/*
 * Copyright 2005-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.xml.stream;

import javax.xml.namespace.NamespaceContext;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLEventWriter;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.XMLEvent;

import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.xml.namespace.SimpleNamespaceContext;

/**
 * @author Arjen Poutsma
 */
public abstract class AbstractXMLEventWriter implements XMLEventWriter {

	private boolean closed;

	private SimpleNamespaceContext namespaceContext = new SimpleNamespaceContext();

	public void flush() throws XMLStreamException {
	}

	public void add(XMLEventReader eventReader) throws XMLStreamException {
		checkIfClosed();
		while (eventReader.hasNext()) {
			XMLEvent event = eventReader.nextEvent();
			add(event);
		}
	}

	public String getPrefix(String uri) throws XMLStreamException {
		return namespaceContext.getPrefix(uri);
	}

	public void setPrefix(String prefix, String uri) throws XMLStreamException {
		namespaceContext.bindNamespaceUri(prefix, uri);
	}

	public void setDefaultNamespace(String uri) throws XMLStreamException {
		namespaceContext.bindDefaultNamespaceUri(uri);
	}

	public void setNamespaceContext(NamespaceContext namespaceContext) throws XMLStreamException {
		Assert.notNull(namespaceContext, "'namespaceContext' must not be null");
		this.namespaceContext = (SimpleNamespaceContext) namespaceContext;
	}

	public NamespaceContext getNamespaceContext() {
		return namespaceContext;
	}

	/**
	 * Returns <code>true</code> if closed; <code>false</code> otherwise.
	 *
	 * @see #close()
	 */
	protected boolean isClosed() {
		return closed;
	}

	/**
	 * Checks if the reader is closed, and throws a <code>XMLStreamException</code> if so.
	 *
	 * @throws XMLStreamException if the reader is closed
	 * @see #close()
	 * @see #isClosed()
	 */
	protected void checkIfClosed() throws XMLStreamException {
		if (closed) {
			throw new XMLStreamException(ClassUtils.getShortName(getClass()) + " has been closed");
		}
	}

	public void close() {
		closed = true;
	}

}