/*
 * 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 (at your option) 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Id: XML2.cmod,v 1.102 2005/12/22 16:22:38 hww3 Exp $
 */

/*
 * File licensing and authorship information block.
 *
 * Version: MPL 1.1/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Initial Developer of the Original Code is
 *
 * Bill Welliver 
 *
 * Portions created by the Initial Developer are Copyright (C) Bill Welliver
 * All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of the LGPL, and not to allow others to use your version
 * of this file under the terms of the MPL, indicate your decision by
 * deleting the provisions above and replace them with the notice
 * and other provisions required by the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL or the LGPL.
 *
 * Significant Contributors to this file are:
 *
 *
 */

#include "xml2.h"

/*! @module Public
 */

/*! @module Parser
 */

/*! @module XML2
 */

/*
  
    start of Public.Parser.XML2 module functions

*/

static void
xmlDetectSAX2(xmlParserCtxtPtr ctxt) {
    if (ctxt == NULL) return;
#ifdef LIBXML_SAX1_ENABLED 
    if ((ctxt->sax) &&  (ctxt->sax->initialized == XML_SAX2_MAGIC) &&
        ((ctxt->sax->startElementNs != NULL) ||
         (ctxt->sax->endElementNs != NULL))) ctxt->sax2 = 1;
#else
    ctxt->sax2 = 1;
#endif /* LIBXML_SAX1_ENABLED */
 
    ctxt->str_xml = xmlDictLookup(ctxt->dict, BAD_CAST "xml", 3);
    ctxt->str_xmlns = xmlDictLookup(ctxt->dict, BAD_CAST "xmlns", 5);
    ctxt->str_xml_ns = xmlDictLookup(ctxt->dict, XML_XML_NAMESPACE, 36);
    if ((ctxt->str_xml==NULL) || (ctxt->str_xmlns==NULL) ||
                (ctxt->str_xml_ns == NULL)) {
        xmlErrMemory(ctxt, NULL);
    }
}


CVAR PARSER_OBJECT_DATA * object_data;
PIKEVAR int silent;

PIKEFUN void create()
{

}

/*! @decl array(Node) select_xpath_nodes(string xpath, object node)
 *!
 *! selects nodes based on an XPath query and returns the result.
 */
PIKEFUN array select_xpath_nodes(string xpath, object node)
{
  xmlXPathContextPtr xpathCtx;
  xmlXPathObjectPtr xpathObj;
  xmlNodeSetPtr set;
  xmlNodePtr xn;
  xmlNsPtr xmlns;
  struct object * o;
  int num_nodes = 0;

  CHECK_NODE_PASSED(node);

  if(OBJ2_NODE(node)->object_data->node == NULL)
  { 
    pop_n_elems(2);
    Pike_error("Node not initialized.\n");
  }

  xpathCtx = xmlXPathNewContext(OBJ2_NODE(node)->object_data->node->doc);
  if(xpathCtx == NULL)
  {
    pop_n_elems(2);
    Pike_error("Unable to create new XPath context.\n");
  }

/*

  xmlns = xmlGetNsList(OBJ2_NODE(node)->object_data->node->doc,
              OBJ2_NODE(node)->object_data->node);

  while(xmlns != NULL)
  {
    printf("registering ns %s, %s\n", xmlns->prefix, xmlns->href);
    xmlXPathRegisterNs(xpathCtx, xmlns->prefix, xmlns->href);
    xmlns = xmlns->next;
  }

*/
  xpathCtx->node = OBJ2_NODE(node)->object_data->node;

  xpathObj = xmlXPathEvalExpression((xmlChar *)xpath->str, xpathCtx);
  if(xpathObj == NULL) {  
    pop_n_elems(2);
    xmlXPathFreeContext(xpathCtx);
    Pike_error("Unable to evaluate the XPath expression.\n");
  }

  /* now we should generate an array from the node set. */
  set = xpathObj->nodesetval;


  if(set == NULL)
  {
    pop_n_elems(2);
    push_int(0);
    xmlXPathFreeContext(xpathCtx);
    xmlXPathFreeObject(xpathObj);
    return;
  }  

  pop_n_elems(2);

  if(set->nodeNr > 0)
  {
  xn = set->nodeTab[0];
    if(xn != NULL && set->nodeNr > 0) do
    {
      struct Node_struct * ns;
      NODE_OBJECT_DATA * od;
      apply(Pike_fp->current_object, "Node", 0);
      ns = OBJ2_NODE((Pike_sp[0-1].u.object));
      od = (NODE_OBJECT_DATA *)(ns->object_data);

      od->node=xn;
      od->parser = this_object();
      od->refs = OBJ2_NODE(node)->object_data->refs;
    
      (* od->refs)++;

      num_nodes++;
      xn = set->nodeTab[num_nodes];
    } 
    while (((num_nodes +1) <= set->nodeNr) && xn != NULL);

    if(num_nodes>0) {
      f_aggregate(num_nodes);
    }
  }
  else push_int(0);

  xmlXPathFreeContext(xpathCtx);
  xmlXPathFreeObject(xpathObj);

  return;
}

/*! @decl void set_xml_parser_options(int options)
 *!
 *! sets parser options. 
 *! 
 *! @param options
 *!   a bitwise or of @[Public.Parser.XML2.Constants] options 
 *!   where valid options start with PARSE_. 
 */
PIKEFUN void set_xml_parser_options(int options)
{
  THIS->object_data->xml_parser_options = options;
  pop_stack();
}

/*! @decl void set_auto_utf8_convert(int flag)
 *!
 *! sets whether the parser should automatically convert input to the parser to and from UTF-8.
 *! libxml2 requires input (aside from data to be parsed, which may be encoded differently) to be
 *! UTF-8 encoded. This module will automatically convert all string input to and from UTF-8. Calling
 *! this function with an argument of zero (0) will turn this feature off. In this case, you will be
 *! responsible for ensuring that any input is properly encoded (if necessary).
 *! 
 *! @param flag
 *!   a boolean value: 0 disables auto conversion, 1 enables.
 */
PIKEFUN void set_auto_utf8_convert(int flag)
{
  THIS->object_data->auto_encode = flag;
  pop_stack();
}

void f_convert_string_utf8(INT32 args)
{
  if(  OBJ2_(THIS_NODE->object_data->parser)->object_data->auto_encode !=0)
  {
    f_string_to_utf8(args);
  }
}

void f_convert_utf8_string(INT32 args)
{
  if(  OBJ2_(THIS_NODE->object_data->parser)->object_data->auto_encode !=0)
  {
    f_utf8_to_string(args);
  }
}

void f_rconvert_string_utf8(INT32 args)
{
  if(THIS_XMLREADER->object_data->autoencode !=0)
  {
    f_string_to_utf8(args);
  }
}

void f_rconvert_utf8_string(INT32 args)
{
  if(  OBJ2_(THIS_XMLREADER->object_data->parser)->object_data->auto_encode !=0)
  {
    f_utf8_to_string(args);
  }
}

/*! @decl void set_html_parser_options(int options)
 *!
 *! sets parser options. 
 *! 
 *! @param options
 *!   a bitwise or of @[Public.Parser.XML2.Constants] options 
 *!   where valid options start with PARSE_. 
 */
PIKEFUN void set_html_parser_options(int options)
{
  THIS->object_data->html_parser_options = options;
  pop_stack();
}

/*! @decl int substituteEntitiesDefault(int def)
 */
PIKEFUN int substituteEntitiesDefault(int def)
{
  def = def ? 1 : 0;

  pop_n_elems(args);

  xmlSubstituteEntitiesDefault(def);

  push_int(def);
}

/* @decl int keepBlanksDefault(int def)
 */
PIKEFUN int keepBlanksDefault(int def)
{
  def = def ? 1 : 0;

  pop_n_elems(args);

  push_int(xmlKeepBlanksDefault(def));
}

/*!  @decl string utf8_to_html(string str)
 *!
 */
PIKEFUN string utf8_to_html(string str)
{
  char *html = NULL;
  int outlen, inlen;

  outlen = str->len << 1;
  html = (char*)malloc(outlen + 1);
  if (!html)
    Pike_error("Out of memory");

  inlen = str->len;
  if ( UTF8ToHtml(html, &outlen, str->str, &inlen) < 0 ) {
    free(html);
    Pike_error("Cannot convert to html!");
  }
  html[outlen] = '\0';
  pop_n_elems(args);
  push_text(html);
  free(html);
}


/*!  @decl string utf8_to_isolat1(string str)
 *!
 */
PIKEFUN string utf8_to_isolat1(string str)
{
  char *html = NULL;
  int outlen, inlen;

  outlen = str->len << 1;
  html = (char*)malloc(outlen + 1);
  if (!html)
    Pike_error("Out of memory");

  inlen = str->len;
  if ( UTF8Toisolat1(html, &outlen, str->str, &inlen) < 0 ) {
    free(html);
    Pike_error("Cannot convert to isolat1!");
  }
  html[outlen] = '\0';
  pop_n_elems(args);
  push_text(html);
  free(html);
}

/*! @decl int utf8_check(string str)
 *!
 */
PIKEFUN int utf8_check(string str)
{
  int result;

  result = xmlCheckUTF8(str->str);
  pop_n_elems(args);
  push_int(result);
}

/*! @decl array(int) get_encodings()
 *!
 *! gets the list of available character encoders.
 *!
 *! @returns
 *!  an array of available encoder identifiers.
 *!
 */
PIKEFUN array get_encodings()
{
   int num = 0;
   int cur = 0;
   int upper_limit = 25;
   xmlCharEncodingHandlerPtr encoder;

   for (cur = 0; cur < upper_limit; cur++)
   {
     encoder = xmlGetCharEncodingHandler((xmlCharEncoding)cur);
     if(encoder != NULL)
     {
       push_int(cur);
       num++;
       xmlFree(encoder);
     }
   }
   f_aggregate(num);
   return;  
}

/*!  @decl string get_encoding_name(int e)
 *!
 */
PIKEFUN string get_encoding_name(int e)
{
  const char * enc = NULL;

  enc = xmlGetCharEncodingName(e);

  if(enc != NULL)
    push_text(enc);

  else 
     push_int(0);
}

/*!  @decl string get_encoding_alias(string e)
 *!
 */
PIKEFUN string get_encoding_alias(string e)
{
  const char * enc = NULL;

  enc = xmlGetEncodingAlias(e->str);

  if(enc != NULL)
    push_text(enc);
  else 
     push_int(0);
}

/*! @decl string render_xml(Node n)
 *!   Renders a node tree as an XML string. The entire document tree will 
 *!  be rendered. To render a portion of a tree, use @[Node.render_xml].
 *!
 *!   @param n
 *!     a Node object for a given XML document.
 *!
 */
PIKEFUN string render_xml(object n)
{
  int dumped;
  xmlChar * buf;
  char * str;
  int bufsize;

  CHECK_NODE_PASSED(n);

//  check_node_created();
  if(OBJ2_NODE(n)->object_data->node == NULL)
  { 
    Pike_error("Node not initialized.\n");
  }

  xmlDocDumpFormatMemory(OBJ2_NODE(n)->object_data->node->doc, &buf, &bufsize, 1);

  if(buf!=NULL)
  {
    str = (char *)xmlStrdup(buf);
    xmlFree(buf);
    push_text(str);
  }  
  else
  {
    push_int(0);
  }
}

/*! @decl string render_html(Node n)
 *!   Renders a node tree as an HTML string. The entire document tree will 
 *!  be rendered. To render a portion of a tree, use @[Node.render_html].
 *!
 *!   @param n
 *!     a Node object for a given HTML document.
 *!
 */
PIKEFUN string render_html(object n)
{
  int dumped;
  xmlChar * buf;
  char * str;
  int bufsize;

  CHECK_NODE_PASSED(n);

//  check_node_created();
  if(OBJ2_NODE(n)->object_data->node == NULL)
  { 
    Pike_error("Node not initialized.\n");
  }

  htmlDocDumpMemory(OBJ2_NODE(n)->object_data->node->doc, &buf, &bufsize, 1);

  if(buf!=NULL)
  {
    str = (char *)xmlStrdup(buf);
    xmlFree(buf);
    push_text(str);
  }  
  else
  {
    push_int(0);
  }
}


void my_relaxng_generic_error(void * userData, const char * error)
{
  push_text(error);
  f_werror(1);
}

void my_structured_error(void * userData, xmlErrorPtr error)
{
  char err[255];

  if(THIS->silent == 0)
  {
    snprintf(err, sizeof(err), "Public.Parser.XML error: %d, message: %s", 
             error->level, error->message);
    push_text(err);

    f_werror(1);
  }

}

/*! @decl Node parse_xml_force(string xml)
 *!   Parse an string containing XML, even if it is not Well Formed.
 *!  @param xml
 *!   String containing XML data to parse.
 *!
 *!  @returns
 *!    a @[Node] object containing the root of the tree.
 */
PIKEFUN object parse_xml_force(string xml)
{
  xmlDocPtr doc;
  xmlNodePtr node;
  struct Node_struct * ns;
  NODE_OBJECT_DATA * od;

  doc = xmlRecoverMemory(xml->str, xml->len);

  if(doc == NULL)
  {
    pop_n_elems(2);
    Pike_error("Unable to parse XML.\n");
  }  

  node = xmlDocGetRootElement(doc);
  if(node == NULL)
  {
    pop_n_elems(2);
    xmlFreeDoc(doc);
    Pike_error("Unable to find Root Node.\n");
  }

  // ok, we have a parsed file. now let's turn it into a real live pike object.

  pop_n_elems(2);

  apply(Pike_fp->current_object, "Node", 0);
  
  ns = OBJ2_NODE((Pike_sp[0-1].u.object));
  od = (NODE_OBJECT_DATA *)(ns->object_data);

  od->parser = this_object();
  od->refs = malloc(sizeof(INT32));
  (* od->refs)=1;
  od->node = node;
}

xmlParserInputPtr my_entity_loader(const char * URL, const char * ID,
   xmlParserCtxtPtr context)
{
  printf("request for entity %s\n", URL);
  return NULL; 
}

/*! @decl Node parse_xml(string xml, string|void name, string|void encoding)
 *!   Parse an string containing XML.
 *!  @param xml
 *!   String containing XML data to parse.
 *!  @param name
 *!   String containing name/URI of file.
 *!
 *!  @returns
 *!    a @[Node] object containing the root of the tree.
 */
PIKEFUN object parse_xml(string xml, string name, string encoding)
{
  xmlDocPtr doc;

  entity_loader = my_entity_loader;

  //  xmlSetExternalEntityLoader(entity_loader);

  doc = xmlReadMemory(xml->str, xml->len, name->str, 
                      (const char *)encoding->str, 
                      THIS->object_data->xml_parser_options);

  handle_parsed_tree(doc, args);
}

xmlEntityPtr my_xml_getent(void * ctx, const xmlChar * name)
{
    xmlEntityPtr ent;
    
    if(strcmp(name, "boo") != 0)
    {
      printf("somebody else's entity: %s!\n", name);
      return xmlSAX2GetEntity(ctx, name);
     }
    ent = xmlMalloc(sizeof(xmlEntity)); 
    if(ent == NULL) printf("unable to allocate entity storage.\n");
        
    memset(ent, 0, sizeof(xmlEntity));
      
    ent->type = XML_ENTITY_DECL;
    ent->etype = XML_INTERNAL_GENERAL_ENTITY;
    ent->name = xmlStrdup(name);   
    ent->content = xmlStrdup(name);
        
    return ent;

}

PIKEFUN object parse_xml_sax(string xml, string name, string encoding)
{
  xmlDocPtr doc;
  xmlSAXHandler * sax;
  xmlParserCtxtPtr ctxt;

  ctxt = xmlCreateMemoryParserCtxt(xml->str, xml->len);

  if(ctxt == NULL) Pike_error("unable to allocate context.\n");

  sax = xmlMalloc(sizeof(xmlSAXHandler));
  xmlSAXVersion(sax, 2);
  sax->getEntity = my_xml_getent;  

  if(ctxt->sax != NULL)
    xmlFree(ctxt->sax);

  ctxt->sax = sax;

  xmlDetectSAX2(ctxt);
  ctxt->recovery = 0;
//  ctxt->replaceEntities = 0;

  xmlParseDocument(ctxt);
  //  entity_loader = my_entity_loader;
  //  xmlSetExternalEntityLoader(entity_loader);

  doc = ctxt->myDoc;

   if (sax != NULL)
        ctxt->sax = NULL;
    xmlFreeParserCtxt(ctxt);

  handle_parsed_tree(doc, args);
}

void handle_parsed_tree(xmlDocPtr doc, INT32 args)
{
  xmlNodePtr node;
  struct Node_struct * ns;
  NODE_OBJECT_DATA * od;
  char * err_ctx = "parse_xml";

  if(doc == NULL)
  {
    pop_n_elems(args);
    Pike_error("Unable to parse XML.\n");
  }  

  node = xmlDocGetRootElement(doc);
  if(node == NULL)
  {
    pop_n_elems(args);
    xmlFreeDoc(doc);
    Pike_error("Unable to find Root Node.\n");
  }

  // ok, we have a parsed file. now let's turn it into a real live pike object.

  pop_n_elems(args);

  apply(Pike_fp->current_object, "Node", 0);
  
  ns = OBJ2_NODE((Pike_sp[0-1].u.object));
  od = (NODE_OBJECT_DATA *)(ns->object_data);

  od->refs = malloc(sizeof(INT32));
  (* od->refs)=1;
  od->node = node;
  od->parser = this_object();
}

PIKEFUN object parse_xml(string xml, string name)
{
  xmlDocPtr doc;

  entity_loader = my_entity_loader;

  //  xmlSetExternalEntityLoader(entity_loader);

  doc = xmlReadMemory(xml->str, xml->len, name->str, 
                      NULL, 
                      THIS->object_data->xml_parser_options);

  handle_parsed_tree(doc, args);
  
}

PIKEFUN object parse_xml(string xml)
{
  push_text("noname.xml");
  f_parse_xml(2);
}

/*! @decl Node parse_html(string html, string|void name, string|void encoding)
 *!   Parse an string containing HTML.
 *!  @param html
 *!   String containing HTML data to parse.
 *!  @param name
 *!   String containing name/URI of file.
 *!
 *!  @returns
 *!    a @[Node] object containing the root of the tree.
 */
PIKEFUN object parse_html(string html, string name, string encoding)
{
  xmlDocPtr doc;

  entity_loader = my_entity_loader;

  //  xmlSetExternalEntityLoader(entity_loader);

  doc = htmlReadMemory(html->str, html->len, name->str, 
                      (const char *)encoding->str, 
                      THIS->object_data->html_parser_options);

  handle_parsed_tree(doc, args);
}

PIKEFUN object parse_html(string html, string name)
{
  xmlDocPtr doc;

  entity_loader = my_entity_loader;

  //  xmlSetExternalEntityLoader(entity_loader);

  doc = htmlReadMemory(html->str, html->len, name->str, 
                      NULL, 
                      THIS->object_data->html_parser_options);

  handle_parsed_tree(doc, args);
  
}

PIKEFUN object parse_html(string html)
{
  push_text("noname.html");
  f_parse_html(2);
}

/*! @decl int validate(Node doc)
 *!
 *! validates a document against its internal and external DTDs.
 *!
 */
PIKEFUN int validate(object doc)
{
  int r;
  xmlValidCtxtPtr valid;
  CHECK_NODE_PASSED(doc);

  if(OBJ2_NODE(doc)->object_data->node->doc==NULL)
  {
    pop_stack();
    Pike_error("whoa, horsie! we don't have an xml document!\n");
  }

  valid = xmlNewValidCtxt();
  if(valid == NULL)
  {
    pop_stack();
    Pike_error("unable to allocate a validation context\n");
  }

  r = xmlValidateDocument(valid, OBJ2_NODE(doc)->object_data->node->doc);

  xmlFreeValidCtxt(valid);

  pop_stack();

  push_int(r);
}

/*! @decl Node new_xml(string version, string root_name)
 *!   Create a new XML document with a root node.
 *!
 *!  @param version
 *!     the version of XML to create
 *!  @param root_name
 *!      the name of the root node
 *!  @returns
 *!    a @[Node] object containing the root of the tree.
 */
PIKEFUN object new_xml(string version, string root_name)
{
  xmlDocPtr doc;
  xmlNodePtr node;
  struct Node_struct * ns;
  NODE_OBJECT_DATA * od;

  // TODO: we need to encode this value!
  doc = xmlNewDoc(version->str);

  if(doc == NULL)
  {
    Pike_error("Unable to create new XML document.\n");
  }  

  // TODO: we need to encode this value!
  node = xmlNewNode(NULL, (xmlChar *)root_name->str);
  xmlDocSetRootElement(doc, node);
  if(node == NULL)
  {
    xmlFreeDoc(doc);
    Pike_error("Unable to find Root Node.\n");
  }

  // ok, we have a parsed file. now let's turn it into a real live pike object.

  pop_stack();

  apply(Pike_fp->current_object, "Node", 0);
  
  ns = OBJ2_NODE((Pike_sp[0-1].u.object));
  od = (NODE_OBJECT_DATA *)(ns->object_data);

  od->refs = malloc(sizeof(INT32));
  (* od->refs)=1;
  od->node = node;
  od->parser = this_object();
}

/*! @decl Node new_node(string name)
 *!   Create a new unlinked XML node.
 *!
 *!  @param name
 *!      the node name
 *!  @returns
 *!    a new @[Node] object.
 */
PIKEFUN object new_node(string name)
{
  xmlNodePtr node;
  struct Node_struct * ns;
  NODE_OBJECT_DATA * od;

  // TODO: we need to encode this value!
  node = xmlNewNode(NULL, name->str);

  if(node == NULL)
  {
    Pike_error("Unable to create new node.\n");
  }  
  node = xmlNewNode(NULL, (xmlChar *)name->str);

  pop_stack();

  apply(Pike_fp->current_object, "Node", 0);
  
  ns = OBJ2_NODE((Pike_sp[0-1].u.object));
  od = (NODE_OBJECT_DATA *)(ns->object_data);

  od->refs = malloc(sizeof(INT32));
  (* od->refs)=1;
  od->node = node;
  od->parser = this_object();
}

/*! @decl Node parse_relaxng(string relaxng, string|void name)
/*! @decl Node parse_relaxng(Node relaxng)
 *!   Parse a string containing an RelaxNG schema.
 *!
 *!  @param name
 *!   String containing name/URI of file.
 *!
 *!  @returns
 *!    a @[RelaxNG] object containing the parsed schema.
 */
PIKEFUN object parse_relaxng(string relaxng)
{
  push_text("noname.rlx");
  f_parse_relaxng(2);
}

PIKEFUN object parse_relaxng(object relaxng)
{
  CHECK_NODE_PASSED(relaxng);

  handle_parse_relaxng(args);

}

PIKEFUN object parse_relaxng(string relaxng, string name)
{
  // first, we must parse the xml file. conveniently, we have a function
  // that does that already!
  f_parse_xml(2);

  handle_parse_relaxng(args);
}

void handle_parse_relaxng(INT32 args)
{
  struct object * node_obj = NULL;
  xmlDocPtr doc = NULL;
  xmlRelaxNGParserCtxtPtr parser;
  xmlRelaxNGPtr relax;
  struct RelaxNG_struct * rn;
  RELAXNG_OBJECT_DATA * od;

  // we're going to hang on to the node object.
  node_obj = Pike_sp[0-1].u.object;
  add_ref(node_obj);

  doc = OBJ2_NODE(node_obj)->object_data->node->doc;

  if(doc==NULL)
  {
    pop_stack();
    Pike_error("whoa, horsie! we don't have an xml document!\n");
  }

  parser = xmlRelaxNGNewDocParserCtxt(doc);
  if(parser == NULL)
  {
    pop_stack();
    Pike_error("Unable to create relaxng parser context.\n");
  }  
  
  relaxng_error_handler = (xmlRelaxNGValidityErrorFunc)my_relaxng_generic_error;
  relaxng_warning_handler = (xmlRelaxNGValidityWarningFunc)my_relaxng_generic_error;

  xmlRelaxNGSetParserErrors(parser, relaxng_error_handler, 
                            relaxng_warning_handler, NULL);

  relax = xmlRelaxNGParse(parser);

  if(relax == NULL)
  {
    pop_stack();
    Pike_error("Unable to parse the relaxng data.\n");
  }  


  // ok, we have a parsed schema. now let's turn it into a real live pike object.

  pop_stack();

  apply(Pike_fp->current_object, "RelaxNG", 0);
  
  rn = OBJ2_RELAXNG((Pike_sp[0-1].u.object));
  od = (RELAXNG_OBJECT_DATA *)(rn->object_data);
  od->parser = this_object();

  od->refs = malloc(sizeof(INT32));
  (* od->refs)=1;

  /* TODO: not sure if this is a leak, but we need it to prevent the 
     xmlNode from being freed a second time at the pike Node's destruction  
     (the Stylesheet will free that itself. Note that this is a tricky 
     subject... since the two are linked, perhaps we should call 
     Node.destroy() when the Stylesheet is destroyed... */
  *(OBJ2_NODE(node_obj)->object_data->refs)++;
  od->context = parser;
  od->valid = relax;
  rn->node = node_obj;
}

/*! @decl Node parse_xslt(string xslt, string|void name)
/*! @decl Node parse_xslt(Node xslt)
 *!   Parse a string containing an XSLT stylesheet.
 *!
 *!  @param name
 *!   String containing name/URI of file.
 *!
 *!  @returns
 *!    a @[Stylesheet] object containing the parsed stylesheet.
 */
PIKEFUN object parse_xslt(string xslt)
{
  push_text("noname.xsl");
  f_parse_xslt(2);
}

PIKEFUN object parse_xslt(object xslt)
{
  CHECK_NODE_PASSED(xslt);

  handle_parse_stylesheet(args);
}

PIKEFUN object parse_xslt(string xslt, string name)
{
  // first, we must parse the xml file. conveniently, we have a function
  // that does that already!
  f_parse_xml(2);

  handle_parse_stylesheet(args);
}

void handle_parse_stylesheet(INT32 args)
{
  struct object * node_obj = NULL;
  xsltStylesheetPtr sty = NULL;
  xmlDocPtr doc = NULL;
  struct Stylesheet_struct * ss;
  STYLESHEET_OBJECT_DATA * od;

  // we're going to hang on to the node object.
  node_obj = Pike_sp[0-1].u.object;
  add_ref(node_obj);

  doc = OBJ2_NODE(node_obj)->object_data->node->doc;

  if(doc==NULL)
  {
    pop_stack();
    Pike_error("whoa, horsie! we don't have an xml document!\n");
  }

  sty = xsltParseStylesheetDoc(doc);

  if(sty == NULL)
  {
    pop_stack();
    Pike_error("Unable to parse stylesheet node.\n");
  }  

  // ok, we have a parsed sheet. now let's turn it into a real live pike object.

  pop_stack();

  apply(Pike_fp->current_object, "Stylesheet", 0);
  
  ss = OBJ2_STYLESHEET((Pike_sp[0-1].u.object));
  od = (STYLESHEET_OBJECT_DATA *)(ss->object_data);
  od->parser = this_object();

  od->refs = malloc(sizeof(INT32));
  (* od->refs)=1;
  add_ref(node_obj);
//  (*(OBJ2_NODE(node_obj)->object_data->refs))++;
  od->stylesheet = sty;
  ss->node = node_obj;
}

EXTRA
{
  struct pike_string * ps;
  char * err_ctx = "parse_xml";

  add_string_constant("__version", "1.38", 0);
  add_string_constant("__author", "Bill Welliver ", 0);

  structured_handler = my_structured_error;
  xmlSetStructuredErrorFunc((void *)err_ctx, structured_handler);

  pike_init_xml2_constants();
  pike_init_xml2_html();
  pike_init_xml2_node();
  pike_init_xml2_sax();
  pike_init_xml2_stylesheet();
  pike_init_xml2_xmlreader();
  pike_init_xml2_relaxng();

}

INIT
{
  PARSER_OBJECT_DATA * dta;

  dta = (PARSER_OBJECT_DATA*)malloc(sizeof(PARSER_OBJECT_DATA));
  if(dta == NULL)
  {
    Pike_error("xml2_init: unable to allocate memory.\n");
  }

  dta->xml_parser_options = 0;
  dta->html_parser_options = 0;
  dta->auto_encode = 1;
  THIS->object_data = dta;
 
  LIBXML_TEST_VERSION
}

EXIT
{

  pike_exit_xml2_relaxng();
  pike_exit_xml2_xmlreader();
  pike_exit_xml2_stylesheet();
  pike_exit_xml2_sax();
  pike_exit_xml2_node();
  pike_exit_xml2_html();
  pike_exit_xml2_constants();
  
#ifdef HAVE_XSLT
xsltCleanupGlobals();
#endif /* HAVE_XSLT */

  xmlCleanupParser();
}

/*! @endmodule
 */

/*! @endmodule
 */

/*! @endmodule
 */