nucleus/businessobjects/src/main/java/org/eclipse/mdm/nodeprovider/control/NodeProviderRepository.java

/********************************************************************************
 * Copyright (c) 2015-2021 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.nodeprovider.control;

import java.io.Serializable;
import java.security.Principal;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.annotation.PostConstruct;
import javax.enterprise.context.SessionScoped;
import javax.inject.Inject;

import org.eclipse.mdm.connector.boundary.ConnectorService;
import org.eclipse.mdm.nodeprovider.entity.NodeProvider;
import org.eclipse.mdm.nodeprovider.entity.NodeProviderRoot;
import org.eclipse.mdm.nodeprovider.utils.SerializationUtil;
import org.eclipse.mdm.preferences.controller.PreferenceService;
import org.eclipse.mdm.preferences.entity.PreferenceMessage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Repository for NodeProviders in a specific session.
 *
 */
@SessionScoped
public class NodeProviderRepository implements Serializable {

	private static final long serialVersionUID = -3081666937067348673L;

	private static final Logger LOG = LoggerFactory.getLogger(NodeProviderRepository.class);

	private Map<String, NodeProvider> nodeProviders = new HashMap<>();

	@Inject
	private ConnectorService connectorService;

	@Inject
	private PreferenceService preferenceService;

	@Inject
	Principal principal;

	/**
	 * Default constructor
	 */
	public NodeProviderRepository() {
	}

	/**
	 * Constructor for unit tests.
	 * 
	 * @param connectorService
	 * @param preferenceService
	 */
	public NodeProviderRepository(ConnectorService connectorService, PreferenceService preferenceService) {
		this.connectorService = connectorService;
		this.preferenceService = preferenceService;
		init();
	}

	/**
	 * Initializes the NodeProviderRepository
	 */
	@PostConstruct
	public void init() {
		LOG.debug("Initializing NodeProviderRepository for user ", principal.getName());

		DefaultNodeProvider defaultNP = new DefaultNodeProvider(connectorService);

		putNodeProvider("default", defaultNP);
		LOG.trace("Registered default nodeprovider.");

		MDMExpressionLanguageService expressionLanguageService = new MDMExpressionLanguageService();

		List<PreferenceMessage> msgs = preferenceService.getPreferences("system", "nodeprovider.");
		for (PreferenceMessage msg : msgs) {
			try {
				NodeProviderRoot root = parsePreference(msg.getValue());
				putNodeProvider(root.getId(),
						new GenericNodeProvider(connectorService, root, expressionLanguageService));
				LOG.trace("Registered generic nodeprovider '{}'.", root.getId());
			} catch (RuntimeException e) {
				e.printStackTrace();
				LOG.warn("Could not deserialize nodeprovider configuration: {}", msg.getValue(), e);
			}
		}
	}

	/**
	 * Add a nodeprovider to the repository.
	 * 
	 * @param id           ID of the nodeprovider
	 * @param nodeProvider {@link NodeProvider}
	 */
	public void putNodeProvider(String id, NodeProvider nodeProvider) {
		nodeProviders.put(id, nodeProvider);
	}

	/**
	 * @return a map of all registered nodeproviders indexed by ID
	 */
	public Map<String, NodeProvider> getNodeProviders() {
		return nodeProviders;
	}

	/**
	 * Parse a JSON string representing a {@link NodeProviderRoot}
	 * 
	 * @param json JSON string
	 * @return parsed {@link NodeProviderRoot}
	 */
	private NodeProviderRoot parsePreference(String json) {
		return SerializationUtil.deserializeNodeProviderRoot(connectorService, json);
	}
}