package org.simantics.xml.sax.base;

import java.util.Collection;
import java.util.Set;

import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;

import org.simantics.databoard.binding.Binding;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.Statement;
import org.simantics.db.exception.DatabaseException;

public abstract class ValueElementWriter implements XMLElementWriter{
	
	String name;
	Binding binding;
	String typeURI;
	
	public ValueElementWriter(String name, String typeURI,Binding binding) {
		this.name = name;
		this.typeURI = typeURI;
		this.binding = binding;
	}
	
	@Override
	public String getElementId() {
		return name;
	}
	
	@Override
	public Resource getType(ReadGraph graph) throws DatabaseException {
		return graph.getResource(typeURI);
	}
	
	@Override
	public void start(ReadGraph graph, WriterElement instance, XMLStreamWriter writer)
			throws XMLStreamException, DatabaseException {
		writer.writeStartElement(getElementId());
	}
	
	@Override
	public void children(ReadGraph graph, WriterElement instance, Set<Resource> sorted)
			throws XMLStreamException, DatabaseException {
		
	}
	
	@Override
	public void end(ReadGraph graph, WriterElement instance, XMLStreamWriter writer)
			throws XMLStreamException, DatabaseException {
		writer.writeEndElement();
	}
	
	@Override
	public void attributes(ReadGraph graph, WriterElement instance, Collection<Statement> attributes,
			XMLStreamWriter writer) throws XMLStreamException, DatabaseException {
		
	}
	
	public abstract String decode(Object value);
	
	@Override
	public void characters(ReadGraph graph, WriterElement instance, XMLStreamWriter writer)
			throws XMLStreamException, DatabaseException {
		Object value = graph.getValue(instance.getResource(), binding);
		writer.writeCharacters(decode(value));
	}

}