D-Net

package eu.dnetlib.msro.workflows.nodes.download;

import java.io.ByteArrayInputStream;

import java.text.SimpleDateFormat;

import java.util.ArrayList;

import java.util.Date;

import java.util.List;

import java.util.function.Function;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.xpath.XPath;

import javax.xml.xpath.XPathConstants;

import javax.xml.xpath.XPathExpression;

import javax.xml.xpath.XPathFactory;

import org.apache.commons.lang3.StringUtils;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.w3c.dom.Document;

import org.w3c.dom.NodeList;

import com.google.gson.Gson;

import eu.dnetlib.rmi.data.DownloadItem;

// TODO: Auto-generated Javadoc

/**

 * The Class UrlExtractor.

 */

public class UrlExtractor implements Function<String, String> {

	/** The Constant log. */

	private static final Log log = LogFactory.getLog(UrlExtractor.class);

	/** The xpath url. */

	private String xpathURL;

	/** The xpath. */

	private String xpathMetadataID;

	/** The xpath open access. */

	private String xpathOpenAccess;

	/** The xpath embargo date. */

	private String xpathEmbargoDate;

	/**

	 * Instantiates a new url extractor.

	 *

	 * @param xpath

	 *            the xpath

	 * @param xpathMetadataID

	 *            the xpath metadata id

	 */

	public UrlExtractor(final String xpath, final String xpathMetadataID, final String xpathOpenAccess, final String xpathEmbargoDate) {

		this.xpathURL = xpath;

		this.xpathMetadataID = xpathMetadataID;

		this.xpathOpenAccess = xpathOpenAccess;

		this.xpathEmbargoDate = xpathEmbargoDate;

	}

	/*

	 * (non-Javadoc)

	 *

	 * @see com.google.common.base.Function#apply(java.lang.Object)

	 */

	@Override

	public String apply(final String input) {

		try {

			final DownloadItem di = new DownloadItem();

			final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

			DocumentBuilder builder;

			builder = factory.newDocumentBuilder();

			if (input == null) {

				log.error("Metadata input is null");

				return null;

			}

			final Document doc = builder.parse(new ByteArrayInputStream(input.getBytes()));

			final XPathFactory xPathFactory = XPathFactory.newInstance();

			final XPath myXpath = xPathFactory.newXPath();

			XPathExpression expression = myXpath.compile(this.xpathURL);

			final Object values = expression.evaluate(doc, XPathConstants.NODESET);

			di.setUrl(getNodes((NodeList) values));

			di.setOriginalUrl(getNodes((NodeList) values));

			if (this.xpathOpenAccess != null) {

				expression = myXpath.compile(this.xpathOpenAccess);

				final String openAccess = expression.evaluate(doc);

				di.setOpenAccess(openAccess);

			}

			if (this.xpathEmbargoDate != null) {

				expression = myXpath.compile(this.xpathEmbargoDate);

				final String embargoDate = expression.evaluate(doc);

				if (!StringUtils.isEmpty(embargoDate)) {

					try {

						final Date date = new SimpleDateFormat("yyyy-MM-dd").parse(embargoDate);

						di.setEmbargoDate(date);

					} catch (final Exception pe) {}

				}

			}

			expression = myXpath.compile(this.xpathMetadataID);

			final String extracted_metadataId = expression.evaluate(doc);

			di.setIdItemMetadata(extracted_metadataId);

			return di.toJSON();

		} catch (final Exception e) {

			log.error("OPSSS... Something bad happen on evaluating ", e);

			return null;

		}

	}

	/**

	 * Gets the nodes.

	 *

	 * @param nodes

	 *            the nodes

	 * @return the nodes

	 */

	private String getNodes(final NodeList nodes) {

		final List<String> extracted_Url = new ArrayList<String>();

		if (nodes != null) {

			for (int i = 0; i < nodes.getLength(); i++) {

				extracted_Url.add(nodes.item(i).getNodeValue());

			}

		}

		return new Gson().toJson(extracted_Url);

	}

	/**

	 * Gets the xpath metadata id.

	 *

	 * @return the xpathMetadataID

	 */

	public String getXpathMetadataID() {

		return this.xpathMetadataID;

	}

	/**

	 * Sets the xpath metadata id.

	 *

	 * @param xpathMetadataID

	 *            the xpathMetadataID to set

	 */

	public void setXpathMetadataID(final String xpathMetadataID) {

		this.xpathMetadataID = xpathMetadataID;

	}

	/**

	 * Gets the xpath url.

	 *

	 * @return the xpath url

	 */

	public String getXpathURL() {

		return this.xpathURL;

	}

	/**

	 * Sets the xpath url.

	 *

	 * @param xpathURL

	 *            the new xpath url

	 */

	public void setXpathURL(final String xpathURL) {

		this.xpathURL = xpathURL;

	}

	/**

	 * Gets the xpath open access.

	 *

	 * @return the xpath open access

	 */

	public String getXpathOpenAccess() {

		return this.xpathOpenAccess;

	}

	/**

	 * Sets the xpath open access.

	 *

	 * @param xpathOpenAccess

	 *            the new xpath open access

	 */

	public void setXpathOpenAccess(final String xpathOpenAccess) {

		this.xpathOpenAccess = xpathOpenAccess;

	}

	/**

	 * Gets the xpath embargo date.

	 *

	 * @return the xpath embargo date

	 */

	public String getXpathEmbargoDate() {

		return this.xpathEmbargoDate;

	}

	/**

	 * Sets the xpath embargo date.

	 *

	 * @param xpathEmbargoDate

	 *            the new xpath embargo date

	 */

	public void setXpathEmbargoDate(final String xpathEmbargoDate) {

		this.xpathEmbargoDate = xpathEmbargoDate;

	}

}