//
//
// Copyright 2002 Rob Tougher <robt@robtougher.com>
//
// This file is part of xmlrpc.
//
// xmlrpc 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.
//
// xmlrpc 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 xmlrpc; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
//


// Implementation of the xml::node class.


#include "node.hpp"
#include <sstream>

namespace xml
{

  void node::add_child ( node * n )
  {
    if ( n )
      {
	m_children.push_back ( n );
      }
  }

  node* node::add_child ( const std::string name, const std::string text )
  {
    node * n = new node ( name, text );
    add_child ( n );
    return n;
  }

  node* node::get_child ( const int index ) const
  {
    if ( m_children.size() > index )
      {
	return * (m_children.begin() + index );
      }
    else
      {
	return 0;
      }
  }


  void node::cleanup()
  {
    if ( ! m_cleanup ) return;

    for ( std::vector<node*>::const_iterator it = m_children.begin();
	  it != m_children.end();
	  it++ )
      {
	if ( it && *it )
	  {
	    node* n = *it;
	    delete n; 
	  }
      }

    m_children.clear();
    set_root ( 0 );
    m_current_node = 0;
  }


  std::string node::get_xml() const
  {
    std::string xml = "<";
    xml += encode ( get_name() );
    xml += ">";

    //
    // Take special characters into account
    //
    xml += encode ( get_text() );

    int child_count = get_child_count();
    for ( int child_index = 0; child_index < child_count; child_index++ )
      {
	node * child = get_child ( child_index );

	if ( child )
	  {
	    xml += child->get_xml();
	  }
      }

    xml += "</";
    xml += encode ( get_name() );
    xml += ">";

    return xml;
  }

  std::string node::encode ( const std::string s ) const
  {
    std::string tmp;

    for ( std::string::const_iterator it = s.begin();
	  it != s.end();
	  it++ )
      {
	char c = *(it);

	if ( c == '&' )
	  {
	    tmp += "&amp;";
	  }
	else if ( c == '<' )
	  {
	    tmp += "&lt;";
	  }
	else if ( c == '>' )
	  {
	    tmp += "&gt;";
	  }
	else if ( c == '"' )
	  {
	    tmp += "&quot;";
	  }
	else if ( c == '\'' )
	  {
	    tmp += "&apos;";
	  }
	else
	  {
	    tmp += c;
	  }
      }
    return tmp;
  }

  // --------------------------------------------------
  //
  // The following code handles the parsing stuff
  //
  // --------------------------------------------------


  //
  // Creates and frees an expat parser
  //
  //
  class expat_parser
  {
  public:
    expat_parser()
    {
      m_p = XML_ParserCreate ( NULL );

      if ( ! m_p )
	{
	  throw parse_exception ( "Couldn't allocate memory for parser.\n" );
	}
    }
    ~expat_parser() { XML_ParserFree ( m_p ); }
    operator XML_Parser () const { return m_p; }
  private:
    XML_Parser m_p;
  };



  void start_element ( void *data, const char *el, const char **attr )
  {
    if ( ! data ) return;
    node * p = (node*)data;

    node* n = new node();

    if ( ! p->root() )
      {
	p->set_root ( n );
      }

    if ( p->current_node() )
      p->current_node()->add_child ( n );


    p->node_stack().push_back ( n );
    p->set_current_node ( n );
    n->set_name ( el );
  }


  void end_element ( void *data, const char *el )
  {
    if ( ! data ) return;
    node * p = (node*)data;

    if ( p->node_stack().size() < 1 )
      {
	return;
      }

    p->node_stack().pop_back();


    if ( p->node_stack().size() == 0 )
      {
	p->set_current_node ( 0 );
      }
    else
      {
	p->set_current_node ( * ( p->node_stack().begin() + p->node_stack().size() - 1 ) );
      }

    return;
  }


  void characters ( void *userData, const XML_Char *s, int len )
  {
    if ( ! userData ) return;
    node * p = ( node* ) userData;

    std::string tmp = s;
    tmp = tmp.substr ( 0, len );

    if ( p->current_node() )
      {
	p->current_node()->append_text ( ( const char * ) tmp.c_str() );
      }

    return;
  }


  void node::load_xml ( const std::string s )
  {
    //
    // Destroys any memory we are holding on to
    //
    cleanup();


    expat_parser p;

    XML_SetElementHandler ( p, start_element, end_element );
    XML_SetCharacterDataHandler ( p, characters );
    XML_SetUserData ( p, this );

    if ( ! XML_Parse ( p, s.c_str(), s.size(), true ) )
      {
	std::ostringstream ost;
	ost << "Parse error at line " << XML_GetCurrentLineNumber(p)
		  << " --- " << XML_ErrorString(XML_GetErrorCode(p));
	throw parse_exception ( ost.str() );
      }

    if ( m_root )
      {
	m_name = m_root->m_name;
	m_text = m_root->m_text;
	m_children = m_root->m_children;
	m_root->m_cleanup = false;
	set_root ( 0 );
      }

  }



};