/*********************************************************************

  * This file is part of the Compod project

  * Contact: Alexander Nussbaumer (AN, alnuss)

  *   <alexander.nussbaumer@uni-graz.at>, <alnuss@gmx.net>

  *   

  *  modified: AN, 20070916

  *********************************************************************/

 package isac.session;

 /**

  * This is a dummy implementation of the ICompod interface.

  * In contrast to a "real" implemenatin, this class does not

  * connect the Compod services.

  * 

  * @author Alexander Nussbaumer (AN)

  */

 public class CompodDummy implements ICompod

 {

 	// --- fields ---

 	/**

 	 * The lmsid. this is not needed in the dummy, however, the dummy

 	 * simulates a 'real' compod interface, so it is neccessary to insist

 	 * of it's usage (exception if not set).

 	 */

 	private String lmsid_ = null;

 	/**

 	 * isac objects. real object IDs, but only a few in the dummy.

 	 */

 	private String[] objects_ = 

 	{ "exp_IsacCore_Tests_1a.xml", "exp_IsacCore_Tests_1b.xml", "exp_IsacCore_Tests_1c.xml" };

 	/**

 	 * Index of the object which will be the next to be shown to the user.

 	 * If session is not active, than index is -1. 

 	 */

 	private int objectindex_ = -1;

 	/**

 	 * Keeps inforamtion which type of session is currently running:

 	 * "assessment" or "course", or null if no session is active.

 	 * Maybe enum would be better than string. 

 	 */

 	private String sessiontype_ = null;

 	/**

 	 * Keeps information about the session state.

 	 */

 	private SessionState sessionstate_ = null;

 	/**

 	 * Keeps availability information about knowledge and competence state. 

 	 */

 	private KnowledgeStateQuality knowledgestatequality_ = null;

 	// --- constructor ---

 	/**

 	 * Constructor: initialisation

 	 */

 	public CompodDummy ()

 	{

 		// initialisation

 		// no session at the beginning

 		sessionstate_ = SessionState.INACTIVE;

 		// empty set at beginning, empty set is also a possible knowledge state

 		knowledgestatequality_ = KnowledgeStateQuality.AVAILABLE; 

 	}

 	/**

 	 * @see ICompod#setLMSID(java.lang.String)

 	 */

 	public void setLMSID(String lmsid) throws Exception

 	{

 		lmsid_ = lmsid;

 	}

     /**

      * @see isac.session.ICompod#setScopeByTopic(java.lang.String, java.lang.String)

      */

     public void setScopeByTopic (String username, String topic) throws Exception

     {

 		if (lmsid_ == null)

 			throw new Exception ("lmsid is not set");

     	// not used in dummy

     }

 	/**

 	 * @see ICompod#startSession(java.lang.String, java.lang.String)

 	 */

 	public boolean startSession(String username, String sessiontype) throws Exception

 	{

 		if (lmsid_ == null)

 			throw new Exception ("lmsid is not set");

 		// user is ignored in this dummy

 		// if a session is already running then return 

 		if (sessionstate_ == SessionState.ACTIVE)

 			return false;

 		// activate and initialise session

 		sessionstate_ = SessionState.ACTIVE;

 		sessiontype_ = sessiontype;

 		objectindex_ = 0; 

 		// during an assessment, the knowledge and competence state is not available

 		if (sessiontype_ == "assessment")

 			knowledgestatequality_ = KnowledgeStateQuality.UNAVAILABLE;

 		return true;

 	}

 	/**

 	 * @see ICompod#stopSession(java.lang.String, boolean)

 	 */

 	public boolean stopSession(String username, boolean cancel) throws Exception

 	{

 		if (lmsid_ == null)

 			throw new Exception ("lmsid is not set");

 		// user and cancel type is ignored in this dummy

 		// if a session is not running then return 

 		if (sessionstate_ == SessionState.INACTIVE)

 			return false;

 		// stop session

 		sessionstate_ = SessionState.INACTIVE;

 		knowledgestatequality_ = KnowledgeStateQuality.PRELIMINARY;

 		objectindex_ = -1; 

 		return true;

 	}

 	/**

 	 * @see ICompod#getSessionStatus(java.lang.String)

 	 */

 	public SessionState getSessionState(String username) throws Exception 

 	{

 		if (lmsid_ == null)

 			throw new Exception ("lmsid is not set");

 		return sessionstate_;

 	}

 	/**

 	 * @see ICompod#getNextObjects(java.lang.String)

 	 */

 	public String[] getNextObjects(String username) throws Exception 

 	{

 		if (lmsid_ == null)

 			throw new Exception ("lmsid is not set");

 		// return if no session is active

 		if (sessionstate_ == SessionState.INACTIVE)

 			return null;

 		// system invariant: this case should not happen

 		int objectnumber = objects_.length;

 		if (objectindex_ < 0 || objectindex_ >= objectnumber)

 			return null; 

 		// return next objects

 		String[] nextobjects = new String[1];

 		nextobjects[0] = objects_[objectindex_];

 		// different behaviour if a course is conducted

 		// in contrast to the assessment, there is no separate update,

 		// therefore the update has to be done here.

 		if (sessiontype_ == "course")

 		{

 			// update and prepare for getNextObjects

 			objectindex_++;

 			// stop if no more objects are available

 			if (objectindex_ >= objectnumber)

 			{

 				sessionstate_ = SessionState.INACTIVE;

 				objectindex_ = -1; 

 			}

 		}

 		return nextobjects;

 	}

 	/**

 	 * @see ICompod#notifyObjectResult(java.lang.String, java.lang.String, boolean)

 	 */

 	public void notifyObjectResult(String username, String objectid,

 			boolean solved) throws Exception 

 	{

 		if (lmsid_ == null)

 			throw new Exception ("lmsid is not set");

 		// TODO write data in a file (or on the console)

 		// update and prepare for getNextObjects

 		// WN090111 objectindex_++; only in getNextObjects

 		// stop if no more objects are available

 		int objectnumber = objects_.length;

 		if (objectindex_ >= objectnumber)

 		{

 			sessionstate_ = SessionState.INACTIVE;

 			knowledgestatequality_ = KnowledgeStateQuality.AVAILABLE;

 			objectindex_ = -1; 

 		}

 	}

 	/**

 	 * @see ICompod#notifyObjectMicroResult(java.lang.String, java.lang.String, java.lang.String, java.lang.String, boolean)

 	 */

 	public void notifyObjectMicroResult(String username, String objectid,

 			String skillid, String masterylevel, boolean solved) throws Exception 

 	{

 		if (lmsid_ == null)

 			throw new Exception ("lmsid is not set");

 		// TODO write data in a file (or on the console)

 	}

 	/**

 	 * @see ICompod#getKnowledgeStateQuality(java.lang.String)

 	 */

 	public KnowledgeStateQuality getKnowledgeStateQuality(String username) throws Exception 

 	{

 		if (lmsid_ == null)

 			throw new Exception ("lmsid is not set");

 		return knowledgestatequality_;

 	}

 	/**

 	 * @see ICompod#getKnowledgeState(java.lang.String)

 	 */

 	public String[] getKnowledgeState(String username) throws Exception 

 	{

 		if (lmsid_ == null)

 			throw new Exception ("lmsid is not set");

 		String[] knowledgestate = null;

 		if (knowledgestatequality_ != KnowledgeStateQuality.UNAVAILABLE)

 			knowledgestate = new String[0];

 		return knowledgestate;

 	}

 	/**

 	 * @see ICompod#getCompetenceState(java.lang.String)

 	 */

 	public String[] getCompetenceState(String username) throws Exception 

 	{

 		if (lmsid_ == null)

 			throw new Exception ("lmsid is not set");

 		String[] competencestate = null;

 		if (knowledgestatequality_ != KnowledgeStateQuality.UNAVAILABLE)

 			competencestate = new String[0];

 		return competencestate;

 	}

 	/**

 	 * This main method is used for 

 	 * 1) testing the dummy implementation and 

 	 * 2) demonstrating the usage of the ICompod interface.

 	 * This could also be placed in an external class.

 	 * 

 	 * @param args 

 	 * 		(Command line arguments) not used

 	 */

 	public static void main (String[] args)

 	{

 		CompodDummy compod = new CompodDummy ();

 		System.out.print("Compod Dummy.\n");

 		// initialisation

 		String lmsid = "isac-beta-xxx";

 		String username = "some wired user";

 		try

 		{

 			compod.setLMSID (lmsid);

 		} 

 		catch (Exception e)

 		{

 			e.printStackTrace();

 			return; // stop

 		}

 		// assessment

 		try

 		{

 			System.out.print("- Assessment.\n");

 			compod.startSession (username, "assessment");

 			while (compod.getSessionState (username) == SessionState.ACTIVE)

 			{

 				String[] nextobjects = compod.getNextObjects (username);

 				// output

 				for (int i = 0; i < nextobjects.length; i++)

 					System.out.print (nextobjects[i]);

 				System.out.println ("");

 				compod.notifyObjectResult(username, nextobjects[0], true);

 			}

 		} 

 		catch (Exception e)

 		{

 			e.printStackTrace();

 		}

 		// course

 		try

 		{

 			System.out.print("- Course.\n");

 			compod.startSession (username, "course");

 			while (compod.getSessionState (username) == SessionState.ACTIVE)

 			{

 				String[] nextobjects = compod.getNextObjects (username);

 				// output

 				for (int i = 0; i < nextobjects.length; i++)

 					System.out.print (nextobjects[i]);

 				System.out.println ("");

 			}

 		} 

 		catch (Exception e)

 		{

 			e.printStackTrace();

 		}

 	}

 }