/*
 * Copyright 2005-2014 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.ws.soap.axiom;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.OutputStream;
import java.io.Writer;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;

import org.apache.axiom.om.OMDataSource;
import org.apache.axiom.om.OMOutputFormat;
import org.apache.axiom.om.util.StAXUtils;

import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.ws.stream.StreamingPayload;

/**
 * Implementation of {@link OMDataSource} that wraps a {@link StreamingPayload}.
 *
 * @author Arjen Poutsma
 * @since 2.0
 */
class StreamingOMDataSource implements OMDataSource {

	private final StreamingPayload payload;

	StreamingOMDataSource(StreamingPayload payload) {
		Assert.notNull(payload, "'payload' must not be null");
		this.payload = payload;
	}

	@Override
	public void serialize(OutputStream output, OMOutputFormat format) throws XMLStreamException {
		XMLStreamWriter streamWriter;
		if (format != null && StringUtils.hasLength(format.getCharSetEncoding())) {
			streamWriter = StAXUtils.createXMLStreamWriter(output, format.getCharSetEncoding());
		}
		else {
			streamWriter = StAXUtils.createXMLStreamWriter(output);
		}
		serialize(streamWriter);
	}

	@Override
	public void serialize(Writer writer, OMOutputFormat format) throws XMLStreamException {
		XMLStreamWriter streamWriter = StAXUtils.createXMLStreamWriter(writer);
		serialize(streamWriter);
	}

	@Override
	public void serialize(XMLStreamWriter xmlWriter) throws XMLStreamException {
		payload.writeTo(xmlWriter);
		xmlWriter.flush();
	}

	@Override
	public XMLStreamReader getReader() throws XMLStreamException {
		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		serialize(bos, null);

		ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
		return StAXUtils.createXMLStreamReader(bis);
	}

}