D-Net

package eu.dnetlib.openaire.exporter.datasource.clients;

import java.io.IOException;

import java.util.Date;

import java.util.List;

import java.util.Map;

import java.util.Queue;

import java.util.concurrent.*;

import javax.annotation.PostConstruct;

import javax.annotation.PreDestroy;

import com.google.common.collect.Iterables;

import com.google.common.util.concurrent.*;

import eu.dnetlib.OpenaireExporterConfig;

import eu.dnetlib.enabling.datasources.common.DsmException;

import eu.dnetlib.miscutils.functional.hash.Hashing;

import eu.dnetlib.openaire.exporter.datasource.clients.utils.DatasourceFunctions;

import eu.dnetlib.openaire.exporter.datasource.clients.utils.IndexDsInfo;

import eu.dnetlib.openaire.exporter.datasource.clients.utils.IndexRecordsInfo;

import org.apache.commons.lang.StringUtils;

import org.apache.commons.lang.time.DateFormatUtils;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.apache.solr.client.solrj.SolrQuery;

import org.apache.solr.client.solrj.SolrServerException;

import org.apache.solr.client.solrj.impl.CloudSolrClient;

import org.apache.solr.client.solrj.impl.CloudSolrClient.Builder;

import org.apache.solr.client.solrj.response.QueryResponse;

import org.apache.solr.common.SolrDocument;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.http.HttpStatus;

import org.springframework.stereotype.Component;

/**

 * Created by claudio on 20/10/2016.

 */

@Component

public class DatasourceIndexClientImpl implements DatasourceIndexClient {

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

	public static final String SEPARATOR = "::";

	public static final String DSVERSION = "__dsversion";

	@Autowired

	private OpenaireExporterConfig config;

	private ListeningExecutorService executor;

	private static Map<String, CloudSolrClient> indexClientMap = new ConcurrentHashMap<>();

	@PostConstruct

	public void init() {

		executor = MoreExecutors.listeningDecorator(

				new ScheduledThreadPoolExecutor(5,

						new ThreadFactoryBuilder().setNameFormat("datasource-index-client-%d").build()));

	}

	@PreDestroy

	public void tearDown() {

		indexClientMap.forEach((name, client) -> {

			try {

				client.close();

			} catch (IOException e) {

				log.warn(String.format("unable to gracefully shutdown client for index %s", name));

			}

		});

	}

	@Override

	public IndexRecordsInfo getIndexInfo(final String dsId, final IndexDsInfo info, final Queue<Throwable> errors) throws DsmException {

		try {

			final String collectedFrom = StringUtils.substringBefore(dsId, SEPARATOR) + SEPARATOR + Hashing.md5(StringUtils.substringAfter(dsId, SEPARATOR));

			final CloudSolrClient indexClient = getIndexClient(info);

			final CountDownLatch latch = new CountDownLatch(2);

			final IndexRecordsInfo indexRecordInfo = new IndexRecordsInfo();

			Futures.addCallback(

					executor.submit(() -> setDateAndTotal(collectedFrom, indexClient)),

					new FutureCallback<IndexRecordsInfo>() {

						@Override

						public void onSuccess(final IndexRecordsInfo info) {

							indexRecordInfo

									.setTotal(info.getTotal())

									.setDate(info.getDate());

							latch.countDown();

						}

						@Override

						public void onFailure(final Throwable e) {

							errors.offer(e);

							latch.countDown();

						}

					}, executor);

			Futures.addCallback(

					executor.submit(() -> setFunded(collectedFrom, indexClient)),

					new FutureCallback<Long>() {

						@Override

						public void onSuccess(final Long numFound) {

							indexRecordInfo.setFunded(numFound);

							latch.countDown();

						}

						@Override

						public void onFailure(final Throwable e) {

							errors.offer(e);

							latch.countDown();

						}

					}, executor);

			waitLatch(latch, errors, config.getRequestTimeout());

			return indexRecordInfo;

		} catch (final Throwable e) {

			throw new DsmException(HttpStatus.INTERNAL_SERVER_ERROR.value(), e.getMessage(), e);

		}

	}

	@Override

	public String getLastIndexingDate(final IndexDsInfo info) throws DsmException {

		try {

			final SolrQuery query = new SolrQuery("oaftype:datasource").setRows(1);

			final QueryResponse rsp = getIndexClient(info).query(query);

			final SolrDocument doc = Iterables.getFirst(rsp.getResults(), null);

			final String dsversion = doc.get("__dsversion").toString();

			return StringUtils.substringBefore(dsversion, "T");

		} catch (SolrServerException | IOException e) {

			throw new DsmException(HttpStatus.INTERNAL_SERVER_ERROR.value(), "Error querying index DS profile: " + info, e);

		}

	}

	private Long setFunded(

			final String collectedFrom,

			final CloudSolrClient indexClient) throws DsmException {

		final String query =

				String.format("oaftype:result AND deletedbyinference:false AND collectedfromdatasourceid:\"%s\" AND relprojectid:*", collectedFrom);

		log.debug(String.format("query: %s", query));

		try {

			return indexClient.query(new SolrQuery(query).setRows(0)).getResults().getNumFound();

		} catch (Throwable e) {

			throw new DsmException(HttpStatus.INTERNAL_SERVER_ERROR.value(), "Error querying information system", e);

		}

	}

	private IndexRecordsInfo setDateAndTotal(

			final String collectedFrom,

			final CloudSolrClient indexClient) throws DsmException {

		try {

			final String query = String.format("oaftype:result AND deletedbyinference:false AND collectedfromdatasourceid:\"%s\"", collectedFrom);

			log.debug(String.format("query: %s", query));

			final QueryResponse rsp = indexClient.query(new SolrQuery(query).setRows(1));

			final SolrDocument doc = Iterables.getFirst(rsp.getResults(), new SolrDocument());

			if (log.isDebugEnabled()) {

				log.debug(String.format("got document %s", doc.get("__indexrecordidentifier")));

			}

			// if (doc.isEmpty()) {

			// throw new DatasourceManagerException(HttpStatus.INTERNAL_SERVER_ERROR.value(), String.format("cannot find document matching

			// query: %s", queryTotal));

			// }

			return new IndexRecordsInfo()

					.setDate(getDate(doc))

					.setTotal(rsp.getResults().getNumFound());

		} catch (Throwable e) {

			throw new DsmException(HttpStatus.INTERNAL_SERVER_ERROR.value(), "Error querying information system", e);

		}

	}

	@SuppressWarnings("unchecked")

	private String getDate(final SolrDocument doc) throws DsmException {

		final List<Date> dsversion = (List<Date>) doc.get(DSVERSION);

		if (dsversion == null || dsversion.isEmpty()) { throw new DsmException(HttpStatus.INTERNAL_SERVER_ERROR.value(),

				String.format("cannot find %s in matched solr document", DSVERSION)); }

		final Date date = Iterables.getLast(dsversion);

		return DateFormatUtils.format(date, DatasourceFunctions.DATE_FORMAT);

	}

	private synchronized CloudSolrClient getIndexClient(final IndexDsInfo info) {

		if (!indexClientMap.containsKey(info.getColl())) {

			final CloudSolrClient client = new Builder().withZkHost(info.getIndexBaseUrl()).build();

			client.setDefaultCollection(info.getColl());

			indexClientMap.put(info.getColl(), client);

		}

		return indexClientMap.get(info.getColl());

	}

	private void waitLatch(final CountDownLatch latch, final Queue<Throwable> errors, final int waitSeconds) {

		try {

			if (!latch.await(waitSeconds, TimeUnit.SECONDS)) {

				errors.offer(new TimeoutException("Waiting for requests to complete has timed out."));

			}

		} catch (final InterruptedException e) {

			errors.offer(e);

		}

	}

}