dnet-applications/libs/dnet-wf-service/src/main/java/eu/dnetlib/manager/wf/workflows/procs/ProcessEngine.java

package eu.dnetlib.manager.wf.workflows.procs;

import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.google.common.base.Throwables;

import eu.dnetlib.manager.wf.WorkflowLogger;
import eu.dnetlib.manager.wf.model.WfProcessExecution;
import eu.dnetlib.manager.wf.nodes.ProcessNode;
import eu.dnetlib.manager.wf.notification.EmailSender;
import eu.dnetlib.manager.wf.workflows.graph.GraphNode;
import eu.dnetlib.manager.wf.workflows.procs.WorkflowProcess.Status;
import eu.dnetlib.manager.wf.workflows.util.NodeHelper;
import eu.dnetlib.manager.wf.workflows.util.NodeTokenCallback;
import eu.dnetlib.manager.wf.workflows.util.WorkflowsConstants;

@Service
public class ProcessEngine {

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

	@Autowired
	private NodeHelper nodeHelper;
	@Autowired
	private EmailSender emailSender;
	@Autowired
	private WorkflowLogger wfLogger;

	public void startProcess(final WorkflowProcess process) {
		log.info(process.getGraph());

		log.info("Starting workflow: " + process);

		final LocalDateTime now = LocalDateTime.now();
		process.setStatus(WorkflowProcess.Status.EXECUTING);
		process.setStartDate(now);
		process.setLastActivityDate(now);

		try {
			for (final GraphNode node : process.getGraph().startNodes()) {
				final ProcessNode pNode = nodeHelper.newProcessNode(node, process, process.getEnv());
				final Token token = new Token(node.getName(), newNodeTokenCallback(process, node));

				token.getEnv().addAttributes(process.getEnv().getAttributes());
				process.getTokens().add(token);

				pNode.execute(token);
			}
		} catch (final Throwable e) {
			log.error("WorkflowProcess node instantiation failed", e);
			process.setStatus(WorkflowProcess.Status.FAILURE);
		}
	}

	public void releaseToken(final WorkflowProcess process, final GraphNode oldGraphNode, final Token oldToken) {
		process.setLastActivityDate(LocalDateTime.now());

		try {
			for (final GraphNode node : process.getGraph().nextNodes(oldGraphNode, oldToken.getNextArc())) {
				if (node.isJoin() || node.isSucessNode()) {
					if (!process.getPausedJoinNodeTokens().containsKey(node.getName())) {
						process.getPausedJoinNodeTokens().put(node.getName(), new ArrayList<Token>());
					}

					final List<Token> list = process.getPausedJoinNodeTokens().get(node.getName());

					list.add(oldToken);

					if (list.size() == process.getGraph().getNumberOfIncomingArcs(node)) {
						final Token token = new Token(node.getName(), newNodeTokenCallback(process, node));
						token.getEnv().addAttributes(mergeEnvParams(list.toArray(new Token[list.size()])));
						final ProcessNode pNode = nodeHelper.newProcessNode(node, process, token.getEnv());

						process.getTokens().add(token);
						process.setLastActivityDate(LocalDateTime.now());

						if (node.isSucessNode()) {
							markAsCompleted(process, token);
						} else {
							pNode.execute(token);
						}
					}
				} else {
					final Token token = new Token(node.getName(), newNodeTokenCallback(process, node));
					token.getEnv().addAttributes(oldToken.getEnv().getAttributes());
					final ProcessNode pNode = nodeHelper.newProcessNode(node, process, token.getEnv());

					process.getTokens().add(token);
					process.setLastActivityDate(LocalDateTime.now());
					pNode.execute(token);
				}
			}
		} catch (final Throwable e) {
			log.error("WorkflowProcess node instantiation failed", e);
			process.setStatus(WorkflowProcess.Status.FAILURE);
			process.setError(e.getMessage());
			process.setErrorStacktrace(Throwables.getStackTraceAsString(e));
			process.setLastActivityDate(LocalDateTime.now());
		}

	}

	private NodeTokenCallback newNodeTokenCallback(final WorkflowProcess process, final GraphNode node) {
		return new NodeTokenCallback() {

			@Override
			public void onSuccess(final Token token) {
				releaseToken(process, node, token);
			}

			@Override
			public void onFail(final Token token) {
				completeProcess(process, token);
			}
		};
	}

	private Map<String, Object> mergeEnvParams(final Token... tokens) {
		final Map<String, Object> map = new HashMap<>();
		Arrays.stream(tokens).forEach(t -> map.putAll(t.getEnv().getAttributes()));
		return map;
	}

	private void markAsCompleted(final WorkflowProcess process, final Token token) {
		completeProcess(process, token);
	}

	private void completeProcess(final WorkflowProcess process, final Token token) {
		if (token.isActive()) {
			if (StringUtils.isNotBlank(token.getError())) {
				token.releaseAsFailed(token.getError());
			} else {
				token.release();
			}
		}

		final LocalDateTime now = token.getEndDate();

		process.setLastActivityDate(now);
		process.setEndDate(now);
		process.setStatus(token.isFailed() ? WorkflowProcess.Status.FAILURE : WorkflowProcess.Status.SUCCESS);

		if (token.isFailed()) {
			process.setStatus(Status.FAILURE);
			process.setError(token.getError());
			process.setErrorStacktrace(token.getErrorStackTrace());
			process.setLastActivityDate(LocalDateTime.now());
		}

		if (process.getCallback() != null) {
			if (token.isFailed()) {
				process.getCallback().onFail();
			} else {
				process.getCallback().onSuccess();
			}
		}

		final Map<String, String> details = new LinkedHashMap<>();
		details.putAll(process.getOutputParams());
		details.put(WorkflowsConstants.LOG_WF_PRIORITY, "" + process.getPriority());
		details.put(WorkflowsConstants.LOG_WF_ID, process.getWfId());
		details.put(WorkflowsConstants.LOG_WF_ID, process.getWfInstanceId());

		if (process.getError() != null) {
			details.put(WorkflowsConstants.LOG_SYSTEM_ERROR, process.getError());
			details.put(WorkflowsConstants.LOG_SYSTEM_ERROR_STACKTRACE, process.getErrorStacktrace());
		}

		final WfProcessExecution pe = new WfProcessExecution();
		pe.setProcessId(process.getId());
		pe.setName(process.getName());
		pe.setFamily(process.getFamily());

		pe.setDsId(process.getDsId());
		pe.setDsName(process.getDsName());
		pe.setDsApi(process.getDsInterface());

		pe.setStartDate(process.getStartDate());
		pe.setEndDate(process.getEndDate());

		pe.setStatus(process.getStatus().toString());

		pe.setDetails(details);

		wfLogger.saveProcessExecution(pe);

		emailSender.sendMails(process);

	}

}