/**
 * ============LICENSE_START=======================================================
 * org.onap.aai
 * ================================================================================
 * Copyright © 2017 AT&T Intellectual Property.
 * Copyright © 2017 Amdocs
 * All rights reserved.
 * ================================================================================
 * 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.
 * ============LICENSE_END=========================================================
 *
 * ECOMP is a trademark and service mark of AT&T Intellectual Property.
 */
package org.onap.aai.modelloader.service;

import org.openecomp.sdc.api.IDistributionClient;
import org.openecomp.sdc.api.results.IDistributionClientResult;
import org.openecomp.sdc.impl.DistributionClientFactory;
import org.openecomp.sdc.utils.DistributionActionResultEnum;
import org.onap.aai.modelloader.config.ModelLoaderConfig;
import org.onap.aai.modelloader.entity.model.ModelArtifactHandler;
import org.onap.aai.modelloader.notification.EventCallback;
import org.onap.aai.cl.api.Logger;
import org.onap.aai.cl.eelf.LoggerFactory;

import java.io.FileInputStream;
import java.io.IOException;
import java.util.Date;
import java.util.Properties;
import java.util.Timer;
import java.util.TimerTask;

import javax.servlet.http.HttpServletRequest;
import javax.ws.rs.core.Response;

/**
 * Service class in charge of managing the negotiating model loading
 * capabilities between AAI and an ASDC.
 */
public class ModelLoaderService implements ModelLoaderInterface {
	
	protected static final String FILESEP = (System.getProperty("file.separator") == null) ? "/"
            : System.getProperty("file.separator");

	protected static final String CONFIG_DIR = System.getProperty("CONFIG_HOME") + FILESEP;
	protected static final String CONFIG_AUTH_LOCATION = CONFIG_DIR + "auth" + FILESEP;
	protected static final String CONFIG_FILE = CONFIG_DIR + "model-loader.properties";

	private IDistributionClient client;
	private ModelLoaderConfig config;
	private Timer timer = null;

	static Logger logger = LoggerFactory.getInstance().getLogger(ModelLoaderService.class.getName());

	/**
	 * Responsible for loading configuration files and calling initialization.
	 */
	public ModelLoaderService() {
		start();
	}

	protected void start() {
		// Load model loader system configuration
		logger.info(ModelLoaderMsgs.LOADING_CONFIGURATION);
		Properties configProperties = new Properties();
		try {
			configProperties.load(new FileInputStream(CONFIG_FILE));
		} catch (IOException e) {
			String errorMsg = "Failed to load configuration: " + e.getMessage();
			logger.error(ModelLoaderMsgs.ASDC_CONNECTION_ERROR, errorMsg);
			shutdown();
		}

		config = new ModelLoaderConfig(configProperties, CONFIG_AUTH_LOCATION);
		init();
		
		Runtime.getRuntime().addShutdownHook(new Thread(new Runnable(){
			public void run() {
				preShutdownOperations();
			}
		}));
	}
	
	/**
	 * Responsible for stopping the connection to the distribution client before
	 * the resource is destroyed.
	 */
	protected void preShutdownOperations() {
		logger.info(ModelLoaderMsgs.STOPPING_CLIENT);
		if (client != null) {
			client.stop();
		}
	}

	/**
	 * Responsible for loading configuration files, initializing model
	 * distribution clients, and starting them.
	 */
	protected void init() {
		// Initialize distribution client
		logger.debug(ModelLoaderMsgs.INITIALIZING, "Initializing distribution client...");
		client = DistributionClientFactory.createDistributionClient();
		EventCallback callback = new EventCallback(client, config);
		
		IDistributionClientResult initResult = client.init(config, callback);

		if (initResult.getDistributionActionResult() != DistributionActionResultEnum.SUCCESS) {
			String errorMsg = "Failed to initialize distribution client: "
					+ initResult.getDistributionMessageResult();
			logger.error(ModelLoaderMsgs.ASDC_CONNECTION_ERROR, errorMsg);
			
			// Kick off a timer to retry the SDC connection
			timer = new Timer();
			TimerTask task = new SdcConnectionJob(client, config, callback, timer);
			timer.schedule(task, new Date(), 60000);
		}
		else {
			// Start distribution client
			logger.debug(ModelLoaderMsgs.INITIALIZING, "Starting distribution client...");
			IDistributionClientResult startResult = client.start();
			if (startResult.getDistributionActionResult() != DistributionActionResultEnum.SUCCESS) {
				String errorMsg = "Failed to start distribution client: "
						+ startResult.getDistributionMessageResult();
				logger.error(ModelLoaderMsgs.ASDC_CONNECTION_ERROR, errorMsg);

				// Kick off a timer to retry the SDC connection
				timer = new Timer();
				TimerTask task = new SdcConnectionJob(client, config, callback, timer);
				timer.schedule(task, new Date(), 60000);
			}
			else {
				logger.info(ModelLoaderMsgs.INITIALIZING, "Connection to SDC established");
			}
		}
	}

	/**
	 * Shut down the process.
	 */
	private void shutdown() {
		preShutdownOperations();

		// TODO: Find a better way to shut down the model loader.
		try {
			// Give logs time to write to file
			Thread.sleep(2000);
		} catch (InterruptedException e) {
			// Nothing we can do at this point
		}

		Runtime.getRuntime().halt(1);
	}

	/** (non-Javadoc)
	 * @see org.onap.aai.modelloader.service.ModelLoaderInterface#loadModel(java.lang.String)
	 */
	@Override
	public Response loadModel(String modelid) {
		Response response = Response.ok("{\"model_loaded\":\"" + modelid + "\"}").build();

		return response;
	}

	/** (non-Javadoc)
	 * @see org.onap.aai.modelloader.service.ModelLoaderInterface#saveModel(java.lang.String, java.lang.String)
	 */
	@Override
	public Response saveModel(String modelid, String modelname) {
		Response response = Response.ok("{\"model_saved\":\"" + modelid + "-" + modelname + "\"}")
				.build();

		return response;
	}

	@Override
	public Response ingestModel(String modelid, HttpServletRequest req, String payload)
			throws IOException {
		Response response;

		if (config.getIngestSimulatorEnabled()) {
			logger.info(ModelLoaderMsgs.DISTRIBUTION_EVENT, "Received test artifact");

			ModelArtifactHandler handler = new ModelArtifactHandler(config);
			handler.loadModelTest(payload.getBytes());

			response = Response.ok().build();
		} else {
			logger.debug("Simulation interface disabled");
			response = Response.serverError().build();
		}

		return response;
	}
}