pstlab / PLATINUm

import java.util.ArrayList;

import java.util.Arrays;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.concurrent.atomic.AtomicInteger;

import it.cnr.istc.pst.platinum.ai.executive.pdb.ExecutionNode;

import it.cnr.istc.pst.platinum.control.lang.AgentTaskDescription;

import it.cnr.istc.pst.platinum.control.lang.PlatformCommand;

import it.cnr.istc.pst.platinum.control.lang.PlatformFeedback;

import it.cnr.istc.pst.platinum.control.lang.PlatformFeedbackType;

import it.cnr.istc.pst.platinum.control.lang.PlatformObservation;

import it.cnr.istc.pst.platinum.control.lang.ex.PlatformException;

/**

 * 

 * @author alessandro

 *

 */

public abstract class PlatformProxy 

{	

	protected static final AtomicInteger obsIdCounter = new AtomicInteger(0);

	protected static final AtomicInteger cmdIdCounter = new AtomicInteger(0);

	protected final List<PlatformObserver> observers;							// list of platform observers

	protected Map<Long, PlatformCommand> dispatchedIndex;						// index of dispatched commands by command ID

	/**

	 * 

	 */

	protected PlatformProxy() {

		// setup data structures

		this.observers = new ArrayList<>();

		this.dispatchedIndex = new HashMap<>();

	}

	/**

	 * 

	 * @param cfgFile

	 * @throws PlatformException

	 */

	public abstract void initialize(String cfgFile) 

			throws PlatformException;

	/**

	 * This method registers an observer to a particular (physical) platform.

	 * 

	 *  The interactions between the executive and the physical platform are 

	 *  managed through a dedicated PROXY which must implement this interface

	 * 

	 * @param executive

	 */

	public void register(PlatformObserver observer) {

		// register a new observer

		synchronized (this.observers) {

			// add the observer

			this.observers.add(observer);

			// send signal

			this.observers.notifyAll();

		}

	}

	/**

	 * Unregister a (previously) registered observer to a particular (physical) platform.

	 * 

	 * 

	 * @param observer

	 */

	public void unregister(PlatformObserver observer) {

		// unregister observers

		synchronized (this.observers) {

			// remove observer

			this.observers.remove(observer);

			// send signal

			this.observers.notifyAll();

		}

	}

	/**

	 * 

	 */

	/**

	 * 

	 * @param cmdId

	 * @return

	 */

	public synchronized PlatformCommand getDispatchedCommand(long cmdId) {

		// get command from cache

		return this.dispatchedIndex.get(cmdId);

	}

	/**

	 * 

	 * This method sends a request to the real/simulated platform to execute a command.

	 * 

	 * This method is usually meant for partially controllable commands. The platform/environment is 

	 * in charge of the execution of the related command and therefore it will then notify the 

	 * acting agent about the successful execution or failures.

	 * 

	 * Feedbacks about the execution of the command will be then received through the PlatformObserver 

	 * interface

	 * 

	 * @param node

	 * @return

	 * @throws PlatformException

	 */

	public abstract PlatformCommand executeNode(ExecutionNode node) 

			throws PlatformException;

	/**

	 * 

	 * This method sends a request to the real/simulated platform to start the execution of a command.

	 * 

	 * This method is usually meant for controllable commands. The acting agent is in charge of 

	 * deciding when to start the execution of a command.

	 * 

	 * @param node

	 * @return

	 * @throws PlatformException

	 */

	public abstract PlatformCommand startNode(ExecutionNode node) 

			throws PlatformException;

	/**

	 * 

	 * This method sends a request to the real/simulated platform to stop the execution of a command

	 * 

	 * This method is usually meant for controllable commands. The acting agent is in charge of 

	 * deciding when to stop the execution of a previously started command.  

	 * 

	 * @param cmd

	 * @throws PlatformException

	 */

	public abstract void stopNode(ExecutionNode node) 

			throws PlatformException;

	/**

	 * This method check whether an execution node represents a platform command or not. 

	 * 

	 *  Namely, the method checks if a particular token of a plan actually represents a 

	 *  command to be executed on some platform. 

	 *  

	 *  Clearly, the implementation of this method strongly depends on the functional layer 

	 *  provided by the hardware or software platform considered for the execution of 

	 *  timeline-based plan.

	 * 

	 * @param node

	 * @return

	 */

	public abstract boolean isPlatformCommand(ExecutionNode node);

	/**

	 * 

	 * @param observation

	 */

	public void notify(PlatformObservation<? extends Object> observation) 

	{

		// get platform observers

		synchronized (observers) {

			// notify observers

			for (PlatformObserver observer : observers) {

				// notify observation to platform observer

				observer.observation(observation);

			}

		}

	}

	/**

	 * 

	 * @param feedback

	 */

	public void notify(PlatformFeedback feedback) 

	{

		// get platform observers

		synchronized (observers) {

			// notify observers

			for (PlatformObserver observer : observers) {

				// notify observation to platform observer

				observer.feedback(feedback);

			}

		}

	}

	/**

	 * 

	 * @param msg

	 */

	public void notify(AgentTaskDescription msg) {

		// get platform observers

		synchronized (observers) {

			// notify observers

			for (PlatformObserver observer : observers) {

				// notify task to platform observers

				observer.task(msg);

			}

		}

	}

	/**

	 * 

	 * @param name

	 * @param params

	 * @return

	 */

	public PlatformCommand create(String name, String[] params, ExecutionNode node) {

		// create platform command

		PlatformCommand cmd = new PlatformCommand(

				cmdIdCounter.getAndIncrement(), 

				name, 

				params, 

				node, 

				0);				// command type 0 = start execution request

		// return created command

		return cmd;

	}

	/**

	 * 

	 * @param cmd

	 */

	public void success(PlatformCommand cmd) {

		// create positive feedback

		PlatformFeedback feedback = new PlatformFeedback(

				obsIdCounter.getAndIncrement(), 

				cmd, 

				PlatformFeedbackType.SUCCESS);

		// notify feedback

		this.notify(feedback);

	}

	/**

	 * 

	 * @param cmd

	 */

	public void failure(PlatformCommand cmd) {

		// create negative feedback

		PlatformFeedback feedback = new PlatformFeedback(

				obsIdCounter.getAndIncrement(), 

				cmd, 

				PlatformFeedbackType.FAILURE);

		// notify feedback

		this.notify(feedback);

	}

	/**

	 * 

	 * @param node

	 * @return

	 */

	public static String extractCommandName(ExecutionNode node) 

	{ 

		// get signature

		String name = node.getGroundSignature();

		// "clear" command name from "control tags"

		if (name.startsWith("_")) {

			// remove partial controllability tag

			name = name.replaceFirst("_", "");

		}

		// discard parameters if any 

		String[] splits = name.split("-");

		// set the first element as command name

		name = splits[0];

		// get cleared command name 

		return name.toLowerCase();

	}

	/**

	 * 

	 * @param node

	 * @return

	 */

	public static String[] extractCommandParameters(ExecutionNode node) {

		// extract command parameter from node to execute

		String[] splits = node.getGroundSignature().split("-");

		// get parameters

		String[] parameters = Arrays.copyOfRange(splits, 1, splits.length);

		// get parameters		

		return parameters;

	}

}