#if !defined( INCLUDED_XML_XMLWRITER_H )
#define INCLUDED_XML_XMLWRITER_H

#include "convert.h"
#include <vector>
#include "xml/ixml.h"

class BufferedTextOutputStream : public TextOutputStream
{
enum { m_bufsize = 1024 };  // aka const std::size_t m_bufsize = 1024;
TextOutputStream& m_ostream;
char m_buffer[m_bufsize];
char* m_pos;
const char* m_end;

const char* end() const {
	return m_end;
}
void reset(){
	m_pos = m_buffer;
}
void flush(){
	m_ostream.write( m_buffer, m_pos - m_buffer );
	reset();
}
public:
BufferedTextOutputStream( TextOutputStream& ostream ) : m_ostream( ostream ), m_pos( m_buffer ), m_end( m_buffer + m_bufsize ){
}
~BufferedTextOutputStream(){
	flush();
}
void write( const char c ){
	if ( m_pos == end() ) {
		flush();
	}
	*m_pos++ = c;
}
std::size_t write( const char* buffer, std::size_t length ){
	const char*const end = buffer + length;
	for ( const char* p = buffer; p != end; ++p )
	{
		write( *p );
	}
	return length;
}
};

class XMLEntityOutputStream
{
BufferedTextOutputStream m_ostream;
public:
XMLEntityOutputStream( TextOutputStream& ostream )
	: m_ostream( ostream ){
}
void write( const char c ){
	m_ostream.write( c );
}
void writeEscaped( const char c ){
	switch ( c )
	{
	case '<':
		write( '&' );
		write( 'l' );
		write( 't' );
		write( ';' );
		break;
	case '>':
		write( '&' );
		write( 'g' );
		write( 't' );
		write( ';' );
		break;
	case '"':
		write( '&' );
		write( 'q' );
		write( 'u' );
		write( 'o' );
		write( 't' );
		write( ';' );
		break;
	case '&':
		write( '&' );
		write( 'a' );
		write( 'm' );
		write( 'p' );
		write( ';' );
		break;
	default:
		write( c );
		break;
	}
}
std::size_t write( const char* buffer, std::size_t length ){
	const char*const end = buffer + length;
	for ( const char* p = buffer; p != end; ++p )
	{
		writeEscaped( *p );
	}
	return length;
}
};

template<typename T>
inline XMLEntityOutputStream& operator<<( XMLEntityOutputStream& ostream, const T& t ){
	return ostream_write( ostream, t );
}


class XMLStreamWriter : public XMLImporter, public XMLAttrVisitor
{
class state_t
{
public:
enum EState
{
	eStartElement,
	eContent,
};
state_t()
	: m_state( eStartElement )
{}
EState m_state;
};

XMLEntityOutputStream m_ostream;
std::vector<state_t> m_elements;

void write_cdata( const char* buffer, std::size_t length ){
	m_ostream << ConvertLocaleToUTF8( StringRange( buffer, buffer + length ) );
}
void write_string( const char* string ){
	m_ostream << string;
}
void write_quoted_string( const char* string ){
	m_ostream.write( '"' );
	m_ostream << string;
	m_ostream.write( '"' );
}
public:
XMLStreamWriter( TextOutputStream& ostream )
	: m_ostream( ostream ){
	m_elements.push_back( state_t() );
	m_elements.back().m_state = state_t::eContent;
	m_ostream.write( '<' );
	m_ostream.write( '?' );
	write_string( "xml" );
	visit( "version", "1.0" );
	m_ostream.write( '?' );
	m_ostream.write( '>' );
}

void pushElement( const XMLElement& element ){
	if ( m_elements.back().m_state == state_t::eStartElement ) {
		m_elements.back().m_state = state_t::eContent;
		m_ostream.write( '>' );
	}

	m_elements.push_back( state_t() );

	m_ostream.write( '<' );
	write_string( element.name() );
	element.forEachAttribute( *this );
}
void popElement( const char* name ){
	if ( m_elements.back().m_state == state_t::eStartElement ) {
		m_ostream.write( '/' );
		m_ostream.write( '>' );
	}
	else
	{
		m_ostream.write( '<' );
		m_ostream.write( '/' );
		write_string( name );
		m_ostream.write( '>' );
	}
}
std::size_t write( const char* data, std::size_t length ){
	if ( m_elements.back().m_state == state_t::eStartElement ) {
		m_elements.back().m_state = state_t::eContent;
		m_ostream.write( '>' );
	}
	write_cdata( data, length );
	return length;
}

void visit( const char* name, const char* value ){
	m_ostream.write( ' ' );
	write_string( name );
	m_ostream.write( '=' );
	write_quoted_string( value );
}
};


#endif