipse.m2e.wtp.internal.StringUtils.tokenizeToStringArray(excl.getValue(), ","); //$NON-NLS-1$
      }
    }
    return new String[0];
  }

  public static final Xpp3Dom getOrCreateChildNode(Xpp3Dom parent, String childName) {
    Assert.isNotNull(parent);
    Assert.isNotNull(childName);
    Xpp3Dom dom = parent.getChild(childName);
    if(dom == null) {
      dom = new Xpp3Dom(childName);
      parent.addChild(dom);
    }
    return dom;
  }

}