D-Net

/**

 * 

 */

package eu.dnetlib.data.collective.transformation.engine.functions;

import java.io.StringReader;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import javax.xml.namespace.NamespaceContext;

import javax.xml.xpath.XPath;

import javax.xml.xpath.XPathExpressionException;

import javax.xml.xpath.XPathFactory;

import org.apache.commons.lang.StringEscapeUtils;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.xml.sax.InputSource;

import eu.dnetlib.common.profile.Resource;

import eu.dnetlib.common.profile.ResourceDao;

import eu.dnetlib.data.collective.transformation.rulelanguage.Argument;

/**

 * @author jochen

 *

 */

public class RetrieveValue extends AbstractTransformationFunction {

	public static final Log log = LogFactory.getLog(RetrieveValue.class);

	public static final String paramFunctionName = "functionName";

	public static final String paramFunctionProfileId = "functionParameterProfileId";

	public static final String paramFunctionExpr = "functionParameterExpr";

	public enum FUNCTION {PROFILEFIELD, CURRENTDATE};

	@javax.annotation.Resource

	private ResourceDao resourceDao;

	/* (non-Javadoc)

	 * @see eu.dnetlib.data.collective.transformation.engine.functions.AbstractTransformationFunction#execute()

	 */

	@Override

	String execute() throws ProcessingException {

		// TODO Auto-generated method stub

		return null;

	}

	public String executeSingleValue(String functionName, List<Argument> arguments, String objRecord, Map<String, String> namespaceMap) throws ProcessingException{

		String result = "";

		FUNCTION function = FUNCTION.valueOf(functionName);

		switch(function){

		case PROFILEFIELD:

			if (arguments.size() != 2){

				throw new ProcessingException("invalid number of arguments - required 2 but found :" + arguments.size());

			}

			String arg = "";

			Resource resource = null;

			try{

				if (arguments.get(0).isValue()){

					arg = arguments.get(0).getArgument();

					if (arg.startsWith("collection(")) { // xquery

						arg = StringEscapeUtils.unescapeXml(arg);

						log.debug("retriev value arg: " + arg);

						resource = resourceDao.getResourceByQuery(arg); // query

					}else

						resource = resourceDao.getResource(arg); // profile id

				}else if (arguments.get(0).isInputField()){

					arg = evaluateXpath(objRecord, arguments.get(0).getArgument(), namespaceMap);

					if (arg.startsWith("collection(")) { // xquery

						arg = StringEscapeUtils.unescapeXml(arg);

						resource = resourceDao.getResourceByQuery(arg); // query

					}else

						resource = resourceDao.getResource(arg); // profile id

				}else if (arguments.get(0).isJobConst()){

					// TODO

				}else if (arguments.get(0).isVariable()){

					// TODO				

					log.warn("RETRIEVEVALUE: support for variables not yet implemented.");

				}				

			}catch(Exception e){

				throw new ProcessingException(e);

			}

			if (resource == null){

				throw new ProcessingException("invalid profileId: " + arg + "; functionName: " + functionName + ", arg1: " + arguments.get(0).getArgument() + ", arg2: " + arguments.get(1).getArgument());

			}

			result = resource.getValue(arguments.get(1).getArgument());  // xpath expr

			break;

		case CURRENTDATE:

			SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'"); // TODO format string

			result = dateFormat.format(new Date());

			default:

				// unsupported

				break;

		}

		return result;

	}

	/**

	 * @return the resourceDao

	 */

	public ResourceDao getResourceDao() {

		return resourceDao;

	}

	/**

	 * @param resourceDao the resourceDao to set

	 */

	public void setResourceDao(ResourceDao resourceDao) {

		this.resourceDao = resourceDao;

	}

	private String evaluateXpath(String record, String xpathExpr, Map<String, String> nsMap){

		XPath xpath = XPathFactory.newInstance().newXPath();

		xpath.setNamespaceContext(new NamespaceContext() {

			@Override

			public Iterator getPrefixes(String namespaceURI) {

				return null;

			}

			@Override

			public String getPrefix(String namespaceURI) {

				// TODO Auto-generated method stub

				return null;

			}

			@Override

			public String getNamespaceURI(String prefix) {

				if ("dri".equals(prefix)){

                    return "http://www.driver-repository.eu/namespace/dri";                      

                }else if ("dr".equals(prefix)){

                        return "http://www.driver-repository.eu/namespace/dr";

                }else if ("dc".equals(prefix)){

                        return "http://purl.org/dc/elements/1.1/";

                }else if ("oaf".equals(prefix)){

                    return "http://namespace.openaire.eu/oaf";

                }else if ("prov".equals(prefix)){

                    return "http://www.openarchives.org/OAI/2.0/provenance";

                }

                return "";

			}

		});

		try {

			return xpath.evaluate(xpathExpr, new InputSource(new StringReader(record)));

		} catch (XPathExpressionException e) {

			log.fatal("cannot evaluate xpath");

			throw new IllegalStateException(e);

		}

	}

}