/*
 * 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.ws.soap.stroap;

import javax.xml.namespace.QName;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;

import org.springframework.ws.soap.SoapBody;
import org.springframework.ws.soap.SoapBodyException;
import org.springframework.ws.soap.SoapEnvelope;
import org.springframework.ws.soap.SoapHeader;
import org.springframework.ws.soap.SoapHeaderException;
import org.springframework.ws.soap.SoapVersion;
import org.springframework.xml.stream.CompositeXMLEventReader;

/**
 * @author Arjen Poutsma
 */
class StroapEnvelope extends StroapElement implements SoapEnvelope {

	private static final String LOCAL_NAME = "Envelope";

	private StroapHeader header;

	private StroapBody body;

	StroapEnvelope(StroapMessageFactory messageFactory) {
		super(messageFactory.getSoapVersion().getEnvelopeName(), messageFactory);
		this.header = null;
		this.body = new Stroap11Body(messageFactory);
	}

	private StroapEnvelope(StartElement startElement,
						   StroapHeader header,
						   StroapBody body,
						   StroapMessageFactory messageFactory) {
		super(startElement, messageFactory);
		this.header = header;
		this.body = body;
	}

	static StroapEnvelope build(XMLEventReader eventReader, StroapMessageFactory messageFactory)
			throws XMLStreamException {
		XMLEvent event = eventReader.nextTag();
		if (!event.isStartElement()) {
			throw new StroapMessageCreationException("Unexpected event: " + event + ", expected StartElement");
		}
		StartElement startElement = event.asStartElement();
		SoapVersion soapVersion = messageFactory.getSoapVersion();
		if (!soapVersion.getEnvelopeName().equals(startElement.getName())) {
			throw new StroapMessageCreationException(
					"Unexpected name: " + startElement.getName() + ", expected " + soapVersion.getEnvelopeName());
		}
		StroapHeader header = null;
		StroapBody body = null;
		XMLEvent peekedEvent = eventReader.peek();
		while (peekedEvent != null) {
			if (peekedEvent.isStartElement()) {
				QName headerOrBodyName = peekedEvent.asStartElement().getName();
				if (soapVersion.getHeaderName().equals(headerOrBodyName)) {
					header = StroapHeader.build(eventReader, messageFactory);
				}
				else if (soapVersion.getBodyName().equals(headerOrBodyName)) {
					body = StroapBody.build(eventReader, messageFactory);
					break;
				}
				else {
					throw new StroapMessageCreationException(
							"Unexpected start element name [" + headerOrBodyName + "]");
				}
			}
			else {
				eventReader.nextEvent();
			}
			peekedEvent = eventReader.peek();
		}
		if (body == null) {
			throw new StroapMessageCreationException("No SOAP body found");
		}

		return new StroapEnvelope(startElement, header, body, messageFactory);
	}

	public SoapHeader getHeader() throws SoapHeaderException {
		if (header == null) {
			header = new Stroap11Header(getMessageFactory());
		}
		return header;
	}

	public SoapBody getBody() throws SoapBodyException {
		if (body == null) {
			body = new Stroap11Body(getMessageFactory());
		}
		return body;
	}

	@Override
	protected XMLEventReader getChildEventReader() {
		if (header != null) {
			return new CompositeXMLEventReader(header.getEventReader(false), body.getEventReader(false));
		}
		else {
			return body.getEventReader(false);
		}
	}

}