components/basys.components/basyx.components.lib/src/main/java/org/eclipse/basyx/components/device/BaseTCPControllableDeviceAdapter.java

/*******************************************************************************
 * Copyright (C) 2021 the Eclipse BaSyx Authors
 * 
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 * 
 * SPDX-License-Identifier: EPL-2.0
 ******************************************************************************/
package org.eclipse.basyx.components.device;

import org.eclipse.basyx.components.netcomm.NetworkReceiver;
import org.eclipse.basyx.components.netcomm.TCPClient;
import org.eclipse.basyx.models.controlcomponent.ExecutionState;



/**
 * Base class for integrating controllable devices with BaSys
 * 
 * This controllable device uses a Thread for string based TCP communication. It implements a string based communication protocol 
 * with the control component of the device manager.
 * 
 * @author kuhn
 *
 */
public abstract class BaseTCPControllableDeviceAdapter extends BaseTCPDeviceAdapter implements IBaSysNativeDeviceStatus, NetworkReceiver {

	
	/**
	 * Receive thread
	 */
	protected Thread rxThread = null;
	
	
	/**
	 * Selected device operation mode
	 */
	protected String opMode = "";
	
	
	/**
	 * Device execution state
	 */
	protected ExecutionState exState = null;


	/**
	 * Constructor
	 */
	public BaseTCPControllableDeviceAdapter(int port) {
		// Invoke base constructor
		super(port);
	}
	
	
	/**
	 * Start the device
	 */
	@Override
	public void start() {
		// Invoke base implementation
		super.start();
		
		// Add this component as message listener
		communicationClient.addTCPMessageListener(this);
		// - Start receive thread
		rxThread = new Thread(communicationClient);
		// - Start receiving
		rxThread.start();
	}
	
	
	/**
	 * Stop the device
	 */
	@Override
	public void stop() {
		// Invoke base implementation
		super.stop();
		
		// End communication
		communicationClient.close();
	}

	
	/**
	 * Wait for end of all threads
	 */
	@Override
	public void waitFor() {
		// Invoke base implementation
		super.waitFor();
		
		// Wait for end of TCP thread
		try {rxThread.join();} catch (InterruptedException e) {e.printStackTrace();}
	}
	
	
	
	
	/**
	 * Process device status changes
	 */
	@Override
	protected void statusChange(String newStatus) {
		// React to device status change
		// - Indicate running service in EXECUTE state
		if (newStatus.equals(ExecutionState.EXECUTE.getValue()))  onServiceInvocation();
				
		// Set requested device execution state
		exState = ExecutionState.byValue(newStatus);
	}
	
	
	/**
	 * Changed operation mode
	 */
	protected void onOperationModeChange(String newOperationMode) {
		// Set requested device operation mode
		opMode = newOperationMode;
	}

	
	/**
	 * A message has been received
	 */
	@Override
	public void onReceive(byte[] message) {
		// Convert message to String
		String rxMessage = TCPClient.toString(message);
		
		// Process message
		if (rxMessage.startsWith("state:"))  {statusChange(rxMessage.substring("state:".length())); return;}
		if (rxMessage.startsWith("opMode:")) {onOperationModeChange(rxMessage.substring("opMode:".length())); return;}
		
		// Indicate exception
		throw new RuntimeException("Unexpected message received:"+rxMessage);
	}

	public String getOpMode() {
		return opMode;
	}

	public ExecutionState getExState() {
		return exState;
	}

}