/*
A KIPI plugin to generate HTML image galleries
Copyright 2006 by Aurelien Gateau <aurelien dot gateau at free.fr>

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., 51 Franklin Street, Fifth Floor, Cambridge, MA 02110-1301, USA.

*/
#ifndef XMLUTILS_H
#define XMLUTILS_H

#include <kdebug.h>

#include <libxml/xmlwriter.h>

namespace KIPIHTMLExport {


/**
 * A simple wrapper for a C structure pointed to by @Ptr, which must be freed
 * with @freeFcn
 */
template <class Ptr, void(*freeFcn)(Ptr)>
class CWrapper {
public:
	CWrapper() : mPtr(0) {}
	CWrapper(Ptr ptr)
	: mPtr(ptr) {}

	~CWrapper() {
		freeFcn(mPtr);
	}

	operator Ptr() const {
		return mPtr;
	}

	bool operator!() const {
		return !mPtr;
	}

	void assign(Ptr ptr) {
		if (mPtr) freeFcn(mPtr);
		mPtr=ptr;
	}

private:
	Ptr mPtr;
};


/**
 * Simple wrapper around xmlTextWriter
 */
class XMLWriter {
public:
	bool open(const TQString& name) {
		xmlTextWriterPtr ptr=xmlNewTextWriterFilename(name.local8Bit(), 0);
		if (!ptr) return false;
		mWriter.assign(ptr);

		int rc=xmlTextWriterStartDocument(ptr, NULL, "UTF-8", NULL);
		if (rc<0) {
			mWriter.assign(0);
			return false;
		}

		xmlTextWriterSetIndent(ptr, 1);

		return true;
	}

	operator xmlTextWriterPtr() const {
		return mWriter;
	}

	void writeElement(const char* element, const TQString& value) {
		xmlTextWriterWriteElement(mWriter, BAD_CAST element, BAD_CAST value.utf8().data());
	}

	void writeElement(const char* element, int value) {
		writeElement(element, TQString::number(value));
	}

private:
	CWrapper<xmlTextWriterPtr,xmlFreeTextWriter> mWriter;
};


/**
 * A list of attributes for an XML element. To be used with @ref XMLElement
 */
class XMLAttributeList {
	typedef TQMap<TQString, TQString> Map;
public:
	void write(XMLWriter& writer) const {
		Map::const_iterator it=mMap.begin();
		Map::const_iterator end=mMap.end();
		for (; it!=end; ++it) {
			xmlTextWriterWriteAttribute(writer,
				BAD_CAST it.key().ascii(),
				BAD_CAST it.data().utf8().data());
		}
	}
	
	void append(const TQString& key, const TQString& value) {
		mMap[key]=value;
	}
	
	void append(const TQString& key, int value) {
		mMap[key]=TQString::number(value);
	}

private:
	Map mMap;
};


/**
 * A class to generate an XML element
 */
class XMLElement {
public:
	XMLElement(XMLWriter& writer, const TQString& element, const XMLAttributeList* attributeList=0)
	: mWriter(writer)
	{
		xmlTextWriterStartElement(writer, BAD_CAST element.ascii());
		if (attributeList) {
			attributeList->write(writer);
		}
	}

	~XMLElement() {
		xmlTextWriterEndElement(mWriter);
	}

private:
	XMLWriter& mWriter;
};


} // namespace

#endif /* XMLUTILS_H */