EDIT

// $Id$

/**

* Copyright (C) 2009 EDIT

* European Distributed Institute of Taxonomy 

* http://www.e-taxonomy.eu

* 

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.io.common;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.net.URI;

import java.util.NoSuchElementException;

import javax.xml.namespace.QName;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;

import javax.xml.stream.FactoryConfigurationError;

import javax.xml.stream.XMLEventReader;

import javax.xml.stream.XMLInputFactory;

import javax.xml.stream.XMLStreamException;

import javax.xml.stream.events.XMLEvent;

import org.apache.log4j.Logger;

import org.xml.sax.SAXException;

import eu.etaxonomy.cdm.io.common.events.IIoEvent;

import eu.etaxonomy.cdm.io.common.events.IIoObserver;

/**

 * Base class for XML imports

 * @author a.mueller

 * @date 28.06.2011

 *

 */

public abstract class XmlImportBase<CONFIG extends XmlImportConfiguratorBase<STATE>, STATE extends XmlImportState<CONFIG, ?>> extends CdmImportBase<CONFIG, STATE> implements IIoObserver {

	@SuppressWarnings("unused")

	private static final Logger logger = Logger.getLogger(XmlImportBase.class);

	protected void fireSchemaConflictEventExpectedStartTag(String elName, XMLEventReader reader) throws XMLStreamException {

		String type = "ElementStart";

		XMLEvent next = reader.nextEvent();

		fireSchemaConflictEvent(type, elName, next);

	}

	/**

	 * @param r

	 * @return

	 * @throws XMLStreamException

	 */

	protected boolean validateStartOfDocument(XMLEventReader reader) throws XMLStreamException {

		XMLEvent next = reader.nextEvent();

		if (next.isStartDocument()){

			return true;

		}else {

			fireWarningEvent("Missing start of document", next.getLocation().toString(), 16);

			return false;

		}

	}

	/**

	 * TODO namespace

	 * @param elName

	 * @param reader

	 * @return

	 * @throws XMLStreamException

	 */

	protected boolean isStartingElement(XMLEventReader reader, String elName) throws XMLStreamException {

		XMLEvent next;

		try {

			next = reader.peek();

		} catch (NoSuchElementException e) {

			return false;

		}

		return isStartingElement(next, elName);

	}

	protected boolean isStartingElement(XMLEvent event, String elName) throws XMLStreamException {

		boolean result = false;

		boolean isStart = event.isStartElement();

		if (isStart){

			QName name = event.asStartElement().getName();

			boolean equals = name.getLocalPart().equals(elName);

			result = equals;

		}

		return result;

	}

	protected boolean isEndingElement(XMLEventReader reader, String elName) throws XMLStreamException {

		XMLEvent next;

		try {

			next = reader.peek();

		} catch (NoSuchElementException e) {

			return false;

		}

		return isEndingElement(next, elName);

	}

	protected boolean isEndingElement(XMLEvent event, String elName) throws XMLStreamException {

		boolean result = false;

		boolean isEnd = event.isEndElement();

		if (isEnd){

			QName name = event.asEndElement().getName();

			result = name.getLocalPart().equals(elName);

		}

		return result;

	}

	/**

	 * Returns an input stream for the given source.

	 * @param config

	 * @return

	 */

	protected InputStream getInputStream(CONFIG config) {

			try {

				URI uri = config.getSource();

				File file = new File(uri);

				InputStream is = new FileInputStream(file);

				return is;

			}catch (Exception e) {

				String message = "Problem reading source file %s. Import can not be executed. Reason: %s.";

				message = String.format(message, config.getSource(), e.getMessage());

				fireWarningEvent(message, "Read file", 16);

				return null;

			}

	}

	/**

	 * @param elName

	 * @param next

	 * @param message

	 * @param type

	 */

	private void fireSchemaConflictEvent(String expectedType, String expectedName, XMLEvent next) {

		String message = "Schema conflict: expected %s '%s' but was %s ";

		String eventString;

		if (next.isStartElement()){

			eventString = next.asStartElement().getName().getLocalPart();

		}else if(next.isEndElement()){

			eventString = next.asEndElement().getName().getLocalPart();

		}else{

			eventString = next.toString();

		}

		message = String.format(message, expectedType, expectedName, eventString);

		String location = "l." + next.getLocation().getLineNumber() + "/c." + next.getLocation().getColumnNumber();

		fireWarningEvent(message, location, 16);

	}

	/**

	 * Returns the StAX-Reader (XMLEventReader) for the source.

	 * @param state

	 * @return

	 * @throws FactoryConfigurationError

	 * @throws XMLStreamException

	 */

	protected XMLEventReader getStaxReader(STATE state)	throws FactoryConfigurationError, XMLStreamException {

		String fileName = state.getConfig().getSource().toString();

		InputStream is = getInputStream(state.getConfig());

		XMLInputFactory staxFactory = XMLInputFactory.newInstance();

		XMLEventReader reader = staxFactory.createXMLEventReader(fileName, is);

		return reader;

	}

	/**

	 * Parses the source file with the given handler

	 * @param is

	 * @param handler

	 * @throws ParserConfigurationException

	 * @throws SAXException

	 * @throws IOException

	 */

	protected void parseSAX(STATE state, ImportHandlerBase handler)

			throws ParserConfigurationException, SAXException, IOException {

		handler.addObserver(this);

		InputStream is = getInputStream(state.getConfig());

	    SAXParserFactory saxFactory = SAXParserFactory.newInstance();

		SAXParser saxParser = saxFactory.newSAXParser();

		saxParser.parse(is, handler);

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.io.common.events.IIoObserver#handleEvent(eu.etaxonomy.cdm.io.common.events.IIoEvent)

	 */

	@Override

	public void handleEvent(IIoEvent event) {

		fire(event);

	}

}