Metacat

package edu.ucsb.nceas.metacat.mdq;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.InputStream;

import java.math.BigInteger;

import java.util.Calendar;

import java.util.Date;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import org.apache.commons.io.IOUtils;

import org.apache.http.HttpEntity;

import org.apache.http.client.methods.CloseableHttpResponse;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.impl.client.CloseableHttpClient;

import org.apache.http.impl.client.HttpClients;

import org.apache.log4j.Logger;

import org.dataone.client.types.AccessPolicyEditor;

import org.dataone.client.v2.formats.ObjectFormatCache;

import org.dataone.configuration.Settings;

import org.dataone.mimemultipart.SimpleMultipartEntity;

import org.dataone.service.types.v1.Identifier;

import org.dataone.service.types.v1.ObjectFormatIdentifier;

import org.dataone.service.types.v1.Session;

import org.dataone.service.types.v1.util.ChecksumUtil;

import org.dataone.service.types.v2.ObjectFormat;

import org.dataone.service.types.v2.SystemMetadata;

import org.dataone.service.util.TypeMarshaller;

import edu.ucsb.nceas.metacat.IdentifierManager;

import edu.ucsb.nceas.metacat.MetacatHandler;

import edu.ucsb.nceas.metacat.dataone.MNodeService;

public class MDQClient {

	private static boolean mdqEnabled =  Settings.getConfiguration().getBoolean("mdq.service.enabled", false);

	private static String mdqURL =  Settings.getConfiguration().getString("mdq.service.url", "https://quality.nceas.ucsb.edu/quality/suites/arctic.data.center.suite.1/run");

	private static String mdqRunNamespace = Settings.getConfiguration().getString("mdq.run.namespace", "https://nceas.ucsb.edu/mdqe/v1#run");

	private static Logger logMetacat = Logger.getLogger(MDQClient.class);

	private static ExecutorService executor = Executors.newSingleThreadExecutor();

	public static void submit(final SystemMetadata sysMeta) {

		if (!mdqEnabled) {

			logMetacat.info("MDQ not enabled, skipping quality check for " + sysMeta.getIdentifier().getValue());

			return;

		}

		// can we even run QC on this object?

		try {

			// check that it is a ME

			ObjectFormat objFormat = ObjectFormatCache.getInstance().getFormat(sysMeta.getFormatId());

			// must know what we are dealing with

			if (objFormat == null) {

				logMetacat.info("Object format not found for formatId: " + sysMeta.getFormatId());

				return;

			}

			// only METADATA types

			if (!objFormat.getFormatType().equals("METADATA")) {

				logMetacat.info("MDQ not applicable to non METADATA object of: " + objFormat.getFormatType());

				return;

			}

			// don't run QC on a QC document

			if (objFormat.getFormatId().getValue().equals(mdqRunNamespace)) {

				logMetacat.info("Cannot run MDQ on a run document");

				return;

			}

		} catch (Exception e) {

			logMetacat.error("Could not inspect object format: " +  e.getMessage(), e);

			return;

		}

		// run the MDQ routine in a new thread

		Runnable task = new Runnable() {

			@Override

			public void run() {

				try {

					InputStream run = MDQClient.run(sysMeta);

					logMetacat.debug("Generated MDQ run for pid: " + sysMeta.getIdentifier().getValue());

					Identifier id = MDQClient.saveRun(run, sysMeta);

					logMetacat.info("Saved MDQ run " + id.getValue());

				} catch (Exception e) {

					logMetacat.error(e.getMessage(), e);

				}

			}

		};

		executor.submit(task);	

	}

	/**

	 * Runs MDQ suite for object identified in SystemMetadata param

	 * @param sysMeta

	 * @return InputStream for run result (XML)

	 * @throws Exception

	 */

	private static InputStream run(SystemMetadata sysMeta) throws Exception {

		InputStream runResult = null;

		// get the metadata content

		String docid = IdentifierManager.getInstance().getLocalId(sysMeta.getIdentifier().getValue());

		InputStream docStream = MetacatHandler.read(docid);

		// Construct the REST call

		HttpPost post = new HttpPost(mdqURL);

		// add document

		SimpleMultipartEntity entity = new SimpleMultipartEntity();

		entity.addFilePart("document", docStream);

		// add sysMeta 

		ByteArrayOutputStream baos = new ByteArrayOutputStream();

		TypeMarshaller.marshalTypeToOutputStream(sysMeta, baos);

		entity.addFilePart("systemMetadata", new ByteArrayInputStream(baos.toByteArray()));

		// send to service

		post.setEntity(entity);

		CloseableHttpClient client = HttpClients.createDefault();

		CloseableHttpResponse response = client.execute(post);

		// retrieve results

		HttpEntity reponseEntity = response.getEntity();

		if (reponseEntity != null) {

			runResult  = reponseEntity.getContent(); 

		}

		return runResult;

	}

	private static Identifier saveRun(InputStream runStream, SystemMetadata metadataSysMeta) throws Exception {

		MNodeService mn = MNodeService.getInstance(null);

		// copy the properties from the metadata sysmeta to the run sysmeta

		byte[] bytes = IOUtils.toByteArray(runStream);

		SystemMetadata sysmeta = generateSystemMetadata(bytes, metadataSysMeta);

		// generate an identifier for the run result

		Session session = new Session();

		session.setSubject(sysmeta.getRightsHolder());

		Identifier pid = mn.generateIdentifier(session, "UUID", null);

		sysmeta.setIdentifier(pid);

		// save to this repo

		Identifier id = mn.create(session, pid, new ByteArrayInputStream(bytes), sysmeta);

		return id;

	}

	private static SystemMetadata generateSystemMetadata(byte[] bytes, SystemMetadata origSysMeta) 

			throws Exception {

		SystemMetadata sysMeta = new SystemMetadata();	

		// format id for the run

		ObjectFormatIdentifier formatId = new ObjectFormatIdentifier();

		formatId.setValue(mdqRunNamespace);

		sysMeta.setFormatId(formatId);

		// roles

		sysMeta.setRightsHolder(origSysMeta.getRightsHolder());	

		sysMeta.setSubmitter(origSysMeta.getRightsHolder());

		sysMeta.setAuthoritativeMemberNode(origSysMeta.getAuthoritativeMemberNode());

		sysMeta.setOriginMemberNode(origSysMeta.getOriginMemberNode());

		// for now, make them all public for easier debugging

		AccessPolicyEditor accessPolicyEditor = new AccessPolicyEditor(null);

		accessPolicyEditor.setPublicAccess();

		sysMeta.setAccessPolicy(accessPolicyEditor.getAccessPolicy());

		// size

		sysMeta.setSize(BigInteger.valueOf(bytes.length));

		sysMeta.setChecksum(ChecksumUtil.checksum(bytes, "MD5"));

		sysMeta.setFileName("run.xml");

		// timestamps

		Date now = Calendar.getInstance().getTime();

		sysMeta.setDateSysMetadataModified(now);

		sysMeta.setDateUploaded(now);

		return sysMeta;

	}

}