/********************************************************************************
 * 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.api.atfxadapter;

import java.util.Map;
import java.util.Optional;

import org.asam.ods.AoException;
import org.asam.ods.AoSession;
import org.asam.ods.ErrorCode;
import org.asam.ods.SeverityFlag;
import org.eclipse.mdm.api.base.adapter.ModelManager;
import org.eclipse.mdm.api.base.query.DataAccessException;
import org.eclipse.mdm.api.base.query.QueryService;
import org.eclipse.mdm.api.dflt.ApplicationContext;
import org.eclipse.mdm.api.dflt.EntityManager;
import org.eclipse.mdm.api.dflt.model.EntityFactory;
import org.eclipse.mdm.api.odsadapter.lookup.config.EntityConfigRepositoryLoader;
import org.eclipse.mdm.api.odsadapter.query.ODSEntityFactory;
import org.eclipse.mdm.api.odsadapter.query.ODSModelManager;
import org.eclipse.mdm.api.odsadapter.query.ODSQueryService;
import org.omg.CORBA.ORB;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * ATFXContext encapsulates a session to the ASAM ODS CORBA API of openATFX
 *
 */
public class ATFXContext implements ApplicationContext {

	private static final Logger LOGGER = LoggerFactory.getLogger(ATFXContext.class);

	private Map<String, String> parameters;

	private ODSModelManager modelManager;
	private ATFXEntityManager entityManager;

	/**
	 * Creates a new ATFX application context.
	 * 
	 * @param orb        the CORBA ORB used to connect to the ODS API
	 * @param aoSession
	 * @param parameters
	 * @throws AoException
	 */
	public ATFXContext(ORB orb, AoSession aoSession, Map<String, String> parameters) throws AoException {

		final String ENTITYCONFIGREPOSITORYLOADERCLASS_ATTRIBUTE_NAME = "entityConfigRepositoryLoaderClass";

		// check parameters for configured custom EntityConfigRepositoryLoader
		String entityConfigRepositoryLoaderClassName = parameters.get(ENTITYCONFIGREPOSITORYLOADERCLASS_ATTRIBUTE_NAME);

		// if custom loader is configured
		if (entityConfigRepositoryLoaderClassName != null) {
			EntityConfigRepositoryLoader entityConfigRepositoryLoader;
			try {
				entityConfigRepositoryLoader = Thread.currentThread().getContextClassLoader()
						.loadClass(entityConfigRepositoryLoaderClassName).asSubclass(EntityConfigRepositoryLoader.class)
						.newInstance();
				this.modelManager = new ODSModelManager(orb, aoSession, entityConfigRepositoryLoader);
			} catch (Exception e) {
				// just log an error, but recover using the default loader
				LOGGER.error("Failed to initialize EntityConfigRepositoryLoaderClass. Using default.", e);
				this.modelManager = new ODSModelManager(orb, aoSession, new ATFXEntityConfigRepositoryLoader());
			}
		}

		// if not, use default
		else {
			this.modelManager = new ODSModelManager(orb, aoSession, new ATFXEntityConfigRepositoryLoader());
		}

		this.parameters = parameters;
		this.entityManager = new ATFXEntityManager(this);

		LOGGER.debug("ATFXContext initialized.");
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public Optional<EntityManager> getEntityManager() {
		return Optional.of(entityManager);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public Optional<ModelManager> getModelManager() {
		return Optional.of(modelManager);
	}

	@Override
	public Optional<EntityFactory> getEntityFactory() {
		try {
			return Optional.of(new ODSEntityFactory(modelManager, entityManager.loadLoggedOnUser()));
		} catch (DataAccessException e) {
			throw new IllegalStateException("Unable to load instance of the logged in user.");
		}
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public Optional<QueryService> getQueryService() {
		return Optional.of(new ODSQueryService(modelManager));
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public Map<String, String> getParameters() {
		return parameters;
	}

	/**
	 * @returns the string "atfx"
	 */
	@Override
	public String getAdapterType() {
		return "atfx";
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void close() {
		try {
			modelManager.close();
		} catch (AoException e) {
			LOGGER.warn("Unable to close sesssion due to: " + e.reason, e);
		}
	}

	/**
	 * Returns the {@link ATFXModelManager} used for this context.
	 * 
	 * @return the {@link ATFXModelManager}
	 */
	public ODSModelManager getODSModelManager() {
		return modelManager;
	}

	/**
	 * Returns the {@link AoSession} used for this context.
	 * 
	 * @return {@link AoSession} used for this context.
	 */
	public AoSession getAoSession() {
		return modelManager.getAoSession();
	}

	/**
	 * Returns the ORB used for this context
	 * 
	 * @return ORB used for this context
	 */
	public ORB getORB() {
		return modelManager.getORB();
	}

	/**
	 * Returns a new {@link ATFXContext} with a new ODS co-session.
	 *
	 * @return The created {@code ODSContext} is returned.
	 * @throws AoException Thrown on errors.
	 */
	public ATFXContext newContext() throws AoException {
		throw new AoException(ErrorCode.AO_NOT_IMPLEMENTED, SeverityFlag.ERROR, 0,
				"Method 'createCoSession' not implemented in openATFX");
	}
}