/*
 * XPathNode.java - Represents an XPath 1.0 node
 *
 * Copyright (c) 2002 Robert McKinnon
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

package xslt;

import org.apache.xml.dtm.DTM;
import org.apache.xpath.NodeSetDTM;

/**
 * Represents a <a href="http://www.w3.org/TR/xpath#data-model">XPath 1.0 node</a>.
 *
 * @author Robert McKinnon
 */
public class XPathNode {

  private final int nodeHandle;
  private final DTM dtm;
  private final short nodeType;


  /**
   * Returns a XPathNode representing the node at the given index in the
   * supplied node set, or null if the node at the given index is does not
   * have a node type from the
   * <a href="http://www.w3.org/TR/xpath#data-model">XPath 1.0 data model</a>.
   *
   * @return an XPathNode or null.
   */
  public static XPathNode getXPathNode(NodeSetDTM nodeSet, int index) {
    int nodeHandle = nodeSet.item(index);
    DTM dtm = nodeSet.getDTM(nodeHandle);
    short nodeType = dtm.getNodeType(nodeHandle);

    if(isXPathNodeType(nodeType)) {
      return new XPathNode(nodeHandle, dtm, nodeType);
    } else {
      return null;
    }
  }


  /**
   * Returns true if the node type from the
   * <a href="http://www.w3.org/TR/xpath#data-model">XPath 1.0 data model</a>.
   */
  private static boolean isXPathNodeType(short nodeType) {
    switch(nodeType) {
      case DTM.ATTRIBUTE_NODE:
      case DTM.ELEMENT_NODE:
      case DTM.NAMESPACE_NODE:
      case DTM.PROCESSING_INSTRUCTION_NODE:
      case DTM.COMMENT_NODE:
      case DTM.DOCUMENT_NODE:
      case DTM.TEXT_NODE:
        return true;
      default:
        return false;
    }
  }


  /**
   * Constructs node with the given node type identifier.
   * @param nodeType from {@link org.apache.xml.dtm.DTM} interface
   * @throws IllegalArgumentException if nodeType is not valid.
   */
  private XPathNode(int nodeHandle, DTM dtm, short nodeType) {
    this.nodeHandle = nodeHandle;
    this.dtm = dtm;
    this.nodeType = nodeType;
  }


  /**
   * Returns the <a href="http://www.w3.org/TR/xpath#data-model">node type</a> name.
   *
   * @return node type name, one of:
   *         root, element, text, attribute,
   *         processing instruction,
   *         namespace, or comment.
   */
  public String getType() {
    switch(this.nodeType) {
      case DTM.ATTRIBUTE_NODE:
        return "attribute";
      case DTM.COMMENT_NODE:
        return "comment";
      case DTM.ELEMENT_NODE:
        return "element";
      case DTM.NAMESPACE_NODE:
        return "namespace";
      case DTM.PROCESSING_INSTRUCTION_NODE:
        return "processing instruction";
      case DTM.TEXT_NODE:
        return "text";
      default:
        return "root";
    }
  }


  /**
   * Returns true if the node has an
   * <a href="http://www.w3.org/TR/xpath#dt-expanded-name">expanded-name</a>.
   */
  public boolean hasExpandedName() {
    switch(this.nodeType) {
      case DTM.COMMENT_NODE:
      case DTM.DOCUMENT_NODE:
      case DTM.TEXT_NODE:
        return false;
      default:
        return true;
    }
  }


  /**
   * There are seven XPath nodes: root, element,
   * text, attribute, processing instruction,
   * namespace, and comment.
   */
  public boolean hasDomValue() {
    switch(this.nodeType) {
      case DTM.DOCUMENT_NODE:
      case DTM.ELEMENT_NODE:
        return false;
      default:
        return true;
    }
  }


  public String getName() {
    return this.dtm.getNodeNameX(this.nodeHandle);
  }


  public String getDomValue() {
    String domValue = this.dtm.getNodeValue(this.nodeHandle);

    if(hasDomValue()) {
      domValue = XSLTUtilities.removeIn(domValue, (char)10); //remove '\r' to temporarily fix a bug in the display of results in Windows
    }

    return domValue;
  }


}