FirehoseReindexListener.java

/*
 * Copyright 2021 Global Crop Diversity Trust
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.genesys.server.component.elastic;

import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.BlockingQueue;

import javax.annotation.Resource;

import org.genesys.blocks.model.EmptyModel;
import org.genesys.server.component.firehose.FirehoseDeleteAllEvent;
import org.genesys.server.component.firehose.FirehoseEvent;
import org.genesys.server.model.genesys.Accession;
import org.genesys.server.model.genesys.AccessionId;
import org.genesys.server.model.genesys.AccessionRef;
import org.genesys.server.service.ElasticsearchService;
import org.genesys.server.exception.SearchException;
import org.hibernate.proxy.HibernateProxy;
import org.hibernate.proxy.LazyInitializer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.event.EventListener;
import org.springframework.transaction.event.TransactionPhase;
import org.springframework.transaction.event.TransactionalApplicationListener;
import org.springframework.transaction.event.TransactionalEventListener;

/**
 * The FirehoseReindexListener is a {@link TransactionalApplicationListener} that
 * is attached to the {@link TransactionPhase} {@code TransactionPhase.AFTER_COMMIT}
 * This event listener updates the Elasticsearch update queues immediately.
 *
 * @author Matija Obreza
 */
// Instantiated in ElasticsearchConfig! @Component
public class FirehoseReindexListener implements InitializingBean {
	private final static Logger LOG = LoggerFactory.getLogger(FirehoseReindexListener.class);

	private List<Class<?>> includedClasses;

	@Resource
	private BlockingQueue<ElasticReindex> elasticReindexQueue;

	@Autowired
	private ElasticsearchService elasticsearchService;

	@Override
	public void afterPropertiesSet() throws Exception {
		includedClasses = elasticsearchService.getIndexedEntities();
	}

	@TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)
	public void handleEvent(FirehoseEvent firehoseEvent) {
		Class<?> clazz = firehoseEvent.getClazz();
		Object entity = firehoseEvent.getEntity();

		if (entity == null) return;

		if (entity instanceof AccessionId) {
			AccessionId accessionId = (AccessionId) entity;
			LOG.trace("Scheduling reindexing of {} {}", Accession.class.getName(), accessionId.getId());
			addNotNull(elasticReindexQueue, new ElasticReindex(Accession.class, accessionId.getId()));

		} else if (entity instanceof AccessionRef){
			AccessionRef<?> accessionRef = (AccessionRef<?>) entity;
			if (accessionRef.getAccession() != null) {
				LOG.trace("Scheduling reindexing of {} {}", Accession.class.getName(), accessionRef.getAccession().getId());
				addNotNull(elasticReindexQueue, new ElasticReindex(Accession.class, accessionRef.getAccession().getId()));
			}

		} else if (isIndexed(clazz) && entity instanceof EmptyModel) {
			scheduleReindexing(entity);
		} else if (ElasticTrigger.class.isAssignableFrom(clazz)) {
			try {
				Object[] reindexedEntities = ((ElasticTrigger) entity).reindexedEntities();
				if (reindexedEntities != null) {
					for (var m : reindexedEntities) {
						if (m instanceof EmptyModel) {
							var toReindex = new ElasticReindex((EmptyModel) m);
							var newlyAdded = elasticReindexQueue.add(toReindex);
							LOG.info("Firehose dependency {} was (newly={}) queued.", toReindex, newlyAdded);
						}
					}
				}
			} catch (Throwable e) {
				LOG.error("Error inspecting reindexed entities of {} id={}: {}", clazz, firehoseEvent.getId(), e.getMessage()); // , e);
			}
		}
	}

	@EventListener(classes = { FirehoseDeleteAllEvent.class })
	// @TransactionalEventListener doesn't work in unit tests
	// @TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)
	public void handleDeleteAllEvent(FirehoseDeleteAllEvent firehoseDeleteAllEvent) {
		if (!isIndexed(firehoseDeleteAllEvent.getClazz())) {
			return;
		}
		// Remove from created and updated only
		var clazz = firehoseDeleteAllEvent.getClazz();
		LOG.debug("Removing all queued items of {}", clazz);
		elasticReindexQueue.removeIf(reference -> Objects.equals(reference.getClazz(), clazz));
		try {
			elasticsearchService.removeAll(clazz);
		} catch (SearchException e) {
			LOG.warn("Error reindexing {}: {}", clazz, e.getMessage()); //, e);
		}
	}

	public void scheduleReindexing(Object toReindex) {
		if (toReindex == null) {
			return;
		}

		HashSet<Object> visited = new HashSet<Object>();

		maybeReindex(toReindex, visited);
	}

	private void maybeReindex(Object toReindex, HashSet<Object> visited) {
		if (toReindex == null || visited.contains(toReindex)) {
			return;
		}
		visited.add(toReindex);

		ElasticReindex fri = forReindexing(toReindex);
		if (fri != null) {
			LOG.trace("Scheduling {}#{}", fri.getClazz(), fri.getId());
			addNotNull(elasticReindexQueue, fri);
		}
		if (toReindex instanceof ElasticTrigger) {
			Object[] rels = ((ElasticTrigger) toReindex).reindexedEntities();
			if (rels != null) {
				for (Object related : rels) {
					maybeReindex(related, visited);
				}
			}
		}
	}

	private <T> void addNotNull(Collection<T> destination, T element) {
		if (element != null && !destination.contains(element)) {
			destination.add(element);
		}
	}

	private ElasticReindex forReindexing(Object toReindex) {
		Class<?> clazz = toReindex.getClass();

		if (toReindex instanceof HibernateProxy) {
			LazyInitializer lazyInitializer = ((HibernateProxy) toReindex).getHibernateLazyInitializer();
			clazz = lazyInitializer.getPersistentClass();
			if (isIndexed(clazz)) {
				LOG.trace("Scheduling reindexing of {} {}", clazz, toReindex);
				return new ElasticReindex(clazz, (Long) lazyInitializer.getIdentifier());
			} else {
				return null;
			}
		} else if (isIndexed(clazz)) {
			if (toReindex instanceof EmptyModel) {
				LOG.trace("Scheduling reindexing of {} {}", clazz, toReindex);
				return new ElasticReindex(clazz, ((EmptyModel) toReindex).getId());
			} else {
				LOG.warn("Don't know how to index {}. Not an EmptyModel.", clazz.getName());
				return null;
			}
		}
		return null;
	}

	private boolean isIndexed(Class<?> clazz) {
		if (includedClasses.contains(clazz)) {
			return true;
		}
		return false;
	}
}