/********************************************************************************
 * Copyright (c) 2015-2018 Contributors to the Eclipse Foundation
 *
 * See the NOTICE file(s) distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 ********************************************************************************/


package org.eclipse.mdm.businessobjects.control;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;

import javax.ejb.Stateless;
import javax.inject.Inject;

import org.eclipse.mdm.api.base.model.ContextComponent;
import org.eclipse.mdm.api.base.model.ContextDescribable;
import org.eclipse.mdm.api.base.model.ContextRoot;
import org.eclipse.mdm.api.base.model.ContextSensor;
import org.eclipse.mdm.api.base.model.ContextType;
import org.eclipse.mdm.api.base.model.Measurement;
import org.eclipse.mdm.api.base.model.TestStep;
import org.eclipse.mdm.api.base.query.DataAccessException;
import org.eclipse.mdm.api.dflt.EntityManager;
import org.eclipse.mdm.connector.boundary.ConnectorService;

/**
 * ContextActivity Bean implementation to get ordered and measured context data
 * for {@link ContextDescribable} business objects (e.g. TestStep)
 * 
 * @author Sebastian Dirsch, Gigatronik Ingolstadt GmbH
 *
 */
@Stateless
public class ContextActivity implements Serializable {

	public static final String CONTEXT_GROUP_ORDERED = "ordered";
	public static final String CONTEXT_GROUP_MEASURED = "measured";

	public static final String CONTEXT_SENSOR_GROUP_ORDERED = "sensor_ordered";
	public static final String CONTEXT_SENSOR_GROUP_MEASURED = "sensor_measured";

	@Inject
	private ConnectorService connectorService;

	/**
	 * returns the ordered and measurement context for a {@link TestStep} MDM
	 * business object identified by the given MDM system name and
	 * {@link TestStep} ID. If no {@link ContextType}s are defined for this
	 * method call, the method returns all context informations of the available
	 * {@link ContextType}s. Otherwise you can specify a list of
	 * {@link ContextType}s.
	 * 
	 * Possible {@link ContextType}s are {@link ContextType}.UNITUNDERTEST,
	 * {@link ContextType}.TESTSEQUENCE and {@link ContextType}.TESTEQUIPMENT.
	 * 
	 * @param sourceName
	 *            the MDM system name
	 * @param testStepID
	 *            instance id if the {@link TestStep}
	 * @param contextTypes
	 *            list of {@link ContextType}s
	 * @return the ordered and measured context data as context object for the
	 *         identified {@link TestStep}
	 * @throws ContextProviderException
	 *             if an error occurs during lookup the context informations
	 */
	public Map<String, Map<ContextType, ContextRoot>> getTestStepContext(String sourceName, String testStepID,
			ContextType... contextTypes) {
		try {

			EntityManager em = this.connectorService.getContextByName(sourceName)
					.getEntityManager()
					.orElseThrow(() -> new MDMEntityAccessException("Entity manager not present!"));
			TestStep testStep = em.load(TestStep.class, testStepID);

			Map<ContextType, ContextRoot> orderedContext = em.loadContexts(testStep, contextTypes);
			Map<ContextType, ContextRoot> measuredContext = lookupMeasuredContextByTestStep(em, testStep, contextTypes);

			Map<String, Map<ContextType, ContextRoot>> contextMap = new HashMap<>();
			contextMap.put(CONTEXT_GROUP_ORDERED, orderedContext);
			contextMap.put(CONTEXT_GROUP_MEASURED, measuredContext);

			return contextMap;

		} catch (DataAccessException e) {
			throw new MDMEntityAccessException(e.getMessage(), e);
		}
	}

	/**
	 * returns the ordered and measurement context for a {@link Measurement} MDM
	 * business object identified by the given MDM system name and
	 * {@link Measurement} ID. If no {@link ContextType}s are defined for this
	 * method call, the method returns all context informations of the available
	 * {@link ContextType}s. Otherwise you can specify a list of
	 * {@link ContextType}s.
	 * 
	 * Possible {@link ContextType}s are {@link ContextType}.UNITUNDERTEST,
	 * {@link ContextType}.TESTSEQUENCE and {@link ContextType}.TESTEQUIPMENT.
	 * 
	 * @param sourceName
	 *            the MDM system name
	 * @param measurementID
	 *            instance id if the {@link Measurement}
	 * @param contextTypes
	 *            list of {@link ContextType}s
	 * @return the ordered and measured context data as context object for the
	 *         identified {@link Measurement}
	 * @throws ContextProviderException
	 *             if an error occurs during lookup the context informations
	 */
	public Map<String, Map<ContextType, ContextRoot>> getMeasurementContext(String sourceName, String measurementID,
			ContextType... contextTypes) {

		try {

			EntityManager em = this.connectorService.getContextByName(sourceName)
					.getEntityManager()
					.orElseThrow(() -> new MDMEntityAccessException("Entity manager not present!"));
			Measurement measurement = em.load(Measurement.class, measurementID);

			Map<ContextType, ContextRoot> measuredContext = em.loadContexts(measurement, contextTypes);
			Map<ContextType, ContextRoot> orderedContext = lookupOrderedContextByMeasurement(em, measurement,
					contextTypes);

			Map<String, Map<ContextType, ContextRoot>> contextMap = new HashMap<>();
			contextMap.put(CONTEXT_GROUP_ORDERED, orderedContext);
			contextMap.put(CONTEXT_GROUP_MEASURED, measuredContext);

			return contextMap;

		} catch (DataAccessException e) {
			throw new MDMEntityAccessException(e.getMessage(), e);
		}

	}

	/**
	 * returns the sensor context of the given {@link TestStep}. The sensor
	 * informations will extracted from the TestEquipment part of the context
	 * data.
	 * 
	 * @param sourceName
	 *            the MDM system name
	 * @param testStepID
	 *            instance id if the {@link TestStep}
	 * @return a map with the TestEquipment sensor context data (ordered and
	 *         measured)
	 */
	public Map<String, List<ContextSensor>> getTestStepSensorContext(String sourceName, String testStepID) {

		try {
			EntityManager em = this.connectorService.getContextByName(sourceName)
					.getEntityManager()
					.orElseThrow(() -> new MDMEntityAccessException("Entity manager not present!"));
			
			TestStep testStep = em.load(TestStep.class, testStepID);

			Map<ContextType, ContextRoot> orderedContext = em.loadContexts(testStep, ContextType.TESTEQUIPMENT);
			Map<ContextType, ContextRoot> measuredContext = lookupMeasuredContextByTestStep(em, testStep,
					ContextType.TESTEQUIPMENT);

			return createSensorMap(orderedContext, measuredContext);

		} catch (DataAccessException e) {
			throw new MDMEntityAccessException(e.getMessage(), e);
		}
	}

	/**
	 * returns the sensor context of the given {@link Measurement}. The sensor
	 * informations will extracted from the TestEquipment part of the context
	 * data.
	 * 
	 * @param sourceName
	 *            the MDM system name
	 * @param measurementID
	 *            instance id if the {@link Measurement}
	 * @return a map with the TestEquipment sensor context data (ordered and
	 *         measured)
	 */
	public Map<String, List<ContextSensor>> getMeasurementSensorContext(String sourceName, String measurementID) {
		try {

			EntityManager em = this.connectorService.getContextByName(sourceName)
					.getEntityManager()
					.orElseThrow(() -> new MDMEntityAccessException("Entity manager not present!"));
			Measurement measurement = em.load(Measurement.class, measurementID);

			Map<ContextType, ContextRoot> measuredContext = em.loadContexts(measurement, ContextType.TESTEQUIPMENT);
			Map<ContextType, ContextRoot> orderedContext = lookupOrderedContextByMeasurement(em, measurement,
					ContextType.TESTEQUIPMENT);

			return createSensorMap(orderedContext, measuredContext);

		} catch (DataAccessException e) {
			throw new MDMEntityAccessException(e.getMessage(), e);
		}
	}

	private Map<ContextType, ContextRoot> lookupOrderedContextByMeasurement(EntityManager em, Measurement measurement,
			ContextType... contextTypes) throws DataAccessException {

		Optional<TestStep> optional = em.loadParent(measurement, Measurement.PARENT_TYPE_TESTSTEP);

		if (!optional.isPresent()) {
			return Collections.emptyMap();
		}

		TestStep testStep = optional.get();
		return em.loadContexts(testStep, contextTypes);
	}

	private Map<ContextType, ContextRoot> lookupMeasuredContextByTestStep(EntityManager em, TestStep testStep,
			ContextType... contextTypes) throws DataAccessException {

		List<Measurement> childList = em.loadChildren(testStep, TestStep.CHILD_TYPE_MEASUREMENT);
		if (childList.size() > 0) {
			return em.loadContexts(childList.get(0), contextTypes);
		}
		return Collections.emptyMap();
	}

	private Map<String, List<ContextSensor>> createSensorMap(Map<ContextType, ContextRoot> orderedContext,
			Map<ContextType, ContextRoot> measuredContext) {

		Map<String, List<ContextSensor>> sensorMap = new HashMap<String, List<ContextSensor>>();

		ContextRoot orderedContextRoot = orderedContext.get(ContextType.TESTEQUIPMENT);
		if (orderedContextRoot != null) {
			List<ContextSensor> orderedSensors = extractContextSensors(orderedContextRoot);
			sensorMap.put(CONTEXT_SENSOR_GROUP_ORDERED, orderedSensors);
		}

		ContextRoot measuredContextRoot = measuredContext.get(ContextType.TESTEQUIPMENT);
		if (measuredContextRoot != null) {
			List<ContextSensor> measuredSensors = extractContextSensors(measuredContextRoot);
			sensorMap.put(CONTEXT_SENSOR_GROUP_MEASURED, measuredSensors);
		}

		return sensorMap;
	}

	private List<ContextSensor> extractContextSensors(ContextRoot contextRoot) {
		List<ContextSensor> contextSensors = new ArrayList<ContextSensor>();
		List<ContextComponent> contextComponents = contextRoot.getContextComponents();
		for (ContextComponent contextComponent : contextComponents) {
			contextSensors.addAll(contextComponent.getContextSensors());
		}
		return contextSensors;
	}

}