/*

 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You 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 com.sun.org.apache.xml.internal.serializer;

import com.sun.org.apache.xml.internal.utils.AttList;

import com.sun.org.apache.xml.internal.utils.DOM2Helper;

import javax.xml.transform.Result;

import org.w3c.dom.Comment;

import org.w3c.dom.Element;

import org.w3c.dom.EntityReference;

import org.w3c.dom.NamedNodeMap;

import org.w3c.dom.Node;

import org.w3c.dom.ProcessingInstruction;

import org.w3c.dom.Text;

import org.xml.sax.ContentHandler;

import org.xml.sax.Locator;

import org.xml.sax.ext.LexicalHandler;

import org.xml.sax.helpers.LocatorImpl;

/**

 * This class does a pre-order walk of the DOM tree, calling a ContentHandler

 * interface as it goes.

 *

 * This class is a copy of the one in com.sun.org.apache.xml.internal.utils.

 * It exists to cut the serializers dependancy on that package.

 *

 * @xsl.usage internal

 */

public final class TreeWalker

{

  /** Local reference to a ContentHandler          */

  final private ContentHandler m_contentHandler;

  /**

   * If m_contentHandler is a SerializationHandler, then this is

   * a reference to the same object.

   */

  final private SerializationHandler m_Serializer;

  /** Locator object for this TreeWalker          */

  final private LocatorImpl m_locator = new LocatorImpl();

  /**

   * Get the ContentHandler used for the tree walk.

   *

   * @return the ContentHandler used for the tree walk

   */

  public ContentHandler getContentHandler()

  {

    return m_contentHandler;

  }

  public TreeWalker(ContentHandler ch) {

      this(ch, null);

  }

  /**

   * Constructor.

   * @param   contentHandler The implemention of the

   * contentHandler operation (toXMLString, digest, ...)

   */

  public TreeWalker(ContentHandler contentHandler, String systemId)

  {

      // Set the content handler

      m_contentHandler = contentHandler;

      if (m_contentHandler instanceof SerializationHandler) {

          m_Serializer = (SerializationHandler) m_contentHandler;

      } else {

          m_Serializer = null;

      }

      // Set the system ID, if it is given

      m_contentHandler.setDocumentLocator(m_locator);

      if (systemId != null) {

          m_locator.setSystemId(systemId);

      }

  }

  /**

   * Perform a pre-order traversal non-recursive style.

   *

   * Note that TreeWalker assumes that the subtree is intended to represent

   * a complete (though not necessarily well-formed) document and, during a

   * traversal, startDocument and endDocument will always be issued to the

   * SAX listener.

   *

   * @param pos Node in the tree where to start traversal

   *

   * @throws TransformerException

   */

  public void traverse(Node pos) throws org.xml.sax.SAXException

  {

    this.m_contentHandler.startDocument();

    Node top = pos;

    while (null != pos)

    {

      startNode(pos);

      Node nextNode = pos.getFirstChild();

      while (null == nextNode)

      {

        endNode(pos);

        if (top.equals(pos))

          break;

        nextNode = pos.getNextSibling();

        if (null == nextNode)

        {

          pos = pos.getParentNode();

          if ((null == pos) || (top.equals(pos)))

          {

            if (null != pos)

              endNode(pos);

            nextNode = null;

            break;

          }

        }

      }

      pos = nextNode;

    }

    this.m_contentHandler.endDocument();

  }

  /**

   * Perform a pre-order traversal non-recursive style.

   * Note that TreeWalker assumes that the subtree is intended to represent

   * a complete (though not necessarily well-formed) document and, during a

   * traversal, startDocument and endDocument will always be issued to the

   * SAX listener.

   *

   * @param pos Node in the tree where to start traversal

   * @param top Node in the tree where to end traversal

   *

   * @throws TransformerException

   */

  public void traverse(Node pos, Node top) throws org.xml.sax.SAXException

  {

    this.m_contentHandler.startDocument();

    while (null != pos)

    {

      startNode(pos);

      Node nextNode = pos.getFirstChild();

      while (null == nextNode)

      {

        endNode(pos);

        if ((null != top) && top.equals(pos))

          break;

        nextNode = pos.getNextSibling();

        if (null == nextNode)

        {

          pos = pos.getParentNode();

          if ((null == pos) || ((null != top) && top.equals(pos)))

          {

            nextNode = null;

            break;

          }

        }

      }

      pos = nextNode;

    }

    this.m_contentHandler.endDocument();

  }

  // Flag indicating whether following text to be processed is raw text

  boolean nextIsRaw = false;

  /**

   * Optimized dispatch of characters.

   */

  private final void dispatachChars(Node node)

     throws org.xml.sax.SAXException

  {

    if(m_Serializer != null)

    {

      this.m_Serializer.characters(node);

    }

    else

    {

      String data = ((Text) node).getData();

      this.m_contentHandler.characters(data.toCharArray(), 0, data.length());

    }

  }

  /**

   * Start processing given node

   *

   *

   * @param node Node to process

   *

   * @throws org.xml.sax.SAXException

   */

  protected void startNode(Node node) throws org.xml.sax.SAXException

  {

//   TODO: <REVIEW>

//    A Serializer implements ContentHandler, but not NodeConsumer

//    so drop this reference to NodeConsumer which would otherwise

//    pull in all sorts of things

//    if (m_contentHandler instanceof NodeConsumer)

//    {

//      ((NodeConsumer) m_contentHandler).setOriginatingNode(node);

//    }

//    TODO: </REVIEW>

                if (node instanceof Locator)

                {

                        Locator loc = (Locator)node;

                        m_locator.setColumnNumber(loc.getColumnNumber());

                        m_locator.setLineNumber(loc.getLineNumber());

                        m_locator.setPublicId(loc.getPublicId());

                        m_locator.setSystemId(loc.getSystemId());

                }

                else

                {

                        m_locator.setColumnNumber(0);

      m_locator.setLineNumber(0);

                }

    switch (node.getNodeType())

    {

    case Node.COMMENT_NODE :

    {

      String data = ((Comment) node).getData();

      if (m_contentHandler instanceof LexicalHandler)

      {

        LexicalHandler lh = ((LexicalHandler) this.m_contentHandler);

        lh.comment(data.toCharArray(), 0, data.length());

      }

    }

    break;

    case Node.DOCUMENT_FRAGMENT_NODE :

      // ??;

      break;

    case Node.DOCUMENT_NODE :

      break;

    case Node.ELEMENT_NODE :

      Element elem_node = (Element) node;

      {

          // Make sure the namespace node

          // for the element itself is declared

          // to the ContentHandler

          String uri = elem_node.getNamespaceURI();

          if (uri != null) {

              String prefix = elem_node.getPrefix();

              if (prefix==null)

                prefix="";

              this.m_contentHandler.startPrefixMapping(prefix,uri);

          }

      }

      NamedNodeMap atts = elem_node.getAttributes();

      int nAttrs = atts.getLength();

      // System.out.println("TreeWalker#startNode: "+node.getNodeName());

      // Make sure the namespace node of

      // each attribute is declared to the ContentHandler

      for (int i = 0; i < nAttrs; i++)

      {

        final Node attr = atts.item(i);

        final String attrName = attr.getNodeName();

        final int colon = attrName.indexOf(':');

        final String prefix;

        if (attrName.equals("xmlns") || attrName.startsWith("xmlns:"))

        {

          // Use "" instead of null, as Xerces likes "" for the

          // name of the default namespace.  Fix attributed

          // to "Steven Murray" <smurray@ebt.com>.

          if (colon < 0)

            prefix = "";

          else

            prefix = attrName.substring(colon + 1);

          this.m_contentHandler.startPrefixMapping(prefix,

                                                   attr.getNodeValue());

        }

        else if (colon > 0) {

            prefix = attrName.substring(0,colon);

            String uri = attr.getNamespaceURI();

            if (uri != null)

                this.m_contentHandler.startPrefixMapping(prefix,uri);

        }

      }

      String ns = DOM2Helper.getNamespaceOfNode(node);

      if(null == ns)

        ns = "";

      this.m_contentHandler.startElement(ns,

                                         DOM2Helper.getLocalNameOfNode(node),

                                         node.getNodeName(),

                                         new AttList(atts));

      break;

    case Node.PROCESSING_INSTRUCTION_NODE :

    {

      ProcessingInstruction pi = (ProcessingInstruction) node;

      String name = pi.getNodeName();

      // String data = pi.getData();

      if (name.equals("xslt-next-is-raw"))

      {

        nextIsRaw = true;

      }

      else

      {

        this.m_contentHandler.processingInstruction(pi.getNodeName(),

                                                    pi.getData());

      }

    }

    break;

    case Node.CDATA_SECTION_NODE :

    {

      boolean isLexH = (m_contentHandler instanceof LexicalHandler);

      LexicalHandler lh = isLexH

                          ? ((LexicalHandler) this.m_contentHandler) : null;

      if (isLexH)

      {

        lh.startCDATA();

      }

      dispatachChars(node);

      {

        if (isLexH)

        {

          lh.endCDATA();

        }

      }

    }

    break;

    case Node.TEXT_NODE :

    {

      //String data = ((Text) node).getData();

      if (nextIsRaw)

      {

        nextIsRaw = false;

        m_contentHandler.processingInstruction(Result.PI_DISABLE_OUTPUT_ESCAPING, "");

        dispatachChars(node);

        m_contentHandler.processingInstruction(Result.PI_ENABLE_OUTPUT_ESCAPING, "");

      }

      else

      {

        dispatachChars(node);

      }

    }

    break;

    case Node.ENTITY_REFERENCE_NODE :

    {

      EntityReference eref = (EntityReference) node;

      if (m_contentHandler instanceof LexicalHandler)

      {

        ((LexicalHandler) this.m_contentHandler).startEntity(

          eref.getNodeName());

      }

      else

      {

        // warning("Can not output entity to a pure SAX ContentHandler");

      }

    }

    break;

    default :

    }

  }

  /**

   * End processing of given node

   *

   *

   * @param node Node we just finished processing

   *

   * @throws org.xml.sax.SAXException

   */

  protected void endNode(Node node) throws org.xml.sax.SAXException

  {

    switch (node.getNodeType())

    {

    case Node.DOCUMENT_NODE :

      break;

    case Node.ELEMENT_NODE :

      String ns = DOM2Helper.getNamespaceOfNode(node);

      if(null == ns)

        ns = "";

      this.m_contentHandler.endElement(ns,

              DOM2Helper.getLocalNameOfNode(node),

              node.getNodeName());

      if (m_Serializer == null) {

      // Don't bother with endPrefixMapping calls if the ContentHandler is a

      // SerializationHandler because SerializationHandler's ignore the

      // endPrefixMapping() calls anyways. . . .  This is an optimization.

      Element elem_node = (Element) node;

      NamedNodeMap atts = elem_node.getAttributes();

      int nAttrs = atts.getLength();

      // do the endPrefixMapping calls in reverse order

      // of the startPrefixMapping calls

      for (int i = (nAttrs-1); 0 <= i; i--)

      {

        final Node attr = atts.item(i);

        final String attrName = attr.getNodeName();

        final int colon = attrName.indexOf(':');

        final String prefix;

        if (attrName.equals("xmlns") || attrName.startsWith("xmlns:"))

        {

          // Use "" instead of null, as Xerces likes "" for the

          // name of the default namespace.  Fix attributed

          // to "Steven Murray" <smurray@ebt.com>.

          if (colon < 0)

            prefix = "";

          else

            prefix = attrName.substring(colon + 1);

          this.m_contentHandler.endPrefixMapping(prefix);

        }

        else if (colon > 0) {

            prefix = attrName.substring(0, colon);

            this.m_contentHandler.endPrefixMapping(prefix);

        }

      }

      {

          String uri = elem_node.getNamespaceURI();

          if (uri != null) {

              String prefix = elem_node.getPrefix();

              if (prefix==null)

                prefix="";

              this.m_contentHandler.endPrefixMapping(prefix);

          }

      }

      }

      break;

    case Node.CDATA_SECTION_NODE :

      break;

    case Node.ENTITY_REFERENCE_NODE :

    {

      EntityReference eref = (EntityReference) node;

      if (m_contentHandler instanceof LexicalHandler)

      {

        LexicalHandler lh = ((LexicalHandler) this.m_contentHandler);

        lh.endEntity(eref.getNodeName());

      }

    }

    break;

    default :

    }

  }

}  //TreeWalker